Peter Morcombe copied me into an email last week asking for feedback on a reworking of his calculations on Nikolov & Zeller’s theory. He’s had some feedback, notably from Robert G. Brown. Peter emails:
“Robert’s objections are based on dimensional analysis whereas I am just trying to check two theories against observations. I did the Radiance plot backwards with the X-axis as frequency rather than wavelength or wave number. In my opinion that makes it a little easier to appreciate the effect of the main CO2 absorption bands.
I wanted to show where the numbers come from for the benefit of people who will want to explain where I went wrong.”
I’m not in a position to comment, but I have no objection to providing an opportunity for it to be discussed here.
Unified Theory of Climate Revisited
Guest post by Peter Morcombe
The Nikolov & Zeller poster titled a “Unified Theory of Climate” claims that planetary surface temperatures can be calculated if pressure and TSI (Total Solar Irradiance) are known. The theory implies that other variables such as atmospheric composition, seas, ice caps and the presence of vapors are of minor importance. Instead of dismissing this as implausible I decided to check the predictive skill of N&K’s equations on gas giants, something the authors had not envisaged.
In an earlier post I used the N&K approach to calculate temperatures at 1 bar pressure for several planets and moons. The calculated temperatures were compared with observations and they agreed closely for Earth, Venus and Titan. The correlation for Jupiter, Saturn, Uranus and Neptune was less impressive until a correction was made for internal sources of heat. The N&K analysis is based on the energy balance at the surface of rocky planets, so it may seem surprising that it has any relevance to gas giants. However, the common thread is thermodynamics that applies to gas giants as well as rocky planets. Whereas N&K calculated their energy balance at the surface of rocky planets, their approach should work even better when applied at the cloud tops which provide a radiative layer at almost constant temperature.
Before anyone gets the idea that I believe N&K’s theory let me say categorically that I don’t. I don’t believe in Einstein’s General Theory of Relativity either. However if you insist on ignoring Einstein your GPS will be less accurate. This post aims to see which of two theories comes closest to explaining what is observed. On the one hand N&K’s Universal Theory of Climate and on the other the Arrhenius greenhouse theory originally stated thus:
“….if the quantity of carbonic acid [H2CO3] increases in geometric progression, the augmentation of the temperature will increase nearly in arithmetic progression.”
Arrhenius’ idea has been accepted by “Climate Scientists” and they teach the theory in universities around the world so we can rely on it. Or can we? Let’s check both theories against the best data available for the Earth and for the Moon.
Calculating Earth’s Tgb
The “Consensus” theory explaining Earth’s surface temperature was first proposed by Arrhenius in the 19th century. Scott Denning, Monfort Professor of Climate Science, Colorado State University explains it as well as anyone in this powerpoint presentation.
Here is slide 4 showing the derivation of Tgb, Earth’s average surface temperature if the atmosphere was magically removed.
Tgb = {So(1-α)/4εσ}0.25 = 255 K
Where So is TSI = 1367 W m-2, α is albedo = 0.3, ε is emissivity = 1.0, and σ is the Stefan-Boltzmann constant = 5.6704 x 10-8 kg s-3 K-4
This calculation is suspect because the assumed values of albedo and emissivity are dubious. Why would the albedo of an airless Earth be different from our Moon? Recalculating with albedo = 0.12 and emissivity = 0.955 gives Tgb = 273 Kelvin.
These calculations could be “Sanity Checked” if there was an airless body receiving the same TSI as Earth. Doh, there is one! Let’s look at the Diviner LRE observations of the Moon and see how Earth compares:
| Moon | Earth | |
| Equator Average Temperature (K) | ~206K (390K at noon; ~95 K midnight) | ~299K (303K at noon, ~295K at midnight) |
| Polar Average Temperature (K) | ~98K (outside of shadow) | ~256K (North Pole) ~230K (South Pole) |
| Minimum temperature (K) | ~25K (Hermite Crater) | ~184K (Vostok Station, Antartica) |
| Maximum Temperature (K) | ~410K (small equatorial craters) | ~331K (El Azizia, Libya) |
The observed Tgb for the Moon is about 154 Kelvin so Denning’s calculation fails this “Sanity Check” in spectacular fashion. Tweaking the albedo or emissivity won’t be nearly enough to correct a 100 Kelvin error! Is there something wrong with the equations? The short answer is that the equations are perfect (as equations should be) but for generations people we now call “Climate Scientists” got a little lazy in their cozy “Consensus” so now they need to admit they were using the equations incorrectly. The Moon’s observed temperature would have come out as they predicted if the Moon was a thermal “Super Conductor”, thus ensuring a uniform surface temperature. Given that this is an unrealistic assumption what needs to be done?
Simply said, use the right equation. Equation (2) in the N&K poster delivers a temperature that closely agrees with observations for the Moon. Take a look at Table 1 in the N&K paper. You will find Tgb = 154.3 Kelvin for the Moon. Then N&K use the same figure for planet Earth but that can’t be correct. The Diviner LRE shows temperature excursions of about 290 Kelvin for the lunar equator whereas the corresponding excursions for an airless Earth must be smaller given the fact that Earth rotates about 30 times faster than the Moon (relative to the Sun). Denning’s calculation of Earth’s Tgb is wrong but N&K’s is likely to be wrong too, even if by just a couple of Kelvin!
Who is closest to the truth? Right now I don’t know so let’s move on to reviewing what happens when one adds an atmosphere to a rocky planet.
Calculating Earth’s Ts
In Denning’s slides 10 and 11, Ts is calculated using the same equations as in slide 4 (sans atmosphere case) but with Earth’s albedo and emissivity as measured by satellites. Here is slide 11:
Tgb = {So(1-α)/4εσ}0.25 = 287.5 K which Denning rounds to 288 K
Where So and σ are as before. Albedo (α) = 0.306, emissivity (ε) = 0.612
Denning’s analysis says that Earth’s average temperature is 33 Kelvin higher than it would be without an atmosphere.
Michael Mann of Penn State University has his own version of the Denning analysis and you can find his “One Layer Energy Balance Model” in N&K’s Figure 1. This approach produces essentially the same answer as Denning’s method but it introduces an intermediate layer above the planet surface that is assumed to have a uniform temperature. This is a good approximation for planets with 100% cloud cover (e.g. Venus) because there is a radiating surface at a constant temperature defined by the physical properties of whatever the clouds are made of. In the case of Venus the cloud top temperature is defined by sulphuric acid vapor.
But I digress. The observed average temperature on the Moon is 100 Kelvin lower than predicted by the Denning model because there is nothing to spread the heat to high latitudes. The hot areas radiate directly into space with no “Green House Gases” to capture part of the radiant energy. With no gases or clouds, the amount of radiation emitted is proportional to “T” to the fourth power; so any departure from a uniform surface temperature increases the total rate of heat loss and thereby reduces the average temperature.
The Greenhouse Effect
Scott Denning uses calculus to derive a relationship between Earth’s emissivity and the average temperature. He states that CO2 contributes an additional 4 W/m-2 for each “Doubling” compared to the 240 W/m-2 average solar energy absorbed or about 1.67% of the total. Absent any other effects, the average temperature would therefore increase by 1.2 Kelvin for each doubling. This is in sharp contrast to Nikolov & Zeller who say that the composition of a planet’s atmosphere is not important; the GHE (Green House Effect) can be computed accurately using only surface pressure and TSI alone.
According to Denning the GHE for Earth amounts to 288-255 = 33 Kelvin. N&K point out that the real GHE is 288-154 = 134 Kelvin. Thus far I have been unable to find a clear mathematical explanation from “Consensus Scientists” to show how CO2 accounts for a GHE of 33 Kelvin. There is a good reason for this; it simply can’t be done.
To produce the claimed warming of 33 K would take 33/1.2 = 27.5 doublings. This could be achieved by reducing the amount of CO2 in the atmosphere by a factor of 227.5 = 190,000,000 or from 3,000 Giga-tonnes to 15,800 tonnes. If this made any sense you could expect that reducing the amount of CO2 by another factor of 227.5 would deliver another 33 K of cooling while the mass of CO2 would fall from 15,800 tonnes to 83 grams of CO2 remaining. Reductio ad absurdum!
On Venus things are even more absurd given that Tgb = 182 K while Ts = 738. Substituting the measured data for Venus there would be 3.1 K warming per doubling using Denning’s approach so it would take 179 doublings to achieve the observed greenhouse effect. That is quite an impressive number; 2179 = 7.6 followed by 53 zeros. If you started the doubling with one CO2 molecule you would end up with 5.6 x 1028 kg which is 10,000 times more than the mass of the entire planet (4.87 x 1024 kg).
There is a simple way to calculate the maximum amount of warming that CO2 can produce. Let’s try a thought experiment. Think of Earth stripped of oceans and atmosphere. It would be a larger version of the Moon with an average temperature similar to the Moon (154 K) if you are in the N&K camp or 255 K if you support Denning.
Now add 3,000 Giga-tonnes of CO2, the same amount that exists in the atmosphere today (390 ppm). The surface pressure is now 39 Pascals compared to the 101,300 Pascals pressure that you are used to.
Let’s see what CO2 can do on its own without any help from other gases or water. This diagram shows the radiation spectrum for “Black Bodies” at various temperatures overlaid with two blue bars representing the CO2 absorption bands in the “Thermal IR” region. This diagram makes it easy to visualize what proportion of the outgoing radiation CO2 is capable of capturing under ideal circumstances where it has no competition from water vapor, Methane or other compounds. One might guess that CO2 could absorb around 10% of the total radiance. No need to guess, here are the numbers:
Watts/square meter
150 K 200 K 250 K 300 K
Absorption 4.3-4.6μ
(65.2-69.8 THz) 0.0 0.1 2.0 11.9
Absorption 14-17μ
(17.6-21.4 THz) 4.9 13.0 21.6 28.7
Total absorption by
CO2 4.9 13.1 23.6 40.6
Percent of total
radiance 16.9 14.5 10.7 8.9
The average incoming power is TSI*(1-Albedo)/4 = 300.7 W per square meter, so at equilibrium that is the power radiated by the surface. Let’s be generous and assume that the CO2 absorbs 10% of that or 30 W/m2. What does the CO2 do with all that power? Most of it is re-radiated at longer wavelengths that are not absorbed by CO2 so half returns to the surface and the other half is “Lost in Space” as postulated in Mike Mann’s single layer model (Figure 1 in N&K’s poster).
Thus the maximum warming that CO2 can deliver is 15 W/m2.. The temperature change that will bring about (ΔT ) depends on which Tgb you find most plausible:
Authority Tgb ΔT (K) Ts
Scott Denning 255 3.1 258
This camel 156 1.9 158
N&K 154 1.9 156
It should be easy to calculate how the Moon’s average temperature would change if the rate of rotation was equal to Earth’s. When I tried to make this computation my spreadsheet could not handle even the “Level 3” Diviner LRE data. Thus I was forced to make the above outrageous guess. The critical issue is the thermal properties of the Moon’s surface. Clearly the conductivity is very low. If the conductivity were high (e.g like metallic copper) the local surface temperatures would change very slowly. If the conductivity resembles your roof space insulation the temperature will change rapidly. By choosing an intermediate number I am more likely to be closest to the right answer than the other “Authorities”!
Discussion
No matter whether you believe Scott Denning, N&K or this camel, CO2 can deliver at most 3.1 K of warming. Probably much less when one factors in 4.1 million Giga-tonnes of Nitrogen, 1.1 million Giga-tonnes of Oxygen, 50,000 Giga-Tonnes of Argon, water vapor, clouds, oceans and ice. So the books written by Hansen and others about a “Runaway GHE” driven by CO2 are absurd fantasies.
One physicist whose opinions I respect more than my own tells me that N&K are crazy. If that is so I am at a loss to describe people who still cling to the far crazier Arrhenius theory.
I don’t expect to hear from the CAGW echo chambers run by Joe Romm, John Cook, Gavin Schmidt, Tim Lambert, Ken Perrott, Barry Brook, Grant Foster, William Connolley, Dana Nuccitelli, Eric Grimsrud, Scott Mandia and many more. These folks can’t participate in an honest debate because they still cling to Arrhenius.
Digging in the Clay 
It’ll take a while to absorb this in its entirety. however, you say
“According to Denning the GHE for Earth amounts to 288-255 = 33 Kelvin”
,,, and according to others who support the “classic theory”. However, there’s as serious problem with that figure. The calculation assumes that the Earth, less GHE, would emit 240 W/sq.m as it does at present, yet there’s nothing to support that figure – it’s an assumption. Part of the 240 comes from GHGs, part from clouds, and the rest from the surface.
Without an atmosphere, and with the surface albedo the same as at present (an impossibility, as no vegetation and no oceans), the average temperature with average 341 W/sq.m insolation would be 269°K or -4.1°C.
With an atmosphere, and with surface and clouds as at present, without GHE, neither clouds nor GHGs would absorb or radiate. Clouds are, after all, not a small component of the GHE. Reflection by clouds and atmosphere, and by the surface, would result in a net 240 W/sq.m being absorbed and re-radiated. Some of that would be reflected back by clouds (as would some solar reflected by the surface – I’ll ignore that). The surface would warm until 240 W/sq.m was being re-radiated through the “cloud window”, in essence a “cloud GHE”, and analogous to radiation from the surface through the “atmospheric window” as with GHE. Only the part of the surface uncovered by cloud would radiate to space. There’s something amiss in the state of Denmark, an assumption based on too little thought, and a convenient one for calculating somewhat inflated climate sensitivity.
I haven’t calculated the resultant surface temperature in my “scenario” as I’ve forgotten the cloud cover %age assumed in radiation budgets, but I’ll post back. It’s gonna be significantly higher than -18°C though (15°C perhaps?)
MostlyHarmless,
Water with all its tricky phases is way too complex for me. I don’t feel too bad about it as even the “Experts” are all over the map. That is why I looked at CO2 on its own and found it lacking.
My new paper on this topic is now online …
[snip]
Reply – Doug you are supposed (as a courtesy at others’ sites) to comment on the post, as in ‘discuss’ it, not just promote your own work by posting the abstract. V.
I found a link to Doug’s paper on Roy Spencer’s blog but it does not work. The paper should be on the PSI web site (Tim Ball) but I could not get to it.
Doug,
I would like to read your paper so why not email a copy or a link that works to my email at info@gallopingcamel.info?
Doug: Has your “paper” appeared anywhere but in your very own vanity journal, constructed specifically to publish crackpottery like yours?
Peter writes that slide 4 shows the derivation of Tgb, “Earth’s average surface temperature if the atmosphere was magically removed.”
But it’s not the atmosphere that’s being removed, it’s only the greenhouse gases.
Denning’s back-of-the-envelope calculation — which is, of course, not Denning’s all, but was done decades ago — agrees closely with a climate model calculation (=numerical solution to the underlying PDEs) by Lacis et al (Figure 2):
Lacis, A.A, G.A. Schmidt, D. Rind, and R.A. Ruedy, 2010: Atmospheric CO2: Principal control knob governing Earth’s temperature. Science, 330, 356-359, doi:10.1126/science.1190653.
http://pubs.giss.nasa.gov/abs/la09300d.html
Peter Morcombe says “There is a simple way to calculate the maximum amount of warming that CO2 can produce”. No, there’s not. Then he says “Let’s see what CO2 can do on its own without any help from other gases or water” next to the “Radiance vs, Frequency” diagram. I fear this where his story starts to go astray. If the Earth had an atmosphere which consisted of just the equivalent of 390 ppm CO2, his conclusions here might well be right However, as most absorption/emission of LWIR from CO2 is collision-induced, and since almost all of those collisions would be with N2 & O2 molecules in the real atmosphere, there would be very few such collisions in a his CO2-only scenario. The mean free path of CO2 molecules in this case would be very great. This part of his submission is not just unrealistic – it’s fatally flawed.
He says
“Let’s be generous and assume that the CO2 absorbs 10% of that or 30 W/m². What does the CO2 do with all that power? Most of it is re-radiated at longer wavelengths that are not absorbed by CO2 so half returns to the surface and the other half is “Lost in Space” as postulated in Mike Mann’s single layer model”
Nonsense – CO2 radiates and absorbs in the same bands. Before making assertions like this he should do some homework. Absorption induces bond flexing, stretching and rotation, in very narrow photon-frequency related bands which integrate to the observed broad bands. Radiation releases photons of exactly the same frequency as those absorbed. Effects such as Doppler frequency shifts result in broadening of the narrow, and ultimately the wide bands. In the simple model half goes up and half goes down. Simple as that – nothing to do with what is radiated and at what frequencies.
And “assume”? I thought this post was based on mathematical calculations. I was wrong. Also wrong is his “Radiance vs, Frequency” diagram. It is, if you’ll excuse the expression “arse-backwards”. It shows an inverse correlation between radiation and temperature. Does a cooler temperature result in higher radiation? The blue curve and un-broadened CO2 absorption bands are about right; the rest is fantasy.
Comparisons with the moon are clearly irrelevant once it’s realised that the surface absorbs and conducts within far more heat during the lunar “day” of 14 Earth days than does Earth’s surface during 12 hours. That heat is conducted back to the lunar surface during its long “night”, keeping the temperature well above what it would have been with a 12-hour “night”. Also, the moon’s albedo and emissivity is different from that of Earth.
There’s another problem with almost all calculations involving average radiation per unit area compared with average temperature over an entire sphere or hemisphere. A calculation which takes average radiation and calculates average temperature has an inbuilt error which depends on the distribution of the radiation. Radiation varies with the 4th. power of the temperature. On the moon, with no atmosphere, I estimate from some back-of-the spreadsheet calculations that the error might be as high as 5-10%, taking into account the long lunar “days” and “nights”. On Earth, with an atmosphere, it’s lower at around 5%, or perhaps a little less, depending on assumptions. Kiehl & Trenberth (2009) had to model outgoing radiation over a “gridded” surface to account for the induced discrepancy due to the 4th. power relationship.
MostlyHarmless,
I enjoyed your idea that CO2 “absorbs and radiates in the same bands”. Dream on! My field is quantum electro optics (lasers) where your cuckoo ideas are disproved every day. When CO2 absorbs at ~4.6 microns much of the energy is re-radiated at 9.6 and 10.6 microns. Hence CO2 lasers with their amazingly high average power and wallplug efficiency. The energy that is lost through collisions heats up the CO2 (or other gases if they are present).
When the source of radiation is thermal IR, the main relevant absorption band for CO2 is centered at 15 microns, so the related radiative transitions are at longer wavelengths.
I have been building lasers for fun and profit since 1970 so you can trust me on this.
It’s not “my idea”, nor is is “cuckoo”, but well-established by observation and quantum theory. Internal CO2 bond vibrations expand and contract their amplitude in quantum amounts. The quanta have frequency-related energy content. Each change in energy of specific types of vibration is quantised. Your
“cuckoo idea” is simply disproved by examination of any atmospheric spectrum. GHGs absorb and emit in the same bands, and in the same quantities. What happens in a high-energy laser might well be what you observe, but is the mechanism identical?
Example from Infrared Spectroscopy: Theory,University of Colorado, Boulder, Dept. of Chem. and Biochem. (2002)
Click to access IRtheory.pdf
You can find similar descriptions on most university sites where Infrared spectroscopy and internal molecular bond vibrations are discussed and quantified:
Vibrational motion is quantized: it must follow the rules of quantum mechanics, and the only transitions which are allowed fit the following formula:
E = (n + 1/2)hv
where v is the frequency of the vibration and n is the quantum number (0, 1, 2, 3, . . . )
The lowest energy level is E0 = 1/2 h?, the next highest is E1 = 3/2 h?. According to the selection rule, only transitions to the next energy level are allowed; therefore molecules will absorb an amount of energy equal to 3/2 – 1/2 h? or h?. This rule is not inflexible, and occasionally transitions of 2 hv, 3 hv, or higher are observed. These correspond to bands called overtones in an IR spectrum. They are of lower intensity than the fundamental vibration bands.
MostlyHarmless is, of course, right — CO2 in the atmosphere can absorb and radiate in the same bands. That’s elementary physics. But this this isn’t what’s going on in a CO2 laser, where the strongest transition (10.6 microns) is a simultaneous change of vibrational and (a number of) rotational quantum states.
More details are here: “CO2 Laser Theory,” David R. Whitehouse
http://www.laserk.com/newsletters/whiteTHE.html
MostlyHarmless,
Congratulations! When delivering courses on electro-optics I include deliberate mistakes to see whether my students are paying attention. You found the deliberate mistake in my plot of radiation intensity versus freedom when you said:
“It shows an inverse correlation between radiation and temperature.”
I would have been even more impressed if you had noticed that the plots were labeled in reverse order. The line labeled 50 K is actually the 300 K line. The key issue is where the irradiance peaks and you will find that frequency is directly proportional to temperature (Wien’s Law).
Nevertheless, well done! You were the first to spot it.
But they’re not labelled in reverse order. The blue curve, with its peak at around 15THz on your diagram, is, as I said, about right. The other curves represent progressively higher temperatures, as the peaks are higher and shifted to the right.
And don’t be a smart-arse, it doesn’t become you.
Good catch, MH. Peter, if you make an error, just own up to it instead of inventing stories about inventing deliberate errors — it’s not convincing at all. (Not to mention, there is no “50 K” line.)
As MH said, fatal flaws. Crackpottery.
MostlyHarmless,
Let me try again. According to Wien’s Law the peak radiance for a black body at 300 K occurs at 9.66 microns or 31.06 THz. Look at my plot again and you will see that is the green line (labeled “150 K”). The blue line is correct for 150 K with its peak at 15.5 THz (19.3 microns).
I read Wien’s law the way you do. However, all the spectral curves I’ve seen show the 300k peak at 17µm and not at 10µm. It’s always bothered me that the curves appeared to have the wrong relationship between wavenumber and µm, by a factor of 10. I always wrote it off as my poor understanding. An assumption can become a “tablet of stone”.
Lets’ leave that for a moment. I think you and I have (and in very different ways) identified some poor assumptions which may have some major implications.
MostlyHarmless,
There is nothing in that link you sent to support the quaint idea that CO2 (or anything else) always re-radiates a photon at the same energy as was absorbed. That would work if there was just one excited state and the ground state. In reality there are many excited states.
The folks at Harvard have taken the trouble to document spectra for many compounds (HITRAN-96) and just below my radiance plot you will find a link to their CO2 spectrum. It is pretty complicated with hundreds of lines representing transitions between quantized energy states.
Even if things worked the way you imagine, half the energy captured by the CO2 would still be radiated upwards (lost in space as long as there are no clouds) and the other half would return to the surface which would absorb most of it and then re-radiate it according to Stefan-Boltzmann.
The “Deliberate Mistake” thing works both ways. I distribute cans of “Bullshit Repellant” in my classes and encourage my students to spray the air around them whenever they think I have strayed from the path of truth. Usually a lively discussion ensues and we all learn more than might otherwise have been the case.
I’m not trying to be destructive, but your misunderstanding is total. The first diagram in your pdf shows the individual spectral lines corresponding with absorption of photons with differing energy and therefore frequency.
“Even if things worked the way you imagine, half the energy captured by the CO2 would still be radiated upwards (lost in space as long as there are no clouds) and the other half would return to the surface which would absorb most of it and then re-radiate it according to Stefan-Boltzmann.”
But that’s exactly what the simple one-layer model which N&Z posted shows; half going up, and half going down. Do you think that radiation has the property of selective direction?
That simple model doesn’t work; it’s used to illustrate the first step in understanding GHE, if it’s used at all. N&Z are using exactly the same questionable tactic as the “dragon slayers” do – misrepresenting “how GHE is taught at universities”.
I warned you not to be a “smart-arse” – with your “bullshit” comment you’re crossed the demarcation line. You have zero understanding of absorption.& emission at the molecular level, and yet you stoop to insults.
While I’m here, you may have worked with CO2 lasers, but you also have zero understanding of how they work. The CO2 doesn’t absorb LWIR, but has energy transferred during collisions with nitrogen molecules (sound familiar – my comment re atmospheric absorption?)
Here’s a simple summary, taken from a standard work, (Weber, Marvin J. Handbook of Laser Science and Technology. Volume II – Gas Lasers. Boca Raton: CRC Press, Inc., 1982.),
which includes a simple summary of CO2 emission, and is reproduced here: http://www.phy.davidson.edu/stuhome/sethvc/laser-final/co2.htm
In the CO2 molecule, the individual atoms are bound by a force which acts much like that of the force due to a spring – a harmonic oscillator. Molecules vibrate due to their lacking fixed orientations within the molecule (as seen above). They are able to rotate and spin because they are in a gaseous state. These states, as in electronic states, are quantized. Transitions between vibrational energy states/levels results in photon emission in the infrared, while transitions between rotational states emit photons in the microwave region.
Necessary mechanisms for operation of the CO2 laser, as listed by Weber (318) are:
1. Excitation of N2 vibration by electron impact
2. Transfer of vibrational energy from N2 to the nearly resonant v3 mode of CO2
3. Laser transition from v3 to v1 mode.
4. Sharing of population between v1 and 2v2l modes and relaxation within the v2 manifold
5. The vibrational energy in the v2 manifold converted into translational energy by collisions with He
Also here: http://www.rp-photonics.com/co2_lasers.html
The CO2 laser (carbon dioxide laser) is a laser based on a gas mixture as the gain medium, which contains carbon dioxide (CO2), helium (He), nitrogen (N2), and possibly some hydrogen (H2), water vapor and/or xenon (Xe). Such a laser is electrically pumped via a gas discharge, which can be operated with DC current, with AC current (e.g. 20–50 kHz) or in the radio frequency (RF) domain. Nitrogen molecules are excited by the discharge into a metastable vibrational level and transfer their excitation energy to the CO2 molecules when colliding with them. Helium serves to depopulate the lower laser level and to remove the heat.
David Appell,
You seem to understand the physics much better than most journalists. You quoted the “right equation” for calculating the Moon’s average temperature but you can’t bring yourself to accept what it says. When I pointed that out to you on your own blog you completely “lost it” and started with the name calling and rhetoric. Here is what you said:
“Crackpots like you certainly don’t get a say about whether Lacis et al belongs in Science magazine. Your blog posts are riddled with elementary errors that would make an undergraduate blush.”
I did include a “Schoolboy Howler” in my post but you failed to find it. In future please confer the title “Crackpot” to those who have earned it such as James Hansen. He wrote a book about the “Runaway Greenhouse Effect” on Venus which he attributed to CO2. The ability of CO2 to absorb outgoing radiation from a planet’s surface has no relevance on a planet with 100% cloud cover. If you don’t understand that you are as crazy as he is.
Carl Sagan explained the surface temperature of Venus in 1969 by calculating a radiative balance at the cloud tops and then applying thermodynamics to calculate the temperature gradient in the troposphere. The ability of CO2 to absorb thermal IR radiation was irrelevant as Venus’ emissivity is dominated by its clouds that consist of sulphuric acid. Subsequent observations (e.g. Magellan, Jenkins et al.) have vindicated Sagan’s analysis.
N&K are following in Sagan’s footsteps. They are calculating the energy balance at the surface rather than at the cloud tops but the rest is thermodynamics (aka the adiabatic lapse rate).
You have a touching faith in “Peer Review”. The folks who reviewed the Lacis paper you quoted above are all members of the “Team”. I will be happy to explain what is wrong with it on your blog if you will stop your heavy handed “Moderation” (= censorship). If the facts were on your side “Quark Soup” and the other “Echo Chambers” would not need censorship.
Peter, you clearly fit the definition of a crackpot:
The Crackpot Index
http://math.ucr.edu/home/baez/crackpot.html
For some reason you still think N&Z are on to something, even though they (or you) can’t predict something very simple like the lunar surface temperature. Meanwhile, simple physics based on the Stefan-Boltzmann law predicts it exactly — not just the average, but the value at all longitudes along the equator:
http://davidappell.blogspot.com/2012/04/norfolk-constabulary-made-wrong-charges.html
This is another reason why you’re a crackpot — evidence has no bearing on your beliefs; you just keep repeating them over and over whether they work or not. Whatever you’re doing, it certainly isn’t science.
Peer review is the kind of thing that at least makes sure one’s curves are labeled correctly. Clearly, you need some of it.
(And you don’t know who reviewed the Lacis et al paper. I doubt they know either, since most peer review is anonymous.)
David,
Some comments on your “ad hominem” attack on Roger Tattersall (the Norfolk Constabulary link above). Roger is a seeker after truth who does not pretend to know all the answers but he does get us thinking. His mind is open. You on the other hand have blinkers on when it comes to problems with the Arrhenius theory.
1. In your post, the Diviner LRE lunar mean temperature is shown as 213 K. This is the mean temperature at equatorial latitudes. The Diviner web site claims a 206 K average for equatorial latitudes and 98 K for polar latitudes. Consensus scientists assume the Earth’s average temperature in the absence of the GHE to be 255 K. Why won’t you admit they got the wrong answer?
2. To get a value for the Moon’s average temperature that agrees with observations you should have used equation (2) from N&K’s poster. You included the equation in your post but failed to use it, otherwise you would know where N&K got their 154 K figure. Can you or anyone else explain a GHE of 134 K using the Arrhenius theory?
3. You then say (referring to N&K) “And so, they say, there is no greenhouse effect, but that atmospheric pressure accounts for the enhanced Earth’s surface temperature…..”. N&K say there is a GHE but it depends on total gas pressure rather than minor components of the atmosphere such as CO2 or water vapor.
4. You say “Alas, N&Z are confused about the physics, and Tattersall is even more confused in his defense of them. (He doesn’t like it when people point this out, and routinely bans people who insist on pointing out his errors. [snip] often resort to this tactic when obfuscation has failed.)” What a fine piece of Chutzpah coming from the heavy handed “Moderator” of a CAGW echo chamber.
All scientific theories are eventually superceded. I don’t get emotionally invested in anybody’s theories; not even mine. The harder I try to prove N&K wrong the better they look in comparison to Arrhenius. The CO2 GHE is about as real as Phlogiston.
You ignored my point about the 100% cloud cover on Venus rendering CO2 powerless to affect the surface temperature, let alone cause a “Runaway Greenhouse Effect”.
If you will address these issues we can have a serious discussion.
Why would I use N&Z’s equation 2 — it’s incorrect.
THAT’s THE POINT — basic, standard physics gives the correct lunar temperature all points.
N&Z does not. Yet for some reason you still cling to it.
Re: moderation. Have any of your comments at my blog not been published? No — so your claim of “a heavy handed moderator” is false. In fact, I only have moderation on for posts that are more than 10 days old, and that’s only to prevent comment spam.
The model doesn’t even conserve energy. The surface is radiating at an average 390 W/m2, and the TOA at 240 W//m2. What happened to the other 150 W/m2?
MostlyHarmless said:
“But that’s exactly what the simple one-layer model which N&Z posted shows; half going up, and half going down. Do you think that radiation has the property of selective direction?”
Michael Mann’s version of the one-layer model makes perfect sense when you realize that the CO2 radiates uniformly over 4 “Pi” steradians. Owing to the fact that the Earth is approximately flat (this is to give David Appell a chance to call me a “Flat Earther”) 2 “Pi” steradians are “UP” and the other 2 “Pi” are “DOWN”, thus neatly distributing the radiation on a 50:50 basis.
This effect is not wavelength dependent.
Peter, Thank you for inviting me into your blog.
Here are a couple of thought experiments for you:
1) Why does it get cold at night (even though the pressure doesn’t change)? Why doesn’t it get MUCH colder at night (even though there’s no sunshine)? Why does it get colder on clear nights than on cloudy nights?
2) Suppose you put heat lamps over the whole Earth that emitted 4 Watts downward on each square meter. Hold the surface pressure and solar radiation constant. Would you expect the average surface temperature to change? Why or why not?
Ned Nikolov’s model can’t explain either of these results.
Can you explain why not?
Best regards,
Scott Denning
K&Z get it wrong from the start, and their error is elegantly expressed and revealed by what they write. They quote the ideal gas law PV = nRT, and say that the kinetic energy of a gas is quantified by PV. So it it, but we know from Boyle’s law that the pressure and volume of a fixed mass of gas are inversely related; PV = constant. Therefore the kinetic energy of a fixed mass of gas is also constant. That applies to the atmosphere as much as it does to air in a bottle. Logic tells us that the KE is constant; nothing added, nothing taken away. No energy is added or removed by changing either pressure or volume, but if the volume of a confined gas is changed by changing the pressure, the temperature changes. That’s simply because the density, the number of molecules of gas per unit volume changes, and the number of molecular collisions with the container (or thermometer) changes.
However, on Earth the atmosphere is not confined in a container, yet the mass of gas above any defined area of the surface is (virtually) constant. We know that because it’s the weight of that gas which defines the surface pressure.The pressure actually decreases slightly from equator to poles because the atmosphere isn’t uniformly distributed due to Earth’s rotation – a thicker layer at the equator. When that’s taken into account, the slight poleward drop in pressure is accounted for; 1025hPa at the equator to 995hPa at the poles, a drop of only 3%. At the poles, the winter temperature is about -40C while the temperature at a point with the Sun overhead is about 30C. The pressure difference of 3% can’t account for the discrepancy, so what does? Insolation of course – there’s none at the poles in winter.
K&Z state that if pressure and density is taken into account, it’s possible to predict mean surface temperature, but any physical mechanism doesn’t work “on average” at all. Their hypothesis has to explain temperature at the poles as much as in the tropics; in the absence of insolation it does not. It’s insolation which fundamentally drives the high temperature in the tropics, and lack of it which results in the low observed temperature at the poles in winter.
They also state that
The gases in a CO2 laser also have “negligible heat storage capacity”, yet it generates a high radiation output. The element in an electrical heater has “negligible heat storage capacity”, yet it generates a high radiation output. Both are “pumped” with a high energy input – electrons in both cases. The atmosphere certainly has “negligible heat storage capacity”, yet it generates a high radiation output because it’s pumped with a high energy input; that part of insolation which is absorbed (mostly SWIR by water vapour), and LWIR from the surface absorbed by GHGs.
They say “Thus, empirical evidence indicates that the lower atmosphere contains more kinetic energy than provided by the Sun”. Of course it does, because most of that KE is provided by the surface in the form of conduction/convection, evaporation, and upward LWIR, all of these getting their energy originally from the Sun. They also say “Understanding the origin of this extra energy is a key to the GHE” – gerraway – is that right? I must have been missing something along the way. They demonstrate with their simple one-layer model that they don’t actually understand (or choose not to understand) the GHE. The simple model omits, in order of importance, clouds, atmospheric absorption of insolation, evaporation, albedo and convection. If it doesn’t in essence model the Earth/atmosphere system then it can’t model GHE.
L&Z’s “hypothesis” consists largely of smoke and mirrors – diverting attention from what’s actually going on in the atmosphere, and not actually explaining it.
For K&Z and L&Z read N&Z of course – it’s my “deliberate mistake”.
I’ll add some clarification. N&Z state
“Equations (5) and (6) imply that pressure directly controls the kinetic energy and temperature of the atmosphere. Under equal solar insolation, a higher surface pressure (due to a larger atmospheric mass) would produce a warmer troposphere, while a lower pressure would result in a cooler troposphere.”
Pressure cannot control kinetic energy; that violates the first law of thermodynamics. They refuted this themselves by showing that kinetic energy can be expressed as PV, and for a fixed mass of gas that’s constant. Increase the pressure, volume decreases; KE is unchanged. As I said (in essence) above, increasing pressure increases gas density, and Increased gas density results in increased temperature. They’re right about a higher atmospheric mass creating higher surface pressure, and this does indeed increase temperature, but only by increasing density. They’re committing the unpardonable sins of confusing cause and effect, and ignoring one of the fundamental physical laws. Not bad for a first attempt.
Scott Denning,
Thanks for showing up; you are indeed a “good sport”. I will do my best to keep my answers to your questions short. I hope you will be kind enough to grade my efforts!
1a) Why does it get cold at night (even though the pressure doesn’t change)?
My understanding is that the radiation balance at the surface turns negative when the sun goes down because the ground continues to emit in the thermal IR spectrum but there is no direct solar radiation to balance or exceed the outgoing radiation.
1b) Why doesn’t it get MUCH colder at night (even though there’s no sunshine)?
How much colder it gets at night depends on a number of factors. In Florida we have high humidity so when there is not much wind we get temperature inversions that create fog which prevents the ground radiation from being lost directly into space. In general the “Dew Point” sets a limit on how cold it can get near the ground.
When it is windy (as is more likely on the east coast of Florida) fog is less likely but rapid surface cooling is moderated by convection, clouds (often 100% cover) etc.
Robert G. Brown tells me that in regions with very low humidity and low winds there can be spectacular drops in surface temperature at night presumably because most of the ground radiation is lost directly into space. According to my analysis only 15 W/sq. meter will be returned to the surface by CO2 no matter how much is present in the atmoshere so that is not likely to make much difference.
1c) Why does it get colder on clear nights than on cloudy nights?
CO2 can return some energy to the ground from a clear sky but clouds do a much better job in this respect.
2) Suppose you put heat lamps over the whole Earth that emitted 4 Watts downward on each square meter. Hold the surface pressure and solar radiation constant. Would you expect the average surface temperature to change? Why or why not?
I tested the N&K theory on some gas giants and found significant differences between observations and their predictions until I factored in the internal heat sources. In essence this says it does not matter where the heat comes from. Internal heat has the same effect as TSI heat. Here is a link to that guest post:
Perhaps you would be kind enough to answer a question from me. David Appell has stated in earlier comments that I misrepresented your slide presentation. If that is the case, what changes would you suggest to set things straight?
MostlyHarmless,
My purpose was to compare two theories; N&K vs. Arrhenius. Both theories have the attraction of elegant simplicity but when you dig a little deeper there are things that don’t make sense.
I am trying to keep in mind the original objective so as to avoid being dragged into interesting but irrelevant discusssions
You think that discussing (and disproving) the fundamental principle of Nikolov & Zeller is an “interesting but irrelevant discussion”? There’s a simple and well-known phrase for your mindset – total denial. I leave others to come to their own conclusion.
Would it be an “interesting but irrelevant discussion” to explore why certain observations cannot be explained by Newtonian mechanics? Or that disproving the consensus that excess stomach acid causes ulcers would be an “interesting but irrelevant discussion”?
You persistently, and annoyingly, respond out of thread. Is that a ploy to distract the reader from what’s been said previously?
MostlyHarmless,
N&K have a theory that is as simple and elegant as the Arrhenius theory. Like you I started out by doubting the N&K theory because it said the only variables that matter are TSI and gas pressure. I find it difficult to accept that albedo, emissivity and water in its various forms can simply be ignored.
I doubted the Arrhenius theory for similar reasons. It puts too much emphasis on a single variable (atmospheric CO2 concentration). I looked for a mathematical derivation of the GHE in terms of CO2 but could not find one. My rough analysis of the maximum possible forcing due to CO2 alone (15 W/sq. meter) is sound. This implies a maximum contribution of 3.1 K from CO2 but probably at least an order of magnitude lower due to clouds, water vapor, convection and phase changes that strongly affect heat transfer in the troposphere.
You seem to expect me to defend N&K while my goal is exactly the opposite. I started out trying to disprove their theory by testing it on planets they had not considered. The equations stood up pretty well so this guest post is my second attempt to falsify their theory. In the process I found the Arrhenius theory fails for Earth and has zero relevance for planets with 100% cloud cover (e.g. Venus).
N&Z’s theory does not predict the lunar surface temperatures. So why believe a failed theory?
When considering planetary surface temperatures I find that most have no explanation as to how the Venus surface receives enough energy to warm up by about 5 degrees during its 4 month day. The direct solar radiation received by the surface is only of the order of 10W/m^2 as deduced from the Russian probe measurements. Yet the temperature of over 730K would require an input of about 16,000W/m^2. How does the required energy get there? The only plausible (and hitherto unpublished) explanation is in my latest paper [snip – as linked below – Doug – I’ll limit you to one link to your paper where relevant, per page. V.]
Peter, you keep making the same simple mistakes over and over again, and seem impervious to basic physics reasoning.
In the post you write, “Here is slide 4 showing the derivation of Tgb, Earth’s average surface temperature if the atmosphere was magically removed.”
THIS IS INCORRECT. An atmosphere is assumed, because the assumption behind the calculation is that the surface temperature is the same everywhere, with the equilibrium created by heat spread via the atmosphere.
But this is NOT true on the Moon, which has no atmosphere. There you cannot assume the surface is at a constant temperature. So you have to apply the Stefan-Boltzmann Law at every point, accounting for the angular dependence of the incoming sunlight. As I’ve showed you several times now, that gives the correct lunar temperature at all points.
This really couldn’t be simpler.
The unified theory is wrong because pressure does not maintain any particular temperature. That is simply because temperature depends on the mean kinetic energy, but not the density of molecules, whereas pressure is determined by both. This is basic physics completely overlooked.
All planetary core and surface temperatures may be determined by the method explained in my latest paper, and, unlike the unified theory, I have provided an explanation as to how the energy actually gets to the surface of planets such as Venus, and even Earth, and also how core temperatures are maintained and can be calculated. Such core temperatures cannot exceed the radiating temperature of the Sun.
See http://principia-scientific.org/publications/PROM/PROM-COTTON_Planetary_Core_and_Surface_Temperatures.pdf
Has this so-called “paper” been published anywhere other than your vanity press? You know, in a real scientific journal? Or even submitted to one?
Prof Nasif Nahle has done studies on backradiation in his paper
[snip – see comment above on excessive paper self promotion, V.]
1. The thermal gradient (AKA “effective lapse rate”) is pre-determined by the force of gravity, the weighted mean specific heat of the gases in a planet’s atmosphere (at that altitude) and the degree of intra-molecular radiation which, in the case of Earth, is somewhat dependent on the percentage of water vapour which, as is well known, makes the gradient less steep.
2. The overall level of the plot is established by the autonomous propensity for there to be radiative equilibrium with incident Solar radiation. The area under the curved plot of outward radiative intensity thus has a propensity to remain constant if the gradient alters. So extra water vapour makes it less steep by lowering the surface end and raising the tropopause end.
3. The surface temperature can then be calculated by extrapolation of the thermal plot of temperature against altitude in the troposphere. The temperature can be derived using SBL from the values of radiative flux at each altitude from (2). The higher the tropopause, the greater the distance over which the temperature can rise, this explaining why Venus is much hotter than Earth.
4. The mechanism whereby the thermal plot is maintained involves the absorption of energy originally from the Sun (both in downwelling and upwelling radiation) which is then dispersed in all directions over the thermal plane, in order to maintain thermodynamic equilibrium, in accord with the requirements of the Second Law of Thermodynamics.
5. The thermal plot continues its upward climb more steeply in the crust (due to lower specific heat) but far less steeply in the hottest regions of the mantle because specific heat increases significantly with increasing temperatures.
6. Heat creep, as described in (4) allows thermal energy to enter deeply into the subsurface regions and, eventually, to support core temperatures and provide energy which can contribute to that in volcanoes and thermal springs and vents.
7.The surface warms temporarily during the day and then both radiative and non-radiative processes slow its rate of cooling, but there is a limit to such cooling due to the underlying very stable thermal plot of temperature against altitude or underground depth. This is why the base of the atmosphere does not continue cooling at a fast rate all through the night. The force of gravity redistributes absorbed energy in such a way as to provide a supporting temperature at the boundary of the surface and atmosphere, and even at the boundary of the mantle and core.
Doug: When are you going to respond to my question on Spencer’s blog?
http://www.drroyspencer.com/2013/02/apparent-reason-for-january-2013-tropospheric-warmth/#comment-70314
How does an absorbing body know the temperature of the emitting body, based only on the radiation it receives?
Absorption occurs at the quantum level: electrons absorb photons. This process is described by the theory of quantum electrodynamics (QED), the most precise theory ever created.
The effects of absorption have been calculated to about 12 decimal places, and the predictions agree with experiment for quantities like the anomalous g factor of the electron.
In none of these calculations does the temperature of the radiating body appear.
So which experiments support your contention that absorption depends on the temperature of the body which emits the radiation absorbed?
Doug Cotton,
I have been trying to comment on your paper at your web site without success so here are comments against your bullet points:
1. I agree about the prime importance of the Adiabatic Lapse Rate. While the ADL is lower in the tropics, the depth of the atmosphere is greater.
2. I think you are saying what I tried to say in 1.) above.
3. I agree and have said so elsewhere on many occasions.
4. The tropospheres (Venus, Earth, Jupiter, Titan etc) all have adiabatic lapse rates that conform closely to the -g/Cp formula. This formula can be derived using thermodynamics and Newtonian gravity so one wonders why so many people are hell bent on using theories based on the radiative properties of “Greenhouse Gases” that deliver wrong answers.
5. Where internal sources of heat are significant I have included them with the assumption that it makes no difference where the heat comes from:https://diggingintheclay.wordpress.com/2012/03/13/unified-theory-of-climate/
6. I have nothing to say about what goes on beneath the surface.
7. I don’t consider this speculation relevant to a discussion of Venus, Earth, Mars of Titan.
Re #4: Because failure to include GHGs gives the wrong answers.
g/c_p is the *dry* adiabatic lapse rate; the rate is different if the air is saturated with water vapor.
And the lapse rate is linear only up to the tropospause. If pressure determines temperature, why does the lapse rate cease to be linear above the tropospause?
One only needs to examine the Earth’s actual outgoing spectrum to see that large chunks of it are “missing”:
http://www.giss.nasa.gov/research/briefs/schmidt_05/
If pressure determines temperature, why does the TOA outgoing spectrum have all these holes in it?
You have a simple and direct measurement of the greenhouse effect, and still you can’t accept it.
David Appell,
“THIS IS INCORRECT. An atmosphere is assumed, because the assumption behind the calculation is that the surface temperature is the same everywhere, with the equilibrium created by heat spread via the atmosphere.”
I have asked Scott Denning to say whether I misrepresented his presentation. Let’s leave this until he has time to respond.
Obviously your interpretation is wrong. The trivial derivation of Tgb assumes the planetary temperature is the same everywhere, i.e. that an atmosphere establishes an equilibrium temperature.
This is a good approximate for the Earth, where average annual surface temperatures varies by about 10% from equator to the poles, but not for the Moon.
Doug Cotton (February 27, 2013 at 8:41 pm),
I agree with most of your numbered bullet points. I am in Houston right now and won’t have an opportunity to make a more considered reply until next week.
In cases where there is significant internal heat I have simply treated it as equivalent to the TSI heat. This approach eliminated most of the gap between N&K’s equations and observed temperatures for the gas giants:
Hi Peter,
1) You really can’t compare Arrhenius and N&K in a meaningful way. N&K is just a curve fit.
If we mean by “Arrhenius” the energy balance equation S/4 * (1-albedo) = sigma * T^4 then it can’t really be “wrong.” It just states that energy is conserved for a spherical blackbody being heated by radiation. I don’t think even Ned could dispute that.
As it turns out, this energy balance is nearly perfectly observed for both all planets and moons (including Venus and the gas giants as well). The observed outgoing longwave radiation from the Earth is in fact almost precisely equal to what’s predicted here, and corresponds to an equivalent blackbody temperature of 255 K.
2) Ned Nikolov is being silly by cooking up his alternative “definition” of the magnitude of the greenhouse effect. It’s sophistry. By definition, this number is the difference between the surface temperature and the equivalent blackbody temperature. It’s not a particularly important number: it’s just used to illustrate the effect, not used in any further calculation. For the Earth, the mean surface temp is about 288 K and the equivalent radiative temperature is 255 K. Both are measured quantities, and are really not arguable by Ned or anybody else. The difference between these two temps is 33 K, so that’s (by definition) the magnitude of the “greenhouse effect,” following a definition that’s been around for over a century.
Ned argues that we should adopt a new definition based on his curve-fitting, but that’s just Ned. No matter what he says the measured temps are what they are.
3) That whole business about the temperature of the Moon on Ned’s poster is a red herring, just a lot of pseudo-scientific hand-waving that shows it’s colder on the Moon at night than it is during the day. If you actually walk your way through Ned’s equations, he’s assuming that the Moon doesn’t rotate. In reality the temperatures get colder and colder with LONGITUDE on the night side, because the lunar nights are so long. Check his math. I’ve explained this to Ned but he’s a stubborn coot.
One of these days when I have nothing better to do, I will download the DIVINER data set and redo Ned’s calculations to show where he went wrong. But I can guarantee he will ignore the results. He’s a “true believer.”
4) Nobody is “clinging” to Arrhenius. We refer to his paper to point out the historical context of these observations, because many people are under the incorrect impression that “greenhouse warming” is a recent idea concocted to explain observed trends when in fact our current temperature trends were predicted as early as 1822 (by Fourier).
I don’t see how I can really post a rebuttal to your blog post because there’s so much in there and it’s so long.
If you like, I can write a shorter guest post of my own, and try to explain what’s really going on. It’s a whole lot simpler than you seem to think. There’s no “climate science” involved. Just basic first-year physics.
Thanks Scott. I hope this ends the debate here (but I have my doubts).
I showed here how standard physics — simply applying the Stefan Boltzmann Law to the moon at each local point, based on the sunlight it receives — easily reproduces the curve of the equatorial lunar surface temperature vs longitude:
http://davidappell.blogspot.com/2012/04/norfolk-constabulary-made-wrong-charges.html
Scott Denning,
Given that you are busy this week, thanks for taking the time to comment.
You ask “If we mean by “Arrhenius” the energy balance equation S/4 * (1-albedo) = sigma * T^4”.
That is not what I meant. That is the equation predicting the surface temperature of a body consisting of a thermal superconductor but lacking an atmosphere.
What I mean by “Arrhenius” is:
“….if the quantity of carbonic acid [H2CO3] increases in geometric progression, the augmentation of the temperature will increase nearly in arithmetic progression.”
This is my second attempt to falsify N&K. To avoid the “Curve Fitting” argument I examined data at a constant pressure of 1 bar so N&K’s “NTE” became a constant with a value = 47.41.
You confirm the 255 K and 288 K temperatures from your slide presentation. That takes care of David Appell’s assertion that I misrepresented your presentation.
I agree with you (and disagree with N&K) when you say that the rate of rotation of an airless body matters.
When you say:
” There’s no “climate science” involved. Just basic first-year physics.”
I agree but ain’t it amazing how James Hansen still managed to get the general public to believe in the Easter Bunny and Tooth Fairies while better scientists like Carl Sagan have been ignored?
The Diviner data is a little too fine grained for me. Even the “Level 3” data crashes my spreadsheet. I am hoping NASA will boil it down a little so that one does not need a supercomputer or “R” programming expertise to use it.
Peter, please. Simply examine the derivation of the equation you give for Tgb. It assumes the surface temperature is the same everywhere, i.e. that some kind of atmosphere provides an equilibrium.
It explicitedly does not assume an Earth without an atmosphere. Such a body (like the Moon) would have no way to be establish an equilibrium — as the Diviner results show explicitedly.
If your interest is with Arrhenius’ statement:
“….if the quantity of carbonic acid [H2CO3] increases in geometric progression, the augmentation of the temperature will increase nearly in arithmetic progression.”
then I suggest you start a new thread.
The temperature of the Moon has literally nothing to do with this statement, nor does Ned Nikolov.
You need to decide whether you’re interested in infrared radiative transfer by gases, or in the sensitivity of surface temperature to changes in downwelling radiation. Both of these subjects are important to any attempt to falsify the hypothesis above. There is a huge body of work (many lifetimes!) available to address both subjects, and we can explore some of that if you’re actually interested.
But the temperature of airless moons is completely irrelevant, as far as I can see!
Scott,
If one starts with an airless planet and then adds one molecule of CO2, double that to four molecules, double again and again …………pretty soon the planet has an atmosphere.
Arrhenius says the temperature should rise in linear fashion after each doubling. In that huge body of work you mention is there an equation linking the temperature rise to the CO2 pressure at the surface other than Ned Nikolov’s?
Peter: Haven’t you read Arrhenius’s paper?
“On the Influence of Carbonic Acid in the Air Upon the Temperature of the Ground”, Philosophical Magazine 1896(41): 237-76
Click to access Arrhenius.pdf
David Appell,
No I had not read that Arrhenius paper.
Are you offering “Table VII” in lieu of the equation linking CO2 concentration to temperature rise that I asked for?
Arrhenius appears to have claimed ~5 K per doubling while Scott Denning says 1.2 K per doubling and Nikolov says 0.0 K per doubling. So which one do you think is right and why?
Why are you insisting on an equation linking CO2 concentration to temperature? It is a very complicated calculation that cannot be summarized in a simple formula. What’s wrong with that?
Modern science finds 1.2 K for CO2 doubling, before feedbacks.
Governments around the world are spending hundreds of billions of dollars in the belief that the concentration of CO2 in the atmosphere affects the global temperature.
If you can’t produce a scientifically valid connection between these two variables why should anyone spend a single dollar to control CO2? That “doubling” idea is nonsense no matter whether you use 5 K (Arrhenius) or 1.2 K (Scott Denning).
Ice cores provide hard scientific evidence that temperature and atmospheric CO2 concentration are well correlated. The fact that CO2 lags temperature suggests that when the global temperature rises, the oceans release CO2 into the atmosphere.
Of course the concentration of CO2 in the atmosphere affects the global temperature. This has been known for over 100 years and is bedrock science.
Just because there isn’t a simple equation that quantifies the effect doesn’t mean the effect isn’t real. The equation for Tgb, while it’s based on a very simple model, shows the basics of the situation — the Earth’s surface is about 30 C warmer than it would be based on the amount of sunlight it receives, because some atmospheric gases absorb the infrared radiation the Earth emits.
All you have to do to verify the greenhouse effect is look at the Earth’s outgoing spectrum from a satellite and see the big holes where the GHGs are:
Perhaps you think society shouldn’t do anything about CO2 and warming, or perhaps you think, for certain reasons, the warming will be relatively small, but arguing against the basic science of the greenhouse effect is just…well, goofy.
gallopingcamel wrote:
> “Ice cores provide hard scientific evidence that temperature
> and atmospheric CO2 concentration are well correlated.”
But all bets are off when you have independent actors (humans) who are shoveling up fossil fuels and burning them. That increases the CO2 atmospheric level independent of anything that’s going on with the temperature, and quickly.
It’s much more like a CO2-rich comet hit Earth, with the collision stretching out over the span of 50-100 years, and delivered all its carbon dioxide, If such an injection occurred, it would occur regardless of the Earth’s temperature or any changes it’s undergoing naturally.
Study the Paleocene-Eocene Thermal Maximum (PETM) and the evidence that a large slug of carbon showed up, and the resulting warming and changes. That’s probably the best analog for our current situation.
Peter asked me to comment on here, but it’s hard for me to make out what there is to comment on. If this is supposed to be a useful discussion rather than a shouting match, let’s separate two things here:
1) What’s the sensitivity of the Earth’s surface temperature (in degrees Celsius or Kelvin) to a change in radiation of 1 Watt per square meter. It shouldn’t matter whether the extra radiation comes from CO2, sunshine, reflection by snow, or volcanic aerosol.
2) How many Watts per square meter of change in the radiative heating are produced by a doubling of CO2.
Notice neither question has anything to do with airless moons.
To answer question (1): Without any amplification or damping, the surface temperature sensitivity is about 0.3 degrees per Watt per square meter. You can derive this yourself by taking the derivative of the energy balance equation S * (1-albedo) / 4 = sigma * T^4 with respect to temperature.
If there was no amplification we couldn’t have had ice ages, Medieval Warm Periods, Little Ice Ages, or much of any climate change in the past, because the change in radiation is so small. At the end of the last Ice Age, the Earth’s albedo decreased and CO2 increased for a total change of about 7.1 Watts per square meter, and the temperature responded by rising 5 K. So the observed sensitivity of surface temperature is about (5 K / 7.1 W/m2) = 0.7 K / (W/m2), quite a bit stronger than the “no feedback” case. Similar analysis for the Medieval Warm Period and the Little Ice Age give similar numbers. So do global climate models, but you can argue that’s just dumb luck if you want.
To answer question (2): You need to measure the absorption and emission spectrum of the gas itself and then do some calculations. This is a lot harder than answering question (1). It was first attempted by Arrhenius over 110 years ago, but of course modern measurements are much better and we also have satellites to help us get the large-scale coverage. The generally-accepted value is 3.7 Watts per square meter per doubling of CO2.
Combining the answers from question (1) with question (2) gives 3.7 W/m2 * 0.7 K/(W/m2) = 2.8 K of surface warming per doubling of CO2. This is quite consistent with the paleo record and also with modern climate models.
The Arrhenius statement with which Peter seemed to have trouble was this business of a linear increase in temperature (3 K) for a geometric increase (doubling) in CO2. This arises because the change in radiation (3.7 Watts/m2) applies per doubling rather than for a certain number of additional molecules of emitting gas. The reason for the declining effect of “the next 100 ppm” of CO2 relative to “the previous 100 ppm” is that there is less thermal radiation left to be absorbed.
But really, this is very simple if you split the problem up as I’ve shown here:
1) How much does surface temperature change per Watt of heat?
2) How many Watts are absorbed by each doubling of CO2?
Some of the comments above seem to suggest that there is no reason to believe CO2 absorbs heat. This is simply a matter of laboratory measurement, backed up by other data from outdoors under the sky or from satellites.
Peter said he’s a physicist. Surely a physicist can recognize that if we measure heat being emitted from the sky, and that heat is absorbed by the ground, then the temperature of the ground has to change?
I hope this has helped. I’d be happy to discuss by phone if you prefer.
Scott Denning
David Appell,
That Arrhenius paper was most helpful. I am kicking myself for not having read it before. Breathtakingly brilliant and elegant! It deserves a more considered response.
Yes, I do think that we should stop trying to do something about CO2. Governments love to invent heroic problems that will engage the best and brightest. The great pyramids of Egypt come to mind. In hindsight all that effort might have been more usefully employed constructing humdrum stuff like roads, aqueducts and schools.
Our ancestors will wish that we had not spent so much money “Mitigating” CO2 emissions, if they turn out to be “Holy Grails” or “Great Pyramids”. If you like “Heroic Projects” why not commit to bringing electricity to every dusty hamlet in Africa?
With regard to your theories about the PETM I find it more plausible that the planet’s surface pressure was 65% higher 50 million years ago.
As to the origin of CO2, you may have it backwards. Earth’s atmosphere was mostly CO2 until life got going with the effect that CO2 was “Sequestered” into carbonate rocks. At the same time plants released oxygen into the atmosphere leading to the oxidation of iron salts in the oceans. Eventually most of the iron precipitated out allowing the oxygen concentration in the atmosphere to rise enough to allow land based animals to evolve.
I speculate that most of our water arrived after the surface of the planet cooled down. Otherwise our atmosphere would consist mostly of steam with a surface pressure of 300 bars. For once I agree with James Hansen. There would be no way back from that “Runaway Greenhouse”.
The PETM was not caused by CO2. The temperature 60 million years ago was 12 K higher than today which would require ten “Doublings” (1.2 K/doubling). Ten doublings implies a partial pressure of 0.3 bars of CO2.
I really appreciate your participation in this discussion. Scott Denning thinks it may deteriorate into a shouting match, so I will try to restrain my flights of rhetoric and stick to the numbers!
Why not bring electricity to hamlets and also solve climate change at the same time? Nothing says the world can work on only one problems at a time.
What evidence says the planet’s surface pressure was 65% higher during the PETM? What evidence would that have left?
On the other hand, we know for a fact that there was a large injection of carbon into the Earth’s system, from looking at abundances of carbon isotopes in fossils and such. Though they don’t yet know where it came from, they know its amount: 4000-6000 billion tons of carbon.
Average temperatures rose about 6 C in 20,000 years. (Your value of 1.2 K per CO2 doubling is before feedbacks).
Scott Denning,
While I still make a decent living as a semi-retired physicist, my field is somewhat specialized (quantum electro-optics). When it comes to “Climate Science” I am a rank amateur but I can’t help questioning and challenging “Authority”.
Fortunately, I have been able to keep in touch with several (much smarter) ex-colleagues in the Duke university physics department, Jefferson Lab, BNL and the University of Maryland who understand thermodynamics, solar radiations and much more. Some are of a “Warmist” persuasion but it is the “Skeptics” like Nicola Scafetta and Robert G. Brown who impress me. In this discussion I do not have their support which worries me a little.
I don’t have any problem understanding that CO2 absorbs in the “Thermal Infra-Red”. However as a “Laser Guy” I understand HITRAN. At best, CO2 absorbs 10% of the available IR and can therefore return no more than 5% of the outgoing radiation to the ground. This limits the “Forcing” attributable to CO2 here on planet Earth to ~15 W/m^2.
Like you I am not interested in “Shouting Matches” so I would prefer to continue this “off line”. Several professional climate scientists have been surprisingly helpful considering my “Skeptical” opinions. For example Albert Klein-Tank, Richard Alley and Tom Peterson. While we don’t agree on much I really appreciate their help and respect their opinions.
At best, CO2 absorbs 10% of the available IR
Says what? This figure, which measures the outgoing spectrum as a function of wavelength by satellite, tells you what you are looking for:
It’s that simple.
My thought experiment was for CO2 only. Thus I calculated the maximum absorption for CO2 at 300 K from from 14-17 microns and 4.3-4.6 microns as 8.9% of the total.
Gavin Schmidt’s chart shows the measured radiation with water vapor present. Water vapor absorbs the 4.3-4.6 micron radiation which reduces the amount of absorption that can be attributed to CO2 to less than 7%. If you don’t believe my spreadsheet, you can “Eye-ball” Gavin’s chart and see my number is correct. Wave numbers 580-730 are equivalent to 13.7-17.2 microns or 17.4-21.9 THz.
When water vapor is present, the most that CO2 can absorb is therefore only 21 W/sq. meter rather than the overly generous 30 Watts/sq. meter in my post.
Water vapor absorbs the 4.3-4.6 micron radiation which reduces the amount of absorption that can be attributed to CO2 to less than 7%.
What spreadsheet calculates the 7% number?
In any vertical column, there is no water vapor high in the atmosphere. But there is CO2.
—
P.S. Do you honestly think scientists haven’t thought about all this with a thousand times greater detail than you are? Have you picked up a textbook like “Principles of Planetary Climatology” by Ray Pierrehumbert? I just find it amazing that anyone who knows anything about science and its culture would think a couple of quick and easy spreadsheets somehow disproves over a century of work on a subject.
As I suggested earlier you can eye-ball Gavin’s chart to get a feel for how much of the total Thermal IR can be absorbed by CO2. Are you going to suggest 20%? You should be able to see that is way too high.
I am not impressed by Pierrehumbert. I find Rodrigo Caballero at UCD more useful. My apologies for the length of the link below. I used to have a more compact one but it no longer works:
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&cad=rja&sqi=2&ved=0CFUQFjAG&url=http%3A%2F%2Fciteseerx.ist.psu.edu%2Fviewdoc%2Fdownload%3Fdoi%3D10.1.1.180.4815%26rep%3Drep1%26type%3Dpdf&ei=2k83UczMOorC9gSL5oC4CA&usg=AFQjCNGhEjEfSLKc7jjR0dU4fYgkqeehGw
Physics isn’t done by “eyeballing,” it’s done by calculation.
In this case you need to consider the fact that there is little water vapor in the upper atmosphere because it is too cold. But there is CO2 up there. How did you account for this?
What about Pierrehumbert do you find unimpressive?
Rodrigo Caballero puts the greenhouse effect at 33 C (page 132 in the notes you linked to), the same as everyone else.
“A related saturation fallacy, also popularized by Ångström, is that CO2 could have no influence on radiation balance because water vapor already absorbs all the IR that CO2 would absorb. Earth’s very moist, near-surface tropical atmosphere is nearly saturated in that sense, but the flaw in Ångström’s argument is that radiation in the portion of the spectrum affected by CO2 escapes to space from the cold, dry upper portions of the atmosphere, not from the warm, moist lower portions. Also, as displayed in the inset to figure 2, the individual water-vapor and CO2 spectral lines interleave but do not totally overlap. That structure limits the competition between CO2 and water vapor.”
— R Pierrehumbert, Physics Today, Jan 2011
Click to access PhysTodayRT2011.pdf
“I’m not really sure what Table 1 assumes, especially for the albedo, which is as you know, very high for Venus.”
Sagan was correcting page 732 in the Astrophysical Journal, Vol. 149. You can find it here:
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?bibcode=1967ApJ…149..731S&db_key=AST&page_ind=0&plate_select=NO&data_type=GIF&type=SCREEN_GIF&classic=YES
Table I assumes atmospheric compositions ranging from 100% CO2 to 100% Nitrogen. The cloud top altitude was considered as 45 km and 65 km although the latest measurements show 72 +/1 km.
While Caballero and Pierrehumbert are both “Warmists”, the former is more rational in debate. If you want a hint of what I mean, look here:
If you want to indulge in a kind of trench warfare where the parties lob weblinks at one another, I won’t co-operate.
If you want to discuss the physics I will be here as long as it takes.
If you want to discuss the physics I will be here as long as it takes.
Peter, you are in no way qualified to make judgements about a scientist like Pierrehumbert, any more than a Little Leaguer should decide who goes into the Hall of Fame.
Apparently, David Appell does not want to discuss the physics.
Dr. Roy Clark has some relevant physics calculations (for the “eye-balling” adverse) on his website: http://www.venturaphotonics.com/GlobalWarming.html
I prefer discussing the current science, not endlessly rehashing the errors of 100 years ago. Angstrom was wrong. The saturation fallacy has been known for a long time and discussed in lots of places. Pretending otherwise isn’t very interesting or worthwhile.
Dr. Clark and others argue, like Angstrom, that water vapor absorbs preferentially close to the surface. In contrast, as Prof. Pierrehumbert puts it, “radiation in the portion of the spectrum affected by CO2 escapes to space from the cold, dry upper portions of the atmosphere.” The net effect may be that additional CO2 cools the planet not warms it.
Have you ever stopped to ask why “Dr Clark” doesn’t bother to make his genius results available to the entire world via publication in the peer viewed literature? The journals that everyone reads and takes seriously? Instead he keeps them hidden away on some amateurish Web page.
There they are safe, because no one will pay them any attention at all. “Dr Clark” can pretend he’s right and the rest of the world is oh-so-wrong, with no risks on his part at all.
You people will believe anything, as long as it meets your emotional needs.
Unlike the peer reviewed literature, his paper is available, free and uncensored, to the whole world here on the internet. He’s not as you claim, pretending anything. If his calculations or conclusions are in error, simply explain it to me.
David Appell,
If you mean that electricity can be generated without burning fossil fuels you have my support. The only thing that is stopping me from buying a 5 kW “Rooftop Solar” installation is my wife who thinks that granite counter tops are a higher priority. Industrial scale solar on the other hand makes much less sense:
How do you feel about nuclear power? I spent a week in a 1.8 GW nuclear plant in South Carolina last year but have not got around to writing about it.
“What evidence says the planet’s surface pressure was 65% higher during the PETM?”
It may be a month or a couple of years before you get to see that evidence. The peer review process is unpredictable if the message does not support the “Consensus”.
Vostok says 10 K cooler, 20,000 years ago.
It may be a month or a couple of years before you get to see that evidence. The peer review process is unpredictable if the message does not support the “Consensus”.
Much more likely is that such analysis is just flat out wrong. That’s a much simpler explanation than invoking Grand Conspiracies.
I don’t give any credence to “Grand Conspiracies”.
What is going on in “Climate Science” can easily be understood if you realize that those in power act in their own self interest.
Because you might always act in your own best interest doesn’t mean everyone else does likewise.
Science is a self-correcting process that has uncovered more truth than any other system of knowledge. A large number of groundbreaking, paradigm-shifting papers have been published by scientific journals over the centuries, because their ideas were a superior description of observed facts. N&Z can’t even predict the temperature of the moon, which scientists did successfully about 80 years ago.
I’m more interested in your emotional approach to the greenhouse effect. (You also said you didn’t accept general relativity.) What do you have against the greenhouse effect? You seem to have a great need to think it doesn’t exist. It’s just a natural phenomenon, like superconductivity or tornadoes, with a great deal of evidence supporting it. Why would you not want to understand a natural phenomenon? Is it that you’re afraid it might cost a few extra dollars a month on your utility bill?
Someone who claims to be a journalist should exhibit better reading comprehension. You keep refuting things I never said!
First the Greenhouse effect is real and it is much larger than the 33 K claimed by consensus climate scientists.
General Relativity like all scientific theories will eventually be superceded. Einstein himself explained why when he said:
“No amount of experimentation can ever prove me right; a single experiment can prove me wrong.”
Nevertheless, GR has practical applications to objects that are accelerating. I mentioned the example of GPS systems that would be less accurate if “General Relativity” was ignored. For many years I worked on Free Electron Lasers that used relativistic electrons as a “Working Fluid”. Our bending magnets were 2,000 times stronger than Newtonian mechanics required. If we had trusted Newton over Einstein the machine would not have worked.
Actually special relativity is all you need to handle acceleration (and lasers). General relativity includes gravity.
But you said somewhere you don’t accept general relativity. Why not? Because of Einstein’s quote? His thought applies to ALL science…. and general relativity has passed all experimental tests so far.
Frankly I can’t tell what you believe about the greenhouse effect. It seems to be all over the map, as long as it’s not what consensus science says.
David, we are having “a failure to communicate” (Cool Hand Luke). I am doing my best to put things in simple terms. As a teacher I understand the need to be patient.
All science is fallible and the inimitable Albert summed it up so neatly.
If your house was too cold you might decide to insulate the roof space. Would it matter how thick the insulation was? Of course it would.
Would it matter if there was a layer of aluminum foil on top (cf. clouds) to reduce the loss of heat by radiation? Of course it would.
Here is Arrhenius’ counter intuitive idea:
“The selective absorption of the atmosphere is……………..not exerted by the chief mass of the air, but in a high degree by aqueous vapor and carbonic acid, which are present in the air in small quantities.”
This conjecture is false. The chief mass of air does matter thanks to the adiabatic lapse rate in the troposphere which operates with the blessing of thermodynamics and (Newtonian) gravity. Carl Sagan understood this in 1969. His calculations for the planet Venus were published in peer reviewed journals. His predictions were vindicated by the Magellan Orbiter in the early 1990s.
In what way is general relativity “fallible?” It has passed all experimental tests to-date, and made many predictions that have all been verified. What more do you want from a theory?
Sagan did great work on Venus by realizing it has an extreme greenhouse effect, but he thought that greenhouse effect was due to ammonia. Later he thought it was due to water vapor, but Venus has little water vapor in its atmosphere. Its greenhouse effect is due mostly to CO2.
from: Spencer Weart, http://www.aip.org/history/climate/Venus.htm
David,
If Sagan ever thought that Venus had ammonia in its atmosphere he was not of that opinion when he published a correction to an earlier paper. At this point he thought the atmosphere was a mixture of Nitrogen and CO2.
http://adsabs.harvard.edu/abs/1968ApJ…152.1119S
We now know that the Venusian atmosphere is ~97% CO2. The appropriate temperature in Table 1 is therefore 865 K. This is much higher than the temperatures estimated in the Mariner mission (479 to 607 K) so Sagan revisited his calculations.
His error was to use the Cp (Specific heat at constant pressure) for CO2 measured at one bar. At high pressures, the Cp of CO2 rises, thus reducing the local adiabatic lapse rate. With this correction the predicted temperature falls to 721 K which is close enough (for government work) to the Magellan Orbiter (1990) figure of 735 K.
It is interesting to note that Sagan thought the temperature would hardly change if the atmosphere turned out to be pure Nitrogen. He reasoned that the specific heats were almost identical. Sagan’s prediction for a Nitrogen atmosphere was 727 K.
Notice that there was no need to discuss the spectral properties of Nitrogen versus CO2 as Venus has 100% cloud cover. All Sagan needed was the (measured) temperature at the cloud tops, thermodynamics and Newtonian gravity.
Ooooops! I see that link does not work. Please use this link and then click on the “Send PDF” button:
http://adsabs.harvard.edu/doi/10.1086/149625
Thanks for the corrected link. I’m not really sure what Table 1 assumes, especially for the albedo, which is as you know, very high for Venus.
It may have been young Earth that Sagan thought had an ammonia greenhouse effect, to resolve the Faint Young Sun Paradox. Spencer Weart (a historian) writes:
“Studies of Mars stimulated interest in a puzzle concerning a third planet, like yet unlike our own world, that gave an additional reason to believe that CO2 plays a crucial role in temperature regulation. That planet was the Earth itself, as it was several billion years ago. Sagan and a colleague pointed out in 1972 what became known as the “faint early Sun paradox.” Astrophysical calculations show that the Sun changes as it burns its hydrogen fuel, gradually getting brighter. Three billion years ago, if the atmosphere was like the present, the seas should have been permanently frozen. But geological evidence shows there was liquid water. Sagan suggested this was thanks to the greenhouse effect of ammonia gas, but further geological studies showed that such an atmosphere was unlikely. In 1979 another group produced a model whereby a very high concentration of CO2 provided the necessary warmth.”
http://www.aip.org/history/climate/Venus.htm
Did you notice that, in his lecture notes, Caballero lists Pierrehumbert’s textbook as a “useful reference?”
Pingback: Arrhenius Revisited | Digging in the Clay
Chic Bowdrie,
Many thanks for that Roy Clark link which I have bookmarked.
http://www.venturaphotonics.com/GlobalWarming.html
Roy calculates that the increase in CO2 concentration since the 19th century should have produced “……..a 1.7 Watt per square meter increase in downward LWIR flux….”
That agrees with my much cruder calculations but he then goes on to make a point I have made many times elsewhere. The downward LWIR from CO2 is irrelevant in the troposphere where it is merely a minor contributor to heat transfer processes dominated by convection, baroclinic eddies and various phase changes involving water.
Roy Clark goes on to say:
“The troposphere is an open thermodynamic system so heat and flux are not conserved.”
This is why people like Carl Sagan and N&K can predict planetary surface temperature with good accuracy using only thermodynamics, Stefan-Boltzmann and Newtonian gravity.
Glad you liked Dr. Clark’s take on the CO2 debate. And thanks for the educational discussion you inspired here.
I would be interested to know your view on the degree to which the Kiehl-Trenberth energy balance diagrams mislead the majority of those in the AGW camp. Reality is far different than a quarter strength sun shining 24/7 on a non-rotating Earth with a relatively static atmosphere. As Roy Clark points out, “there is no requirement that the local flux be conserved on any time scale.”
GHGs facilitate warming in the morning by transferring absorbed energy by collisions with other molecules. As soon as the sun goes down, those same GHGs facilitate radiation of that energy to space. As I think you are pointing out, the minor contribution of downward LWIR from CO2 doesn’t amplify energy carried over to the next day.
The Kiel-Trenberth energy balance diagrams are useful in many ways but if you want to calculate a planet’s surface temperature with any accuracy you need more information. For example you can calculate the surface temperature if you know the temperature and altitude of the cloud tops.
In 1967 Carl Sagan took the observed temperature of the cloud tops but he did not know the altitude so he calculated for 45 km and 65 km. Today we know the altitude is ~72 km. Carl Sagan was embarrassed that his “crude” calculations got the right right answer for the surface temperature of Venus. Sophisticated people like James Hansen continue to get the wrong answer because they are fixated on CO2.
More and more people are realizing that the properties of CO2 (other than its Cp) have no relevance to planetary surface temperatures. The adiabatic lapse and the depth of a planet’s atmosphere are the major factors determining the size of a planet’s “Greenhouse Effect”. Until “Climate Scientists” accept this they will continue to tie themselves in knots trying to maintain Arrhenius’ false conjecture:
“The selective absorption of the atmosphere is……………..not exerted by the chief mass of the air, but in a high degree by aqueous vapor and carbonic acid, which are present in the air in small quantities.”
“Why Atmospheric Pressure Cannot Explain the Elevated Surface Temperature of the Earth,” Roy Spencer, December 30th, 2011
http://www.drroyspencer.com/2011/12/why-atmospheric-pressure-cannot-explain-the-elevated-surface-temperature-of-the-earth/
As just one of Spencer’s points:
“Why is the average temperature of the stratosphere virtually constant with height, despite the air pressure at the base of the stratosphere (200 millibars) being about 100x that at the top of the stratosphere (2 millibars)?”
N&K can’t even predict the surface temperature of the moon — about as simple as it gets.
Standard physics predicts it just fine.
Also, their equation for ATE (eq 7 in your link to WUWT) is a *regression fit*, not any calculation from first principles. And, as people have shown elsewhere, not even a very good one, given that they have four free parameters to play with.
David,
While I respect Roy Spencer, I disagree with him on some issues. For example here is one of my comments that appears on the link you cited:
http://www.drroyspencer.com/2011/12/why-atmospheric-pressure-cannot-explain-the-elevated-surface-temperature-of-the-earth/#comment-32539
In the troposphere the properties of CO2 (other than Cp) are irrelevant as other processes dominate heat transfer.
In the stratosphere, radiation can be the dominant heat transfer process. Where this is so, temperature should rise with altitude (temperature inversion).
Excuse me for being a little dense. N&K’s equations use only TSI and pressure to predict surface temperature. What parameters did I miss?
The equations also work above the surface at a constant pressure of 1 bar.
If pressure determines temperature, why are there big chunks missing from the Earth’s outgoing spectrum?
http://www.giss.nasa.gov/research/briefs/schmidt_05/
Why is the lapse rate not linear above the tropospause?
Where is the derivation from physics for N&K’s equation for ATE(Ps)? All they’ve done is curve-fitting.
And note, N&K believe their equations works for the Moon; see Figure 5 here:
Except it predicts the wrong average temperature for the Moon, and doesn’t come close to predicting its variation with longitude and latitude. Standard physics does all of these things:
http://davidappell.blogspot.com/2012/04/norfolk-constabulary-made-wrong-charges.html
Why are you buying a theory whose predictions don’t agree with simple measurements?
Excuse me for being a little dense. N&K’s equations use only TSI and pressure to predict surface temperature. What parameters did I miss?
You missed the absorptive properties of greenhouse gases.
Have you found your missing 150 W/m2 yet? Even Chic sees you’re not on the up-and-up….
It seems that at least you have been disabused of the notion that Carl Sagan knew there was a large greenhouse effect on Venus, and that is, not pressure, explains that planet’s high surface temperature. (I’ve learned that when you igrnore a reply it means you realize you can’t counter it.)
By the way, I looked at the 1968 Sagan paper you linked to, claiming it showed thermodynamics and gravity explained Venus. Not surprisingly, it showed no such thing. In fact, it was a correction to an earlier paper, and that 1967 paper set up the equations of radiative transfer on Venus.
Claiming a paper says one thing when it says something else is dishonest, pure and simple.
So the books written by Hansen and others about a “Runaway GHE” driven by CO2 are absurd fantasies.
You are also mischaracterizing what Hansen and others have said about a runaway greenhouse effect on Earth.
IPCC, 2004: “A ‘runaway greenhouse effect’—analogous to Venus—appears to have virtually no chance of being induced by anthropogenic activities.”
Click to access inf3.pdf
What Hansen has said is this:
“In my opinion, if we burn all the coal, there is a good chance that we will initiate the runaway greenhouse effect.”
http://www.columbia.edu/~jeh1/2008/AGUBjerknes_20081217.pdf (pg 23)
That is a VERY big if. The amount of coal on the planet is estimated to be 98.6e17 g C (Swart and Weaver, Nature Climate Change, 2012). That’s 10,000 gigatonnes of carbon! — we have emitted only 380 GtC so far from burning fossil fuels.
No one knows for sure what would happen if we burned that much carbon — there are simply no models that can go there. Hansen, who made his bones studying Venus, has earned his opinion on this subject in a way that few can match.
Where are Hansen’s equations? His unscientific fairy stories are an embarrassment.
For the record I am against burning all that carbon as our ancestors will find much better uses for it. We need a truly sustainable energy source such as Thorium.
That said, burning it would theoretically raise the CO2 concentration in the atmosphere by a factor of 12. That would be around 4,800 ppm. In the past it has been much higher than that. In practice, given the take up into the oceans my guess would be less than 2,000 ppm.
This is getting a little “Off Topic” but if you like this sort of thing let me recommend David Archer:http://geosci.uchicago.edu/~archer/reprints/archer.2005.fate_co2.pdf
4,800 ppm CO2 would start to put some humans to sleep.
In any case, no one really knows what the CO2 content of the atmosphere would be if we burned 10,000 GtC, because no one understands the global carbon cycle well enough to be sure where all that carbon would go. You can’t assume the ratio of what percentage of emissions stays in the atmosphere (the “airborne fraction”) is the same as today’s.
Plus ocean acidification would go through the roof.
Hansen’s papers have plenty of equations. If you’re still hung up on an equation for the exact temperature of the greenhouse effect, you’ll have to keep hanging — the full resuls is too complicated to be expressed in analytic form, so the results are given in graphs and charts and pictures. This is true for a lot of science (can you should me an equation that predicts the freezing point of water?).
Your idea that “…the full resuls is too complicated to be expressed in analytic form…” is an appeal to mysticism or non-science.
The reality is that high school science classes cover the adiabatic lapse rate from which planetary surface temperatures can be correctly calculated. This works for Earth but also for Venus as demonstrated by Sagan in 1967. More recently, probes of the atmoshere’s of Titan and Jupiter have found lapse rates within 0.1 K/km of the theoretical values.
If you have an equation from Hansen or any other Arrhenius disciple that can correctly predict surface temperatures why can’t you cite it?
Mysticism?
Show me an equation that predicts the freezing point of water. The critical temperature of a superconductor? Air resistance on a flying plane? The severity of a disease from someone infected with a virus? The length of a solar cycle?
There isn’t even an analytical solution to the 3-body problem, and that’s been around for 400 years.
So it is mysticism to use a computer to figure how to get to the moon, given the gravitational influences of Earth, the Moon, and the Sun?
Please don’t try to raise a smokescreen of irrelevant issues. All I asked for was a mathematical derivation of planetary surface temperatures.
I say it can’t be done using the Arrhenius theory.
It’s not irrelevant, Peter — there are many seemingly simple phenomena whose behavior cannot be summarized in an equation.
Such as the motions of three gravitationally bound objects. It doesn’t get much simpler than this, and yet no general solution exists.
In physics, it’s often the case that you can have simple (Tgb in your post), or accurate. For the greenhouse effect, the only accurate solution is a numerical solution.
Stephen,
The freezing point of water (an intensive property of water) does not depend on how much of it exists, but it can be calculated from pressure. If the theory that the amount of CO2 in the atmosphere affects the average global temperature (whatever that is) is true, then there should be some way to estimate/calculate that effect from other measurable properties regardless of how difficult it is to do. Climate models haven’t yet done it and some scientists have explained why it can’t be done at all.
BTW, the freezing point of water doesn’t change much with pressure. I’m guessing average global temps won’t change much with CO2 either, as the temperature record over the last century bears out.
Of course, climate models do exactly what you say they don’t. And the greenhouse effect can be determined from this measured data:
http://www.giss.nasa.gov/research/briefs/schmidt_05/
You simply have to integrate both the red and black curves, and subtract the difference. That is precisely the greenhouse effect.
David, sorry about misnaming you.
The red curve is only hypothetical curve calculated for an arbitrary temperature. And isn’t the black curve an average or a snapshot under specific conditions, e.g. clear sky? Wouldn’t the black curve fluctuate widely between night and day and depend greatly on variations in humidity and clouds? So how do simply integrate two disparate curves and declare the greenhouse effect measured?
You’re going to argue that climate models predicted the last 15 years correctly? Or that recent modifications will predict the next 15 better.
Yes, the curves are global averages.
You’re going to argue that climate models predicted the last 15 years correctly?
Climate models don’t “predict,” they project, based on certain assumptions.
GCMs still cannot predict every bit of noise in the climate system, or ENSOs. And of course they cannot know the future of air pollution and other aerosols, volcanic eruptions, or changes in solar irradiance.
But they do, clearly get the big picture right; see the figure here:
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-8-1.html
They capture many aspects of the climate system that are being observed: warmer surface temperatures, warmer oceans, cooler stratosphere, melting land and sea ice, changes in tropospause height, etc.
Remember, we are only in the beginning of global warming. We’re trying to pick out the global warming signal before it becomes obvious, out of a lot of noise in the climate system.
There is such an equation: the Schwarzschild equations.
But as input, we need to absorption spectrum of the GHGs. What equation describes that spectrum — absorption as a function of frequency?
As a “Laser Guy” I love “Schwarzschild equations”. If Arrhenius was right they would be of great importance. They could be used to show where the doubling or halving processes “Saturate”. You will find that nobody in the CAGW camp wants to talk about that. Take a look at Figures 22 & 23 on this link to understand why:
http://www.venturaphotonics.com/GlobalWarming.html
You are not a spectroscopist so let me assure you that these plots show that my (admitedly crude) proof that CO2 cannot deliver more that 15 W/square meter of “Forcing” is overly generous by a factor of nine (1.7 W/square meter). It will not surprise me if other physicists using more sophisticated methods can demonstrate that the real contribution of CO2 to “Global Warming” on Earth is 0.0 K/doubling.
You are seriously hung up on Arrhenius.
He did his work 117 years ago.
That was well before even the Bohr atom.
Just because Arrhenius is all you know doesn’t mean science stopped there.
It isn’t a matter of being a spectroscopist — all that stuff was settled long ago, and is available in the HITRAN data base.
It’s a matter of doing the integral over the Earth’s atmosphere.
Your “factor of nine” is a meaningless as all the other numbers you guess at and throw around as if you know what you’re doing. You clearly don’t.
Peter, are you ever going to tell us why the TOA outgoing spectrum of Earth isn’t a direct measurement of the greenhouse effect?
http://www.giss.nasa.gov/research/briefs/schmidt_05/
You’ve been pointedly ignoring it so far.
Far from ignoring Gavin’s excellent plot I have cited it several times in support of my refutation of the Arrhenius theory. It supports this:
Re: https://diggingintheclay.files.wordpress.com/2013/02/morcombe3.jpg
Yours is the idealized curve, not the observed results. The observed data has big chunks out of it, at the absorption frequencies of H2O, CO2, CH4, etc.
Why?
“The observed data has big chunks out of it, at the absorption frequencies of H2O, CO2, CH4, etc.”
As usual you have misunderstood what the measured data says. Gavin shows the correct profile for thermal IR emitted by a black body at 300 K and then compares it with the radiation from the top of the atmosphere.
The CO2 is such a good absorber of thermal IR in the 15 micron band that the radiation leaving the surface is completely absorbed in the lower troposphere. The 15 micron radiation seen at the top of the atmosphere comes from CO2 at a temperature of about 245 K (approximate cloud top temperature).
The spectral intensity for a black body is a function of T (Kelvin) raised to the 5th power:
http://www.spectralcalc.com/blackbody/units_of_wavelength.html
Thus the intensity of 15 micron radiation at the cloud tops should be (245/294)^5 = 0.40 of what it would be from a body at 294 K.
If you eyeball Gavin’s curves you will see about 160 W/m^2 at wave number 667 (15 microns) compared to the 480 W/m^2 for the T = 294 K plot. Not exactly a ratio of 0.40 but close enough for government work.
You can apply similar reasoning to CH4, N20, O3 but not to H20.
The spectral intensity for a black body is a function of T (Kelvin) raised to the 5th power
No, it certainly is not. It’s given by the Planck formula, which does not go like T^5:
http://en.wikipedia.org/wiki/Planck's_law
Jeez.
The spectral intensity for a black body is a function of T (Kelvin) raised to the 5th power.
You are confusing basic concepts here.
The spectral intensity — i.e. the spectrum integrated over all wavelengths — is the Stefan Boltzmann law, which scales at T^4.
The equation you’ve pointed to is the peak of the spectral distribution, which is a very different thing.
Thus the intensity of 15 micron radiation at the cloud tops should be (245/294)^5 = 0.40 of what it would be from a body at 294 K.
Peter, you have seriously confused different concepts here, and as a result your numbers are wrong.
The PEAK SPECTRAL RADIANCE of a blackbody spectrum ~ T^5.
The TOTAL ENERGY of a blackbody spectrum ~ T^4.
The latter is just the Stefan Boltzmann law. The former is just the Planck Law at the wavelength given by Wien’s displacement law.
Of course, these two things are not equal. They aren’t even similar quantities, because one if a spectral energy density, and the other is an energy.
If you look closely at the page you gave, equation 9, you see that L doesn’t have units of energy (per unit area), it has units of energy per unit area per unit wavelength per steradian. It’s not energy.
You need to try again with the Stefan Boltzmann law.
David and Peter,
You may find this article relevant to the current discussion:
http://climateclash.com/g8-co2-cannot-cause-any-more-global-warming/#more-750
“Understanding the downwelling and upwelling long-wave fluxes in the atmosphere is essential if we are to compute the Earth’s global energy balance and its greenhouse effect accurately.”
Several other papers (labeled G1 to G12) with comments discussing the calculations and magnitude of the greenhouse effect can be found there as well.
It seems you guys will believe anything and everything, as long as it says CO2 isn’t a significant greenhouse gas.
“Rebuttal of Miskolczi’s alternative greenhouse theory,” Rob van Dorland and Piers M. Forster
Click to access Rebuttal_Miskolczi_20100927.pdf
Chic Bowdrie.
Much as it grieves me I have to agree with David on this one. Miskolczi is correct when he says that the LWIR from CO2 (and anything else) is split 50:50 between “Up” and “Down”. This was one of the points I made in my post above.
The rest of Miskolczi’s conjecture is wrong for the same reason that Arrhenius is wrong. Attempts to explain surface temperature in terms of trace gases such as CO2, methane, ozone or water vapor are doomed to failure. The real “Greenhouse Gases” are Nitrogen and Oxygen on Earth. On Venus the GHG is CO2. The ALR and depth of atmosphere dominate.
The real “Greenhouse Gases” are Nitrogen and Oxygen on Earth.
Simple spectroscopy shows that this is absurd.
Simple thermodynamics trumps your spectroscopy.
You haven’t done any thermodynamics (while completely ignoring spectroscopy). All you have done is take a formula from N&K — one that doesn’t even predict the correct lunar temperature — that they obtained, not from thermodynamics, but from curve-fitting. And rather bad curve fitting.
Anyone can do curve fitting — it doesn’t explain anything. It certainly isn’t a derivation from first principles.
Peter,
OK I’d better just watch and learn from your debate with David. However, I am confused on whether you are arguing how to calculate a greenhouse effect vs. whether or not a change in CO2 will affect global temperature and, if so, by how much. Or is showing that the greenhouse effect can be explained without a dependence on CO2 a problem, because it threatens the “consensus” view?
Adding an atmosphere to a planet increases the average surface temperature. The “Main Stream Media” calls that the “Greenhouse Effect” or GHE.
We are debating whether the GHE results from trace gases (Arrhenius) or the main mass of the atmosphere, namely Nitrogen/Oxygen for Earth or CO2 for Venus.
At present the majority opinion among “Climate Scientists” seems to favor the Arrhenius theory while many physicists contend that the main mass of the atmosphere determines the GHE.
The idea that a doubling of CO2 concentration will raise the average global temperature by 1.2 K (or 5.4 K) cannot explain the GHE on Earth or Venus. Likewise the Arrhenius theory cannot explain the large temperature excursions (~10 K) over the last 700,000 years. Even so there are many people who believe CO2 affects global temperatures in the short term.
I support the idea that the GHE depends on the main bulk of the atmosphere (Nitrogen and Oxygen). However, these gases vary over tens of millions of years so you can’t attribute short term temperature changes on them. So what causes short term temperature changes? The CAGW zealots discount most natural effects and claim that man made CO2 is the main driver.
The weakness of my position is that while I can explain the GHE, I can’t explain short term climate changes or glaciation cycles.
while I can explain the GHE
Except, without the IR absorption by GHGs, you can’t come close to explaining the observed TOA outgoing spectrum:
http://www.giss.nasa.gov/research/briefs/schmidt_05/
Science is about explaining observed phenomena, not ignoring the ones you find inconvenient.
As I said earlier Gavin’s chart supports my analysis showing the absolute maximum forcing that CO2 could provide if Arrhenius’ doubling concept was valid.
The outgoing spectrum at 15 microns is what one would expect from CO2 at a temperature of ~245 K instead of the 294 K profile shown in Gavin’s chart.
False. You must take into account the vertical distribution of water vapor in the atmosphere.
The CAGW zealots discount most natural effects….
Which natural effects, exactly, are discounted?
Here are a few for your consideration. Clouds, water vapor, Ozone, ice fields, ocean currents, cosmic rays, volcanoes, solar wind and sunspot cycles.
The variations in Earth’s average temperature are tiny compared to the huge excursions from day to night, season to season and equator to poles. We are a long way from understanding the relative importance of these and other natural processes that may (or may not) affect climate.
Climate scientists study, consider, and, when necessary, include every one of the factors you list. (The effect of the last four has not changed in about 60 years.)
The variations in Earth’s average temperature are tiny compared to the huge excursions from day to night, season to season and equator to poles.
So what you’re saying is that the daily temperature swing in your backyard (~15 C) is a more significant change than an ice age (~7 C)?
We are a long way from understanding the relative importance of these and other natural processes that may (or may not) affect climate.
Some of us are further than others.
That helps, thanks. With regard to short term and glaciation cycles, what about solar winds, cosmic rays, orbital variations, and continental drift, etc?
Solar winds: no change in average solar activity in last 60 years (when the warming has occurred)
Cosmic rays: no net change in cosmic ray incidence over last 60 years.
Orbital variations: of course; they initiate the glacial/interglacial cycle, but are insufficient to account for its wide swing (that requires CO2 and feedback effects)
Continental drift: ~ a few mm/yr. Significant only over very large time scales.
David calls absurd Peter’s claim that NO2 and O2 are Earth’s real greenhouse gases. The majority (vis a vis consensus) of the commenter’s on the link to Roy Spencer’s blog that David offered previously seem to agree with Peter (especially Stephen Wilde, e.g. comments 32628ff and 32708):
http://www.drroyspencer.com/2011/12/why-atmospheric-pressure-cannot-explain-the-elevated-surface-temperature-of-the-earth/
Thinking surface pressure determines surface temperature (it doesn’t, as Roy Spencer shows) is very different from saying that nitrogen and oxygen are “greenhouse gases.” GHGs work by absorbing and reemitting infrared radiation. Oxygen doesn’t do that, and nitrogen doesn’t do that in the current climate regime.
Look, all you have to do is look at the Earth’s TOA outing spectrum:
http://www.giss.nasa.gov/research/briefs/schmidt_05/
This is a DIRECT MEASUREMENT that anyone can do. It needs to be explained. There is a similar one for Venus. It needs to be explained. Surface temperature as a function of surface pressure doesn’t explain it at all (besides the other reasons that notion is wrong, as Spencer says).
You don’t get to ignore experimental evidence just because you have some other pet theory. If your theory doesn’t explain the evidence, it is wrong, PERIOD.
David says:
“There is a similar one for Venus.”
Indeed there is and the “Thermal IR” spectrum is what you would expect from cloud tops at a temperature of ~250 K. The only “Thermal IR” radiation that comes direct from the surface is at around 1 micron so you see a large “spike” there.
Here is chart that compares the temperature gradient in the Venusian atmospere with Earth:
It shows the Venusian troposphere starting at an altitude of 65 Km compared to Earth’s 16 km. From there to the surface the Adiabatic Lapse Rate rules. It is simply a matter of -g/Cp times the depth of the troposphere.
If the mass of the Venusian atmosphere was equal to that of Earth, the Venusian troposphere would shrink to only 16 km instead of 65 km. This would mean that the surface temperature would fall by (65-16)*7.9 = 387 K to around 350 K (cf 737 K today).
Note that the composition of the Venus atmosphere is unchanged (97% CO2). It is the depth of the troposphere that matters and that depends on the mass of the atmosphere rather than its composition.
If pressure determines temperature, why is the lapse rate nonlinear above the tropospause?
On Earth it gets *warmer* as you go up through the stratosphere, even though the pressure gets lower.
I guess I’m wondering — why do you think those commenter’s opinions matter more than a trained, experienced climatologist? Do you think science is a democracy?
I’ll go with whatever theory can explain the measurements.
Except, clearly, if it’s a measurement of the Moon’s temperature — a simple situation that standard physics explains exactly, but which N&K can’t, even for the average,
You are defining “greenhouse gas” as a molecule capable of absorbing and re-emitting infrared radiation. Peter et al. argue that your “greenhouse gases” have little, if anything, to do with the observed so-called “greenhouse effect” which creates a planetary temperature greater than that which would occur without its atmosphere. If they are right, the true “greenhouse gases” are nitrogen and oxygen, not infrared absorbing gases.
There’s a lot more to it than looking at Gavin Schmidt’s graph. The red curve is only hypothetical curve calculated for an arbitrary temperature. And isn’t the black curve an average or a snapshot under specific conditions, e.g. clear sky? Wouldn’t the black curve fluctuate widely between night and day and depend greatly on variations in humidity and clouds? So how do simply integrate two disparate curves and declare the greenhouse effect measured?
It is not my theory, but it seems reasonable and I’m inclined to continue to study it. Frankly, I don’t see how it conflicts with Gavin Schmidt’s graph. What I do see is that the theory conflicts with your mindset and it troubles you. Anyway, I’ll leave it to Peter Morcombe to carry on.
A climatologist over physicists? Not on this one. Science vs. democracy (consensus anyone?) How ironic.
You may be on to something when you characterize this as a “Climate Scientists” versus Physicists event.
The “Climate Scientists” have been getting away with their meme that “The Debate Is Over” so it will be interesting to see how they cope with rampant Physicists. Certainly they won’t be able to ignore us.
Do you honestly have a degree in physics? Really??
PS: It was the physicists who invented climate science.
Certainly they won’t be able to ignore us.
Yes, I’ve noticed the great multitude of comments here from the global climatological community.
My understanding of the “Greenhouse Effect” is the increase in average surface temperature of a planet or moon attributable to its atmosphere. Are you disagreeing with that?
You say that trace gases are responsible for a GHE of ~33 K on Earth even though I have shown that the idea fails several “Sanity Tests”.
I say that the GHE depends on the bulk of the atmosphere, namely Nitrogen/Oxygen for Earth and CO2 for Venus. I have shown you how to calculate surface temperature using cloud top temperatures and the adiabatic lapse rate. Nikolov & Zeller have taken it a step further by developing some equations with TSI and pressure as the only variables.
The fact that they work while your “Doublings” don’t should get you thinking.
Peter, are you ever going to address the question of why you believe in the N&K theory when it doesn’t predict the temperature of the moon?
Or are you going to avoid this, too?
The term “greenhouse gas” has a specific meaning: one whose molecules absorb and emit in the infrared. The greenhouse effect isn’t just *any* warming, no matter the cause — it’s warming due to the properties of greenhouse gases in the atmosphere.
Confusing terms like this doesn’t help anything.
Yes, Gavin’s black curve is specific (probably an average, in this case). So? It still needs to be explained, and the pressure-explains-temperature ideas doesn’t explain it at all. In fact, as far as I can tell that idea predicts the *red* curve. Which isn’t what is measured. Ergo, it must be false.
Few (if any) of the commenters at Spencer’s site are physicists — most are just anonymous Internet commenters. Yes, Spencer’s opinion (which he explains carefully) means more than the rabble’s. Can you point to *any* professional climatologist who thinks surface pressure determines surface temperature? Just one?
I clicked on the wrong comment so my answer to this one appears above it.
Your question about qualifications was discourteous. I thought we had put that nonsense behind us. Nevertheless, here is the answer:
I have degrees in Physics and Electrical Engineering earned at Pembroke College, Cambridge. I studied Physics at the Cavendish Laboratory. My tutors included G.C. Smith (Physics), J.C.P. Miller (Mathematics) and A.H.W. Beck (Microwaves). Today, I teach electro-optics on a part time basis:
http://www.bdidatalynk.com/PeterMorcombe.html
So you have a bachelors in physics from this Pembroke College? Or did you just study it somewhere?
Any advanced degrees from anywhere?
Masters? Doctorate?
By the way, Gavin’s curve is hardly the only curve on this — this subject has gotten a great deal of study. A good place to start your reading (and see a lot of such curves under conditions) is:
The Far Infrared Earth, J Harries et al, Reviews of Geophysics, Volume 46, Issue 4, December 2008
http://onlinelibrary.wiley.com/doi/10.1029/2007RG000233/abstract
No matter the conditions, these curves all have similar features — holes where GHGs absorb and reemit.
Here is Venus’s LW spectrum:
http://www.sciencedirect.com/science/article/pii/S0032063306001589
The thermal IR part of that spectrum is exactly what one would expect from cloud tops at a temperature of ~240 K. Those cloud tops are at an altitude of ~65 km and the effective adiabatic lapse rate is 7.9 K/km. The surface temperature is therefore ~753 K. Once again, close enough for government work.
Now show me how to calculate the surface temperature using using the Arrhenius conjecture.
But I don’t work for the government.
Now show me how to calculate the surface temperature using using the Arrhenius conjecture.
Sure. You take the incoming sunlight and albedo and account for the greenhouse effect:
Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature
Andrew A. Lacis, Gavin A. Schmidt, David Rind, Reto A. Ruedy
Science 15 October 2010:
Vol. 330 no. 6002 pp. 356-359
You were going to comment on my blog — remember? — about why Lacis and these other experts are all wrong, in your expert opinion. Did you forget?
My understanding of the “Greenhouse Effect” is the increase in average surface temperature of a planet or moon attributable to its atmosphere. Are you disagreeing with that?
Yes, Peter. The greenhouse effect comes from greenhouse gases, which, analagously to a real greenhouse, stop the outflow of infrared radiation.
By the way, if the surface temperature of the Earth is increasing — 0.8 C in the last century — why haven’t we seen a corresponding increase in surface pressure?
Surface pressure is easily measured by a barometer, to high accuracy.
So where is the data showing an increase in Ps?
Pressure based theories (e.g. from Sagan to Nikolov & Zeller) are pretty good at explaining the GHE for all seven bodies in our solar system that have significant atmospheres. Arrhenius totally fails to predict the GHE anywhere.
As you correctly point out atmospheris pressure changes on Earth can’t account for the tiny temperatures variations that have been going on here for the last 10,000 years.
These tiny changes may be caused by CO2 as you seem to believe or they may be caused by some or all of the natural causes mentioned here:
Our understanding of climate is pitifully incomplete so anyone who believes that CO2 plays a dominant role needs to produce more convincing evidence than you have come up with thus far.
In the longer term the larger temperature changes exemplified by the recent Ice Age cycles and the huge decline in temperature over the last 65 million years may be due to cosmic rays, Milankovic cycles, continental drift or changes in atmospheric pressure.
N&K claim the decline in temperatures since the Permian Eocene Temperature Maximum (PETM) was mainly driven by a change in atmospheric pressure. See:
Click to access unified_theory_of_climate_poster_nikolov_zeller.pdf
Figures 8 & 9 in the N&K poster point to a 53% net loss in atmospheric pressure over the last 65 million years. If this conjecture has any validity, such a radical change in the planet’s atmosphere should be detectable by Geologists. Here’s how they may be able to test N&K’s hypothesis.
A major change in atmospheric pressure is much more likely to involve Oxygen rather than Nitrogen as volcanic activity releases more SO2 and CO2 than Nitrogen. Plants convert CO2 into Oxygen (and carbon compounds) so if N&K are right Earth’s atmosphere during the PETM had a at least three times more Oxygen than our modern atmosphere. Imagine how large flying creatures could become with all that Oxygen!
N&K need to show that the atmospheric composition 65 million years ago had a much higher oxygen content than our modern atmosphere. If they are able to do that would you still deny the idea that pressure drives surface temperatures?
Pressure based theories (e.g. from Sagan to Nikolov & Zeller) are pretty good at explaining the GHE
They don’t explain, AT ALL, the frequency variation of the Earth’s TOA outgoing spectrum.
In the satellite era, this is a trivial measurment.
Why do you keep ignoring it?
These tiny changes may be caused by CO2
FINALLY we’re getting somewhere!
At least you admit that surface pressure hasn’t changed noticeably in the last century. Hence, it does not explain modern warming.
Nor do any of these other factors, Peter. They have all been looked at closely — educate yourself, instead of sticking your head in the sand.
N&K claim the decline in temperatures since the Permian Eocene Temperature Maximum (PETM) was mainly driven by a change in atmospheric pressure
N&K are idiots, ignoring a large negative excursion then in light carbon isotopes.
And you, too, are an idiot if you ignore such basic, fundmental data.
Would you read something besides what makes you comfortable and only conforms to your narrow, anti-CO2 beliefs?
Carbon dioxide forcing alone insufficient to explain Palaeocene–Eocene Thermal Maximum warming, Richard E. Zeebe et al
Nature Geoscience 2, 576 – 580 (2009)
http://www.nature.com/ngeo/journal/v2/n8/abs/ngeo578.html
You claim you’re a scientist — so start acting like one.
Our understanding of climate is pitifully incomplete so anyone who believes that CO2 plays a dominant role needs to produce more convincing evidence than you have come up with thus far.
Peter, you should be ashamed of yourself. You like to pretend you’re a scientist, but you ignore any evidence that doesn’t fit your narrow point of view. That is not scientific in the least. Scientists follow evidence, wherever it leads, whatever it might cost them or society.
Frankly, you seem more interested in minimizing your heating bill than understanding anything about nature.
I honestly do not know how people like you live with yourselves, spouting unscientific nonsense ideas that do not agree with the evidence, thinking you are somehow smarter than the thousands of scientists who have come before you.
You’re not smarter than them, Peter, and you have no original ideas that they didn’t consider decades ago. And it is scandalous that you dismiss evidence and ideas just because you find them uncomfortable.
Grow up. For God’s sake, the existence (and enhancement) of a greenhouse effect is not going to kill you. Be a man.
The personal attacks and “grow up” “be a man” comments are out of line, David. I call for an apology.
David,
I keep telling you that the GHE is real and much larger than you think it is. Why can’t you comprehend simple English?
All you have is rhetoric and the ability to misunderstand physics.
Frankly, Peter, I can’t understand what you think — anytihng, it seems, as long as it isn’t the canonical view.
You believe a theory that:
(1) doesn’t conserve energy
(2) can’t predict the lunar temperature,
(3) ignores all spectroscopic results
(4) can’t explain the Earth’s TOA outgoing spectrum
(5) has a GHE 5 times larger than the canonical view, but that somehow doesn’t involve CO2,
(6) can’t explain the ice ages or PETM
Am I missing anything?
Oh yeah:
(7) has to rely on a formula that is not derived from first principles, but is simply curve fitting with a large number of free parameters.
N&K say that Earth’s atmospheric pressure was much higher 65 million years ago, so yesterday I tried to suggest how one could prove or disprove that conjecture.
Somehow that sent David Appell off the deep end. Has his faith in the crackpot Arrhenius theory morphed into religious fervor?
David claims that N&Z do not explain the TOA spectrum. To make sure I’m understanding this, do N&Z have to explain the TOA spectrum if it doesn’t conflict with their theory? As you’ve explained over and over, “the outgoing spectrum at 15 microns is what one would expect from CO2 at a temperature of ~245 K instead of the 294 K profile shown in Gavin’s chart.” This is consistent with temperatures high enough in the atmosphere where CO2 emissions exceed absorption and collisions with other atmospheric gases.
Also, after defaming N&K, David cites Zeebe et al. in an attempt to discredit N&K’s claim that the decline in temperatures since the PETM was mainly driven by a change in atmospheric pressure. I don’t have access to the full article. From the abstract, the authors don’t seem to address the influence of pressure on the temperature of the Earth since the PETM, only that CO2 cannot explain it alone. Does the article even show that CO2 explains it at all?
N&K’s theory is based on thermodynamics so they regard radiative transfer as just one of several ways to move heat around. Radiative transfer does not have any special significance relative to convection, baroclinic eddies or phase changes involving water.
Gavin Schmidt is not a scientist according to my understanding of the term. He and James Hansen are political activists who bring dishonour to the objective science we used to expect from NASA.
Gavin’s chart shows the emission from a cloud free area of Earth at a temperature of around 21 Centigrade. Consequently you can easily see how CO2 affects Earth’s emissivity in such regions. The spectra for cloud covered areas looks quite different. According to N&K all of these spectra are irrelevant if you are trying to calculate planetary surface temperatures.
In the 14-16 micron band, CO2 is such an effective absorber of radiation that these wavelengths are blocked in the lower troposphere as shown clearly in one of the links you cited earlier:
http://www.venturaphotonics.com/GlobalWarming.html
Consequently, in the 14-16 micron band the radiation emitted into space is being radiated from the stratosphere which is much cooler than the surface (294 K). I hate to keep repeating myself but David Appell is a slow learner.
With regard to N&K’s claim that the PETM resulted from an atmospheric pressure much higher than today I don’t believe it any more than David Appell does.
However, if N&K come up with some evidence my opinion is likely to change. Earlier I asked David Appell whether such evidence would change his opinion and he reacted with a series of rants. Draw your own conclusions about his objectivity or lack thereof.
I really appreciate your reasoned contributions to this debate.
Of course N&K’s theory must be at least consistent with the measurement of the TOA outgoing spectrum, if not explain it. It does neither.
Radiative transfer is not just another way to move “heat” around, and classical thermodynamics does not consider or include radiative transfer.
N&K’s theory does not conserve energy. The surface radiates at 390 W/m2, and the TOA at 240 W/m2. Where is the missing 150 W/m2??
David, how is the 390 W/m2 determined?
The Stefan-Boltzmann Law for T=15 C.
In other words, 390 W/m2 is calculated, not measured.
In other words, 390 W/m2 is calculated, not measured.
Wow — so now you’re questioning the fundamentals of blackbody radiation?
Do you have ANY idea how much time and effort was spent on that about a hundred years ago? A few days ago you didn’t even know what the Stefan Boltzmann law was. Now suddenly you’re an expert on radiative physics?
If not, are you at least familar with experiments like these?
“Radiative forcing – measured at Earth’s surface – corroborate the increasing greenhouse effect,” R. Phillipona et al, Geo Res Letters, v31 L03202 (2004)
http://onlinelibrary.wiley.com/doi/10.1029/2003GL018765/abstract
“Measurements of the Radiative Surface Forcing of Climate,” W.F.J. Evans, Jan 2006
https://ams.confex.com/ams/Annual2006/techprogram/paper_100737.htm
I just started reading the Philipona et al. 2004 article. In paragraph (7) it says “LW downward IR is expected to increase with increasing greenhouse gas concentrations, but also with the increase in temperature and cloud amount.” So isn’t it possible that the increase in temperature and cloud amount is sufficient to explain all the observed increase in downward LWIR?
Yes, and Philipona et al discuss this throughout their paper, by comparing fluxes for cloudy and for clear-sky conditions, and by accounting for changes in humidity (which are what changes in temperature cause). They find that downward radiation increased by 5.2 W/m2, of which 1.0 W/m2 was due to increased clouds. They then correct for humidity and conclude “…the increase of cloud-free longwave downward radiation (+1.8(0.8) W/m2) remains statistically significant and demonstrates radiative forcing due to an enhanced greenhouse effect.”
N&K’s theory is based on thermodynamics so they regard radiative transfer as just one of several ways to move heat around.
Where does N&K consider radiative transfer?
The whole point of radiative transfer is that it’s *not* like other ways to “move heat around.” Classical thermodynamics doesn’t consider radiation. It envisions gas particles to basically be billard balls, and they don’t interact with radiation. They don’t even obey the same statistics as radiation.
The Earth’s atmosphere is almsot entirely N2 and O2. Neither absorbs in the infrared(*). So they have no way to absorb infrared radiation.
(*) There is a tiny effect called collision induced absorption, but it is very small. See, for example:
http://onlinelibrary.wiley.com/doi/10.1029/2012GL051409/abstract
In the 14-16 micron band, CO2 is such an effective absorber of radiation that these wavelengths are blocked in the lower troposphere as shown clearly in one of the links you cited earlier: http://www.venturaphotonics.com/GlobalWarming.html
I didn’t cite this link. He’s another [snip] who doesn’t really understand the science.
According to N&K all of these spectra are irrelevant if you are trying to calculate planetary surface temperatures.
N&K don’t calculate planetary surface temperatures — they merely do curve fitting to existing data, and cannot derive their formula from first principles. Arrhenius was the first one to do a calculation of the Earth’s temperature, and in 1967 Manabe and Wetherald were the first ones to put all the pieces together and get the correct value.
You made four replies to my one comment. Is this argument by verbiage?
On March 23, 2013 at 2:26 pm you agreed that the increase in temperature and cloud amount is sufficient to explain all the observed increase in downward LWIR. Therefore Philipona’s data only supports a hypothesis that IR absorbing gases cause the temperature and humidity effects. The data do not “demonstrate” as they put it, or more correctly, prove it.
At 2:34 pm you argue radiative transfer is “not like other ways to move heat around” and cite a paper which you claim shows that collision-induced absorption “is a tiny effect.” That paper refers to outgoing longwave radiation only. Anyway is 15% tiny? What moves heat around is when CO2 and water vapor absorb radiation and immediately bump into O2/N2 molecules transferring the absorbed energy before emitting it. Collisions predominate over emissions near the surface, the opposite of what happens near the TOA.
At 2:36 pm you thought someone claimed you cited the venturaphotonics.com link when actually Peter was responding to me. I’m not accusing you of anything except maybe hypocrisy when you say “he’s another [snip] who doesn’t really understand the science.”
At 2:38 pm you respond to an earlier comment where Peter explained N&Z’s view that spectra are irrelevant for calculating planetary temperatures. How is calculating surface temperature by manipulating emissivity and albedo values any different than curve fitting?
You made four replies to my one comment. Is this argument by verbiage?
I add replies when I think I have something to say. Why would the number bother you?
On March 23, 2013 at 2:26 pm you agreed that the increase in temperature and cloud amount is sufficient to explain all the observed increase in downward LWIR.
I certainly did not agree with that. Reread it.
It’s difficult to make any headway here when I write A and you and Peter read it as not-A.
Anyway is 15% tiny?
Please, read better. It’s 15% of anthropogenic CH4’s effect, which is itself about 28% of anthropogenic CO2’s effect.
CIA (collision induced absorption) has a total radiative forcing of 0.28 W/m2, according to the paper I cited. The number for anthropogenic CO2 is 1.82 W/m2. The total due to all anthropogenic GHGs is 2.84 W/m2:
http://www.esrl.noaa.gov/gmd/aggi/
However (and importantly), the CIA isn’t *new* — it’s been in the atmosphere since before the Industrial Revolution, which is why the paper refers to it as “natural.” So its proper comparision is to the total GHE, or about 150 W/m2.
How is calculating surface temperature by manipulating emissivity and albedo values any different than curve fitting?
What is manipulated?
Emissivity and albedo are *measured*. The S-B Law has been *verified* by an armada of experimental results going back over 100 years. They are then *applied* to the situation at hand.
This is the very essence of science — taking results that have already been scientifically established as true and applying them to other situations.
If you don’t agree that increases in temperature and cloud cover could account for all increased longwave downward radiation, how do you distinguish the contributions of increased temperature and cloud cover from those of increased CO2, H2O, etc.?
I should not have mentioned 15% because it is beside the real point that collisions predominate over emissions for IR absorbing gases close to the surface. The article you cited deals with OLR. Wouldn’t you agree the influence of CIA is much less at the TOA where OLR is measured? And doesn’t it then follow that CIA near the surface could account for most, if not all, the 150 W/m2?
I didn’t know emissivity and albedo are measured. I can see how they could be estimated, but they seem difficult to actually measure. Is verifying the S-B law the same as measuring emissivity and albedo?
If you don’t agree that increases in temperature and cloud cover could account for all increased longwave downward radiation, how do you distinguish the contributions of increased temperature and cloud cover from those of increased CO2, H2O, etc.?
Measure the observed spectrum at the ground as a function of wavelength. Figure 1 here has such a measurement:
“Measurements of the Radiative Surface Forcing of Climate,” W.F.J. Evans, Jan 2006
https://ams.confex.com/ams/Annual2006/techprogram/paper_100737.htm
Also, measurements during clear-sky conditions remove the effects of clouds. This paper has a lot of such measurements:
“The Far-infrared Earth,” J. Harries, et al, Reviews of Geophysics, Volume 46, Issue 4, December 2008
http://onlinelibrary.wiley.com/doi/10.1029/2007RG000233/abstract
Wouldn’t you agree the influence of CIA is much less at the TOA where OLR is measured?
Sure, because the density of N2 and O2 molecules is much lower (essentially zero) at the TOA.
And doesn’t it then follow that CIA near the surface could account for most, if not all, the 150 W/m2?
Not at all. Outside of the absorption bands of the GHGs, most of the upward outgoing radiation comes from the surface, Look at the outgoing spectrum:
http://www.giss.nasa.gov/research/briefs/schmidt_05/
Outside of the GHG absorption bands the spectrum is essentially a blackbody at T=288 K.
Besides, there is the Hopfner paper. Here professional scientists used a combination of theory and experiments to determing the CIA RF.
This is something I don’t understand. You still seem to be learning the basics of this physics, which is great, but then you jump to conclusions that aren’t supported by the science at all, like here. Do you really honestly think you would have deduced something incredibly basic and important about the GHE — that, as you claim here, it’s almost all because of CIA — that somehow would have escaped all scientists for the last 200 years? It makes no sense at all. What do you think scientists have been doing for the last 200 years, and why do you think they’re so certain about their claims? You almost make it sound like they got up one morning, said, Whatever, this sounds good, now let’s go play golf. It just astonishes me that people who know so little science think their wacky ideas have anything to them.
I appreciate your patience while I sort out 200 years of radiation physics. Earlier you cited Philipona et al. 2004 and Evans 2006 as evidence of measurements supporting the 390 W/m2 attributed to radiation from the surface. Before even looking at the Evans poster, I commented that Philipona et al. looked at the effect of temperature and humidity changes on downward radiation. The authors used data from the Alps in central Europe where temperature and humidity increases “are considerably larger than global average.” Right off the bat, can we agree this data is somewhat less than typical? At least their data spanned an eight year period. For Evans’ poster only two spectra were obtained, one in winter and one later in the summer. His/her “evidence” of a measured greenhouse effect consisted of comparing the strength of the absorption bands for various gases with model calculations. Nothing in Evans’ paper has anything to do with changes in upward or downward fluxes attributable to any change in the composition of atmospheric gases. It’s possible, but not unambiguously obvious, that the increase in the concentration of CO2 and other gases was responsible for the increased downward radiation in the Alps during the period Philipona et al. studied. Changes in cloud cover or temperature increases due to natural causes could also explain the results presented.
I don’t understand why you keep referring to the Schmidt spectra. It shows CO2, water vapor, and other gas emissions at lower temperatures in the atmosphere compared to the window where no radiation is absorbed. This is to be expected. But you can’t distinguish where and what magnitude radiation occurs at various heights. But in general, wouldn’t you expect CIA to be maximum at the surface gradually ending up near zero at the TOA?
Perhaps things will clear up when I get access to the full Hopfner paper.
BTW, which conclusions have I jumped to that aren’t supported by science? And who judges what is and is not science?
Nothing in Evans’ paper has anything to do with changes in upward or downward fluxes attributable to any change in the composition of atmospheric gases.
It’s a measurement of the greenhouse effect at the surface, but no, not changes.in the GHE. You had asked, “how do you distinguish the contributions of increased temperature and cloud cover from those of increased CO2, H2O, etc.?” Evans and Puckrin show that part of the downward radation is coming directly from the non-H2O GHGs.
Harries et al Nature 2001 (cited earlier) show that the GHE, measured at the TOA for clear-sky conditions, is increasing independent of anything to do with clouds.
But in general, wouldn’t you expect CIA to be maximum at the surface gradually ending up near zero at the TOA?
Yes, it depends on particle density (or, put another way, on the pressure). The Hopfner et al paper sums up the CIA’s over the entire atmosphere.
BTW, which conclusions have I jumped to that aren’t supported by science? And who judges what is and is not science?
You wrote, “doesn’t it then follow that CIA near the surface could account for most, if not all, the 150 W/m2?”
Don’t you think that something as fundamental as the operation of the greenhouse effect — settled science of which there isn’t any doubt — is known well enough to distinguish between GHGs and CIA?
Like I wrote, this is something I just don’t get. I was taught that to contribute to science you first need to understand what has already been established. What’s the point of endlessly assuming parts of the science (that were proved long ago) are wrong? That your belief about CIA is somehow more correct than the decades of work that has already been done? If you want to learn the science, that’s great, but that’s not what you and Peter are doing here, you’re just trying to throw up roadblocks based on your misunderstanding of the science, without regard for what’s already known.
And your skepticism is selective.
If you’re trying to learn something new, and you get to something you don’t understand or that strikes you as dubious, why do you immediately jump to the suspicion (conclusion?) that the rest of the world is wrong? Why not ask yourself, why does everyone think that way? What do they know that I do not?
Perhaps you are the one in 10 billion people who will make an Einstein-like advancement in overthrowing the accepted paradigm. The changes are very, very, very high that you are not, and if you are you it’s going to take a huge amount of work and a huge amount of evidence to overthrow it, because scientists do not think what they do on a whim, or because of politics, or because they woke up one morning and decide there ought to be a GHE just because. They have reasons, and very good ones — better ones than in any other arena of life that purports to have knowledge. So maybe this is a failure to understand the culture of science more than the science itself.
“It’s a measurement of the greenhouse effect at the surface, but no, not changes in the GHE.”
Evans and Puckrin’s conclusions note that water vapor reduces the fluxes of the other greenhouse gases. In other words, the IR absorbing gases all compete for whatever radiation there is to be absorbed. Just showing a fingerprint of a gas in the spectrum does not guarantee banking any specific amount of energy. The authors exaggerate their findings when they conclude “that the greenhouse effect from trace gases in the atmosphere is real and ADDS significantly to the radiative burden of the atmosphere.” Maybe their poster needed more peer review.
Similarly, Harries et al. show changes in spectra indicating growth of IR absorbing gases, but they do not show these fingerprints have any effect on the net radiative fluxes. Do they?
Nowhere do I see where Evans and Puckrin measured 340 W/m2. So I’m still left with the impression that it is a calculated value based on the accepted average surface temperature.
I’m waiting for access to the Hopfner paper for further comment on CIA.
You may think that the greenhouse effect is settled science, but a whole host of physicist’s and others have doubts including N&Z, Peter Morcombe, and Roy Clark. That’s the whole point of this discussion. Even Roy Spencer, who uses AGW language, thinks CO2 sensitivity is highly overrated and feedbacks may be negative.
I can’t speak for Peter, but I am not throwing up roadblocks. When my misunderstanding of science is clearly explained, I will acknowledge it. Unfortunately, you are the one who suffers from a disadvantage of thinking that the rest of the world agrees with you. I haven’t taken any such stance carved in stone.
Back to CIA being an explanation of your missing 150 W/m2. You wrote somewhere earlier that it goes into the IR absorbing gases like CO2 and water vapor. What are the chances that a CO2 molecule more than 10 meters off the ground will absorb any radiation directly from the surface as opposed to energy absorbed from a water molecule or another CO2 molecule in its immediate vicinity? Most likely the density of the atmosphere near the surface will ensure that collisions will dominate over emissions. The farther away from the surface, the more likely absorbed radiation is recycled as opposed to direct absorption from the surface. Far enough away from the surface where the density is much less, collisions will be less important and emissions will take precedence. Only it’s cold there and the radiation is less intense despite the contribution of heat released when water molecules condense. Also when the sun goes down, the original source of energy from below disappears. Of course clouds keep it a bit warmer from above. Eventually the day’s energy is dissipated because CO2 etc doesn’t stay excited for more than a split second. From what I know so far, these processes have not all been integrated into a coherent model. Is that settled science or not?
Even Roy Spencer, who uses AGW language, thinks CO2 sensitivity is highly overrated and feedbacks may be negative.
That’s very different from denying the greenhouse effect, which Spencer explicitedly does not do.
First of all, four people don’t constitute a “host.”
Peter Marcombe is an engineering technician, not a scientist.
N&K work for the Forest Service,
I don’t know who Roy Clark is, but you can always find a PhD who will say anything, and if there were anything to his ideas they woudl be published in a real journal and not a mere Web site, and scientists everywhere would be clamoring to know what he had figured out that they didn’t. He’s just another crackpot who uses scientific language.
Unfortunately, you are the one who suffers from a disadvantage of thinking that the rest of the world agrees with you.
Everyone does agree with me; or rather, I agree with them. There isn’t an iota of doubt among scientists that the greenhouse effect exists and about it impact here, on Venus, or on Mars. It is all established science. You won’t find one serious paper in any scientific journal anywhere that argues against the greenhouse effect, nor one in the last several decades. It’s as proven and proven as any other fundamental principle of science.
The safety and efficacy of every medicine you’ve ever taken is far less established than the existence of the greenhouse effect. Yet, like everyone else, you take them when you need them.
“The CO2 greenhouse effect is directly visible in satellite observations of the bite taken out of the IR spectrum near 667 cm^-1, a feature whose details agree precisely with results of calculations based on first-principles radiative transfer calculations. Laboratory spectroscopy demonstrates that the width of the bite will increase as CO2 increases, and warming inevitably follows as a consequence of well-established energy-balance principles. The precise magnitude of the resulting warming depends on the fairly well-known amount of amplification by water-vapor feedbacks and on the less-known amount of cloud feedback. There are indeed uncertainties in the magnitude and impact of anthropogenic global warming, but the basic radiative physics of the anthropogenic greenhouse effect is unassailable.”
— Raymond Pierrehumbert, “Infrared radiation and planetary temperature,” Physics Today, January 2011
Click to access PhysTodayRT2011.pdf
(a good, concise but thorough introduction into all this business)
Nowhere do I see where Evans and Puckrin measured 340 W/m2. So I’m still left with the impression that it is a calculated value based on the accepted average surface temperature.
I think you mean 390 W/m2.
Are you seriously now reduced to questioning the laws of blackbody radiation??
Next you will be questioning the rules of arithmetic.
I was wrong when I claimed that Evans and Puckrin’s paper had nothing to do with changes in upward or downward fluxes attributable to any change in the composition of atmospheric gases. But their calculation of contributions to the spectra data isn’t the same as showing that extra IR absorbing gases increase upward or downward radiation. And I am not questioning the laws of blackbody radiation when I point out that Evans and Puckrin didn’t measure 390 W/m2. They simply didn’t measure that. And they over-reach when they claim calculated contributions to downward radiation from non-H2O IR absorbing gases adds to the total “greenhouse radiation.” The fact that water vapor obscures those contributions self-contradicts their conclusions.
…Evans and Puckrin didn’t measure 390 W/m2. They simply didn’t measure that.
Of course not — and they don’t claim that they did.
The 390 W/m2 is a GLOBAL AVERAGE, based on a surface temperature of 255 K. It’s simply the Stefan Boltzmann law.
Evans and Puckrin are measuring their downward local flux, at 45 degrees N latitude, at different times of the year. All will be different from the 390 W/m2 global average. From their data they then extract the greenhouse flux of individual gases,
And they over-reach when they claim calculated contributions to downward radiation from non-H2O IR absorbing gases adds to the total “greenhouse radiation.” The fact that water vapor obscures those contributions self-contradicts their conclusions.
Did you even read the paper before dismissing it? I honestly can’t tell.
The authors write: “In order to extract the greenhouse flux from individual gases, the background emission of the atmosphere was simulated using the radiative transfer code, FASCOD3 (Clough et al., 1988). The simulations incorporated the temperature, relative
humidity and pressure profiles from radiosonde measurements obtained at Maniwaki, Quebec, a location 280 km distant from Peterborough.”
That is to say, they are subtracting out the contributions of humidity (water vapor), etc.
David Appell said:
“You were going to comment on my blog — remember? — about why Lacis and these other experts are all wrong, in your expert opinion. Did you forget?”
No, I did not forget. A death in the family and related activity distracted me. Then the resurgence of the Tar Heels got my attention. Now that Maryland have eliminated UNC’s Nemesis (Duke) it may be possible for UNC to win the ACC tournament. You may wonder why someone who made a small fortune building the Duke University Free Electron Lasers is a Tar Heel fan. That is a story for another day.
With regard to planet Earth, the Lacis paper is exactly in “Synch” with Scott Denning. A GHE of 33 K and 1.2 K per doubling of CO2. This “Guest Post” has explained why that is “Non-Science” = nonsense.
Lacis et al. lost any vestige of credibility when they started talking abour Mars and Venus. Here is their Table I:
15 OCTOBER 2010 , VOL 330 , SCIENCE, Lacis et al., Table 1.
Mars Earth Venus
TS (K) 215 288 730
TE (K) 210 255 230
σTS4 (W/m2) 121 390 16,100
σTE4 (W/m2) 111 240 157
GT (K) 5 33 500
GF (W/m2) 10 150 ~16,000
PS (bar) 0.01 1 100
They claim that the GHE for Mars amounts to 5 K. The partial pressure of CO2 on Mars is 685 Pascals whereas the the partial pressure of CO2 on Earth is 39 Pascals. Gavin & Co. claim a GHE of 33 K due to CO2 on Earth or perhaps as little as 8 K if you believe the “Positive Feedback” conjecture. Yet Mars has 17 times more CO2 but the claimed GHE is only 5 K. The real GHE for Mars is 57 K so Lacis et al. fail dismally. These guys don’t bother to do the simplest of sanity checks.
Moving on to Venus, Lacis et al. postulate an absurd “Forcing” of 16,100 W/square meter. You have to wonder whether these folks have even a tiny grain of common sense. How can CO2 cause any “Forcing” at all via radiative processes when the planet has 100% cloud cover? You cited the spectra for the Venus clouds dominated by thermal radiation at ~240 K with a few narrow “Lines” corrresponding to radiation direct from the surface (737 K). Can you explain where that 16 kW/square meter “Forcing” comes from?
Peter, it’s very cute that you think you can dismiss the work of professional, expert climate scientists based on a couple of numbers in a table, but not very convincing.
Re: Mars. Are you aware that the GHE depends not only on the fraction of atmospheric particles that are CO2, but on their density too? This is basic physics.
Venus’s clouds aren’t water vapor — Venus has no water. Its clouds are made of sulfuric acid. The large forcing comes from the immense optical thickness of Venus’s CO2. Unlike Earth, where most of the carbon is bound up in rocks, most of the carbon in Venus is in its atmosphere. The Urey reactions that take CO2 from the atmosphere depend on the availablity of water; this is called “weathering.” There is no weathering on Venus. Once carbon gets into its atmosphere, it stays there.
Chic Bowdrie says:
March 17, 2013 at 1:31 am
David, how is the 390 W/m2 determined?
I think David and I can agree on this one. According the Stefan, black bodies radiate according to the equation E = σT^4 where sigma is is the Stefan-Boltzmann constant (5.67E-08) and T is the temperature on the Kelvin scale. If you assume that Earth’s average tempertaure is 288 K the calculation yields 390 Watts per square meter.
One might quibble on the grounds that Earth is not a black body (emissivity = 1 for all wavelengths) but its emissivity in the thermal Infra-Red is close to unity for both land and ocean in the absence of cloud cover.
So it is only a theoretical derivation assuming an average global temperature. Yet everywhere, everyday, global temperatures are over the map, literally and figuratively. If you take a Trenberth/Kiehl diagram and adjust the upward and downward LWIR values up as much as you want, none of the other values need to change, in particular the 240 at TOA. Similarly, subtract all the downward component from each of the LWIR impacting the surface (backradiation now zero) and the rest of the values don’t need to change. Point being what’s happening at the surface swings widely constantly and need not have any affect on what’s happening higher up in the atmosphere. The importance of CO2 in this context is a possible explanation for the “greenhouse effect” but not a necessary one. Aside from the importance of providing plant food, of course.
Nobody disputes that planetary bodies can only emit energy via radiation. Conduction, convection, Coriolis eddies and phase changes only work within the confines of a body’s atmosphere.
Thus calculations according to Trenberth/Kiehl can be used to calculate an energy balance at the cloud tops of Venus with good precision. When the same idea is applied to Earth things are more complicated owing to the variability of cloud cover.
Models such ar CMIP5 and papers such as the one David Appell is so fond of (Lacis et al., 2010) make assumptions about the effect that clouds have on the GHE but they don’t provide any evidence to back up their assertions. Academics can get away with this kind of sloppiness whereas engineers are held to a higher standard. When engineers get things wrong we are liable for the death and destruction of wealth that ensues.
Yes, it’s an average. But so is the 240 W/m2 for the TOA.
That they’re averages still poses the question: Where is the missing 150 W/m2?
When the same idea is applied to Earth things are more complicated owing to the variability of cloud cover.
The 240 W/m2 comes from a direct measurement:
http://www.giss.nasa.gov/research/briefs/schmidt_05/
So where is the missing 150 W/m2? And why is it missing exactly at the absorption frequencies of H2O, CO2, O3 and CH4 if they are not, in fact, absorbing energy? And what happens to the energy they absorb?
The TOA measurement is exceedingly strong, direct proof of the Earth’s greenhouse effect. Moreover, many measurements have been down on outgoing and downwelling LWR, and find it behaving (and changing) just as the standard picture of the GHE predicts:
“Increases in greenhouse forcing inferred from the outgoing longwave radiation spectra of the Earth in 1970 and 1997,” J.E. Harries et al, Nature 410, 355-357 (15 March 2001).
http://www.nature.com/nature/journal/v410/n6826/abs/410355a0.html
“Comparison of spectrally resolved outgoing longwave data between 1970 and present,” J.A. Griggs et al, Proc SPIE 164, 5543 (2004). http://spiedigitallibrary.org/proceedings/resource/2/psisdg/5543/1/164_1
“Spectral signatures of climate change in the Earth’s infrared spectrum between 1970 and 2006,” Chen et al, (2007) http://www.eumetsat.int/Home/Main/Publications/Conference_and_Workshop_Proceedings/groups/cps/documents/document/pdf_conf_p50_s9_01_harries_v.pdf
“Radiative forcing – measured at Earth’s surface – corroborate the increasing greenhouse effect,” R. Phillipona et al, Geo Res Letters, v31 L03202 (2004)
http://onlinelibrary.wiley.com/doi/10.1029/2003GL018765/abstract
“Measurements of the Radiative Surface Forcing of Climate,” W.F.J. Evans, Jan 2006
https://ams.confex.com/ams/Annual2006/techprogram/paper_100737.htm
More papers on this subject are listed here:
These measurements are all evidence that N&K have to pretend don’t exist.
When the same idea is applied to Earth things are more complicated owing to the variability of cloud cover.
The 240 W/m2 comes from a direct measurement of the outgoing TOA radiation.
So where is the missing 150 W/m2? And why is it missing exactly at the absorption frequencies of H2O, CO2, O3 and CH4 if they are not, in fact, absorbing energy? And what happens to the energy they absorb?
The TOA measurement is exceedingly strong, direct proof of the Earth’s greenhouse effect. Moreover, many measurements have been down on outgoing and downwelling LWR, and find it behaving (and changing) just as the standard picture of the GHE predicts:
“Increases in greenhouse forcing inferred from the outgoing longwave radiation spectra of the Earth in 1970 and 1997,” J.E. Harries et al, Nature 410, 355-357 (15 March 2001).
“Comparison of spectrally resolved outgoing longwave data between 1970 and present,” J.A. Griggs et al, Proc SPIE 164, 5543 (2004).
“Spectral signatures of climate change in the Earth’s infrared spectrum between 1970 and 2006,” Chen et al, (2007)
“Radiative forcing – measured at Earth’s surface – corroborate the increasing greenhouse effect,” R. Phillipona et al, Geo Res Letters, v31 L03202 (2004)
“Measurements of the Radiative Surface Forcing of Climate,” W.F.J. Evans, Jan 2006
These measurements are all evidence that N&K have to pretend don’t exist.
Yet everywhere, everyday, global temperatures are over the map, literally and figuratively.
Not really. Remember, 71% of the Earth’s surface is ocean, whose temperature varies little throughout the day.
David Appell said:
“N&K’s theory does not conserve energy. The surface radiates at 390 W/m2, and the TOA at 240 W/m2. Where is the missing 150 W/m2??”
Clearly you have not understood N&K’s poster or much else about science. If you want to do an energy balance calculation for the troposphere you choose the surface, the cloud tops or anywhere in between. N&K did their energy balance at the surface of each body considered. They could have done an energy balance at the “Top of the Atmosphere” as Sagan did for Venus. After that, thermodynamics tells you the temperature at any altitude in the troposphere with good precision.
Just to give you a sense of the absurdity of the question you asked, consider Venus. According to Table 1 in the Lacis et al., 2010 paper the planet radiates 157 Watts/sq. meter while the surface radiates 16,000 Watts/sq. meter. So where does the 15,843 Watts/sq. meter come from?
I hope the hints given here enable you to answer your own question.
N&K *couldn’t* have done a energy balance for the TOA, because it doesn’t balance.
The question remains: the Earth’s surface is emitting IR radiation at 390 W/m2. The TOA is emitting IR radiation at 240 W/m2.
How do N&K expalin the missing 150 W/m2? They don’t, because they can’t.
Let me try again. The 390 W/m2 is the radiance of a black body at 288 K which approximates to the radiance of the Earth’s surface. The 240 W/m2 is the figure for a black body at 255 K which approximates to the radiation at the cloud tops. Why would you expect these two things to be in balance? That would mean that the cloud tops and the surface are at the same temperature.
I thought the penny would drop when I pointed out the corresponding numbers for Venus, namely 16,000 W/sq. meter and 157 W/sq. meter.
I get no satisfaction from seeing you embarrass yourself like this so please tell me that you get it.
When has the radiation spectrum been measured at the top of clouds (and which clouds)? Who did this measurement and where is it published?
So the surface is radiating at 390 W/m2, and (you claim) the top of clouds are radiating at 240 W/m2.
So where is the missing 150 W/m2? Somewhere, apparently, between the surface and the top of clouds. Where?
So where does the 15,843 Watts/sq. meter come from?
Radiation from Venus’s atmosphere. The thickness of its CO2 radiates a lot of IR downward, which is why its surface is so warm.
Same as why Earth’s surface is warmer than the amount of sunshine it receives. In fact, our surface gets more energy from the downward radiation of the atmosphere (“back radiation”) than it does from the Sun.
You can’t possibly mean that. The “warmth” of the Earth is a temperature value, while the amount of sunshine is W/m2. Without sunlight, there is no downward radiation of any wavelength. Any downward IR, must have originated from sunlight incident on the surface. Please explain.
For a blackbody, energy fluxes (W/m2) and temperatures (K) are related by the Stefan Boltzmann law.
Without sunlight, there is no downward radiation of any wavelength. Any downward IR, must have originated from sunlight incident on the surface.
Sure; without a sun the Earth would be a dead rock.
I’m referring to the energy fluxes: the shortwave solar radiation that reaches the surface, and the longwave GHG radiation (“back radiation”) that reaches the surface. The former is 168 W/m2; the latter is 324 W/m2. See Figure 7 in
Kiehl, J. T., Kevin E. Trenberth, 1997: Earth’s Annual Global Mean Energy Budget. Bull. Amer. Meteor. Soc., 78, 197–208.
http://journals.ametsoc.org/doi/abs/10.1175/1520-0477(1997)078%3C0197%3AEAGMEB%3E2.0.CO%3B2
So where does the 15,843 Watts/sq. meter come from?
Why is the temperature in a (real) greenhouse warmer than the temperature outside it?
Chic,
You have it exactly right. The energy originates almost entirely from the Sun except in the case of some gas giants that have signifcant internal heat sources. You can ignore internal heat for rocky planets owing to the poor thermal conductivity of rocks. David Appell’s idea that “The thickness of its CO2 radiates a lot of IR downward, which is why its surface is so warm.” is nonsense.
David is stll having trouble understanding that there is an “Energy Balance” at any arbitrary level in a planet’s atmosphere. Thermodynamics works regardless of where the energy comes from. Radiation may be dominant in the stratosphere but not in the troposphere. That is why the thermal gradients are quite different above and below the cloud tops.
The huge thermal flux from the Venusian surface simply confirms that the local temperature is ~730 K. Thermodynamics tells you that the temperature on Venus will fall by 7.9 K per km and observations confirm that with great precision. Within the troposphere the radiative properties of CO2 are therefore………….irrelevant.
I’m learning, slowly but surely. For my benefit, if not for David’s as well, how do you answer his question of the missing 150 W/m2? I know it isn’t missing, but a definitive explanation either wasn’t attempted here or was so complicated that I just missed it. I think it would be worthwhile resolving this apparent paradox. What do you think?
The answer is that this 150 W/m2 is what’s absorbed (net) by greenhouse gases — water vapor, CO2, CH4, O3, etc.
Look at the Kiehl & Trenberth Figure 7 on the link I gave earlier. The GHGs in the atmosphere absorb much of the longwave radiation emitted by the surface, as well as smaller amounts of heat from thermals, evapotranspiration, and a little incoming sunlight. (That totals to 519 W/m2.)
The GHGs in the atmosphere absorb this radiation and re-emit it: 324 W/m2 reaches teh surface, (165+30) W/m2 reaches space. An atmospheric window contributes another 40 W/m2.
Hmmm. You have a net 235 coming in and 235 going out, but somewhere in the middle you get a total of 519. If you subtract the 235 going out that leaves 284 going down. That’s more than what should have been available in the first place. Please try again.
Come on — do you really think scientists would calculate all the numbers and publish such a diagram if the energies didn’t balance?
Look harder.
One radiation flux is at the Earth’s surface (390 W/m^2) and the other is at the top of the atmosphere (240 W/m^2). That is just another way of saying that the ground (288 K) is warmer than the cloud tops (255 K). The radiation flux differential for Venus is much greater owing to the high surface temperature there.
David is wrong along with all the other Arrhenius disciples when he says that the difference (150 W/m^2 for Earth and ~16,000 W/m^2 for Venus) results from “Radiative Forcing”. That is so absurd that I feel really sorry for people who claim to believe it.
Blackbodies at different temperatures have different spectra and different spectral peaks.
You’re still missing 150 W/m2. Where is it? I’ve asked you this about a dozen times and you have avoided it each time.
Where is it?
Peter, do you realize your missing energy adds up to over 75,000 terawatts for the entire planet? That’s 4,500 times the energy use of all of human civilization.
Of course, on Venus what’s missing is much larger: about 16,500 W/m2. I’m wonder where that is, too.
There is no “Missing Energy”. What we have here is a failure to understand thermodynamics.
390 minus 240 does not equal zero.
So 150 W/m2 is missing — the difference between what the surface radiates, and what the TOA radiates.
So where is this missing energy?
By the way, your missing energy is equivalent to over 1200 Hiroshima bombs going off ever second of every day.
Take a closer look at Kiehl-Trenberth’s energy flow diagram. You will find that the surface energy flows don’t balance exactly and the atmospheric ones don’t either. There is nothing wrong with that. For example, the surface energy does not have to balance if you postulate that some energy is being stored in the oceans. That is Kevin’s “Missing Heat” and in principle that is a reasonable idea.
The problems become apparent when you try to reconcile the “Missing Heat” with precise physical measurements such as those made by the Argo buoys.
False. The energy balances at all levels — as, of course, it must. Energy conservation is a bedrock principle of physics. One that N&K’s hypothesis doesn’t come close to meeting, and which doesn’t seem to bother Peter at all.
Still having problems with your reading comprehension I see. Kevin Trenberth will find out how to get the enegry balance right. He thinks the discrepancy can be explained by heat absorbed in the oceans (I think he is right about that). The measurements are quite difficult.
The Trenberth paper under discussion has nothing to do with the oceans, but with balances at the surface. The “missing energy” is < 1 W/m2, far smaller than the balances in his paper with Kiehl.
Peter, why is the surface pressure so high on Venus?
After all, its surface gravity (8.9 m/s2) is smaller than Earth’s.
You have to be kidding. You MUST know the answer to that one!
Just in case you can’t figure it out here is a hint:
Mass of Earth’s atmosphere 5.1 * 10^18 kg (Trenberth et al., 1994)
Mass of Venus’ atmosphere 4.8 * 10^20 kg
You will note that the masses are in the ratio of ~94:1 whereas the surface pressures are in the ratio ~93:1. Yes, mass and pressure are directly related other things being equal. Remember PV = nRT?
http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html
While we are tallking physics I would like to correct a comment you made much earlier when I pointed out the importance of the General Theory of Relativity to our GPS system:
“Actually special relativity is all you need to handle acceleration (and lasers).”
Simply untrue. There are five separate relativistic corrections that affect the GPS system. All of them depend on “General Relativity”. The largest effect is the slowing of clocks in gravitational fields (38 micro-seconds per day). You know my fondness for equations so here is one that really works:
f(frequency) = f(0) * (1 – 2GM/Rc^2)^0.5
This effect is easily compensated because it remains constant.
The second one is roughly three times smaller than the first. It is caused by the acceleration of the GPS satellites with respect to the observer’s frame of reference. This keeps changing as the relative acceleration vectors change.
You are probably confused by the fact that the Special Theory of Relativity affects clocks too. When a clock is moving relative to an observer it speeds up or slows down. This is simply a consequence of the Lorentz equations; it is quite different from the Doppler effect.
OF COURSE I know that surface pressure is proportional to the mass of the atmosphere.
But why is the mass of Venus’s atmosphere so big? Compared to Earth’s…?
Simply untrue. There are five separate relativistic corrections that affect the GPS system. All of them depend on “General Relativity”.
Read my statement again: It pertained to lasers per se, not anything to do with gravity.
Special relativity is completely capable of dealing with accelerated reference frames, and with atomic and molecular reactions.
QED is necessary to describe all of chemistry (even down to the intracies of the hydrogen atom), not quantum gravity.
Special relativity applies to frames of reference that are moving at constant velocity relative to each other. It has nothing to say about frames of reference that are accelerating.
Very false, Peter. Read some textbooks. Or some papers like these:
Click to access RMF52110.pdf
http://math.ucr.edu/home/baez/physics/Relativity/SR/acceleration.html
Have you ever tried to build a laser? If so did it work?
Why is Venus’ atmosphere so big?
Its all a matter of accretion. The larger planets are better at hanging on to gases. Jupiter is large enough to retain Hydrogen.
Probably a better question would be why is Earth’s atmosphere so small? I suspect that CO2 used to be the dominant component of Earth’s atmosphere. Then living things converted most of it to carbonate rocks and Oxygen which removed most of the dissolved Iron from the oceans. Now this is just idle speculation on my part so don’t throw a hissy fit.
The larger planets are better at hanging on to gases.
Except Venus is smaller than Earth, in mass, radius, and surface gravity.
Try again.
It seems likely that Earth had a much denser atmosphere 1 billion years ago. That might help solve the “Weak Sun Paradox”.
Accretion is not within our ability to predict. Why did Earth get so much water while Venus seems to be lacking? Venus is 81% of Earth’s mass so it is big enough to hang on to gases other than Helium or Hydrogen.
Here is something a litle more difficult for you to ponder. Titan has a mass ~22% of Earth’s mass and yet it has a denser atmosphere with a surface pressure of 1.5 bar.
What evidence says Earth had a much densier atmosphere 1 billion years ago?
Accretion is not within our ability to predict. Why did Earth get so much water while Venus seems to be lacking?
Planet’s don’t gain an atmosphere by accretion, but (for Venus and Earth) by volcanism, chemistry, and biology.
The ratio of deuterium-to-hydrogen in Venus’s atmosphere is a good indicator it too once had water. But the brightening sun reached the point where, at Venus’s orbital distance, it triggered a runaway greenhouse effect. Its oceans boiled, sending the water into the atmosphere, where it was dissociated by UV rays and the hydrogen escaped. Since there is no more water on Venus, the CO2 outgassed from volcanoes cannot participate in the Urey reactions (“weathering) that draws down CO2 into rock. Hence most of its CO2 stays in the atmosphere, where it creates its huge greenhouse effect.
The Earth, too, will suffer this fate as the Sun continues to brighten, but its runaway greenhouse effect won’t occur for about 0.5-1 billion years.
Just to clarify: planets can obtain material (like water) from comet strikes, but I don’t think that’s considered “accretion” per se.
David,
Phillip Gibbs is a smart guy and he is welcome to try updating Einstein after 91 years. Note that he does not take himself quite as seriously as you appear to.
Here is the “Special Relativity” I was talking about. It was “Peer Reviewed”:
http://www.casavaria.com/hotspring/2008/05/21/123/einsteins-special-theory-of-relativity-the-original-paper-1905/
And?
Special relativity applies to accelerating bodies. This is verified every day at particle accelerators across the world, none of whom would work without considering special relativity.
I spent four years building a relativistic electron synchrotron (1 GeV) and 8 years operating it. The electron mass was up to 2,000 times their rest mass. From memory the equation goes something like this:
m = m(0) / (1-v^2/c^2)^0.5
Thus our electrons were moving at 0.999999875 of light speed. Put another way they were just 84 mph slower than photons in a vacuum. Thanks for reminding me how much physics I have forgotten.
Building a laser makes you an expert in building lasers, not in special relativity. As this episode shows.
Here is a tutorial for you, if you understand what a 4-vector is:
http://physicspages.com/2011/05/25/acceleration-in-special-relativity/
And this is from Bryce DeWitt’s lectures on gravity:
http://is.gd/qx7u2t
By some weird coincidence I was thinking about the relative consequences of real space travel only last week. The kind where one has a nuclear motor that can deliver an acceleration greater than 1 “g”, 24/7 thus solving the bone weakening “zero gravity” problem while getting you tens of thousands of light years in a human life time.
Pretty soon you are moving so fast that starlight from ahead of the spaceship is experienced as gamma rays. The gamma rays from a 1 GeV synchrotron require roughly one foot of concrete to reduce their intensity by a factor of 10 and it gets worse as the energy increases. To keep the weight down it will be necessary to slow down before approaching a star.
This is fascinating stuff but it is getting way “Off Topic”.
David Appell said:
“Its oceans boiled, sending the water into the atmosphere, where it was dissociated by UV rays and the hydrogen escaped.”
It must be great to be so certain of everything. Personally, I would like to see more evidence and less dogmatism.
It’s called science, the very opposite of dogmatism — it’s build on a logical chain of evidence, starting with Venus’s high D/H ratio, huge atmospheric CO2 level, and extreme surface tempertature. The runaway greenhouse effect on Venus ties it all together elegantly — and is completely expected on theoretical grounds as well.
So why can’t Hansen produce any equations to disprove Sagan’s analysis?
Hansen’s theory for the Venusian surface temperature is nonsense. Wake up!
There are plenty of equations — Tgb above, the equation for the Kombayashi-Ingersoll limit, an many more. You should find a copy of this and read it:
“The Runaway Greenhouse and the Accumulation of CO2 in the Venus atmosphere,” S.I. Rasool and C. de Bergh, Nature v226, June 13 1970.
And Hansen et al give some simple equations that approximate the radiative forcings of CO2, CH4, and other GHGs. See Appendix A in:
“Global Climate Changes as Forecast by Goddard Institute for Space Studies Three-Dimensional Model,” J. Hansen et al, Jour Geo Research, v93 nD8 pp 9341-9364, August 20 1988.
(Even with curve fits for the radiative forcings, the underlying equations are still too difficult to solve for a realistic surface temperature, though, without using a computer.)
This page gives (Table 1) very similar equations for radiative forcings:
http://www.esrl.noaa.gov/gmd/aggi/
Also, in his textbook (Table 4.3, p. 275) Pierrehumbert gives some cubic polynomial fits to a 1-dimensional climate model, that gives the greenhouse effect at various humidities and CO2 levels. Sort of a climate model on a postcard.
Urey is best remembered for his theory about Earth’s primordial atmosphere creating the precursors of life (amino acids). I learned that stuff in high school.
While his work on the weathering of silicate rocks is interesting there are huge mountains of chalk all around the world that attest to the influence of living things.
So now you’re denying silicate weathering, too?
Are you denying that living things created those chalk mountains?
Of course not, but there is a lot more weathering taking place than what ends up as limestone. Lots of weathering used to take place on Venus, too, when it had lots of water, even in the absence of life. As well as on primordial Earth before it had animal life.
At least we are back “On Topic”. N&K claim that 50 million years ago the atmospheric pressure was ~50% higher than today. This strikes me as a dubious claim but I have to admit that it is within the bounds of possibility.
Suppose that current levels of seismic activity are much lower than the norm. In the run up to the PETM (Permian Eocene Thermal Maximum) there could have been intense seismic activity that raised the atmospheric pressure. Suppose that seismic activity declined sharply 50 million years ago. A combination of the weathering of silicate rocks and the activity of small sea creatures could sequester huge amounts of CO2 leading to the dangerously low CO2 concentrations that characterize the modern era.
What evidence do N&K cite to support their assertion that surface pressure was 50% higher 50 Mya?
None that I am aware of.
Just suppose they produce such evidence. Would it affect your opinion of their “Unified Theory of Climate”?
Just suppose they produce such evidence. Would it affect your opinion of their “Unified Theory of Climate”?
No, because the idea (it doesn’t even rise to the level of a hypothesis) has a fundamental problem: it doesn’t conserve energy. The idea can’t even get out of the gate.
How would “intense seismic activity” raise the atmospheric pressure, and what evidence is there of such activity?
Geology is not my subject but what would you expect to happen if carbonate rocks were subducted into the mantle? Maybe those rocks would decompose giving off (you guessed it) CO2. Other rocks would decompose, releasing SO2.
Plants would then convert the CO2 into oxygen, thus raising the atmospheric pressure. Just a hypothesis but if it were correct our atmosphere could have had quite a different composition 50 million years ago than it does today.
I am not aware of any evidence one way or another. Why not ask a geologist?
Carbonate rocks are already being subducted into the mantle and their CO2 outgassed — this is the normal process of the Earth’s carbon cycle. An earthquake isn’t going to change that to any substantial degree.
What evidence says CO2 concentrations are “dangerously” low in the modern era? Life has thrived during the modern era.
You have to be joking.
According to ice core samples in Antarctica, during the last three glacial cycles temperatures were 10 Kelvin lower than today. What does that imply in terms of average global temperature?
My guess is about 5 or 6 Kelvin, so if the modern version of the Arrhenius theory was correct that would correspond to more than four “Halvings” at 1.2 K/Halving. Four halvings means about 25 ppm of CO2.
We know that did not happen as most plants on land die when the CO2 concentration falls below 150 ppm. So I would call the modern 395 ppm “Dangerously Low” and the pre-industrial 280 ppm “Scary”.
,,,if the modern version of the Arrhenius theory was correct that would correspond to more than four “Halvings” at 1.2 K/Halving. Four halvings means about 25 ppm of CO2.
Would you please stop with your unscientific and just plain stupid “halvings.” You are completely misapplying the science and clearly do not know what you are doing, and no matter how many times this is pointed out to you you wantonly make the same dumb mistakes time after time.
I feel sorry for your students.
Four halvings means about 25 ppm of CO2.
And long, long before that point the planet would freeze over into an icehouse climate because of the decrease in the greenhouse effect and most plants would die for other reasons. Which hasn’t happened since at least about 700 million years ago. So once again your extrapolation is completely unphysical and, well, mindless.
David Appell, please clear up a couple points for me.
Scott Denning defines greenhouse effect as the difference between the measured surface temperature (288K) and the equivalent radiative temperature (255K). This 33 degree difference does not explain what causes it. How do you define greenhouse effect?
Scott Denning separates the greenhouse argument into two parts.
1) What’s the sensitivity of the Earth’s surface temperature to a change in radiation of 1 W/m2?
2) How many W/m2 of change in the radiative heating are produced by a doubling of CO2?
For the latter, Scott says we “need to measure the absorption and emission spectrum of the gas itself and then do some calculations.” Where are these calculations?
When a CO2 molecule absorbs radiation, does it heat up? If so, how is the temperature change measured?
Yes, the greenhouse effect is the difference between the Earth’s observed surface temperature (288 K) and its emission temperature (255 K).
The basic calculation is the solution of the “two-stream equations,” linear first-order differential equations that describe the upward and downward flux of radiation in the atmosphere. (If one does not include scattering, they’re called the “Schwarzschild equations.”)
They are, as you might guess, quite complicated, depending on the wavelength of the radiation, the emissivity and absorptivity of the atmosphere as a function of space and of wavelength, and temperature as a function of space.
The emissivity and absorptivity — gathered into a quantity called the “optical thickness,” is a very complicated function, because the atmospheric gases have extremely complicated absorption and emission spectra consisting of thousands of spectral lines. Solving the equations with real spectra thus requires a numerical approach.
For many cases, though, one can assume the optical thickness is independent of wavelength, and this is called the “gray gas” approximation. The equations can still be difficult to solve, so various approximations are made to glean insight into different properties of the climate.
David Appell said:
“The basic calculation is the solution of the “two-stream equations,” linear first-order differential equations that describe the upward and downward flux of radiation in the atmosphere. (If one does not include scattering, they’re called the “Schwarzschild equations.”
Unless you can show the equations and how to solve them you are indulging in mysticism, rather than science.
“The equations can still be difficult to solve, so various approximations are made to glean insight into different properties of the climate.”
So can we all agree there is no definitive solution to the equations for calculating how many W/m2 of change in the radiative heating will be produced by a doubling of CO2?
And as the distance from the surface increases, the temperature gets colder and, therefore, the kinetic energy of atmospheric gases decreases concurrently.
Do we also agree that collisions outweigh emissions close to the surface and the opposite is true near the TOA?
So can we all agree there is no definitive solution to the equations for calculating how many W/m2 of change in the radiative heating will be produced by a doubling of CO2?
Of course not — the equations are solved numerically.
Do you think numerical solutions are less science-worthy than analytic ones? They’re usually *more* worthy, because solving equations analytically is often so hard they require simplications that compromise their reality?
Do you fly on airplanes? The design of every one of them relies on numerical solutions, because solving the fluid equations that determine their flight are too difficult to do analytially.
Do you sit around and worry that orbiting satellites are going to fall on your head? Of course not, but they are kept in their orbits by numerical solutions — because even the basic 3-body gravitational equations cannot be solved analytically.
You are grasping at straws.
And as the distance from the surface increases, the temperature gets colder and, therefore, the kinetic energy of atmospheric gases decreases concurrently.
Only up to the tropospause. Temperature increases above it. EXPLAIN THAT.
Do we also agree that collisions outweigh emissions close to the surface and the opposite is true near the TOA?
What do you mean by “outweigh?” In what sense?
Unless you can show the equations and how to solve them you are indulging in mysticism, rather than science.
The equations are derived in most textbooks (Pierrehumbert pg. 191) and solved for certain simple and limiting cases. Rodrigo Caballero gives a less general form in section 5.12 of his manuscript.
The absoprtion spectra of real GHGs is far too complex for these equations to be solved analytically; hence they are solved numerically.
When a CO2 molecule absorbs radiation, does it heat up? If so, how is the temperature change measured?
No, it’s internal energy changes as electrons absorb photons and jump up into a higher energy state (quantum level). That excited state doesn’t last long, and the molecule emits a photon and goes back to its unexcited state. That photon is emitted in a random direction, but some of them are emitted downward and some of them get to the surface, warming it.
But these infrared photons can scatter off molecules too, when their energy can’t be absorbed (because the molecule doesn’t have an inernal energy level it could jump to, given the photon’s energy). That transfers energy and alters kinetic energy, and temperature is proportional to the average kinetic energy of the gas molecules. So more IR photons means more scattering which means more energy transfer which means a higher temperature.
Chic,
No answer to your request for calculations from David. Just more nonsense backed up by rhetoric.
Chic’s question was answered.
Chic Bowdrie said, March 31, 2013 at 2:31 am
“They simply didn’t measure that. And they over-reach when they claim calculated contributions to downward radiation from non-H2O IR absorbing gases adds to the total “greenhouse radiation.” The fact that water vapor obscures those contributions self-contradicts their conclusions.”
Thank you Chic Bowdrie for realizing that the Evans and Puckrin, 2006 paper is wrong for the same reason that the Arrhenius, 1896 paper is wrong. They assume that trace gases dominate while the bulk of the atmosphere does not matter.
The Arrhenius faithful have to tie themselves in knots explaining the GHE on Earth and Venus in terms of CO2, CH4, O3, particulates or water vapor. N&K’s pressure based theory on the other hand works throughout the solar system with good accuracy.
That is why I am inclined to believe N&K when they say that the mass of the atmosphere is the major determinant of the Greenhouse Effect which amounts to about 130 K on Earth.
After that, temperature changes of a few degrees Centigrade may be caused by Milankovitch cycles, cloud cover, cosmic rays, the extent of ice caps, the Eath’s magnetic field and many other factors. CO2 may have some small effect but it can’t be significant given the fact that CO2 has lagged temperature for the last 750,000 years.
Folks like David Appell want us to believe in the “Positive Feedbacks” postulated by the IPCC. As an electrical engineer schooled in Nyquist diagrams and Fourier Transforms I can assure you that the feedbacks are negative. If they were not, humankind would be here to have this interesting discussion.
Folks like David Appell want us to believe in the “Positive Feedbacks” postulated by the IPCC.
You’re not supposed to “believe” in anything. It’s a matter of evidence, and the evidence clearly shows that without positive feedbacks you can’t explain much in climate science, including the recent ice ages — there simply isn’t enough orbital forcing to account for them.
Feedbacks are scientifically expected, especially the water vapor feedback and the ice-albedo feedback. And the evidence shows they are already happening — atmospheric water vapor content is up 4% in 30 years.
I’d like to see an explanation of the recent glacial/interglacial transitions without feedbacks.
The feedbacks I am talking about are the ones relating to CO2 “Doublings”. Depending which “Expert” you quote they cover quite a range. On the low side the Lindzen & Choi papers (2009 & 2010) suggest the feedback is negative thereby reducing the effect of a doubling of CO2 to about 0.6 K/doubling. At the other extreme you have the IPCC’s CMIP series of models which sensitivities as high as 4.5 K/Doubling.
Frankly, the “Experts” might as well debate the number of angels dancing on the head of a pin or bishop Usher’s calculation of the date of Earth’s creation. No matter how precise their calculations, the result must be nonsense simply because the underlying hypothesis is false.
The hypothesis in Arrhenius’ 1896 paper has no basis in reality. The concept of “Doublings” is absurd.
From the ice core record it is clear that the variations in CO2 levels over the last 750,000 years were driven by temperature changes (oceans out-gassing as the surface temperature rises).
I don’t have an explanation for the Ice Age temperature oscillations (amplitude ~10 K) at high latitudes. Nor does anyone else. People who claim that “CO2 caused it” are crackpots whether they are published in peer review journal or not.
The concept of “Doublings” is absurd.
Do now you don’t think the level of CO2 in the atmosphere can double — is that where you’re at now?
Did you just double it 20 times a few days ago? Yes, you did.
You should know that the Lindzen and Choi paper isn’t regarded as correct, as Andrew Dessler showed.
The hypothesis in Arrhenius’ 1896 paper has no basis in reality.
That’s odd, because a simple satellilte sensor measurement shows a great deal of outgoing radiation being absorbed by CO2 and other GHGs:
http://www.giss.nasa.gov/research/briefs/schmidt_05/
Are you suggesting such measurements are all wrong?
From the ice core record it is clear that the variations in CO2 levels over the last 750,000 years were driven by temperature changes (oceans out-gassing as the surface temperature rises).
That isn’t the question — it’s about whether feedbacks exist. You seem to think changes in orbital factors alone have enough radiative forcing to cause 6-7 C of warming. They do not, as has been known for decades.
People who claim that “CO2 caused it” are crackpots whether they are published in peer review journal or not.
People who are themselves crackpots don’t get to make such judgements.
N&K’s pressure based theory on the other hand works throughout the solar system with good accuracy.
1) It does not — it can’t even calculate the temperature of the moon.
2) The idea is a massive violation of conservation of energy. It’s easy to propose ideas if that is your standard, but it is not my standard.
My understanding is that N&K did not calculate the Moon’s average temperature. They quoted the average temperature measured in the Diviner experiment.
One of the things I tried to do to support this post was to process the Diviner data and come up with my own figure. The data was simply too large for my spreadsheet to handle. So I failed. In the end the best I could do was to “Eyeball” the plots shown here:
http://www.diviner.ucla.edu/science.shtml
If you have even a grain of sense you will see that the average over all latitudes cannot be more than 160 K. Even at the Moon’s equator it can’t be more than 200 K. Scott Denning’s 255 K is what the temperature would be if the Moon’s temperature was the same from pole to pole.
My understanding is that N&K did not calculate the Moon’s average temperature.
They did, on the Tallbloke blog soon after their idea was first presented. The couldn’t get the right answer. Look it up.
If you have even a grain of sense you will see that the average over all latitudes cannot be more than 160 K. Even at the Moon’s equator it can’t be more than 200 K.
The Vasavada results (same as Diviner) finds Tmean = 213 K along the lunar equator. So much for your “grain of sense.”
http://davidappell.blogspot.com/2012/04/norfolk-constabulary-made-wrong-charges.html
Standard radiative physics calculates the number exactly, and quite easily:
http://davidappell.blogspot.com/2012/04/norfolk-constabulary-made-wrong-charges.html
Scott Denning’s 255 K is what the temperature would be if the Moon’s temperature was the same from pole to pole.
I can’t tell if you keep making the same mistakes out of obstinancy, or if you really do not understand these basic points. (Which is it?)
As I’ve said about a dozen times, the “Scott Denning” formula does not apply to the Moon, because its derivation assumes a surface in equilibrium, i.e. all at the same temperature. That clearly does not apply to the lunar surface, to the formula for Tgb does not apply.
The “gb” in Tgb stands for grey body. Do you know what that is?
The Arrhenius faithful have to tie themselves in knots explaining the GHE on Earth and Venus in terms of CO2, CH4, O3, particulates or water vapor.
It’s not knots at all, just basic science: the Earth emits infrared radiation, and GHGs absorb it. Some of what they reemit is downward.
Given this, it’s just a matter of summing up the net downward flux. Obviously it will not be zero.
That is why I am inclined to believe N&K when they say that the mass of the atmosphere is the major determinant of the Greenhouse Effect which amounts to about 130 K on Earth.
This is simply absurd.
The emission temperature of the Earth — i.e that calculated from the Stefan-Boltzmann law, based on the observed solar constant and albedo, is 255 K. Your greenhouse effect would put the surface temperature at 385 K. That’s above the boiling point of water.
Do you notice any water spontaneously boiling around you?
Think.
I don’t know why you bother to read so many scientific papers if you can’t understand even high school physics. The Earth’s albedo is low because it has clouds and ice caps. The Moon on the other hand does not so its albedo is high.
Think of the “Greenhouse Effect” as the temperature difference attributable to adding an atmosphere to a rocky body.
First figure out what the Earth’s temperature would be without an atmosphere. You and Scott Denning say 255 K. N&K say that an airless Earth would have approximately the same temperature as the Moon (~154 K). In my opinion you are all wrong. My “outrageous guess” is 156 K.
Why would you add N&K’s 130 K GHE to Denning’s 255 K airless Earth number? We all know the answer is 288 K. You may have a great future as a comedian; you certainly have me chuckling.
The Earth’s albedo is low because it has clouds and ice caps. The Moon on the other hand does not so its albedo is high.
At least get your basic facts straight — the Moon’s albedo is lower than the Earth’s:
http://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html
The Earth’s albedo is middling; much smaller than Venus’s, for example.
First figure out what the Earth’s temperature would be without an atmosphere. You and Scott Denning say 255 K.
Wrong. For about the 20th time.
The Tgb formula assumes an atmosphere that provides equilibrium.
Peter, I am getting annoyed with your fundamental dishonesty. This mistake has been repeatedly pointed out to you, yet you continue to blithely repeat it as if it never was. Worse, you then attribute the same mistake to me.
You are lying. What you wrote above is a lie, and you know it. Lies like this are the only way you can keep your flimsy house of cards from collapsing.
I will not waste time dealing with a liar.
David,
I have no problem with you disagreeing or pointing out errors. In fact you are widely read and make a lot of good points, and your activeness in the debate is great. What we all take exception to is your attitude and ad hominem comments.
Tell me how, in this little backwater of the blogosphere Peter has any reason to lie? What gain does he get from it? Dishonesty and lies happen when someone presents a position that they know is not true. Do you think Peter would bother to push something that he knew was not true? And again why – why bother? If you think it is just to argue with you, you have an overinflated sense of yourself. Why do his thoughts and opinions get under your skin so much when it is not as if there is a wide audience for his remarks here?
The very act of calling him a liar says far more about you than it does about him. Either you debate courteously as the others are doing or you let it go.
I don’t know why Peter Marcombe is lying — ask him. But he is purposely, obviously, repeatedly misrepresenting the applicability of the Tgb formula, despite my repeatedly showing what the assumptions of its derivaton are.
I’m not going to waste time with such a person.
Well then don’t otherwise we might assume you have nothing better to do.
Do you think Peter would bother to push something that he knew was not true?
I don’t just think that — that’s clearly what he’s doing. He knows this formula for Tgb, what he (mistakenly) calls the “Scott Denning formula,” does not apply to an airless body. I’ve told him that about a half-dozen times, and why. Yet he keeps applying it there….
Why would someone do that? I don’t think it’s because he doesn’t understand the point. He’s willfully misrepresenting it, and what I’ve said earlier, and that’s fundamentally dishonest.
Well then don’t otherwise we might assume you have nothing better to do.
I honestly don’t care what you assume about me. But I do care that someone who disparages lots of well-regarded climate scientists, and teaches students, is purposely misrepresenting the science. I’m wondering why I’m the only one here who finds that troubling.
Oooops!,
….humankind would NOT be here…….
Wow this has been an interesting if acrimonious debate. Let me comment from the point of view of the interested observer, albeit one whose engineering background enables me I think to judge the merits of the debate and perhaps some of the science. I also comment as an ordinary tax payer who has seen their standard of living altered quiet dramatically over the last few years in response to policies that have been enacted to “save the planet” And as I have been actively following the debate for about 15 years now, I think I have a good idea of the merits of the arguments on both sides.
The first thing that strikes me, and something that is becoming more apparent as time moves on is the pro AGW brigade are become very shrill and in many cases intolerant of other views. To me this is a sure sign they feel they are losing the argument, and that the debate is moving to the root cause.
One of the obstacles to getting to the root of the argument has been the obsession about arguing over what the temperature has been over the last 100 or so years, and of trying to prove that for 1000 years the temperature was the same until the last 30 to 40. During this time the debate over the mechanics of how CO2 is the cause of recent minuscule warming has been lost. Now the debate is shifting because the temperature is not playing ball, which has allowed many scientist who never believed in Arrhenius to come out of the woodwork and say so. It is in my opinion to the eternal shame of science that many have lazily accepted Arrhenius without debate or calculation. Still today its as if many won’t do the calculation or thinking for fear they will prove Arrhenius wrong.
The other factor that has struck me, and again I look at these things as an engineer, is that Arrhenius supporters look at CO2 without considering the role it has played in life and the formation of rocks on earth. Its not just the limestone rocks but we have all the dolomite as well. We have the explosions of life and then the extinctions. I suppose its in our nature to always look for disasters to explain these phenomenon, but I’m inclined to think that most of them were natural and that we read too much into asteroid impacts being able to wipe out all life. Perhaps life was on the wane anyway.
The 1 bar atmosphere. I have read enough now to be confident that at some point in the near future we will come to understand that our atmosphere today is very different to what the norm for most of the 4.5 billion years has been. Unfortunately for us it is really only the last 500 million years that we can get any sort of reliable geological evidence. But I believe this will be enough for us to realise if CO2 was to continue to decline in our atmosphere life as we know it will be extinguished. I believe that for most of earths history that CO2 has been a major constituent, and not a trace gas, but as life uses CO2 as it primary food it is used up. This could explain the mass extinctions, simple lack of food. At times oxygen has been more abundant than it is today, but again as a proportion of the atmosphere I don’t believe oxygen can be much more than the 22% it is today, otherwise many things would too readily oxidise.
And here is an interesting bit of information; the amount of nitrogen in our atmosphere is similar to that on Venus but in proportion to the mass of the two planets. Does this suggest that Venus and Earth are made of the same stuff, and must have evolved in the same way. The difference being that water was able to condense on earth faster than the UV could disassociate it, allowing life forms to develop that produced O2 that allowed O3 to protect us from UV. Once water condensed, the high pressure of the early atmosphere would have force a large proportion of the CO2 to dissolve in the water. The thick atmosphere would have been much better at heat transfer and would easily explain the much higher average temperatures seen on earth for 90% of its 4.5 billion years of existence.
These are but a few thoughts, and it clear to me that the N&K theory seems to be able to explain the how the earths average temperature can change so dramatically far better than the Arrhenius theory can. Certainly if our atmosphere was 5 bar 100 million years ago, as it must have been for not only the flying dinosaurs but also to support the very large herbivores (and perhaps even greater if some are to be believed), the nitrogen would be the same as today, so it would have been CO2 that made up most of the extra weight along with as much O2 as could be sustained. That thick atmosphere would have transferred heat from the equatorial regions to the poles much more effectively than does our current atmosphere.
I think we haven’t even begun to understand our atmosphere and climate, and that we need to get back into science some real leadership that encourages scientist to join up the thinking, share their ideas more effectively and prevent the dogma that is sullying the reputation of science today. As a life long lover of science I have never been so appalled at what passes for science in the media and out of some of our universities. If it continues the public will vote to cut the funding.
Name one scientist who “never believed in Arrhenius” and has said so.
The greenhouse effect is an immutable fact, very well understood theoretically and easily demonstrated by observation. This is an iota of scientific doubt about its existence, which has been known for over 150 years.
It is in my opinion to the eternal shame of science that many have lazily accepted Arrhenius without debate or calculation.
You are woefully lacking in knowledge if you think the greenhouse effect was not soundly debated for years, or that it hasn’t been addressed theoretically and analytically.
You’re another person who doesn’t know the science, and chooses instead to blame the world for what you are ignorant about.
The other factor that has struck me, and again I look at these things as an engineer, is that Arrhenius supporters look at CO2 without considering the role it has played in life and the formation of rocks on earth.
More raw ignorance on your part. Climate scientists are completely aware of carbon’s cycles, and many of them have refined that knowledge, and continue to do so.
As a life long lover of science I have never been so appalled at what passes for science in the media and out of some of our universities.
As someone who is clearly uneducated and ignorant about large swaths of science, your being appalled really doesn’t matter much.
I believe that for most of earths history that CO2 has been a major constituent, and not a trace gas, but as life uses CO2 as it primary food it is used up.
Are you aware that above a level of about 1% (10,000 ppmv), CO2 is toxic to humans? Persumably it could/would have similar effects on other animal life, and the immense greenhouse effect at that level would be deleterious to plant life as well.
Great comment Peter – I’d was not aware of that fact re nitrogen on Venus before, and interesting thoughts about early Earth.
Some very interesting speculations here. I am pretty busy this week so I can only comment on the easier points you raise.
It seems likely that the Earth’s atmosphere was mostly CO2 before life got going. Living things created the oxygen that vertebrate animals rely on. Living things also “sequestered” CO2 in the “White Cliffs of Dover”, coal, natural gas and carbon bearing rocks.
As you point out the amount of Nitrogen on Earth and Venus is consistent but why is there such a huge discrepancy in the amount of water? David Appell says that the water vapor was dissociated in the Venusian atmoshere, allowing the Hydrogen to escape. If that is so, where did the Oxygen go?
I think we are agreed that the Arrhenius idea that trace gases cause the “Greenhouse Effect” is absurd. It is plausible that the bulk of the atmosphere causes the GHE but I can’t accept N&K’s theory unless they can:
1. Present a physical mechanism showing how their equation explains what is observed. Without that, the charge of “Curve Fitting” will be believed by many.
2. Prove that the atmospheric pressure during the PETM was over 1.5bars.
If that is so, where did the Oxygen go?
C + O2 -> CO2
“That thick atmosphere would have transferred heat from the equatorial regions to the poles much more effectively than does our current atmosphere. ”
Have you looked at this?
http://www.scotese.com/climate.htm
Have you looked at this?
Has it been published anywhere decent?
Why should I look at another dumb Web site by another dumb conspiratoralist who will believe anything as long as isn’t accepted science?
More to the point, why would you? (And have you found the missing 150 W/m2 yet?)
Thank you peter I have looked at this but not as throughly as I would like to. These sites are always worth going back to as each time you find another tit-bit that helps solve the puzzle.
Now the debate is shifting because the temperature is not playing ball…
There are plenty of factors that can cause a decade and a half haitus in surface temperatures, including internal variability (ENSOs mostly), uptake by the deep ocean, aerosols, and a slightly cooler sun.
The CO2 part of the picture is the most understood, and there is very little uncertainty about its radiative forcing on climate.
The one thing we should be able to agree on is that the concentration of CO2 in the atmosphere has been increasing monotonically since the Industrial Revolution.
If you say that the Industrial Revolution caused the rise in CO2 concentration I agree.
If you say that the rise in CO2 concentration is “Catastrophic” I will disagree. Can you prove any negative consequences from rising levels of CO2 in the atmosphere?
Do you know what I would like to see? 12 months of real chemical analysis of the CO2 content in the atmosphere. The way it is done now is not by direct analysis, and I don’t care how vehemently people argue that the instruments are accurate, there are a number of issue about the measurement of CO2 that could be very misleading.
Number one is that mans emission are but a pinprick compare to the natural world, something that is deliberately obscured when presenting information to the uninformed section of the public. So not only is CO2 a trace gas, but the man made part from the burning of hydrocarbon fuels is a tiny fraction.
Also its not the cities that are the great emitters as has be presented. Its the rain forests and tropical areas of Ocean. This again is obscured when being presented. About 2 years ago a satellite was sent up to monitor CO2 emitters. The data that came back was unsurprisingly just as above so was quickly withdrawn as we non scientists are obviously too stupid to be able to analyse the results without being total wrong. Just as well we were protected from ourselves I say.
Another interesting thing I came across and unfortunately lost the link when my hard disk failed on my laptop was video footage of pools of liquid CO2 at the bottom of the ocean. Of course CO2 does not have a liquid state in our above the surface world but something I didn’t know was that under great pressure it forms as a liquid. So all around those mid ocean volcanic vents we could have huge, really huge stores of liquid CO2 that could suddenly be released by a seismic event or something similar. It could be happening now for all we know and that this is what’s causing CO2 to rise. So much we don’t know.
Do you know what I would like to see? 12 months of real chemical analysis of the CO2 content in the atmosphere.
Just how do you think they do it? They chemically analyze captured flasks of air:
I’m flabbergasted. David says “Just how do you think they do it? They chemically analyse captured flasks of air:”
Do they just ok then where is all the data, sites and readings?????????????
Carbon dioxide measurements at the Mauna Loa observatory in Hawaii are made with a type of infrared spectrophotometer commonly called a capnograph but more accurately known as a nondispersive infrared sensor. I believe that there are only about four or five of these things due to the difficulty in calibration and no doubt cost. As I say I’m personally dubious of the figure, but don’t let that stop you believing it is the last world in CO2 concentration in the atmosphere. I’m also dubious of the pre-industrial figure for a variety of reasons, and following back the figures we get from the ice cores.
I believe that the ice cores may give us a indication of change, but the way we band about the absolute figures based on the ice cores is silly. And unless we can see events such as the 181AD Taupo eruption we know ice core data must be used with caution when used for absolute values.
Peter I don’t know where you get the patience. I would have loved to have had you as one of my teachers.
Do they just ok then where is all the data, sites and readings.
You mean you haven’t even attempted to look — you just assume there isn’t any, that’s it’s all a conspiracy?
Have you searched the peer reviewed literature?
Have you searched sites like CDIAC?
http://cdiac.ornl.gov/tracegases.html
Have you written to the scientists doing this work to ask? (Start with Ralph Keeling, Program Director of the Scripps CO2 program and son of Charles Keeling).
The NOAA Paleoclimate Data Archive?
http://www.ncdc.noaa.gov/paleo/recons.html
You guys are something else. You have no idea what’s going on in the science, and don’t even bother to look, but just assume it’s all a big conspiracy and people are suppressing results, blah blah. It’s really pathetic.
And unless we can see events such as the 181AD Taupo eruption we know ice core data must be used with caution when used for absolute values.
Have you heard of this newfangled thing called “Google?”
If you use it with the terms “Taupo” and “ice core”, you get this scientific paper for the first result:
Click to access 20110603134248990.pdf
See Figure 2.
Or, just assume this is also part of the grand conspiracy — that’s always easier.
I rest my case.
Reply – indeed! V.
“Peter I don’t know where you get the patience. I would have loved to have had you as one of my teachers.”
As you will see from my last post, it is proving difficult to find anything that David Appell and I can agree on. He seems to shy away from agreement. Without some agreement on the basic issues it is difficult to have a worthwhile discussion.
He did cite some papers that turned out to be worth reading such as the Arrhenius (1896) and the Lacis, A.A, G.A. Schmidt, D. Rind, and R.A. Ruedy, 2010: Atmospheric CO2: Principal control knob governing Earth’s temperature. Science, 330, 356-359, doi:10.1126/science.1190653.
http://pubs.giss.nasa.gov/abs/la09300d.html
I wonder if Peter teaches his students about conservation of energy.
David Appell: ” Why should I look at another dumb Web site by another dumb conspiratoralist who will believe anything as long as isn’t accepted science?”
Why do you insult Scotese? Is “ad hominem” all you have?
Do you imagine that “Climate Scientists” are more to be trusted than geologists? Perhaps you have something against the University of Chicago with its unusually large accumulation of Nobel prizes?
David Appell: “And have you found the missing 150 W/m2 yet?”
I answered that. If I got it wrong please explain.
Do you have any real science to offer? Some arbitrary Web site isn’t science.
Where is your missing 150 W/m2? It equals 45% of the solar radiation incident on the planet.
I answered that.
You certainly did not. You made up some weasely answer like you always do, this time about Trenberths’ missing heat or something, that didn’t solve anything and in fact didn’t even address the issue.
Yet more disnonesty. I should have realized dishonesty is a trait of yours when you were caught mislabeling a graph, and instead of just saying “Oops” and fixing it you made up some obvious lie about how you test your students by presenting incorrect information to see if they catch it. It was pathetic, and the pattern continues.
David
I really do not want to get involved in the more bad tempered parts of this debate, but I was interested in the paper you referenced at 11.49 with regards to ice cores and eruptions.
There was a lively discussion about the massive spike around 1259AD-much bigger than any other in the record.The discussion is below. I have numbered the responses for ease of understanding
—- ——- —-
1)gbaikie | June 2, 2012 at 11:20 am | Reply
“Ice cores from both the Arctic and Antarctic record a massive volcanic eruption in around AD 1258. The inter-hemispheric transport of ash and sulphate aerosol suggests a low-latitude explosive eruption, but the volcano responsible is not known. This is remarkable given estimates of the magnitude of the event, which range up to 5 × 10^14–2 × 10^15 kg”
http://onlinelibrary.wiley.com/doi/10.1002/joc.891/pdf
So this unknown eruption was bigger than Tambora.:
Wiki: “With an estimated ejecta volume of 160 km3 (38 cu mi), Tambora’s 1815 outburst was the largest volcanic eruption in recorded history.”
160 km3 or say 320 trillion kg- 3.2 x 10^14 kg.
So unknown eruption is seemingly much bigger than Tambora.
Both these scales of eruption utterly dwarf the ones in more modern times.
Mount Pinatubo[1991]: 1 X 10^13 and Krakatoa[1883] : 4 x10^13
So around AD 1258 an eruption as much as 200 times more ejecta
Pinatubo, or perhaps as small as 10 times more than both of them combined.
2) R. Gates | June 2, 2012 at 2:04 pm |
Though there was a very large one around 1258, it wasn’t the only one as Ice core data show several lessor ones, but still larger than Pinatubo.
3) climatereason | June 2, 2012 at 3:18 pm |
r gates
uncertainty in the 1258 record
http://www.wired.com/wiredscience/2012/02/the-mysterious-missing-eruption-of-1258-a-d/
tonyb
4) climatereason | June 2, 2012 at 3:36 pm |
gbaikie
the paper says it could have been a small eruption that was sulfur rich. The evidence for the severe cold seems to come from tree ring reconstructions.
tonyb
5) Tony, thanks for your historical perspective. In the Sept/Oct issue of Archaeology Magazine, in an article on the LIA in Iceland, Mann is quoted as saying a volcano near the equator erupted in 1258, sending the temperature down 2-2.5°C (3-4.6°F). If one inserts this information into the the HS, it rather disrupts the fantasy of a stable past, and makes the current warming, well rather small, since we have had to recover those two degrees already, prior to the current warm period. http://i48.tinypic.com/2qlxtkz.jpg
—– ——- ——
The evidence for an eruption in 1258 is strong in the historic observed record with the net result (in the UK) of heavy rain and Northerly winds although 1257 was just as bad as 1258 it must be said. However it is also clear that the effect was very short lived and the following year was reasonable.
I wondered how long lasting the effect of these volcanic eruptions are supposed to be?
tonyb
I really do not want to get involved in the more bad tempered parts of this debate
Too late. Peter Morcombe has preceded you, and he is a [snip]. He’s been caught in lies more than once now, and until these lies get settled — that is, until he admits to his lies — there is not more discussion here from anyone who, like me, has a clue what is going on.
[Reply – drop the ad hominem. Either be patient and polite here, or don’t bother coming back. My party, my rules. Verity]
I thought it was for others to decide if one has a clue or not.
climatereason,
Many thanks for all that. As you demonstrate there is ample historical evidence showing that volcanic activity affects climate in dramatic fashion. We think of Mount Tambora as a huge event but it is a firecracker compared to more ancient eruptions such as Taupo (18,000 years B.P), Yellowstone (70,000 years B.P.) and the Siberian traps (250,000,000 years B.P). We are indeed fortunate to be living in an era of very low volcanic activity.
N&K claim that the PETM (51,000,000 B.P.) was caused by an atmospheric pressure of ~1.50 bars. What could cause such a huge change in the mass of our atmosphere? The only thing that makes sense to me is volcanic activity orders of magnitude greater than we see today. The sad thing is that most researchers are blind to any hypothesis other than the idea that tiny quantities of CO2 somehow control climate in spite of all the evidence to the contrary:
Do you know of any research aimed at testing the idea that atmospheric pressure defines the GHE? One would imagine that human ingenuity could determine the total pressure of Earth’s atmosphere during the PETM and thereby confirm or falsify N&K’s “Unified Theory of Climate”.
A larger PETM surface pressure due to CO2 would leave HUGE excursions in the carbon isotope fractionalization record. But that record pins the PETM excursion at about 5000 GtC, not nearly enough to significantly affect surface pressure.
This falsifies your hypothesis.
Also N&K’s hypothesis is falsified on several other levels, such as nonconservation of energy. I can’t understand why anyone is even taking it seriously.
David Appell seems to be determined to prove that PeterMG was correct when he said that the AGW team are becoming more shrill and intolerant as they lose the argument.
We appear shrill only because the denier arguments have gotten more and more absurd, completely divorced from data and observations.
We have someone here hawking a idea that is a massive violation of energy conservation. Yet he completely avoids the question. What else is to be done?
Galloping camel
I have just returned from Iceland and there is no doubt that their ancient climate records show many more volcanic eruptions in the past than in recent centuries. Their size and duration of explosion would affect weather in the wider worlds but I suspect for relatively short periods.
I spoke to a volcanologist at cambridge university Who said current thinking was that there were 10000 times more underwater volcanoes than we recently believed. What effect they have on anything I don’t know.
There is a good chart from NASA that lists all known volcanoes and that may refer to your query. If you are interested I will hunt it out
Tonyb
CO2 from volcanic eruptions has a different carbon isotopic signature than CO2 from burning fossil fuels.
Also, atmospheric CO2 is known (from ice cores) to have been relatively constant over the Holocene, up until the Industrial Revolution, since when it has increased steadily. Is there some reason to think these undersea eruptions increased sharply at the same time?
David Appell. Are you telling us that the earths atmosphere has been 1 bar for the last 4.5 billion years? Are you tell us categorically, against all common sense that it was 1 bar 150 million years ago with the same constituents as we have at present at the height of the dinosaurs. If so please for me calculate the concentration of CO2 that according to Arrhenius would have given us constant temperatures from the equator to the poles.
I’m not in a position today to get the references, but the ice cores do not go back far enough to make any judgement from them on the PETM. And remember at that point most life on earth was extinct, so CO2 usage would have been very low.
It would be more helpful if you stopped being so aggressively negative to everyone and at least tried explain in layman’s language how you think the last 500 million years of the earth has been, or even the last 100 million years. Perhaps if you gave that more thought then you would have a clearer idea about the present. Because many of the things you ask us to believe just don’t pass any sort of sanity test, and so far your have offered zero explanation. Once you outline what you think then we can apply the equations that we know about and see who has the more plausable explanation. Isn’t that how science works?
Above comment is from me, tempestnut is an alias I use for aviation forums
The ice cores cover ~800,000 years. The CO2 concentration throughout the period was low (~240 ppm +/- 60 ppm). Since the Industrial Revolution the CO2 concentration has “has risen steadily”. Is this is a Hockey stick we can agree on?
The ice cores are not much help when one is looking further back in time. N&K postulate that Earth’s atmospheric pressure was ~1.5 bars at the height of the PETM. Is there any evidence to back up their bold claim?
This is surely a “Testable Hypothesis”.
The ice cores are not much help when one is looking further back in time.
I didn’t refer to ice cores, but to the carbon and oxygen isotope fractionalization recorded in fossils and other carbonates. It indicates, for the PETM, a drop in delta-13 C of about 3 mils and a carbon pulse of about 3000 PgC. That would barely affect surface pressure at all.
Or do you have other isotopic records that indicate a large increase in oxygen or some other crucial atmospheric component?
Does your friend at Cambridge have any comment on the intensity of volcanic activity in the distant past relative to today? Someone must know whether volcanos could have raised the atmospheric pressure around the time of the PETM.
I looked at the NASA site you mentioned but could not find anything relating to the PETM.
With regard to volcanos under the ocean it seems likely that large quantities of CO2 are stored at the ocean floor with the potential of sudden release as at Lake Nyos. If a sudden evolution of CO2 happened in the ocean would anyone notice?
http://en.wikipedia.org/wiki/Lake_Nyos
The amount of carbon stored as CO2 in the atmosphere is ~600 Pg (Giga-tonnes) compared to 37,500 Pg stored in the oceans. The CO2 now stored as marine sediments (30,000,000 Pg) is sufficient to raise the atmospheric pressure to 20 bars, so the 1.5 bars postulated by N&K is plausible but is there any evidence?
Here is something linking Sea Surface Temperature to volcanic activity:
http://www.greenworldtrust.org.uk/Science/Scientific/SSTvolcanic.htm
Someone must know whether volcanos could have raised the atmospheric pressure around the time of the PETM.
People who study the carbon cycle know — there is no evidence for any of this.
“Here we use published palaeorecords of deep-sea carbonate dissolution and stable carbon isotope composition along with a carbon cycle model to constrain the initial carbon pulse to a magnitude of 3,000 Pg C or less, with an isotopic composition
lighter than -50 mils. As a result, atmospheric carbon dioxide concentrations increased during the main event by less than about 70% compared with pre-event levels.”
— R. Zeebe et al, Nature Geoscience, 13 July 2009
DOI: 10.1038/NGEO578
David
I am merely relaying the comments from a vulcanologist about numbers. What effect if any underwater eruptions have on anything is not something I have studied as yet. Volcanic activity does seem to go in phases and I am currently evaluating the data I mentioned to GC above.
Tonyb
E M Smith had an article about volcanic phases. One of his innumerable interests. I will try and dig it out.
“Marty and Tolstikhin [1998] give a preferred estimate of 0.26 gigaton per year for the present-day global volcanic CO2 emission rate and a range for plausible estimates of 0.18–0.44 gigaton per year (see the online supplement). Their study [is] an evaluation of CO2 emissions from divergent plate (spreading center), intraplate (plume), and convergent plate (arc) volcanism….”
– T Gerlach, “Volcanic Versus Anthropogenic Carbon Dioxide,” Eos, Vol. 92, No. 24, 14 June 2011
David Appell said:
“A larger PETM surface pressure due to CO2 would leave HUGE excursions in the carbon isotope fractionalization record. But that record pins the PETM excursion at about 5000 GtC, not nearly enough to significantly affect surface pressure. ”
He did not quote a source so my guess is this:
Click to access pagani_etal_2006.pdf
This paper postulates that the release of CO2 caused the 5K temperature rise at the onset of the PETM. Pagani et al. arrived at a total release of 5,400 to 112,000 PgC. While they do not show the details of the calculations it seems likely they used Arrhenius style “Doublings”.
Let’s look at things another way. Suppose N&K are right. That would mean that the mass of the atmosphere was 153% of its present value (5,000,000 Pg) at the peak of the PETM. So where do you find another 2,650,000 Pg of gas?
Suppose CO2 was released by volcanos equivalent to many millions of PgC. This is orders of magnitude greater than the top estimate by Pagani et al. but still no big deal for volcanos. Plants convert CO2 into glucose and related compounds releasing one Oxygen atom for each Carbon atom in the CO2. So if plants metabolize 2,000,000 PgC the amount of Oxygen released would be 2,670.000 Pg, just enough to raise the atmospheric pressure to 1.53 bars.
Remember we had the K-T extinction starting around the 65 million before present mark. Much debate surrounds the cause of this with the Chicxulub impact on the Yucatan Peninsula of Mexico now thought to predate the K-T extinction by about 300,000 years. Then we had the Deccan traps super volcano. Was it this that wiped out most life on earth and completely reset the evolutionary clock? It must also have released a huge amount of CO2.
Now if you believe in Arrhenius it does not take much CO2 to get an increase in average temperature of 4 degrees and could happen over a very short time. If you are an N&K believer then 10 million years to increase the pressure to 2 bar seems reasonable. If life had not been wiped out then perhaps CO2 would not have risen. The other thing to remember is that the earths ocean crust, has an average thickness of about seven kilometres and it covers about 70% of the surface, is recycled every 100 million years. Earth is 4.6 billion years old. Multiplying out these numbers and then comparing them with estimates of surface volcanic deposits show that at least a thousand times more magma is oozing out of these submarine volcanoes than what is coming from our more familiar surface volcanoes. With no life to use the CO2 up then presumably it increases naturally.
The very thought of a couple of hundred parts per billion of CO2 making a disastrous change over the course of about 100 years is preposterous and demonstrates that when it come s to arrogance humans have no equal.
I just can’t help but feel that scientist accept too much existing science as a given and look for evidence that fits with these hypothesis. This I feel leads to many false assumptions when analysing proxies. I feel a fresh open mindedness is needed because it is quite obvious that the atmosphere has not been 1 bar for 4.6 billion years. It is quite obvious that life has sucked CO2 out of the atmosphere and this in turn has formed sedimentary rocks, dolomite, limestone and Coal. Life has allowed planet earth to retain its water where as our sister planets have lost theirs. CO2 has been the cornerstone of life and at present there is very little about. There is no way enough vegetation could have grown to feed the dinosaurs in an atmosphere such as our current one. There is no way that the large flying creatures from this time could fly in our atmosphere. 5 bars is closer to what they needed. These questions are all ducked when you ask mainstream science.
Why would the K-T extinction event release a huge amount of CO2?
The very thought of a couple of hundred parts per billion of CO2 making a disastrous change over the course of about 100 years is preposterous and demonstrates that when it come s to arrogance humans have no equal.
Perhaps it is.
A few hundred parts PER MILLION, on the other hand, clearly has the ability — as demonstrated by science, including observations.– of significantly altering climate and ocean acidity. It’s done so in the past, and there’s every expectation that it is enhancing the Earth’s greenhouse effect, which is easily observed by satellite:
http://www.giss.nasa.gov/research/briefs/schmidt_05/
There is no way enough vegetation could have grown to feed the dinosaurs in an atmosphere such as our current one..
Then prove it! Show your evidence. You haven’t shown any at all. All you’re doing is saying this and that can’t be right, but based on nothing but your feelings about how things ought to be. But that isn’t science, it’s pseudoscience.
The Deccan traps occured at just the right time to fit N&K’s hypothesis. The amount of CO2 required to raise the atmospheric pressure by 0.83 bars would be around 4 million Pg. The Deccan traps were active over a period of ~30,000 years so could they have emitted 133 PgC/year?
“Consensus Science” says that modern volcanos emit ~1 PgC per year but the uncertainty is huge. “Climatereason” says “I spoke to a volcanologist at Cambridge university who said current thinking was that there were 10000 times more underwater volcanoes than we recently believed”
Compare the “Consensus” 1 PgC/year for volcanos with the 8 PgC/year estimate for human induced CO2.
There are two stable isotopes of Carbon (C12 & C13) plus one radioactive isotope (C14). Plants show a preference for C12 while discriminating against C13 & C14. It follows that when plants metabolize atmospheric CO2 on a large scale the ratio of heavier isotopes of Carbon in the atmosphere must rise. Based on this process David Appell believes that there could be no more than 5,000 PgC emitted during the PETM.
N&K’s theory implies many millions of PgC emitted so who is right?
If the bio-mass of flora and fauna during the PETM was similar to what exists today, the Carbon fractionation argument would be persuasive. However, you mention mass extinctions around the PETM so we can be sure that the bio-mass 60 million years ago was very different from today.
All this is way above my pay grade but it seems pretty obvious that we know even less about what was going on in the PETM than we do about modern climate. Someone who states categorically that they “KNOW” how much Carbon was emitted by volcanos, methane clathrates or whatever in the run up to the PETM will need to produce some convincing evidence.
The amount of CO2 required to raise the atmospheric pressure by 0.83 bars would be around 4 million Pg.
Please think about this instead of applying formulas willy nilly.
1) Humans suffocate when CO2 levels approach 7-10%. What do you think might happen to oxygen-breathing animals when it approaches 80%?
2) Calculate the acidity of the ocean if the partial pressure of atmospheric CO2 is 0.83 bars. Explain how any fish would still be alive, or why fossilizedd carbonate shells would not have recorded huge, massive spikes in their carbon isotope fractionalizaation records.
These are basic questions, repeated now several times, and as is your pattern you are ignoring them.
By the way, the required amount is 5.2 million Pg CO2, not 4 million. Both are equally absurd. (The Earth would have been the subject of a runaway greenhouse effect.)
Someone who states categorically that they “KNOW” how much Carbon was emitted by volcanos, methane clathrates or whatever in the run up to the PETM will need to produce some convincing evidence.
You didn’t read the Zeebe paper, did you? It contains many references supporting the size of the PETM carbon pulse. Read it.
David says 1) Humans suffocate when CO2 levels approach 7-10%. What do you think might happen to oxygen-breathing animals when it approaches 80%?
Humans were not around 50million years ago, but think about it. If CO2 rises then CO2 based life will also rise, and more Oxygen is produced. Remember the first life forms are reputed to have poisoned themselves with excessive oxygen. And remember these changes take hundreds of thousands of years to occur and in that time life adapts. To apply todays levels to yesterday is to ignore how life adapts.
Humans weren’t around 50 Mya, but some animals that still exist were. They presumably have the same physiology and would have also suffocated in a thicker CO2 atmosphere.
That’s just one of the objections. You are ignoring all the others: no isotope record, massive greenhouse effect, much more acidic ocean, plus spontaneious combustion if oxygen levels get too high.
This idea has pretty much no evidence to support it. Why are we still discussing it as if it does?
This article speculates on atmospheric changes (in order to support large reptile flight — which the PLOS One article I cited earlier argues aren’t necessary), and the changes it envisions are nowhere near the scale you are talking about:
ATMOSPHERIC OXYGEN, GIANT PALEOZOIC INSECTS AND THE EVOLUTION OF
AERIAL LOCOMOTOR PERFORMANCE, ROBERT DUDLEY, The Journal of Experimental Biology 201, 1043–1050 (1998)
http://jeb.biologists.org/content/201/8/1043.full.pdf+html
Figure 1 and its discussion hypothesizes that oxygen levels early in the Phanerozoic (not near the PETM) may have reached 35% (compared to today’s 21%), with nitrogen’s partial pressure about the same. He writes, “Atmospheric oxygen concentrations are unlikely to have exceeded 35%, as this value represents an approximate threshold for spontaneous combustion of the biosphere.” That would be only a small increase in surface pressure relative to today’s.
During the PETM his data gives O and CO2 levels about those of today — that, of course, is consistent with the isotopic records in fossils.
PS: The increase in surface pressure would be about 0.15 bar.
I said There is no way enough vegetation could have grown to feed the dinosaurs in an atmosphere such as our current one.
David said Then prove it! Show your evidence. You haven’t shown any at all. All you’re doing is saying this and that can’t be right, but based on nothing but your feelings about how things ought to be. But that isn’t science, it’s pseudoscience.
I’m saying I grew up in the most fertile and productive agricultural area of the world, the Waikato in New Zealand. Now as a rule of thumb 1 acre can support 1 cow. But that is with all our modern fertilisers and careful land management. If you apply Galileo’s Square-Cube law and work out just how much the huge dinosaurs needed to eat, and how long the land would need to recover you quickly realise that something had to be different, very different.
We do know that with a thick atmosphere that convection would have transferred heat to the pole far more efficiently and is why the world had no ice and even temperatures. So more of the planet was productively available, but more of it was underwater as there was no ice But just having an ideal temperature will not make todays plants grow faster. They need more food, and plant food is CO2. How else could it happen?
David don’t just say prove it, do some original thinking. Tell us how you think these things happened in your own words.
Until you specify how many dinosaurs have to be fed, and the type of vegetation available to them, this proves absolutely nothing.
Plants do not exist on CO2 alone — they also need appropriate temperatures and precipitation. (In fact, already for some crops heat stress is cancelling out the increased fertilization effect [see Lobell and Field 2007]). As soon as you start to thicken the atmosphere you start raising surface temperature, and at the kind of pressures you’re talking about (2-5 atm) you’re talking about a massive greenhouse effect and a very acidic ocean.
A recent review and reappraisal of giant pterosaurs, one of the largest flying reptiles, concludes: “Pterosaur bone strength and flap-gliding performance demonstrate that giant pterosaur anatomy was capable of generating sufficient lift and thrust for powered flight as well as resisting flight loading stresses.”
— Witton MP, Habib MB (2010) On the Size and Flight Diversity of Giant Pterosaurs, the Use of Birds as Pterosaur Analogues and Comments on Pterosaur Flightlessness. PLoS ONE 5(11): e13982. doi:10.1371/journal.pone.0013982
The study contains nothing I can find about a thickened atmosphere.
Ooops! Too much Tullamore Dew. I got N&K’s pressure wrong. It should have been 183% of today’s pressure or 1.83 bars.
That changes the numbers significantly so we are looking for 4,180,000 Pg of Oxygen rather than 2,650,000 Pg.
I got N&K’s pressure wrong. It should have been 183% of today’s pressure or 1.83 bars.
Any such pressure would have left massive excusions in the isotope fractionalization record of carbon and oxygen.
They aren’t there. Are we supposed to just pretend otherwise, or does evidence count for anything here?
I am just as skeptical as you are about N&K’s 1.83 bar claim. If you have any relevant evidence this would be a good time to produce it.
Or do you expect people to believe your unsupported “Ex Cathedra” statements?
If you have any relevant evidence this would be a good time to produce it.
What part of my previous comments on carbon and oxygen isotope fractionalization records are you unable to understand?
Which part of the Zeebe Nature Geoscience paper do you find fault with?
Why are you still applying the N&K formula? The idea is a massive violation of energy conservation, that does not reproduce the Earth’s TOA outgoing spectrum. That makes it incorrect. Period.
Peter you shouldn’t be sceptical of 1.8 bar of pressure. For one thing the flying dinosaurs could not have flown in less that 3.5 to 5 bar (some even suggest much more). That is plain aerodynamics and a subject that palaeontology flaps around without facing. Also when accessing the size of the dinosaurs you must apply Galileo’s Square-Cube law. Very soon you realise that there is no way any of the super large dinosaurs could have supported themselves in anything less that a thick atmosphere. When we get over the absurd notion that the atmosphere has always been the same we will unlock the key to many things that now puzzle us.
An elephant can not jump, a) because it doesn’t have the muscular strength and b) because its bones would break. The Asian elephants that are used for heavy work in Asia are much smaller than African elephants that have a very poor power to weight ratio and are not much good at work. And it is extremely unlikely that evolution would leave behind superior body construction and metabolism and revert back to something more inefficient
1) What constituted this much more massive atmosphere?
2) If it was CO2, why didn’t animals suffocate at such large concentrations?
3) If it was CO2, why didn’t it leave a isotopic record in carbonate shells?
4) If it was CO2, why didn’t it massively acidity the ocean?
5) If it was CO2, why didn’t it lead to a runaway greenhouse effect?
When we get over the absurd notion that the atmosphere has always been the same.
No one claims this. But there is no evidence for the change you claim, and good evidence against it. Continuing to treated a falsified hypothesis as real is cartoon science, not real science.
Hi GC
Here are the various links I mentioned earlier. I don’t know if it is the same Nasa data as you have found. Some of the links refer specfically to the 1258 volcano eruption which I was researching for a future article.
—— —— ——-
http://www.volcano.si.edu/world/largeeruptions.cfm
Click to access 20110603134248990.pdf
http://www.archaeology.co.uk/articles/features/londons-volcanic-winter.htm
the above linkrelates to matthew paris observations in 1258
Click to access ClimImpts1258VolcaClimChg00.pdf
report by nasa on the volcano-good read, Hansen paper mentioned, he had an interest in demonstrating that aerosols mask warming
——- ——- ——
Professor Plimer of course reckoned that Co2 from Volcanoes had a significant effect on atmospheric Co2 levels. I was always more dubious as individually they are relatively small. However, looking at the NASA figures it seems we go in cycles of volcanic activity. If up to 50% of co2 remains in the atmosphere for hundreds of years and there was a peak in volcanic activity over say the last 500 years, that could contribute a legacy that exists with us today. As David mentions, it has a different isoptic signature.
The effect of 10,000 times more underwater volcanoes than previously thought would surely have an effect on things, especially IF they had been more active in the last 500 years. I have no evidence either way so it is nothing more than intersting speculation.You are right that eruptions of gas from the sea bed would not be noticed until recent times.
As regards co2 levels. I am not convinved of the accuracy of ice cores but let us assume they were right. The historic record demonstrates that contrary to the Mannian view of the world climate has varied considerably from the warm MWP to the cold LIA in the last 1000 years. The Roman and Bronze age period were warmer In that context todays climate is nothing special. So we apparently have much the same climate at 280ppm as we do at 400ppm. That makes me suspect that once we get beyond a certain concentration, say 280/300ppm, that co2 really has a very limited effect perhaps demonstrating the logarithmic curve effect that some claim.
tonyb
The historic record demonstrates that contrary to the Mannian view of the world climate has varied considerably from the warm MWP to the cold LIA in the last 1000 years.
In fact the historic record — which is precisely what Mann calculated — does not show that the MWP was a global phenomena. And his work does find a LIA.
And Mann’s results do not apply to the Bronze age, since it was before the period of his proxies.
Nor do we have the same climate at 400 ppmv as we did at 280 ppm. We have an energy imbalance of 0.5-1 W/m2 inward, and as a result we have a rapid rate of temperature change — in the ocean, and on land, and rapidly melting glaciers, ice sheets, and sea ice. We also have a 30% more acidic ocean. None of these changes are small, and all of them are bound to change a great deal more — climate change is just getting started.
Thanks for those links; I book marked the first one and read the others. Poor Plimer got all kinds of scorn for sticking to his guns in discussions of undersea volcanos!
Clearly the effect of volcanos is not much help to the CMIP folks looking for modeling tricks to explain the lack of warming over the last 15 years. Desperation is setting in, leading to ever more implausible hypotheses. Now we are expected to believe in Trenberth’s “Missing Heat” and soot from Chinese coal burning.
Your remarks about the ice core record make perfect sense to me; I am astounded when talented people like Richard Alley (he plays the guitar and sings) use them to support the idea that CO2 is the “Control Knob” of climate.
How can anyone imagine that an oscillation of CO2 concentration over a range of 180-280 ppm could cause the 10 K peak to peak temperature change assoiciated with the last three glaciation cycles? That would imply a climate sensitivity of 16 K/Doubling, even if one could ignore the fact that CO2 concentration lags temperature. In the “Alice Through the Looking Glass” world of Climate Science nobody sees anything wrong with effect preceding cause.
David said;
“In fact the historic record — which is precisely what Mann calculated — does not show that the MWP was a global phenomena. And his work does find a LIA. ”
Sorry, the last thing that MBH98 and MBH99 can claim to be is a historic record. It was primarily tree ring based with some other highly nuanced proxies.
I wrote about it at very great length here.
I am following the temperature reconstructions by Michael Mann and Hubert Lamb and hope to get back to 1000Ad as Dr Mann did. I was able to get back to 1538 for the article referenced above. I have now collected many thousands of additional observational records to around 1240.backed up by scientific papers I wanted to include 1258 because Dr Mann was, I am afraid, misleading in his view of the impact of the volcano in that year which shows up in his hockey stick.
Very many papers show the MWP was near global. It was probably nearer being global than the current warm period is, for as you know around one third of all stations show a long term cooling trend and many more are static.
Dr Mann minimised the MWP and LIA but I think that his resolution is not very good as tree rings for example are accurate to around 50 years in whatever they are supposed to be measuring. That certainly isnt temperature however, bearing in mind that tree ring formation is ‘ turned off’ for the vast majority of the year.
No, of course he didnt go back further to the Bronze age nor the Roman period. However our knowledge of that period enables us to see the present time in a much broader context. Would you like to see my study of sea levels in the Roman period? They were higher than today.
So we have a slightly warmer climate (MWP, Roman and Minoan ages) at 280ppm than today at 400ppm. Which suggests to me that there is limited temperature sensitivity above 280ppm.
The rate of temperature change was greater in the 1920-1940 period as evidenced in a rapidly melting arctic at the time. Would you like to see my study of that?
However the greatest temperature change of all was around 1690 to 1700. Nothing else comes close to it.
tonyb
Very many papers show the MWP was near global.
Which papers?
Would you like to see my study of sea levels in the Roman period? They were higher than today.
Only if your studies have been reviewed and published somewhere real.
The published literature certainly does not show that sea levels in the Roman period where higher than today — they show sea level about 1 meter lower 5000 years ago, rising at about a steady rate until the Industrial Revolution.
Climatereason provided a couple of dozen references to back up his case but you want more.
What studies support your opinion about sea levels during the Roman period?
Look for this when it appears:
PAGES 2k Consortium. Continental-scale temperature variability during the last two millennia. Nature Geoscience, in press.
http://earthweb.ess.washington.edu/~steig/
Thanks for your (long ) paper. It was a good read so I regret not having found it earlier. That tree rings should be regarded as reliable temperature proxies has always struck me as odd. Some studies of Mexican climate used tree rings as proxies for rain fall rather than temperature which got me wondering how one can distinguish between rain fall and temperature effects.
When “Climate Scientists” like Michael Mann contradict historians they are on thin ice. Civilizations rise during periods of abundance (climate optima) and collapse during cold periods that bring famines and pestilence.
In spite of the well documented failings of MBH98 and its many progeny, the AR5 WG1 Paleo chapter is still dominated by the “Hockey Team” while some of the people you quote such as Loehle & McCulloch are dismissed with one liners (e.g. … a low resolution study.)
Click to access Ch5_Paleo_WG1AR5_SOD_Ch05_All_Final.pdf
In my opinion this demonstrates the IPCC’s lack of objectivity and scientific gravitas.
David
Here is a useful site
http://www.populartechnology.net/2009/10/peer-reviewed-papers-supporting.html
I would say the authors are slightly optimistic on some of the papers they chose for this selection but most are meaningful
Here is my study using some 100 scientific papers together with observational material. THe sea oscillates around a metre or more from high to low.
There are links to a study by grinsted and moore complete with graphic demonstrating the evolution of sea levels showing sea levels higher in the past than today
As you know these people are highly alarmist so the projections for the future do not accord with reality The anomaly is set at zero for the year 2000.. Of course the argument is that the IPCC figure is wrong and such as Rahmstorf and Hansen project a rise of 2 metres by 2100. There is no sign whatsoever of that happening.
http://www.glaciology.net/Home/PDFs/Announcements/gslprojection
tonyb
Here is my study using some 100 scientific papers together with observational material.
Where has this been published? (Self-publication doesn’t count.)
Of course the argument is that the IPCC figure is wrong and such as Rahmstorf and Hansen project a rise of 2 metres by 2100.
That is not at all what the IPCC projects. Why are you saying they do?
IPCC 4AR WG1 Ch10 section 6.5:
Projections of Global Average Sea Level Change for the 21st Century
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-6-5.html
Verity
I just made a detailed reply to David. Usually it shows up immediately but as it had a number of links it might have ended up in your firewall. Could you check? Thanks.
Tonyb
David
Hopefully Verity will be able to dig out the post that I sent you. It had several interesting links
Hmmm. An article by Eric Steig eh?. Look out for a response by Jeff Id over at the Air Vent
By the way if Eric wanted to read my article on the ice melt earlier this century he will see the scientific reports from the 1920-1940 period when the Antarctic was melting at the same time as the sea ice and glacier reduction in the arctic.
I am away on Holiday until the end of April so I will leave you in GC’s tender hands
tonyb
Look out for a response by Jeff Id over at the Air Vent.
Link?
I don’t put much faith in little blog posts that are tossed off claiming to dismantle journal results. Blog posts aren’t science.
What article on ice melt? Citation?
Have a great Holiday. Thanks for holding the fort while I was busy teaching.
David Appell said:
“Which part of the Zeebe Nature Geoscience paper do you find fault with?”
Thanks for citing a paper relating to the PETM. You asked me to find fault with the paper so my first objection is that it is behind a “Pay Wall”. Given that the work was paid for by taxpayers, this is shameful.
The abstract is quite interesting as it seems to support the N&K position more than yours. For example the title:
“Carbon dioxide forcing alone insufficient to explain Palaeocene–Eocene Thermal Maximum warming”
I can absolutely agree with that statement given that “Doublings” of CO2 don’t come close to explaining the huge temperature excursions associated with the PETM:
The body of the abstract contains this statement:
” We conclude that in addition to direct CO2 forcing, other processes and/or feedbacks that are hitherto unknown must have caused a substantial portion of the warming during the Palaeocene–Eocene Thermal Maximum.”
I can’t speak for N&K but it seems likely they would claim that the “hitherto unknown” processes involve an 83% increase in atmospheric pressure.
Your claim that the release of CO2 into the atmosphere in the run up to the PETM could not have exceeded 5,000 PgC is a defensible position. You may be right. However, given our limited understanding of modern climate, how can anyone be certain about what was going on 60 million years ago? Let’s hear your comments on this:
This seems to be another serious problem with N&K’s hypothesis.
N&K’s idea violates conservaton of energy. Why is it even being mentioned as viable?
David Appell asked (April 18, 2013 at 8:13 pm):
1) What constituted this much more massive atmosphere?
2) If it was CO2, why didn’t animals suffocate at such large concentrations?
3) If it was CO2, why didn’t it leave a isotopic record in carbonate shells?
4) If it was CO2, why didn’t it massively acidity the ocean?
5) If it was CO2, why didn’t it lead to a runaway greenhouse effect?
These are excellent questions that encourage me to hope that we can agree (or disagree) without further “ad hominem” attacks or flights of empty rhetoric.
I am skeptical about the idea that atmospheric pressure could have been 1.83 bars at the height of the PETM. My attempt to imagine how such a thing could have happened runs into some problems as we shall see. Perhaps N&K have a different mechanism in mind that will side step the problems that I can see.
Q1. If there are any potential sources of Nitrogen to boost atmospheric pressure I am not aware of them, so that gas is ruled out There are vast reservoirs of CO2 in the form of carbonate rocks but there are good reasons for believing that the concentration of CO2 in the atmosphere never exceeded 2,500 ppm during the PETM:
http://141.213.232.243/handle/2027.42/62634
Thus my candidate is Oxygen formed by plants metabolizing CO2. The current atmosphere is composed of:
Nitrogen (0.78 bars), Oxygen (0.21 bars) and other gases (0.01 bars)
To reach a total pressure of 1.83 bars with the same partial pressure of Nitrogen and an additional 0.002 bars of CO2 means that the pressure of Oxygen would have to be 1.04 bars. Given the extreme reactivity of Oxygen, plants on land would be prone to self immolation at a 57% Oxygen concentration. According to Berner the Oxgen concentration was 35% 300 million years ago but only 27% at the peak of the PETM:
http://www.annualreviews.org/doi/abs/10.1146/annurev.earth.31.100901.141329?journalCode=earth
That sounds like a “Show Stopper” to me. Can anyone see a way around this problem?
Q2. Roughly 4,000,000 PgC would have to be released to produce an additional 0.83 bars of Oxygen. Assuming this was produced by the Deccan traps over a period of 30,000 years the annual amount would be 133 PgC/year, which could easily be consumed by the biosphere given that the present rate of metabolism is estimated at ~200 PgC/year. Thus there should be no risk of animals suffocating and as noted in Q1 above it seems likely that the CO2 concentration remained below 2,500 ppm throughout the PETM. Remember that sub-mariners are routinely exposed to 5,000 ppm of CO2.
Could the Deccan traps produce enough CO2? According to McClean the Deccan traps produced only 5 x 10^17 Moles of CO2 (6,000 PgC) which is woefully inadequate:
Click to access KRes.pdf
This seems to be another serious problem with N&K’s hypothesis but given that we can’t find the volcano that erupted in 1258 it seems possible we don’t know much about volcanoes during the run up to the PETM.
Q3. There is ample evidence of a sharp rise in CO2 in the run up to the PETM and a roughly simultaneous massive addition of C13 depleted carbon to the atmosphere. What this means is not so clear given that some carbonate rocks (e.g. chalk) are made of depleted Carbon.
Q4. There is ample evidence of increased acidity in the oceans during the PETM. That is inevitable given levels of CO2 in the atmosphere over five times greater than at present.
Q5. CO2 is not capable of causing a “Runaway Greenhouse Effect”. That is just a silly fairy story written by James Hansen.
This seems to be another serious problem with N&K’s hypothesis.
N&K’s idea violates conservation of energy. Why is it even being mentioned?
You keep saying that but do you have any calculations or evidence to back it up?
You keep saying that but do you have any calculations or evidence to back it up?
Of course — the surface emits an average of 390 W/m2, but only 240 W/m2 exits at the TOA. Without a way to block outgoing infrared radiation, the theory does not conserve energy.
So what is the theory’s explanation for this energy deficit?
Q5. CO2 is not capable of causing a “Runaway Greenhouse Effect”. That is just a silly fairy story written by James Hansen.
Here you go again — unable to admit basic scientific facts.
CO2 is obviously a greenhouse gas, and straightforward calculations show that a runaway GHE could well have happened on Venus, and almost certainly did. It’s the only known explanation that fits all the observations.
It is absurd to suggest that CO2 or any other gas can cause a “Runaway Greenhouse Effect” on Venus, a planet with 100% cloud cover.
Carl Sagan correctly forecast the surface temperature of Venus in the late 1960s using thermodynamics. Why anyone should believe a deranged alarmist like Hansen over Sagan baffles me.
Yes, CO2 is a “Greenhouse Gas” but so are all the others.
It is absurd to suggest that CO2 or any other gas can cause a “Runaway Greenhouse Effect” on Venus, a planet with 100% cloud cover.
Science isn’t based on your feelings of what is absurd or not, but on what you can prove or disprove. The solution to the Schwarzschild equation for high optical thickness is clear: a planet whose atmosphere has a condensable component has a maxiumum amount of outgoing infrared radiation; beyond that limit, the surface heats up.
Sagan understood the greenhouse effect, and did not show it was due to thermodynamics.
Yes, CO2 is a “Greenhouse Gas” but so are all the others.
Really? How do the others absorb infrared radiation?
Q2. Roughly 4,000,000 PgC would have to be released to produce an additional 0.83 bars of Oxygen.
What? This makes no sense at all. How does an increase in atmospheric increase the partial pressure of oxygen? And why isn’t such a massive carbon release recorded in fossilized carbonate shells?
Earth’s atmosphere has a mass of 5,000,000 Pg. Adding mass to the atmosphere increases the surface pressure proportionally.
Given that the present surface pressure is ~ 1 bar it takes (1.83 – 1.0) x 5 x 10^6 = 4.16 x 10^6 Pg to produce the pressure increase claimed by N&K.
I hope this helps.
It doesn’t help. You assumed an input of a huge amount of carbon, and then claimed that increased the partial pressure of oxygen. How does that work?
According to Berner the Oxgen concentration was 35% 300 million years ago but only 27% at the peak of the PETM:
What is the link for a copy of this paper?
And where in the paper does it say this?
Here is the Berner paper you asked for. Please look at Figure 2:
http://www.pnas.org/content/96/20/10955.full
You should like this paper as it refutes my idea that Oxygen alone would be sufficient to raise Earth’s atmospheric pressure to 1.83 bars.
What is the equation for the curve in Figure 2? They used a model, which you have previously said is not allowable. So what’s the analytic solution?
How does Berner’s result lead to anything like Ps~1.83 bars?
Q5. CO2 is not capable of causing a “Runaway Greenhouse Effect”
Are you going to be writing up this finding for publication? If would rock the scientific community.
Please let me know.
My publications relate to laser physics, inverse Compton scattering and relativistic electron linacs and synchrotrons. It should not be too hard for you to find them.
Commenting on climate science is something I do for the fun of it, a sure sign that I have too much time on my hands.
Nevertheless, when I tell you that CO2 is not capable of causing a “Runaway Greenhouse Effect” on Venus, I am correct. Remember you heard it here first!
Nevertheless, when I tell you that CO2 is not capable of causing a “Runaway Greenhouse Effect” on Venus, I am correct.
Science isn’t done by assertion, it’s done by proving or disproving hypotheses. Clearly you are unable to do that here, or to provide an alternative explanation for the state of Venus’s climate.
Q5. CO2 is not capable of causing a “Runaway Greenhouse Effect”
P.S.: In particular, I’m interested to know how you disproved the Kombayashi-Ingersoll limit, since it’s simply the solution to the Schwarzschild equations in the limit of large optical thickness. You can assume the atmosphere is a gray gas (for now).
Please explain how radiative process taking place below the cloud tops on Venus can have any effect on the radiation balance at the cloud tops.
It can’t be done so why not admit it?
Please explain how radiative process taking place below the cloud tops on Venus can have any effect on the radiation balance at the cloud tops.
Clouds have nothing to do with the greenhouse effect. Certain gases absorb infrared radiation, and then reemit it in all directions, so of it downward. This happens on Venus, where there are no water vapor clouds, on Earth even for clear skies, and on Mars where there are no clouds.
The evidence for the greenhouse effect, which you continually ignore, is completely obvious:
http://www.giss.nasa.gov/research/briefs/schmidt_05/
On Venus clouds define the GHE. Carl Sagan calculated the surface temperature of Venus correctly over 40 years ago using thermodynamics and gravity. Poor Gavin Schmidt and James Hansen still cannot get within 200 K of the right answer. If you disagree, I challenge you to show me their calculations.
On Earth it is at least plausible to suggest that CO2 can influence the effective emissivity of the planet and thereby provide “Radiative Forcing” of a few Watts/square meter. I have shown that the total forcing provided by CO2 cannot exceed 15 Watts/square meter.
The forcing idea does not work for Venus with its 100% cloud cover. If “Radiative Forcing” made any sense you would be looking for 16,000 Watts/square meter of forcing on Venus (Lacis et al.). Thermodynamics and gravity get the right answer without any need to mention radiative heat transfer.
Peter, you continue to avoid the main question here.
How does pressure alone block outgoing infrared radiation? Venus’s surface is radiating an average of 16,500 W/m2, yet the TOA is radiating only 65 W/m2.
Where is this missing energy??
On Venus clouds define the GHE.
Venus’s clouds are composed of sulfur dioxide and droplets of sulfuric acid. They do not intereact with infrared radiation. So how do they create a greenhouse effect?
Sagan and Pollack, “An analysis of microwave observations of Venus” (1965)
Click to access jresv69Dn12p1583_A1b.pdf
“One promising attempt to explain the high surface temperature of Venus involves the greenhouse effect. With surface pressures of several tens of atmospheres, and the upper limits on the possible H20 and CO2 abundances of Venus 100 g cm-2 and 106 cm·atm, respectively), cloudless greenhouse models can account for almost all of the high surface temperature….”
It continues:
“With the same pressures, and the lower limits on the possible H20 and CO2 abundances on Venus, only a fraction of the observed temperatures can be accounted for by cloudless greenhouse models. Accordingly we have investigated the contribution to the greenhouse effect made by the same clouds required to explain the visible and near infrared reflection spectrum of Venus. It is found that such clouds, because they are poorly absorbing and strongly forward scattering in the visible, but strongly absorbing and nearly isotropically scattering in the infrared, can provide the additional opacity needed to construct consistent Venus greenhouse models.”
Sagan and Mullen, Science (7 July 1977):
http://www.sciencemag.org/content/177/4043/52.abstract?sid=8d491286-fe2d-4c5f-aa1f-481f4d1fced6
“The present surface temperature of Earth represents an energy balance between the visible and near-infrared sunlight that falls on the planet and the middle-infrared thermal emission…. When the best estimates of these parameters are used, a value for Te of 250 to 255°K is obtained; this is far less than the observed mean surface temperature, Ts, of Earth, 2860 to 288 °K. The difference is due to the greenhouse effect, in which visible and near-infrared sunlight penetrates through Earth’s atmosphere relatively unimpeded, but thermal emission by Earth’s surface is absorbed by atmospheric constituents that have strong absorption bands in the middle infrared.”
Sagan and Mullen, Science (7 July 1977):
http://www.sciencemag.org/content/177/4043/52.abstract?sid=8d491286-fe2d-4c5f-aa1f-481f4d1fced6
“A runaway greenhouse efect will occur on Earth about 4.5 aeons from now, when clement conditions will prevail on Mars.”
Sagan, Science (24 March 1961):
http://www.sciencemag.org/content/133/3456/849.extract?sid=08b12583-8124-44b6-ad38-4870a5e1e05e
“The radiation temperature of an airless planet with the albedo and distance from the sun of Venus is about 250°K, if the period of rotation is a few weeks. The high surface temperature must be due to a very efficient greenhouse effect: Visible radiation strikes the surface and increases its temperature, but the infrared radiation emitted by the
surface does not readily escape to space, because of atmospheric absorption.”
Sagan et al, Science (21 Dec 1979):
http://www.sciencemag.org/content/206/4425/1363.abstract?sid=08b12583-8124-44b6-ad38-4870a5e1e05e
“Observations show that since 1940 the global mean temperature has declined by – 0.2 K, despite an accelerated increase in the carbon dioxide content of the atmosphere (1, 2). Extrapolation of present rates of change of land use suggests a further decline of – I
K in the global temperature by the end of the next century, at least partially compensating for the increase in global temperature through the carbon dioxide greenhouse effect, anticipated from the continued burning of fossil fuels.”
Sagan and Chyba, Science (23 May 1997)
http://www.sciencemag.org/content/276/5316/1217.abstract?sid=08b12583-8124-44b6-ad38-4870a5e1e05e
“For Earth today,Te =~ 255 K, and the difference DeltaT =~ 33 K between Te and the observed mean surface temperature Ts is due to the mainly H2O-CO2 atmospheric greenhouse effect.”
David Appell:
Those statements by Sagan and his associates are of a qualatitive nature. The meaning is not precise in the way that quantitative analysis is. Thus you can interpret the statements one way but my interpretaion may be totally different. It really does not matter; what counts are the calculations and measurements.
For example we both agree that planetary atmospheres produce a “Greenhouse Effect” (GHE). So did Sagan and every scientist worthy of the title. However, Sagan quantified the GHE on Venus without considering radiation and the results of his calculations are shown here:
http://adsabs.harvard.edu/doi/10.1086/149625
Your experts such as James Hansen and Gavin Schmidt can’t produce any comparable calculations to back up their understanding of the GHE. Their theory is wrong so they resort to rhetoric and fairy stories.
Peter, I already told you, this is a correction to a paper — not a paper.
Where is the original paper?
C. Sagan, Ap J 149 (1967) 731?
I have already presented evidence that as early as 1961 Sagan thought “The high surface temperature [of Venus] must be due to a very efficient greenhouse effect”
Peter: Let’s note, for the record, that you were (also) absolutely wrong about Sagan — he was thinking of Venus’s runaway greenhouse effect as early as 1961.
You’ve already admitted that you can’t support the analytical solution to the carbon cycle model you offered as evidence.
Hence, you have no right to complain about a link to the work of Lacis, Schmidt, or Hansen which also uses a model.
Their model incorporates funadmental physics just as does the model you liked.
Your lack of consistency is apparent for all to see.
Sagan’s 1967 paper, which the 1968 paper corrects, is here:
http://articles.adsabs.harvard.edu//full/1967ApJ…149..731S/0000731.000.html
In it he determines Venus’s surface temperature based on *observations*. He does not calculate it from first principles or explain why it is what it is.
This 1967 paper refers to Sagan and Pollack 1965, which says:
“One promising attempt to explain the high surface temperature of Venus involves the greenhouse effect. With surface pressures of several tens of atmospheres, and the upper limits on the possible H20 and CO2 abundances of Venus (~ 100 g cm- 2 and ~106 cm·atm, respectively), cloudless greenhouse models can account for almost all of the high surface temperature.”
Click to access jresv69Dn12p1583_A1b.pdf
Sagan proposed Venus’s massive greenhouse effect as early as 1961, in the work I cited earlier:
http://www.sciencemag.org/content/133/3456/849.extract?sid=08b12583-8124-44b6-ad38-4870a5e1e05e
“The radiation temperature of an airless planet with the albedo and distance from the sun of Venus is about 250°K, if the period of rotation is a few weeks. The high surface temperature must be due to a very efficient greenhouse effect: Visible radiation strikes the surface and increases its temperature, but the infrared radiation emitted by the
surface does not readily escape to space, because of atmospheric absorption.”
Most libraries carry back issues of Science magazine.
See my paper Planetary Core and Surface Temperatures for a more detailed explanation of just exactly how the required energy gets from the Venus atmosphere into the surface. Also read an explanation for crust, mantle and core temperatures.
Has this “paper” been published anywhere real? That is, not by your vanity press?
Thanks for participating. Just in case you did not see it, I commented on your paper here:
This post aimed to kick the tyres of N&K’s “Unified Theory of Climate” one more time. Please don’t be distracted by David Appell’s absurd boot licking (when it comes to “Peer Reviewed Scientists”) or his ridiculing of your well written paper. What I would like to hear is your opinion of the strengths and weaknesses of N&K’s hypothesis because you have obviously given a great deal of thought to climate issues.
In spite of David Appell’s abrasiveness he has cited some scientific papers that have been well worth reading. More recently he asked some excellent questions that have caused me to doubt N&K’s assertion that Earth’s atmospheric pressure at the height of the PETM was 1.83 bars.
What do you think?
refuses
David Appell asks (April 20, 2013 at 6:30 pm):
“How does Berner’s result lead to anything like Ps~1.83 bars?”
Berner’s “Figure 2” implies a maximum atmospheric pressure of 1.06 bars during the PETM thus refuting my idea that Oxygen alone could be responsible for an additional 0.83 bars of atmospheric pressure. As Berner points out there are good reasons for supposing that the Oxygen content of the atmosphere will be limited by the flammability of plants.
In my opinion this invalidates the idea that the atmospheric pressure at the peak of the PETM was 1.83 bars, one of the major claims made by N&K. This means that N&K’s theory has a rather large hole in it. It remains to be seen whether they can come up with convincing measurements or a plausible mechanism for a 1.83 bar pressure during the PETM. Unless thy do, their theory is not going to get much traction.
This means that N&K’s theory has a rather large hole in it.
N&K’s theory has far larger holes than this, such as the fact that it doesn’t conserve energy. That alone makes it pseudoscience.
David Appell (April 20, 2013 at 5:58 pm) says:
April 20, 2013 at 5:58 pm
“Of course — the surface emits an average of 390 W/m2, but only 240 W/m2 exits at the TOA. Without a way to block outgoing infrared radiation, the theory does not conserve energy.”
You are a slow student. Our discussions would go much more smoothly if you were scientifically literate. If only you had paid attention during your high school science classes.
Most people understand that planets radiate heat into space. Also that the amount of radiation increases with temperature. Thanks to Stefan we know that the total energy radiated by a black body is:
E = 5.67 *10^-8 * T^4 Watts/square meter, where T is the temperature in the Kelvin scale.
The average temperature at the Earth’s surface is generally agreed to be roughly 288 K. The Earth approximates to a black body in the “Thermal IR” (Bond albedo of 0.995), so by applying Stefan’s formula we can calculate the radiated energy as 390 Watts/square meter.
At the TOA (Top Of the Atmosphere) the average temperature is ~255 K. According to Stefan’s law one would expect 240 Watts/square meter of radiation and that is what the satelites (e.g ERBE) have found.
If you insist that the TOA radiation be equal to the radiation from the planetary surface you are saying that both must be at the same temperature and that is not going to happen as long as there is a gravitational field.
Rest assured that energy will be conserved. The “blocking of outgoing radiation” is irrelevant. Energy will balance with it or without it.
Yes Peter, I’m scientificailly illiterate, why is why they awarded me a PhD in theoretical physics.
Apparently ad hominem attacks are allowed here by some by not by others. Double standard.
Please accept my apologies. I won’t do it again.
In an earlier exchange I told you that I studied at Pembroke College, Cambridge (UK) and was awarded degrees in Physics and Electrical Engineering. Where did you study for your PhD and what was your thesis about?
My resume is online:
http://www.davidappell.com
The Earth’s surface radiates 390 W/m2 *DIRECTED UPWARD*.
Yet he TOA radiates only 240 W/m2.
Where has the missing energy gone?
You’re not going to be allowed to avoid this question, or wiggle out of it with unscientific arguments. (Save those for Roy Spencer’s site, where no one will challenge you.)
If you insist that the TOA radiation be equal to the radiation from the planetary surface you are saying that both must be at the same temperature and that is not going to happen as long as there is a gravitational field.
This is absurd — gravity’s interaction with electromagnetic radiation is extremely weak. (That, after all, is why satellites can take great pictures of the planet’s surface.)
Care to try again?
Here is a derivation of the adiabatic lapse rate. It is high school physics so you don’t need an advanced degree:
http://en.wikipedia.org/wiki/Lapse_rate
The lapse rate tells how temperature *changes* in certain parts of the atmosphere under certain conditions.
Bu it does not tell you what the temperature *is*.
Is this so difficult to understand?
David Appell says (April 20, 2013 at 6:27 pm):
“What is the equation for the curve in Figure 2? They used a model, which you have previously said is not allowable. So what’s the analytic solution?”
I have no problem with models based on “Hard Science”. We could not have built the Duke University Free Electron Lasers without “Cell Codes” that modeled relativsitic electron behavior, “Finite Element Analysis” programs that modeled heat transfer or magnetic fields and circuit models that predicted the pulse shapes from our 100 MW klystrons and much, much more. The precision of “Hard Science” is usually at the “Three Sigma” level or above.
Berner’s “Models” based on O16/O18 and C12/C13 isotope ratios are “Hard Science”.
Models based on “Fuzzy Science” such as CMIP5 are quite different. “Three Sigma” is out of reach so we are offered bus loads of statisticians with their pathetic 95% confidence limits.
Berner’s “Models” based on O16/O18 and C12/C13 isotope ratios are “Hard Science”.
How do you know? Please point us to a description of his model that shows how it is constructed.
Then, if you want to see some hard science, and your knowledge of mathematics is up to it, you can go and read this:
Description of the NCAR Community Atmosphere Model (CAM 5.0)
NCAR/TN-486+STR, June 2010
Click to access cam5_desc.pdf
Note that this is only their description of the atmosphere; There are several other modesl for other components of the climate system:
http://www.cesm.ucar.edu/models/cesm1.1/
“How do I know?”
The short answer is that I don’t.
The Berner paper was published in a peer reviewed journal (PNAS Vol. 90) so it is reasonable to suppose that it was peer revieved. You tend to sneer at publications that are not peer reivewed; are you now disrespecting the peer reviewed ones as well?
David Appell says: April 22, 2013 at 4:06 pm
“How does pressure alone block outgoing infrared radiation? Venus’s surface is radiating an average of 16,500 W/m2, yet the TOA is radiating only 65 W/m2……..Where is this missing energy??”
Your model based on radiation is simply…..wrong. There is no missing energy. On planets with 100% cloud cover you need only the TOA temperature, the depth of the troposphere, the gravitational field and the specific heat (at constant pressure) of the atmosphere. The radiative properties of gases that make up the atmosphere are irrelevant.
You still don’t seem to understand that the intensity of radiation emitted by bodies varies according to the fourth power of the temperature (Kelvin). I have already explained this several times including here:
Your 16,500 W/m2 corresponds to a temperature of 735 K. You say that the TOA of Venus is radiating 65 W/m2 which would correspond to a temperature of 184 K. Observations of the Venusian cloud tops show an average of 188 W/m2. Was that a deliberate error to see if I was paying attention?
In 1966 Pollack and Sagan (Mariner II) estimated the average TOA temperature of Venus as 234 K. Following Magellan (Jenkins et al.) the generally accepted figure is now 240 K corresponding to 188 W/m2 of outgoing thermal IR radiation.
The surface and the cloud tops on Venus are 65 km apart. The surface gravity is 8.87 m/s2. The measured adiabatic lapse rate is 7.9 K/km. Here is the calculation:
T(s) = 240 + 7.9 x 65 = 753 K
Can you get within 200 K of that figure using the Arrhenius theory of doublings or Radiative Transfer Equations? It won’t help you to read everything that James Hansen and Gavin Schmidt have written about Venus. They are long on rhetoric and short on equations.
Of course I understand the Stefan-Boltzmann Law.
It shows that Earth’s surface is radiating 390 W/m2 upward, but only 240 W/m2 is radiated upward at the top of the atmosphere.
Where is the missing 150 W/m2?
.
You still refuse to answer fundamental questions:
How do clouds — here or on Venus — block outgoing infrared radiation???
How do they explain the outgoing spectrum measured at the TOA:
http://www.giss.nasa.gov/research/briefs/schmidt_05/
Thanks for that link to your resume. It provides a clue as to how we may overcome our long standing “Failure to Communicate” (to quote from “Cool Hand Luke”).
We have both worked in telecommunications. Fifty years ago I was a very junior development engineer working on microwave radio systems in the 2Ghz, 4 GHz and 6 GHz bands using horn paraboloid antennas to transmit up to 1920 phone conversations, line of sight, over distances of up to 30 miles.
I asked my supervisor when we would be moving “up spectrum” into the 10 GHz range. He told me that would never happen owing to the scattering properties of rain drops. Of course he was right. Today, TV satellites use the Ku band (12-18 GHz) but we all know what happens when it rains. Later I was to learn that clouds are pretty good at scattering when you raise the frequency above 10 THz. This is called Mie scattering as opposed to Raleigh scattering that becomes significant above 100 THz.
The surface of Venus is at a temperature of ~730 K which means that 99.9% of the radiated energy is at frequencies above 10 THz. The energy peak is ~75 THz so Mie scattering dominates while Rayleigh scattering is starting to become significant. This means that the huge (16,000 W/m^2) radiation from the surface can’t penetrate the clouds on Venus. The radiative properties of gases below the Venusian cloud tops is not relevant. What matters is the Cp (specific heat at constant pressure) of those gases, the local gravitational field (g) and the depth of the troposphere.
That Schmidt link you provided is for the cloud free areas on Earth. It has little relevance to Earth given that the cloud cover is currently ~70%. It has zero relevance to Venus or any planet with 100% cloud cover.
Oh for crying out loud, this has nothing to do with telecommunications, but with physics.
Where is your missing 150 W/m2??
Now you’re simply getting absurd because you can’t answer the question about enregy conservation.
This has nothing to do with Mie scattering, or any scattering. It has to do with energy conservation.
The surface temperature of Venus is known.
The albedo of Venus is known.
So the amount of radiation from parts of its atmosphere is known.
The surface radiates at 16,500 W/m2.
The TOA radiates at 65 W/m2.
Where is the missing 16,435 W/m2?
I’m getting really sick of your excuses and dissembling. Just answer the question — where is all this missing energy????
Scattering conserves energy.
So the type of scattering doens’t prove anything — energy is still not conserved in your model.
This is elementary physics:
The surface radiates a certain amount of energy.
So does the TOA.
Explain the vast difference.
It can only be explained if the atmosphere blocks a certain amount of energy.
That is precisely the greenhouse effect.
Observations of the Venusian cloud tops show an average of 188 W/m2
Says who?
What measurement says this?
Please provide a citation.
My apologies for quoting the Venusian cloud top temperature as 240 K. Owing to my advanced age I suffer from CRS (Can’t Remember S**t). Jenkins et al. (Magellan) found ~260 K at the Venusian cloud tops (altitude 58 km).
According to Stefan-Boltzman that would imply 300 W/m^2,
So how do you explain your 65 W/m^2 figure? That corresponds to a TOA temperature of 184 K. That does not make sense given that it implies a Bond albedo of 0.9.
More recent researchers found a really small range for TOA temperatures on Venus (237 K at the poles and 243 K at the equator):
http://www.sciencedirect.com/science/article/pii/S0019103512000395
Given that the numbers above are less than a year old and they agree with my 240 K will you concede that your 184 K is wrong?
The tops of clouds do not define a planet’s emission temperature, so the graph you cite is not helpful in this context.
A planet’s emission temperature is the equation at the top of your post:
sigma*T^4 = S(1-albedo)/4
For Venus, S=2614 W/m2 and Bond albedo=0.90:
http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html
That gives Tgb=184 K, whose blackbody radiation is 65 W/m2.
Venus:
solar irradiance = 2609 W/m2
bond albedo = 0.90
Hence OLR at TOA = 65 W/m2
This is all very basic physics, based on the S-B Law. Does Peter Marcombe really disagree?
Yes I do. The OLR is much greater than you imagine.
I haven’t imagined anything — I’ve merely applied the S-B Law.
You seemed to know about this law earlier. Have you forgotten it suddenly?
E = sigma * T^4
Where is your missing energy, here or on Venus?
You’ve been dancing around this question forever. When are you doing to simply answer it?
Can I ask a simple thought question. How do you get Oxygen concentrations up to 35% without everything on earth spontaneously burning up? Certainly in our current atmosphere 21% is about the limit I am told before self combustion can occur.
Where does this Oxygen come from if not life and if not elevated CO2 concentrations. No free oxygen comes out of Volcanoes.
Oxygen is one of the most reactive substances around and will react with anything receptive it comes in contact with. Life has had to adapt to be both resistant and use oxygen.
Just a suggestion. Could not the elevated oxygen levels be a part of a completely different mix in the atmosphere, where the concentration was lower than 35% due to there being more CO2. So whilst there was extra O2 available for the large insects and larger animals, the concentration was at a level to didn’t cause everything to burn.
I proposed a mechanism to explain the additional 0.83 bar atmospheric pressure that N&K claimed in the “Unified Climate Theory” poster. I said that volcanoes released CO2 that the biosphere converted into Oxygen.
My proposal failed on two counts. Firstly, it implied an atmosphere with 56% Oxygen which is not plausible owing to the extreme reactivity of the element as you point out. Secondly it implied the evolution of CO2 from the Deccan traps that was three orders of magnitude higher than previously estimated.
Does this mean that N&K are wrong? In my opinion it does, unless N&K have a better explanation for the high pressure than the one I proposed, one that leaves Oxygen concentrations within plausible limits.
Much as it pains me I must admit that David Appell was right and I was wrong. He is entitled to crow a little, perform a victory lap or whatever.
There is still some debate about how high the Oxygen concentration can go when land plants exist. Remember that the first land plants appeared about 470 Mya. The highest Oxygen concentation since then appears to be ~35% 300 Mya.
http://www.pnas.org/content/96/20/10955.full
The Berner paper above also answers your question about how do plants convert CO2 into Oxygen. Here is the key equation:
CO2 + H2O = CH2O + O2
The equation can go in either direction. It goes from left to right when plants create sugars, starch, cellulose and related compounds using photo-synthesis.
The equation goes from right to left when plant matter burns or rots.
It is good that you accept the evidence, but I don’t take any particular joy in this — it’s science. The evidence said one thing and not another, and I knew that any idea that doesn’t agree with the evidence can’t be right. You simply can’t combat the evidence.
My attempt to imagine where an extra 0.83 bars of atmospheric pressure could have come from failed on two counts. The main problem was that the oxygen concentration would have been implausible causing “everything to burn” as you put it.
It’s good to see you finally admitted this.
“Now you’re simply getting absurd because you can’t answer the question about enregy conservation.”
Nonsense. Nobody doubts that energy is conserved. I have explained why only 188 W/m^2 of the 16,000 W/m^2 emitted from the surface of Venus is radiated into the cosmos,
If you have a PhD in physics you should be able to understand the adiabatic lapse rate that defines the temperature gradient in planetary atmospheres.
The lapse rate — which, remember, only holds up to the tropodpaude — conserves energy.
Your scenario does not.
The surface of Earth radiates 390 W/m2.
The TOA radiates 240 W/m2.
Where is the missing 150 W/m2?
Please answer this direct question.
That should be, “which only holds up to the TROPOSPAUSE….”
Kevin Trenberth’s energy balance makes perfect sense to me. If I differ with Kevin it is in the details such as whether the Argo buoys show his “Missing Heat”.
http://www.cgd.ucar.edu/cas/abstracts/files/kevin1997_1.html
Peter, come on. This isn’t about Trenberth’s “missing heat,” which was only a fraction of a Watt per square meter, and anyway appears to have been found in his latest publication:
http://davidappell.blogspot.com/2013/03/missing-energy-claimed-to-be-found.html
This is about a huge amount of missing energy — 150 W/m2.
Where it is?
“Where is the missing 16,435 W/m2?
I’m getting really sick of your excuses and dissembling. Just answer the question — where is all this missing energy????”
You need to calm down.
I have explained these things many times. Radiative transfer equations are irrelevant in planetary tropospheres as other heat transfer processes dominate. On rare occasions radiative transfer dominates in the troposphere resulting in temperature inversion by which I mean that temperature increases with altitude. Evidence of this is found when low surface temperatures cause fog, extreme surface cooling in deserts or “Freezing Rain”.
In spite of the anomalies mentioned above convection and phase chages dominate in the troposphere so temperature decreases with altitude in a linear manner according to the equation dT = g/Cp
There is no missing energy. The problem is your failure to understand thermodynamics.
I understand thermodynamics quite well.
I also understand that the surface of Earth radiates an average energy of 390 W/m2 upward.
And the top of the atmosphere radiates an average of 240 W/m2 upward.
Where is the missing 150 W/m2?
What physical mechanism based purely on gravity and thermodynamics blocks such a massive amount of infrared radiation?
Please, finally, answer this.
In spite of the anomalies mentioned above convection and phase chages dominate in the troposphere so temperature decreases with altitude in a linear manner according to the equation dT = g/Cp
You have confused temperature with radiative energy.
Temperature is proportional to the average kinetic energy of atmospheric molecules.
Radiative energy is solar and infrared radiation in the form of photons.
These photons do not alter the kinetic energy of the molecules, because their wavelength is huge compared to the molecular sizes. Mie/Rayleight scattering varies like (size/wavelength)^4, which is ~(nanometers/microns)^4 ~ 10^-12, so these photons simply do not “see” such tiny particles.
Thus, thermal IR only interacts with these molecules via quantum processes.
How exactly does a thermal IR photon interact with N2 or O2, which you have previously claimed are also greenhouse gases? These molecules have no bending modes, which are the ones that create the greenhouse effect. (You’ll notice that all GHGs have molecules that consist of at least 3 atoms: CO2, CH4, N2O, H2O, O3, etc.)
So how is N2 or O2 a greenhouse gas?
And why don’t they show up in satellite measurements:
http://www.giss.nasa.gov/research/briefs/schmidt_05/
The temperature gradient in the atmosphere is defined by -g/Cp. The Cp of Nitrogen is very close to that of CO2 so don’t expect much to change if you switch one for the other. Forget radiation; it is just one of the several ways to transfer heat in the troposphere. Thermodynamics rules.
(Sigh.) The list of things you don’t understand is enormous.
Of course the lapse rate doesn’t change much if you change atmospheric constituents. In thermodynamics they are basically just billiard balls.
What does change is the way they interact with infrared radiation streaming up from the surface. CO2 does. N2 doesn’t.
If “thermodynamics rules,” show it it determines the temperature of any level of the troposphere. Not by using some observed value and then applying a lapse rate, but determing the temperature from first principles.
David Appell said:
“You have confused temperature with radiative energy.”
Not so. If you had accused me of mangling the adiabatic lapse rate formula I would be guilty as charged. Here it is what I meant:
dT = -g/Cp dz where z = altitude
You have confused temperature with radiative energy.
The lapse rate specifies the RATE OF CHANGE of temperature with pressure — it does not explain the actual value of the temperature.
For that you need radiative physics.
Wrong again. Webster’s College Dictionary defines the lapse rate thus:
“….the rate of decrease of atmospheric temperature with increase of elevation vertically above a given location.”
Here is how you can estimate the surface temperature of Venus, assuming that the adiabatic lapse rate is 7.9 K/km, cloud tops are 65 km above the surface and their temperature is 240 K:
Surface temperature = 240 + (7.9 x 65) = 753
Now show me how to estimate the surface temperature using radiative physics. hasen and Schmidt can’t do it quantitatively but perhaps you can.
Obviously. But you FIRST have to know the temperature of the cloud tops.
Thus, this is only a calculation based on observations. It does not determine the surface principle from first principles — Manabe was the first to do that. (Lacis et al 2010 have a nice presentation of the various surface temperatures determined by radiative physics.
There is nothing incompatible between the greenhouse effect and a near-constant lapse rate. Both are true on planets with atmospheres.
And (obviously), there is nothing about the lapse rate that blocks outgoing IR. That’s done by GHGs. (N2 and O2 do not absorb in the infrared.)
Ooops! That should have been Hansen not hasen!
David Appell seems to think that the radiation from the Venusian surface (>16 kW/m^2) rises unimpeded through the atmosphere until it encounters the cloud base. If that was the case we would see a sudden jump in temperature at the cloud base. Observations don’t show anything remotely like that. Magellan showed a linear temperature gradient all the way to the cloud tops and above, see Jenkins et al:
It should be obvious from the above chart that the adiabatic lapse rate calculation first performed by Pollack and Sagan in 1967 is an excellent approximation. The derivation of the ALR is in every high school physics text book. The ALR relies on thermodynamics rather than RTEs (Radiative Transfer Equations). If radiation plays any role at all it is just one of several processes (e.g. convection, conduction and phase changes) that work towards achieving thermal equilibrium.
It is reasonable to suppose that thanks to pressure broadening and dust the lower Vensuian atmosphere absorbs most of the surface radiation long before it gets to the cloud base. Just a speculation on my part. Anyone have a better explanation for the near perfect linearity of the observed temperature gradient?
I do my best to respond to David’s questions but he ignores mine. I asked him to show how to calculate surface temperatures using radiation physics.
Rather than answer the question he cites the nonsensical Lacis et al. paper. Then he cites Manabe and Wetherald (1967). This paper does not specifically calculate Earth’s surface temperature. It does say that doubling the CO2 concentration would lead to a temperature increase of 2.3 K.
While Manabe believes the Arrhenius theory he is no “Alarmist”. He talks about “winners an losers” when (if?) the planet warms. He expects Canada and Siberia to be winners as their winters will be milder. He is expresses confidence in the ability of the bio-sphere to adapt whether the temperature rises or falls.
Peter, someone with your misunderstandings of science certainly doesn’t get to call Lacis “nonsensical.”
If you can’t understand that paper, it’s not my problem.
I understand it all too well.
I can’t really tell that you understand much of anything — you’ve made one basic error here after another, and have failed to understand the most basic concepts and how to interpret and apply the evidence.
Only such a person could be supremely confident they’re right when every climate scientist, every Nobel Laureaute, and every National Academy on the planet has come to a different conclusion.
THAT’S the phenomena we ought to be studying here.
Manabe and Wetherald (1967) certainly does have a calculation of the surface temperature — see Figure 12, and several other in the paper:
http://journals.ametsoc.org/doi/abs/10.1175/1520-0469(1967)024%3C0241%3ATEOTAW%3E2.0.CO%3B2
This isn’t the first time I’ve caught you misrepresenting what papers say….
He is expresses confidence in the ability of the bio-sphere to adapt whether the temperature rises or falls.
Clearly you decide what science you will buy based on certain opinions of the scientists, not on whether it is supported by evidence.
Manabe was a meteorologist who did fundamental work on planetary climatology. How does that make him an expert in how the biosphere will react to climate change? Why should I believe his (early) opinion instead of the thousands of more qualified scientists who have studied the problem in greater detail and reached different conclusions?
Poor Manabe. Apparently his lack of politically correct “Alarmism” makes him suspect to CAGW zealots.
Anyone who claims that a warming climate is a bad thing is woefully ignorant. Historians are much more to be trusted than so called “Climate Scientists” who will say whatever is demanded by Neo-Lysenkoism. Here is a link you should enjoy even though it demolishes the idea that a cooler climate is desirable:
My apologies for the Greek sub-titles.
It obviously depends on how much warming and how ocean acidification. 2 C of warming is a huge amount for a civillzation like ours to adapt to in a very short period of time. 4 C — more than half an inverse ice age — is far more likely, with unknown consequences.
And 4 C is the global average. It will be more over land, more in the northern hemisphere, more in the interiors of continents.
Maybe you don’t mind rolling the future’s dice if it saves you a few dollars on your heating bill, but some of us care about the world we leave to others.
Have you given up trying to justify N&K?
Claiming that N2 and O2 are supposed to be greenhouse gases?
Believing that thermodynamics explains surface temperature?
That Sagan wasn’t a proponent of the greenhouse effect?
Then my work here is coming to an end.
Some folks think that the radiation from the Venusian surface (>16 kW/m^2) rises unimpeded through the atmosphere until it encounters the cloud base. If that was the case we would see a sudden jump in temperature at the cloud base. Observations don’t show anything remotely like that. Magellan showed a linear temperature gradient all the way to the cloud tops and above, see Jenkins et al:
It should be obvious from the above chart that the adiabatic lapse rate calculation first performed by Pollack and Sagan in 1967 is an excellent approximation. The derivation of the ALR is in every high school physics text book. The ALR relies on thermodynamics rather than RTEs (Radiative Transfer Equations). If radiation plays any role at all it is just one of several processes (e.g. convection, conduction and phase changes) that work towards achieving thermal equilibrium.
It is reasonable to suppose that thanks to pressure broadening and dust the lower Vensuian atmosphere absorbs most of the surface radiation long before it gets to the cloud base. Just a speculation on my part. Anyone have a better explanation for the near perfect linearity of the observed temperature gradient?
Here is what I said in the original post:
“Before anyone gets the idea that I believe N&K’s theory let me say categorically that I don’t. ”
Far from trying to justify N&K’s theory I have been trying to find problems with it. The theory is clearly not useful for predicting or back casting global temperatures over decades, centuries or even millenia given that there is no reason to believe that total atmospheric pressure varies significantly over such short periods.
So I concentrated on N&K’s claim that the PETM resulted from a total atmospheric pressure of 1.83 bars. I discussed a process to bring this about based on CO2 emittd by the Deccan traps being converted into Oxygen by the bio-sphere. In the end I concluded that this process was not plausible.
Unless N&K can produce convincing evidence to back up their claim of a 1.83 bars of pressure during the PETM nobody should give their theory any credence.
So I find myself unconvinced by the “Unified Theory of Climate”. Any theory that claims that a single variable is the “Control Knob” for climate is going to trigger my “BS Detector”. I can’t accept that pressure is the “Control Knob” any more than I can accept that trace gases such as CO2 and water vapor control climate.
Good to know. So why were you (quite) recently hawking the idea on Roy Spencer’s blog?
And does this mean that you have finally understood that not all atmospheric gases are greenhouse gases?
In particular, that N2 and O2 do not absorb infrared radiation?
I can’t accept that pressure is the “Control Knob” any more than I can accept that trace gases such as CO2 and water vapor control climate.
Are you knowledgeable about the abundance of ozone in the atmosphere?
It is 10 ppmv or less.
Yet without it you would not exist, and would never have existed.
So tell me again about “trace gases.”
“Have you given up trying to justify N&K?”
That was never my aim. However pressure based theories are much better at quantifying GHEs than the Arrhenius theory.
“Claiming that N2 and O2 are supposed to be greenhouse gases?”
The GHE (Greenhouse Effect) is caused by the main bulk of the atmosphere rather than trace gases such as CO2 and water vapor. The Arrhenius theory is a scientific fig leaf used to support the nakedness of “Consensus Climate Scientists”. Science and observations don’t matter when politics is driving the bus.
“Believing that thermodynamics explains surface temperature?”
Since the stratosphere was discovered in 1902 it has been clear that the temperature gradient in the troposphere is the dominant factor defining the GHE. All you need is an understanding of high school physics. Here it is again: dT = -g/Cp dz, the temperature at the cloud tops and their altitude. RTEs can safely be ignored in the troposphere. Not so in the stratosphere where radiation dominates. In the stratosphere temperatures usually rise with altitude as one would expect given that conduction, convection and phase change effects are weak compared to radiation.
N&K are a little smarter than this camel so they perform their energy balance at the surface (rather than the cloud tops) and still manage to get the right answer.
“That Sagan wasn’t a proponent of the greenhouse effect?”
Of course he was. Who is not?
“Then my work here is coming to an end.”
I have to agree with you. For quite a while it has been just the two of us. Nobody else is taking any interest. Once you stopped the “Ad hom”, appeals to authority and the other tired tricks of the CAGW faithful you turned out to be a “Good Sport”. I salute you and look forward to stimulating discussions in the future. I really liked your write up on the “Space Elevator” and several of your other publications.
You should be a little concerned that your most faithful acolyte is “Dano”. John Cook has “Tom Dayton”, “Dana Nukatelly”, “Doug Bostrom”, “Ned Flounders”, “Marcus Hicks”, “Philippe Chantreau” , “Riccardo Reitano” and several more.
If you feel the urge to have the “Last Word” here that is fine with me. You may want to ban my wife from your site too [bahamamamma].
However pressure based theories are much better at quantifying GHEs than the Arrhenius theory.
Completely false, because N2 and O2 do not absorb IR.
It’s astounding that after all this time you do not understand this basic fact.
How can that be??
And amazingly, you STILL do not understand that the lapse rate determines the RATE of change of temperature in the lower troposphere, not its absolute value.
Why should I care who follows my blog?
I accept your complete surrender. You never had the goods, and the evidence showed that all this time….
PS: I have never heard of your wife, and don’t care what her name is.
This is all on you.
You are being completely untruthful about your previous thoughts on Sagan.
How dare you do that.
And I’m tired of people like V.J. who protect those who do not tell the truth.
David Appell. Rather than continuously tell Peter he knows nothing how about showing us your workings and answer his questions. Even some original thinking in your own words rather than cut and paste jobs would be welcome. It appears to me Peter tries to show you how he has calculated his answers to you. But at the end of the day you haven’t answered a single question with your own original thoughts. Knowing that you can think for yourself is important, because it demonstrates a degree of understanding. I don’t see that from you.
There is a bigger problem on display here and it the appeal to authority. It’s what our politicians hide behind all the time. None of us would be discussing this subject if it were not for the fact that our collective governments have taken policy decisions that have adversely affected the majority of the population. Certainly I am not really interested in radiative physics or lapse rates. But now that 99% of the Western world’s population are facing lowering living standards,(not to mention the tenfold knock on effect this will have for the majority of humans in the developing world), some perhaps for the first time in their lives, we have become interested out of necessity, and the effect will be like poking a stick into a hornets nest.
The climate community has been caught out. Right from the beginning I though the notion that CO2 was the key to the temperature on our planet was nonsense. Understanding exactly why and getting to the bigger picture has taken a long time. Getting to the point where scientists are now focussed on this, the root cause of the argument, has taken 20 or more years. Too much time has been wasted pointing out the almost criminal manipulation of recent years temperature data by the climate community. But even though it has now been demonstrated that the temperature has done nothing out of the ordinary over the past 50 years the public is facing an energy crisis of its own governments making. And still these people don’t stop so it will force now a revolution in western politics. It is well underway here in the UK but you won’t read about it in any legacy media reports, but it is happening.
I can’t help but say I think everyone is wrong on the climate. Why do I say this? Because no one is putting anything into context, so there is a whole series of quite confusing arguments going on where both sides are wrong with their scientific argument even when they both agree on certain facts. I have observed the following.
The further back in time we look, the longer things take to happen. As humans a long time is a human life time so it has been quite easy to convince a lot of people, especially those born mid-sixties onwards that our climate has changed and was warming dangerously. For someone such as myself born 10 years earlier I have noticed little difference, and as I’m a keen photographer I notice these things and have the photographic evidence to back this up.
But when science comes up with a temperature record going back 2000 years based on tree rings (dodgy at best) or ice cores (must be very careful) then the uncertainty figure must be much higher. When we go back 15,000 years to the start of the Holocene or 150,000 years we have to be very careful how we interpret the speed with which things happen. I believe in the absence of anything else credible that recent temperature changes are entirely natural, that CO2 per say has had zero real effect and that influences such as the oceans are probably the only mechanism that can change our climate within such short periods as 1 year to 5 years. We know the Sun has cycles and from the 11 year sunspot cycle to the much longer sun cycles and interplanetary actions we can see small changes that occur over hundreds of years. Then there are the changes that occur over thousands of years; what for instance is causing the warm interglacials which humans need to be extremely grateful for right now and why have they lasted historically for such short times.
But the big thing that eluded the thinking is what causes the changes that take millions of years. One hundred and fifty million years ago there where dinosaurs on earth that weighed in at an estimated 100 tones, and despite the palaeontologist community often having their heads in the sand, they did not wander about in a 1 bar atmosphere. The temperature over most of the planet was very even, there was no ice anywhere, not even the top of Mountains as and were geologists can see they are still existent. What conditions allowed this to happen, and how quickly can these conditions change. When we look to understand 50 million years ago and rule things out, it’s best to go back further and do some thinking.
They say it was the change from warms tropical conditions to dryer cooler conditions that set in motion the change of events that allowed modern man to evolve. When did this start. Some say just a few thousand years ago, others 2 million. Some say our ice age started 6 million years ago or 8 million years. 65 million years ago life was almost wiped out. Interestingly the large dinosaurs coming in at 100 tons had gone well before this, something that is always missed out in any discussion. Was this the result of a changing atmosphere?
So many things are not thought about; so much thinking is not joined up. So many questions are ignored. Yet we are asked to believe in a theory that fails even the most rudimentary sanity test. How on earth did we get to the moon is what I want to know?
Just when I thought nobody was taking any notice! I find myself nodding in agreement with most of your points:
The Arrhenius theory claiming that CO2 and water vapor are dominant factors in the Greenhouse Effect that warms our planet did not matter very much when “Climate Science” was a backwater.
Today, “Climate Science” is being used as the basis for raising the price of energy around the world. Governments are using the scientific fig leaf provided by the Arrhenius theory to justify squandering trillions by subsidizing of “Renewables” while side lining coal and nuclear power plants.
With so much at stake people are beginning to ask the right questions. With every day that passes it becomes more and more obvious that CO2 driven climate models simply don’t work. The wheels are falling off the CO2 bandwagon.
Since the discovery of the stratosphere in 1902 pressure based theories convincingly explained the GHE on Earth by multiplying the adiabatic lapse rate by the thickness of the troposphere. This is what I call a “Pressure Based” Greenhouse Gas theory. Such theories say that the main bulk of the atmosphere determines the amount of warming in sharp contrast with Arrhenius who claimed:
“The selective absorption of the atmosphere is……………..not exerted by the chief mass of the air, but in a high degree by aqueous vapor and carbonic acid, which are present in the air in small quantities.”
I see some serious problems with the claims of N&K. For example I failed to answer the question “How could an extra 0.83 bars of atmospheric pressure be created”. Unless N&K can answer this question in a convincing fashion their explanation of the PETM is going to be ignored.
Even if N&K are wrong about the PETM their pressure based theory works well for all the planets that we have measurements for. By this I mean that the surface temperatures predicted by N&K’s equations are strikingly good. In contrast, nobody can make comparable predictions for Earth or Venus using the Arrhenius theory.
Does this mean that N&K are right? No, because you can’t prove that any scientific theory is right. However it does prove that Arrhenius was wrong.
Comments on this post are closed. I have deleted some of the last comments from David Appell as they added nothing but accusations and name-calling.