A reply to Vonk: Radiative Physics Simplified II

Nice clear piece Jeff, thanks. I have to agree CO2 has a warming or insulating effect, but the effect is small and limited, also the water vapor/cloud system appears to be a huge negative feedback.

Thank you jeff.
Like you I believe in moving the discussion FORWARD. There are a couple places where the skeptical “movement” is retarded, err held back. Understanding and accepting the way the greenhouse effects works is one of those areas. The continual refusal to accept the basic physics, makes Skeptics look like the defenders of mann. Otherwise smart people, steadfastly refusing to accept a well proven physics. A well proven physics that works. The refusal on skeptics part to accept this physics is bewildering.
1. The design of working devices depends on this physics.
2. This physics is correct, But it has LITTLE BEARING on the alarmist claims.
3. Denying this physics, Weakens your position when you try to discuss the REAL UNCERTAINITIES.
4. When you deny the obvious and well proven physics, people will not take you seriously when you make valid objections to more questionable aspects of AGW.
5. When you accept this physics, you confuse the hell out of AGW folks, because THEY THINK you are anti-science.
6. When you accept this physics you have a better chance of being heard on the REAL issues.
And just for good measure we will throw in some appeal to authority:
Spenser, lindzen, Monkton,Christy,Willis,Anthony.. All accept the basic physics.
That is why they are not so easily dismissed. The real issue is Feedbacks, sensitivities, damages, and solutions.

All physicists do not include LIFE in their equations and CO2 reactions are intimately related to life on earth. Life needs, in special we, warm blooded animals, an excess of energy to keep negentropy, life itself. This is why exists the UHI effect. Just calculate how much glucose, we the 7 billion inhabitants of the earth, need: We got the energy transforming championship.
Ask yourself how much, how many kilos of those nasty fat growing carbohidrates diets we consume or even how many kilos of jeans, t-shirts and underwear made from that polymer of glucose called cottom we use.
Then WE SHOULD BE REFUNDED , of course in CASH, not in carbon credits.

Nice post. Just a somewhat urgent off-topic comment.
In The Guardian, John Cook thinks that “A new iPhone climate change sceptics’ app [Our Climate] inadvertently reveals the strategies of disinformation and denial they employ”:
http://www.guardian.co.uk/environment/blog/2010/aug/06/iphone-climate-denial-app
Do you agree with him? Please create an account at the Guardian and freely express your opinion.

Can some back-of-the-envelope numbers using Beer’s Law and molar absorptivities/extinction coefficients be provided in this analysis? If not, where can I find something like that? That is where part of my skepticism lies, as anyone who’s run IR in organic chemistry can tell you that it doesn’t take a long pathlength before the CO2 absorption at 2350 wavenumbers (cm-1, around 4.25 microns) becomes saturated. Another fun thing I just realized is that CO2’s other main absorption band maxes out right around 666 cm-1…interesting.
Anyway, the main point of my comment is that I want someone to direct me to where I can get molar absorptivities for CO2 and hopefully water too. If no one has run the actual numbers with respect to saturation, I can start working on that (lots of numerical integrations, I know).
-Scott

OK. That’s a good thought experiment and I have no issues with the conclusions. However, you missed out the other half of the experiment.
Tak two cans, one with dry air, the other with 50% CO2, heat them to the same temperature well above the ambient. Now see how long each of the cans take to reach, say, half way to the ambient. The CO2 can will emit IR more than the dry air, and therefore cool the can quickest.
How does this apply to AGW? CO2 heating in the day is balanced(?) by CO2 cooling at night.
On another topic, why do the global heat flow diagrams only ever depict the situation in the daytime and not at night?
Ed

Another opportunity to promote my description from a while ago in case some find it easier to follow:
http://climaterealists.com/index.php?id=1562&linkbox=true&position=4
“Greenhouse Confusion Resolved”

Actually I think we need both posts for a full explanation.
Tom Vonk’s post explains the physics fairly well for a system in local EQUILIBRIUM without any external input. (It could use a bit of rewrite) This post takes the base laid by tom’s post to the next step, a NON-EQUILIBRIUM situation. If you can understand what Tom was saying about the special case of a system at equilibrium, especially how photons get translated into velocity (heat) then the next step, adding energy in the form of photons that is then translated into heat becomes easier to understand. Also the transport of that energy to space and the time lag become understandable.
And yes I realize Tom was not trying to prove what he actually did prove (physics of a system at equilibrium), the physics and explanation were still OK.

See? Before I got to the diagram with the 1000-watt output reestablished at a different equilibrium, I was ready to throw rocks at you… 🙂
Yes, while reading through the comments here sometimes I wince at both “sides”. However, like many arguments, the real question usually turns out to be the definition of the words rather than the underlying reality (ie, we use the phrase “greenhouse” even though it’s not the same as a greenhouse).
Enneagram points out another obvious issue: the presence of life on this planet alters simple physical processes in a major way. You HAVE to account for:
1) the current influence of life on atmospheric and oceanic processes, and
2) the fact that life WILL change to adapt to conditions, and by doing so will change the conditions.
Are there any purely physical theories to account for 21% O2 in an atmosphere, that do not rely on the presence of life?

“From the perspective of 15 micrometer wavelength infrared laser, the CO2 filled air is black stuff.”
I believe this is incorrect. Chemical bounds within CO2 absorb the energy of specific photons, and at equilibrium emit them at the same rate, though not necessarily in the same direction, as they are whizzing around, smacking into each other. It’s not black stuff, it’s “white” stuff, like a cloud. Does a 15 micrometer detector pointed at the earth from space see a black ball?

I guess you also must add to the equilibrium issue how more seeohtwo affects growth if temp also goes up a bit. Is that a feedback loop comparable to temp issue, smaller or bigger?
Seems to me that the ‘dummies’ posit that seeohtwo PLUS the solar output affect temperatures is arguable from this. Key spectral freqs for solar warm up??
As a moderate skeptic, what’s your thoughts about how radically or weakly seeohtwo warms the earth??

I somehow think or remember that each CO2 molecule can absorb no more than a finite quantity of the electromagnetic (em) radiation at 15 mm. With finite absorption, the temperature will never reach the 1000 watts of input energy as the excess laser em radiation will pass through the canister.

Alexander K says:
August 6, 2010 at 10:02 am
… we are paying for now in terms of too many of us believing for too long the alarmist nonsense cranked out by the Greens, the closet Marxists and the extreme Left. A good education is a wonderful insurance against spin-doctors and snake-oil salesmen!
_______________________________________________
Don’t you believe that nonsense Alexander. Plain common sense and a grounding in reality are what are really needed.
The first place the Marxists targeted was education. In 1958 my brother attended his first year at a college in the frozen north of New York state near the Canadian border. He came home in November, less than three months later, a flaming Marxist. This is a guy who was an electrical engineering student with an IQ of over 200.
Dumbing Down America: http://www.ordination.org/dumbing_down.htm
This article shows what happen to our education system.

“gas can of air diluted by 50 percent CO2”
But it’s less than 0.04%

In my simplistic non-scientific way I worked out that the CO2 in the atmosphere provides
a small but constant warming. Doubling CO2 quantity does not change the warming.
http://www.globalwarmingskeptics.info/forums/thread-249-post-3039.html#pid3039

Why is it that when anyone talks about the “greenhouse effect”, they totally ignore the fact that the atmosphere doesn’t just sit there.
As everyone knows HOT AIR RISES.
So, considering only the radiation bands blocked by CO2, the CO2 laden air will absorb IR close to the ground, it will then heat up, causing the gas to expand and so rise, rise rise, rise, until it finds a way to emit that extra energy … and how is that done? Well it’s full of CO2 which is a superb cooling gas (CO2 provides a convenient extra pathway through which gases can LOSE HEAT by infrared emission. And once CO2 HAS CAUSED THE ATMOSPHERE TO COOL it starts to descend, descend, descend, until it is close enough to the ground to pick up the IR emitted from that blackbody radiator we call the ground.
So, what is the net effect of adding CO2 to the atmosphere? It is first to absorb more radiation at ground level, then to emit more radiation at higher levels where the relatively thin atmosphere creates a window into space. (It’s slightly more complicated because it doesn’t go all the way to the edge of space — but the argument still holds).
So, the net effect of adding CO2 is to heat up and cool the atmosphere more! It has two equal and opposite effects, and the big con of the global warming scaremongerers is to ignore its cooling function in order to pretend it only warms the atmosphere.
Next week, join me for a demonstration whereby a put a plug in the orifice out of which most global warmer communicate to prove to a global warmer that if you only consider what goes in and don’t consider what goes out … it’s pretty painful!

Ken Hall says:
August 6, 2010 at 10:52 am
The “sophisticated” computer models of a chaotic, non-linear system are incomplete and therefore wrong
That’s because chaos only exists only in the mind of the beholders. Those who taught chaos and uncertainty were the rule, were lying on purpose. Their agenda was to derail the train of humanity.

Mike Haseler says:
August 6, 2010 at 10:59 am
Bravo!, chemically pure common sense.
That is why balloons fly when burning propane, which produces CO2+ Water. It goes up, up and away to give its heat back to space.
BTW, water vapor, on my head as low altitude clouds is a negative feedback. I feel colder under a cloud, not warmer.
Think we better prepare some stakes to send CO2 fanatics to explore space. Their heat will surely warm the cold Moon up 🙂

Thanks goodness a return to some refreshing sanity – before all credibility on WUWT is lost. I was appalled when I saw the Tom Vonk posts. I understand however that this is a blog and the beauty of blogs is that some have the cojones to stand to be corrected!!!
I gave up on The Economist – modern news medias are too arrogant and never publish corrections even when they publish bogus science and downright nonsense. (The Economist was once, many years ago, a half decent rag with a reputation that was worth defending – the modern version is so BS prone that you may be better served by the National Enquirer at your local supermarket checkout – at least they make no pretense about being “authoritative”)

PJP says:
August 6, 2010 at 10:22 am
Other questions, to which the answer almost certainly exists, but I have no idea where to look:
The absorption spectrum of CO2 shown indicates some maximum absorption (attenuation of the 15 micrometer radiation). How does this change as the concentration of CO2 increases?
I think this is vitally important to answer. At some concentration the gas will become completely opaque to 15 micrometer radiation. Adding more will make no difference.
Are we already at that point? What is that point?
________________________________________________________
Yes we are essentially at that point just look at the IR fingerprints for CO2 in the article or here: http://upload.wikimedia.org/wikipedia/commons/7/7c/Atmospheric_Transmission.png
CO2 is Logarithmic Explained: http://knowledgedrift.wordpress.com/2010/05/11/co2-is-logarithmic-explained/
Here is another paper you might want to read: http://www.friendsofscience.org/assets/documents/The_Saturated_Greenhouse_Effect.htm
Another very interesting site: http://www.co2web.info/

stevengoddard says:
August 6, 2010 at 11:36 am
CRS, Dr.P.H.
Thanks for the Hansen link.
——
Reply: Any time, Steve!
Thanks for your excellent posts! It will take a lot of folks, ranging from “everyman” to professionals, to shoot this stuff down, and your contribution is appreciated.

I don’t think anyone in their right mind disputes that CO2 and that horrible green house gas H2O do not cause an increase in the mean global temperature. Its the question of the first and second derivative. The last time I saw a first derivative of temperature with respect to CO2 concentration from a source I could respect, it was of the order of 0.00125 to 0.00250 degrees C per ppm of CO2. The second derivative was negative. Of course, this being the complex system that it is with convection and all even static first derivatives are at best a wag.
“CO2 traps part of the infrared radiation between ground and the upper part of the atmosphere” totally ignores the fact that convective activity takes the CO2 heated air upwards into the atmosphere and replaces it with cooler air from higher alititudes. The earth is not a greenhouse. There are no glass plates on the roof. Sometimes it takes that other greenhouse gas up with it and makes these funny things called clouds which make your “window” pretty darn reflecting instead of transparent. (Hint, that is why deserts are hot by and large).

Weather is cold, cloudy, and miserable in UK, a typical summer!
We could do with a bit of CO2 warming feedback! but it looks like it isn’t going to happen.
I am off to Spain! see you all soon!

Thank you for the post which helped me alot. However I see from the comments that I need to read a lot more.
As a none scientific sceptic I can comment on your point about us saying CO2 does not cause warming.
I believe what most of us have meant is that although we might be persuaded that CO2 has a warming effect, there are times when CO2 rises and the planet cools. To a none scientist it seems reasonable to conclude that during those times, CO2 has no warming effect ^.^

The low down of radiative physics:
Crap gets radiated, crap has to go somewhere, crap hits some things some of the time, but most of the time it just keeps going, and going, and going into out space, and beyond. And that’s how all that outer space crap reach us in the first place.
Cheers

Not this “re-radiate” stuff again. Objects “radiate”, they don’t “re-radiate”. When you eat a steak, are you “re-digesting” the grass that the cow ate?
Just drop the “re-” part and all your statements will not only still make sense, but they will be accurate, too.

Absorption of 15 micron radiation by CO2 raises the internal – vibrational – energy of the molecule, this is a quantized reaction and the CO2 rapidly relaxes to its ground state by emitting 15 micron radiation. CO2 molecules in the atmosphere will thus absorb outgoing thermal radiation and re-radiate it in a random direction. Some of this scattered radiation will reach the earth and provide a little extra warming. It is however important to recognise that, because of the quantum nature of this process, the CO2 molecules involved do not gain kinetic energy and are therefore incapable of “warming” (ie. adding kinetic energy)to the atmosphere unless there exist receptors such as dust, or vapours which absorb the 15 micron radiation kinetically.
It is thus correct to state that CO2 absorbs IR and re-radiates some of it back to earth, the so-called Greenhouse Effect. However, in my opinion ,FWIW, the impact on Global temperature pales into insignificance when faced with the complexity of natural feedbacks as Dr Spencer and others have ably demonstrate.

Gail, the Dewey denigrating article you linked to is a bit out of date, or if currently being spread, is somewhat out of touch. While I understand that historically, whole language become the preferred/only (and very unfortunate) method of reading instruction, it is no longer the case. Auditory phonemic awareness (sounds in spoken words) and phonological letter-sound association awareness is a key explicitly taught skill element in reading instruction in kgt through grade 2. Children are tested frequently throughout the year regarding decoding and recoding ability, with targeted phonics-based intervention applied when these skills are not being developed.
My concern is that commercial reading intervention products are not very strong in oral practice of phonics and rely too heavily on teacher talk and worksheets, or worse, try to do too much by including comprehension in the mix. Many also introduce spoken-sound practice and letter-sound practice in less than preferred ways in my opinion.
I have my favorites (one is out of print but I use it anyway and the other has just been re-issued at more than quadruple the price) and my less than favorites (which consists of most of the new programs), and then there is my list of bad, bad, bad interventions (also consisting of new programs) like “Read Naturally”. It is often touted as a computer based reading fluency intervention but is at the top of my bad list. It is a whole language holdover that needs to be entirely removed from our schools, burned till nothing is left but ashes, and the authors tarred and feathered.

There should be no doubt that the downward LWIR flux from both CO2 and H2O in the atmosphere exchanges LWIR flux with the surface and helps keep the surface warmer than it otherwise would be. Most (>90%) of this flux originates in the first km layer above the surface. However, the emission is determined by the species concentrations and the temperature profile (lapse rate) in the lower troposphere. The lapse rate is set by the bulk thermodynamics of the convection. As soon as the sun begins to heat the surface and sets up a temperature difference, the air is warmed at the surface and rises though the atmosphere. Under summer sun conditions with a dry surface, the surface temperature (the one under your bare feet) can easily reach 50 C. The air temperature will be about 25 C because the convection mixes cooler air down to the surface. Just using Stefan’s law, (sigma.T^4), the upper limit to the net LWIR flux radiated from the surface is about 200 W.m-2. The incoming solar flux is ~1000 W.m-2, so the balance is convection. ~80% of the thermal energy from a dry ground surface is transfered to the atmopshere as convection. If the surface is moist, evaporation will reduce the surface temperature and some of the energy will be tranported as latent heat.
The fundamental error in the AGW argument is equating the small increase in downard LWIR flux from 100 ppm CO2 (1.7 W.m-2) with an increase in ‘EQUILIBRIUM SURFACE TEMPERATURE’ using Stefans Law, with ‘WATER VAPOR FEEDBACK’ to fix the discrepancy in the presumed numbers. (These numbers come from the hockey stick calibration, but that is a separate fraud). In reality it is impossible to measure the effect of a 100 ppm increase in CO2 concentration/LWIR flux on the surface temperature. +1.7 in a flux that changes pseudorandomly from +1000 to -100 W.m-2 makes no difference to the surface/subsurface temperature of a cubic meter of soil. Changes in humidity alone will alter the downward LWIR flux by 50 W.m-2. Forget 100 ppm of CO2 – or 200 or even 2000 ppm! Alternatively the whole daily dose of 1.7 W.m-2 100 ppm CO2 LWIR flux is equivalent to less than 3 minutes of sunshine at 1000 W.m-2, or the evaporation of a layer of water 65 microns thick over an area of 1 m^2.
Furthermore, convection is mass transport, which means that the air mass as it rises through the atmosphere has to do work against gravity. That is undelying reason why the air cools as it rises. This is where the excess surface energy goes.
At night there is much less convection, so a stable air layer near the surface slowly cools by LWIR emission up through the atmosphere. The heat capacity of a 1 m^2 x 1 km column of air at the surface is about 1 MJ, so the radiative cooling rate is around 0.1 C/hr. The thermal gradient is reset each day by the surface convection.
The downward LWIR flux from CO2 helps to keep the surface warmer than it would otherwise be, but it does not control the surface temerpature. It is just a relatively stable component in a highly variable surface energy flux. To understand the greenhouse effect we need to look at the short term variations in the entire energy flux, not long term averages of small parts of the radiative flux.

Re: Scott says:
August 6, 2010 at 10:24 am
[Anyway, the main point of my comment is that I want someone to direct me to where I can get molar absorptivities for CO2 and hopefully water too. If no one has run the actual numbers with respect to saturation, I can start working on that (lots of numerical integrations, I know).],
Scott, you can learn a lot about the optical properties of water here:
http://omlc.ogi.edu/spectra/water/abs/
The optical properties of CO2 can be found here:
http://www.spectralcalc.com/info/about.php

Joss, the keyword is net IR energy flow.

Those two ‘black body radiation’ humps are very wrong.
The profile of a lower temp. body’s frequency spectrum is always lower than that of a higher temperature body. So the earth receives more IR in sunlight than it emits at night. Thus the blanket effect that warms the earth at night would by definition shade the earth from incoming sun IR which must be a bigger effect because of the extra IR.
Google ‘black body radiation’ and hit images to see what I mean.

thegoodlocust says:
August 6, 2010 at 10:49 am
I never got this far into physics and perhaps someone could enlighten me.
When CO2 absorbs infrared radiation and then emits it, does that increase the wavelength? If so, how many times would that radiation need to be absorbed and re-emitted by CO2/Earth until it was at a wavelength that CO2 is transparent to?
______________________________________________________
Physicists please correct me if I am wrong:
The photon absorbed and the photon emitted should be exactly the same energy value. The only thing I can think of that would change that is “spectral line broadening”. If I recall “spectral line broadening” is caused by pressure effects: http://www.rsc.org/ebooks/archive/free/BK9780854045754/BK9780854045754-00001.pdf
There is one way the energy of the photon “packet” could be changed. It is when the infrared energized CO2 molecule collides with another gas (N2, O2, H2O…) and the photon energy is translated into velocity. Since velocity ca be of any value subsequent collisions can change the velocity (energy) by dividing it between the colliding partners.
The amount of “heat” (velocity) caused by the infrared energy absorbed by the CO2 depends on how much is translated into velocity of other air molecules and how much is re-radiated downward back to the earth’s surface. Do not forget that this is ONLY the energy from the specific IR bands shown in Figure 2, third line (green) on the right side under the bell shaped black line representing the gray body emissions of earth. Of course H2O (blue line) is going to be competing for some of that energy too. This can be seen in the shape of the black line at the top.

#
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Mike Haseler says:
August 6, 2010 at 10:59 am
Why is it that when anyone talks about the “greenhouse effect”, they totally ignore the fact that the atmosphere doesn’t just sit there.
As everyone knows HOT AIR RISES.
So, considering only the radiation bands blocked by CO2, the CO2 laden air will absorb IR close to the ground, it will then heat up, causing the gas to expand and so rise, rise rise, rise, until it finds a way to emit that extra energy … and how is that done?…..
____________________________________________________________
NOPE.
Absorption of IR causes an electron to go from the ground state to the excited state. VELOCITY of the molecule is what we call heat. You missed a step.
Reread tom’s post closely he explains the difference. http://wattsupwiththat.com/2010/08/05/co2-heats-the-atmosphere-a-counter-view/

Gail Combs says ‘don’t you believe that stuff (about a good education), Alexander.
Sorry Gail, but I meant a non-dumbed down education mal-fashioned by Greens, Marxists and others of devious and malign intent. My idea of a ‘good education’ comes pretty much from the teachings of Aristotle, not some wet-behind-the-ears Marxist camped in an undeserved university tenured professorship. And I believe that many of the essayists who post here at WUWT are giving us a wonderful education.

Jeff Id,
You ignore the FACT that the incoming IR from 1-4 microns is much larger than the outgoing through the earth’s complete power range among other things. It is really hard to compute RTE’s when you ignore large segments of the flux and concentrate on one area.
The graph you show has the sun’s output scaled to under 10 -6. Even Science of doom only used a graph at 10 -6 for the sun to get it on the same graph. Naughty naughty.

A C Osborn says:
August 6, 2010 at 11:15 am
One thing that I find find very confusing about the Wavelength Diagram is how little the H2O has in the spectrum that affects the Incoming radiation and yet as everyone knows when it is cloudy the Temperature changes bu a very Significant amount. How does such a small bandwidth have such a large effect?
__________________________________________________________
Energy can be absorbed by a molecule, that is cause an electron to move to a higher state, or energy can be reflected.
A change in cloud cover causes a change in the albedo. The water in the clouds is reflecting the sun’s energy like a mirror does before it can even hit the ground. That is why skeptics have hissy fits about climate models that keep cloud cover constant.
Albedo: http://www.answers.com/topic/albedo
Changes in cloud cover:
Inter-annual variations in Earth’s reflectance 1999-2007.
http://bbso.njit.edu/Research/EarthShine/literature/Palle_etal_2008_JGR.pdf
Research Article: Automated Observations of the Earthshine
http://www.hindawi.com/journals/aa/2010/963650.html
“For a decade, we have been measuring the Earth’s reflectance by observing the earthshine, which is sunlight reflected from the Earth to the Moon and retroflected to the nighttime Earth. …..The earthshine observations reveal a large decadal variability in the Earth’s reflectance [7], which is yet not fully understood, but which is in line with other satellite and ground-based global radiation data…”

RE: Gail Combs says: (August 6, 2010 at 1:05 pm) “The photon absorbed and the photon emitted should be exactly the same energy value.”
That only applies if there is absolutely no change in the energy of the entity that absorbed the photon in the first place. If you get $20 and it is stolen, then you cannot spend it. If the robber only takes $10, then you might be able to spend the other $10.
In the molecular world, the robbery may take place as a collision between two molecules. Such a collision may also result in the donation of energy.

@crazydung
‘I believe what most of us have meant is that although we might be persuaded that CO2 has a warming effect, there are times when CO2 rises and the planet cools. To a none scientist it seems reasonable to conclude that during those times, CO2 has no warming effect ^.^’
Perhaps a better statement would be ‘History shows that there have been times when the warming produced by an increase in CO2 has been outweighed by other, as yet unclear, cooling mechanisms, leading to an overall drop in temperature’
In other words, its a bit more complicated than just CO2.
(Shine on You Crazy Dungmand……)

The problem I have with Tom’s figure is that it doesn’t say where the reflection happens. Does some of it happen above the surface (such as by clouds)? I certainly think so. And is this reflection just sunlight? What about GHGs above the clouds, do they emit energy? Don’t the clouds reflect this energy too? It seems reasonable to believe so.
So it seems to me that wherever there are clouds, the majority of high-altitude GHG emission goes into space.
During the day I doubt it matters. Why? Because while their emissions are getting lost in space, they are receiving sunlight both directly as well as reflected by the clouds.
During the night I think it matters in 2 ways.
1. There is no sunlight, and yet the clouds keep on reflecting the GHG emissions. So it seems to me that wherever there are clouds, high altitude GHGs cool down more quickly at night.
2. Seems to me the same clouds would reflect GHG emissions from underneath too, but that prevents them from getting lost in space, so it can be re-absorbed by these low altitude GHGs. So it seems to me that wherever there are clouds, low altitude GHGs have trouble cooling down. Now, if high altitude air is cooling down at a faster rate than low altitude, what happens? Well, you get cold air above warm air. Then what happens? Convection.
With convection happening, you can now imagine warmer GHGs ascending above the clouds, where they can cool more quickly (point 1 above). But while this is happening, there are cooler GHGs descending below the clouds. Well, since they are GHGs, they can absorb the glowing warmth of the planet down here, collecting it. Since they are below the clouds, they have trouble getting it back out to space by emission. But this makes convection ever the more eager to raise them above the clouds again.
So let me summarize what I expect from reflection of clouds + GHGs:
Day:
– warming above
– shading below
– upper warm air opposes convection, trapping heat above
Night:
– cooling above
– retaining warmth below
– upper cool air aids convection, transporting heat from below
How much does this matter? I don’t know. So then my question to the scientists is: how well do clouds reflect the spectrum emitted by GHGs?

Michael J. Dunn says:
August 6, 2010 at 12:48 pm
Experimental proof, anyone? The predicted tropospheric “hot spot” does not exist. As Tom has pointed out, it cannot exist. This is a key falsification of the “global warming” theory.
=======================================================
Most excellent Michael, thank you for taking the time.
I’m tired of this “CO2 warming” business.
CO2 doesn’t warm anything, it insulates.

ShrNfr says:
August 6, 2010 at 11:52 am
The last time I saw a first derivative of temperature with respect to CO2 concentration from a source I could respect, it was of the order of 0.00125 to 0.00250 degrees C per ppm of CO2…. Do you have the source handy?
…. The earth is not a greenhouse. There are no glass plates on the roof. Sometimes it takes that other greenhouse gas up with it and makes these funny things called clouds which make your “window” pretty darn reflecting instead of transparent. (Hint, that is why deserts are hot by and large).
________________________________________________
Actually thanks to the lack of H2O deserts are very hot during the day and very cold at night. It would be a great place to check the average temperature and then compare it to the average temperature of a humid area at the exact same latitude.
It would also be a great place to do some CO2 experiments similar to the open field “CO2 fertilization” experiments to see if a large increase in CO2 causes an actual change in temperature.

Can comment only briefly, so apologies.
Crazydung: Thanx and a Hatlo Hat Tip to Tom Vonk.
Jeff: Think of the “absorptive” medium as a “re-radiant” medium. Yes, the laser cavity will get warm, because it is solid material. The gaseous medium will care less, because it is shedding photons as fast as it is picking them up. (Good old spontaneous emission and the Einstein A and B coefficients. Takes me back to grad school!) Or, think of it as a Roaring 20s mirrored ball: redistributing all the energy over 4 pi steradians, but not retaining any. (This is the basis for an even longer discussion, but gas lasers earn their keep by creating flows that are in severe disequilibrium and things are happening so fast that the processes are called “rate chemistry.” In fact, a laser’s inversion state is characterized by a negative temperature. Strange but true.)
Pamela Gray: The molecular weight of CO2 does not matter. Molecular diffusion in the atmosphere is so pervasive and effective that the atmosphere is essentially homogeneous to the upper stratosphere (where ozone production starts to mess with this picture). Parcels of air rise when they are heated by the ground (or ocean). Sometimes the buoyancy is influenced by the addition of water vapor, which is lighter than air. (It is the buoyancy of water vapor that holds clouds up; all the water droplets are actually heavier than air. The droplets maintain an equilibrium with the water vapor and are held up as an aerosol.) Air is best considered as 4/5 nitrogen and 1/5 oxygen, with seasoning in the form of argon, CO2, H2O, and trace gases. Excepting water vapor, the trace gases have no effect on air’s thermodynamic properties or behavior.
Khunkat: I think I have to defend Jeff’s graph. Yes, if the Earth were situated at the surface of the Sun, the Sun’s radiance would outstrip Earth’s all across the spectrum…which is the result that you get when you apply the Stefan-Boltzmann equation right out of the parking lot. But the Earth is 93 million miles away, which attenuates the radiance, so that the portion of the solar spectrum in the far infrared is much lower than the right-in-our-faces Earth emission spectrum.
There’s a lot of physics out there. All of it on the side of truth.

Jeff,
The only place I would have any disagreement with you is in the numbers. I have the same set of atmospheric absorption spectra you have; but I don’t know definitively whether they are calculated or measured; but not too important.
Some people have criticised the incoming and outgoing BB spectra arguing the vertical scales are wrong (including me).
Of course the direct solar BB spectrum is orders of magnitude higher than depicted; BUT that spectrum is attenuated by the inverse square law down to the extra=terrestrial TSI of 1366 W/m^2 or to a somewhat distorted (AM = 1) ground level spectrum at about 1000 W/m^2 .
Your 255 K earth emission source would give only 240 W/m^2, and one would then claim that the 1kW/m^2 only falls on 1/4 of the surface while the 240 is emitted from the entire surface.
I would disagree the 1000 W/m^2 certainly only falls on a portion of the surface; but the effect of that on that portion of the surface is quite different from having 250 W/m^2 fall on the entire surface.
And the 255 K is way too low to correctly represent the outgoing. Even at the mean surface temperature which is allegedly 288 K the outgoing would be 390 W/m^2; but in reality significant amounts of the surface are a lot hotter than 15 deg C so they radiate a more intense and shorter wavelength spectrum than your 255 K source which would peak at 11.4 versus 10.1 for the 288 K source or as low as 8.7 for a hot 60 deg C desert surface; which will emit 1.8 times what a 288 K source emits.
These are small differences I know; but I don’t think they should be ignored because the match between the actual GHG absorption spectra; and the real surface radiation emission spectra is critical for calculating the correct amounts of energy intercepted by GHG.
But I am quite in agreement with your end conclusion that it is all moot because I believe that cloud feedback is ALWAYS negative and highly so as is hinted at in Wentz et al; “How Much more rain Will Globalk Warming Bring ?” SCIENCE for July 7 2007.
Rmember when we talk about cloud feedback what we mean is something like:- If average global cloud cover increases from its present value by say 1% for the next 30 years (climate time scale) will that heat or cool the earth; and the answer is unquestionably it will cool the earth. Wnetz et al results hint that cloud cover; at least the precipitable component of cloud cover in terms of area, optical density, and persistence time should increase by about 7% for a one deg C increase in average global surface temperature; since their measurments show that Global evaporation, total atmospheric moisture and global precipitation ALL do increase by 7% per deg C Temperature rise; and I don’t know about you; but I like to have clouds with my precipitation; I’m kinda funny that way.
So I think the negative cloud feedback is huge, and totally swamps any effect that CO2 or any other GHG could have.
ONLY water (H2O) exists in the atmosphere in all three ordinary phases of matter; and it is the physical and chemical and other properties of water that totally regulate the range of temperatures on earth to the extent that even solar fluctuations get washed out by cloud modulation over the long haul.
I’d like to see the incoming solar spectrum curve at a 4x amplitude relative to the outgoing since the day time surface temperatures reached would never be reached with only 1/4 of the insolation.
On average, absolutely nothing ever happens. Mother Gaia does not do statistical mathematics; she works in real time.

George E. Smith said:
“ONLY water (H2O) exists in the atmosphere in all three ordinary phases of matter; and it is the physical and chemical and other properties of water that totally regulate the range of temperatures on earth to the extent that even solar fluctuations get washed out by cloud modulation over the long haul.”
Thanks, George. That would support my contention that the regulatory mechanism is the speed of the hydrological cycle.

@pamela:
Does it rise all by itself? YES. It’s called gas diffusion. Denser gases will only stay at the bottom of a volume for a limited time, until they diffuse.
@Jeff, nice simple explanation but …
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If feedback is high and positive as the models predict, then …
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AFAIK the models ASSUME high positive feedback, they do not predict it.
“climate sensitivity” is purely a fiddle factor to make make naive models which do not attempt to take “internal variability” into account, do what they want them to do.
The trouble is “internal variability” means things like changes in ocean currents (PDO etc.) and changes in cloud formation.
Having removed nearly all that causes climate variation , they have to scale up the real CO2 effects, predicted by real physical models, and get a very bad fit to climate data.
“climate sensitivity” is an arbitrary , fictitious fiddle factor to make the simplistic model fit the outcome they assumed before starting the model.
They then rerun the model without the fictitious man made warming and it does not fit at all. This is presented as “proof” of the initial models validity.
http://www.metoffice.gov.uk/climatechange/guide/quick/doubts.html
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When natural factors alone are considered, computer models do not reproduce the climate warming we have observed. Only when man-made greenhouse gases are included do they accurately recreate what has happened in the real world.
>>
this is doubly misleading since the models do not “accurately recreate” anything.

Roy Clark says:
August 6, 2010 at 12:47 pm
There should be no doubt that the downward LWIR flux from both CO2 and H2O in the atmosphere exchanges LWIR flux with the surface and helps keep the surface warmer than it otherwise would be….
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Roy how about an article about this with explanations that can be understood by lay people. As others have mentioned Al Gore had great influence because he kept the message simple. We need to refute him with science, but science that the majority of people can understand.

Jeff Id said:
“For those who are discussing convective heat transfer, of course you are right that this happens but it is related to the magnitude of the warming effect rather than whether the effect exists.”
I don’t think that’s quite right because it doesn’t clearly define ‘warming’.
If extra downward IR from more CO2 causes more (or more accurately, earlier /accelerated ) evaporation then the surrounding environment cannot warm because evaporation is a net cooling effect.
Instead the additional latent heat in the evaporated water vapour makes the body of air containing that water vapour lighter so that it rises with an increase in convection but because all the extra energy is in latent form there need be no (possibly cannot be any) discernible temperature increase.
I think that resolves a lot of confusion. There is ‘warming’ of a sort but only by way of more energy in the air in the form of latent heat in water vapour. So you do not necessarily need higher temperatures to create faster convection.
I’m glad I just thought of that because it disposes a problem I’ve had for some time with warmists who say there must be some warming from extra downward IR over water.
Clearly not so, simply because water vapour is lighter than air and more water vapour in a given volume of air will provoke faster convection (and thus a faster hydrological cycle) with no discernible warming at all.

donald penman says:
August 6, 2010 at 1:01 pm
So the idea that co2 does not warm the atmosphere is to be dismissed with a thought experiment,I am open to the idea that co2 does warm the atmosphere but have not seen any proof yet….
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Donald go back to Tom Vonk’s recent post and read it very carefully. A photon packet of energy is absorbed by a CO2 molecule and an electron goes from the rest to the excited state. This does not change the velocity of the molecule unless it collides with another molecule and the energy is translated into velocity. velocity = heat.
The second part is for every excited CO2 molecule that collides with another molecule and increases its velocity, there is an equal number of “high speed” molecules colliding with CO2 and bumping the electron into an excited state.
The net effect is essentially zero AT LOCAL EQUILIBRIUM.
Tom’s post: http://wattsupwiththat.com/2010/08/05/co2-heats-the-atmosphere-a-counter-view/

I have no issue with moderate GH warming, but would like to put up another thought experiment. (This could be tested in practice.)
I have a long tube full of CO2 (looking like a telescope). It has a transparent window at one end and the other end (the closed end) is a solid black surface. The sides are well insulated so it can only receive and radiate through the window.
I launch the tube to a position above our atmosphere and point it into to the sun. This raises the temperature of the black surface at the closed end.
I have an identical tube, except that it is empty (or filled with a non-GHG). I launch this and place it alongside the first tube, pointing into the sun. The temperature of its black surface also rises.
The physics discussed on this thread suggest the closed end of the first tube will rise to a higher temperature compared to the second tube. So I use this “potential difference” to drive an engine: the closed end of the tube full of CO2 is the hot reservoir and (purely for for demonstration) the closed end of the second as the engine heat sink. Both pointing directly into the sun.
The engine would appear to violate a thermodynamic concept that we cannot expect a practical engine to operate if the sun is the ultimate heat source and heat sink.
However, the CO2 has introduced a frequency shift between the incoming radiation and the outgoing radiation. We could call this machine a “thermal diode”?
Question for the physicists: does this engine do any useful work?

Many thanks to Jeff for a nice, easy-to-understand-for-laypeople piece! The inappropriately-named GH-effect does of course exist – but so of course do a zillion other influencing factors, which collectively surely must add up to a self-regulating climate in the long term. Or else the earth would not have survived this long without melting. This layperson is more worried about corrupt governments (is there any other kind?) than anything nature can throw at us – as devastating as nature can be.

Alexander K says:
August 6, 2010 at 1:16 pm
Gail Combs says ‘don’t you believe that stuff (about a good education), Alexander.
Sorry Gail, but I meant a non-dumbed down education…
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On that we certainly agree. My Hubby’s Grandfather came over from Europe, did not speaking any English, had a 6th grade education and still read his way through the entire public library… There is Education and then there is “education”

“”” kuhnkat says:
August 6, 2010 at 1:27 pm
Jeff Id,
You ignore the FACT that the incoming IR from 1-4 microns is much larger than the outgoing through the earth’s complete power range among other things. It is really hard to compute RTE’s when you ignore large segments of the flux and concentrate on one area.
The graph you show has the sun’s output scaled to under 10 -6. Even Science of doom only used a graph at 10 -6 for the sun to get it on the same graph. Naughty naughty. “””
Well I don’t think Jeff really ignored anything. 98% of the solar energy is contained between about 250 nm and 4.0 microns, with only 1% beyond each end of that range; actually less than that at the UV end But water vapor intercepts a considerable amount of that 1-4 micron incoming, in fact H2O starst at around 750-60 nm or so. CO2 on the other hand hardly kicks in to the 4 micron band and as I have said there is less than 1% of the solar energy beyond that.
But you have to take into account the inverse square law attenuation of the Sun’s st3efan-Boltzmann like emission to arrive at the 1366 W/m^2 TSI at earth’s orbit.

“”” Stephen Wilde says:
August 6, 2010 at 3:05 pm
George E. Smith said:
“ONLY water (H2O) exists in the atmosphere in all three ordinary phases of matter; and it is the physical and chemical and other properties of water that totally regulate the range of temperatures on earth to the extent that even solar fluctuations get washed out by cloud modulation over the long haul.”
Thanks, George. That would support my contention that the regulatory mechanism is the speed of the hydrological cycle. “””
I’m not up on your contention; and don’t know quite what you mean by “the speed of the hydrological cycle”
From my point of view it is a quasi static situation with some average amount/density and persistence of cloud cover globally. If the CO2 content of the atmosphere is raised; which would tentd to raise atmospheric temepratures and surface temepratures; that simply leads to more evaporation on a persistent basis; which leads to more clouds in order to get more precipitation and that means more clouds which swamp the effect of the CO2.
Likewise cosmic rays or volcanic dust or arosols which enhance cloud formation simply allow more cloud cover at lower temepratures, so the temperature falls.
All one has to do is do the two mental experiments I have proposed which I call the “Birdseye” experiment after the inventor of quickfrozen foods; and the “Venus Experiment which is its opposite.
In the former one simply cools the entire atmosphere and surface down to zero deg C; unless it is already colder, and then removes the remainder of the atmospheric H2O down to the last molecule, and drop them all on the surface in whatever phase was originally there.
Now Peter Humbug says he already did this on his Playstation except he apparently didn’t drop the temperature to help get rid of the water; he just excommunicated it all; and in his experiment he says he got it all back in three months. I prefer to drop the Temperature to zero but do not freeze the oceans (they don’t freeze at zero anyway).
Absent water vapor in the atmosphere, and hence no clouds, the earth albedo is vastly reduced, and the ground level insolation soars in the mother of all forcings.
Evaporation begins on a massive scale, and the earth returns to some stable state where cloud cover balances against further warming.
IN the Venus experiment we heat the atmosphere and surface to something very high maybe +60 deg C, and we install clouds from ground to say +20 km all over the earth from pole to pole; again without melting all the ice that exists.
Now the ground level insolation is virtually zero so precipitationa nd cooling will begin on a massive scale; and it will rain I am sure for 40 days and 40 nights, until eventually some sunlight will make it to the ground and start to warm the place up again till you reach some new stable temperature where cloud cover balances the situation.
I’m not aware of any Physics that would cause the condition reached fromt he Birdseye experiment to be different from that reached after the Venus experiment. In short; there can be no tipping point that leads to thermal runaway.
Now all that presupposes that earth’s orbit does not shift enough to kick in a new ice age.
Carl Sagan went to his grave having never detected so much as one single digit (bit) of scientific data evidence of some extra-terrestrial intelligence; what a waste.
I wouldn’t want to go to mine having wasted my life stepping into and out of cloud shadows, to try and find a cloud shadow that warmed me up instead of cooling me down.
And I wouldn’t grant so much as a brass razoo to any researcher to try the same study.

Spector says:
August 6, 2010 at 1:50 pm
RE: Gail Combs says: (August 6, 2010 at 1:05 pm) “The photon absorbed and the photon emitted should be exactly the same energy value.”
That only applies if there is absolutely no change in the energy of the entity that absorbed the photon in the first place. If you get $20 and it is stolen, then you cannot spend it. If the robber only takes $10, then you might be able to spend the other $10.
In the molecular world, the robbery may take place as a collision between two molecules. Such a collision may also result in the donation of energy.
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I guess I was not clear. I thought that is what I said.
case# 1. Photon excites CO2, CO2 emits photon of same wavelength and returns to rest state.
case# 2. Photon excites CO2, CO2 collides with another molecule of air and returns to the rest state. The 2nd molecule absorbs the energy in any of a variety of ways including and increase in velocity (increase in kinetic energy) or heat.
However I was under the impression the excitation and emission energy for a specific molecule, and for a specific type of energy (rotational or what not) had to be in discrete “packets” that conform to the wavelengths shown in figure #2.

Great post, Jeff. Just one weak point at the end: that the uncertainty over feedbacks “makes true and high quality results from Anthony’s surfacestations project so critically important”. The problem is that it is extremely hard to know where all the heat goes, so the time taken to reach equilibrium is also unknown. If e.g. there is more mixing with deep ocean than expected then the observed warming at the surface will be at a lower rate but persist much longer. To observe the actual warming with any confidence will take several times the density of metering that we have today, and fifteen or twenty years of data from them. If the alarmists are even half right, that’s time we don’t have. So, much as we distrust them, we are reduced to depending on models and basing policy on risk minimisation. Meanwhile, we do know that there was significant surface warming over the 20th century as a whole. Yes, there are several candidate explanations, but none of them can claim to be more convincing than the known rise in CO2.

Pamela Gray says: “…“Read Naturally” [is] often touted as a computer based reading fluency intervention but is at the top of my bad list. It is a whole language holdover that needs to be entirely removed from our schools, burned till nothing is left but ashes, and the authors tarred and feathered.”
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jorgekafkazar says:
August 6, 2010 at 3:24 pm
Yes, one of my pet peeves. Another tragedy is that the “look-say” method of reading instruction has been paralleled by the “think-say” practise of speech, in which every single thought of the individual is immediately expressed, whether it has any merit or not.
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I got stuck with that “look-say” method of reading. UGH I do have a very high reading speed but I can not pronounce or spell words correctly, I can not read out loud and I also have a problem connecting the idea to the spoken word in conversation. I got some phonetics from my parents at home thank goodness, otherwise I would have had a much harder time of it in school.
It also screwed me up completely with trying to learn a language. Especially when I got stuck in a “total immersion” experimental French class with no text books and no English spoken. I learn through sight not hearing so it was a complete disaster (my only F)

Jeff Id,
With all due respect, your post did not address the same topic as Tom Vonk but was titled “A reply to Vonk . . . “.
WUWT?
John

Stephen Wilde says:
August 6, 2010 at 3:35 pm
Stephen,
I Really liked your hot water bottle post. The atmosphere just transports heat. The oceans are the repository.

Ok, that’s a nice example showing that a CONFINED volume of a gas will selectively absorb and then remit specific wavelengths of light. While a bit fancier than the plastic soda bottle filled with CO2 in front of a light bulb it does not show anything new. Yes indeed gases can selectively absorb certain wavelengths of light, then the gas warms, then the gas emits energy at the same wavelength in all directions, then in a final and very important step, the gas cools by an amount equal to the energy reemitted.
Some more salient observations are;
No point on the surface of the Sun, on the surface of the Earth, or in the gaseous atmosphere of the Earth ever reaches an “equilibrium” temperature. As any point reaches a new higher temperature it immediately starts to cool faster. If this faster cooling is not overwhelmed by another larger warming force it will cause the temperature of that location to start to drop.
As the Sun illuminates the Earth’s surface (with mostly visible light) the surface “races” to catch up to the new “equilibrium” temperature. However, due to the thermal capacities and thermal conductivities (combined they determine the speed of heat) in the materials involved the surface never reaches the “equilibrium” temperature predicted by Kirchhoff’s Law.
As the Earth’s surface “races” to catch up to the new higher “equilibrium” temperature the gases in the atmosphere are also “racing” to catch up to the new higher “equilibrium” temperature at their location.
After the Sun sets the Earth’s surface temperature now switches direction and begins “racing” towards the new lower “equilibrium” temperature, likewise for the gases in the atmosphere.
The whole idea of an “equilibrium” temperature is very useful for a Pizza oven with a thermostat, but it is useless in understanding a system that consists of many different materials each of which respond differently to energy inputs. The only common denominator is that as each material warms it will respond by cooling faster. Some materials (i.e. seawater) radiate across a very broad spectrum, but mostly in one direction. Other materials (i.e. “greenhouse” gases) absorb and radiate selective wavelengths in all directions. Still other materials (i.e.”non-greenhouse” gases) exchange energy with any nearby material mostly via conduction and convection.
The only important question is;
Does the substitution of very small quantities (tens of parts per million) of “non-greenhouse” gases with “greenhouse” gases change the speed at which the temperature at any location “races” to meet up with its new ”equilibrium” temperature ?
My postulated answer is;
The replacement of “non-greenhouse” gases with “greenhouse” gases actually works to increase the SPEED OF HEAT through the atmosphere since more heat/energy travels at the speed of light (i.e. Infrared Radiation) versus at the Speed of Heat (much slower). The result of this is that each location more closely approaches its “equilibrium” temperature during each “Sunlight” .vs. “Sans Sunlight” cycle (i.e. Each Day). This does not cause any permanent increase in the “average” surface temperature of the Earth.
Now you might argue that this causes higher daytime and lower nighttime temperatures, but I think if you do some simple calculations you will find that this effect is so small that we probably could not spend enough money to measure it. For example, calculate the thermal capacity in Joules per cubic meter of sea water and compare it to the thermal capacity in Joules per cubic meter of the atmosphere when it contains 4% water vapor. Or for another analogy, try docking the Queen Mary using a couple of Radio Controlled Hobby Boats, yes, in theory it can be possibly be accomplished, but I don’t want to be around to see the attempts……….
In summary, I do not deny that some gases in the atmosphere selectively absorb and reemit energy (in the form of infrared light) backwards towards the Earth’s surface. I do deny that this can in any conceivable way cause the Earth’s surface to assume a new higher “equilibrium” temperature.
Cheers, Kevin.

Again, I will repeat, co2 does not cause warming in earth’s atmosphere because of it’s effects on H2O. Roy Spencer’s work shows a negative feedback from H2O. Yes co2 does have warming effects on its own and it would stay a warming effect if not for far more powerful forces at work in the atmosphere that keep co2’s effects easily in check. H2O comprises 95% of GHG’s. It is the largest factor in GHG’s and it is the factor that should be getting the most attention in studies.
My oh my how we’ve fretted over CO2 for far too long.

The complexity of Jeff’s post, obscures a simple reality. Realize that the radiation which is reflected in the 15 nm range is very close to constant. Certainly increasing or decreasing the amount of CO2 in the atmosphere does nothing to increase the amount of 15 nm radiation being reflected from the earth. The real issue is, how much does incremental CO2 increase the greenhouse gas effect. Dr. Heinz Hug has done experiments which indicate that doubling CO2 to 700 PPM, would likely result in increasing the temp. or the earth by only a measly .015 deg C.
http://www.john-daly.com/artifact.htm
I thought exercise which can be used to understand why this true might be helpful. Picture a sunny room on a bright day. Now attempt to completely darken the room by adding layers of shades. The first shade leaves only 30% of the incoming light, the next shade leaves only 30% of the light passing through shade 1, which leaves only 9% of the original light level. The next shade leaves 2.7%, shade four leaves .81% etc.. by shade seven, it is nearly pitch black since only .022% of the original light now enters the room. Adding more shades will simply not make much difference to the brightness of the room since it is already 99.98% dark after shade seven. This is the similar to what happens when CO2 is added to the atmosphere since most of the 15 nm range of IR energy available to CO2 is absorbed by the first 300 ppm of CO2. Raising CO2 from .03% to say .07% of the atmosphere will simply have no real impact on global warming. Vegetation however, would flourish.

Derek B says:
August 6, 2010 at 5:07 pm
…So, much as we distrust them, we are reduced to depending on models and basing policy on risk minimisation. Meanwhile, we do know that there was significant surface warming over the 20th century as a whole. Yes, there are several candidate explanations, but none of them can claim to be more convincing than the known rise in CO2.
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You left out the other side of the risk equation: The climate gets a lot colder from natural causes. Funny how everyone always over looks that part of the risk equation.
Woods Hole Oceanographic Institution states:
…It ignores recent and rapidly advancing evidence that Earth’s climate repeatedly has shifted abruptly and dramatically in the past, and is capable of doing so in the future… Fossil evidence clearly demonstrates that Earth vs climate can shift gears within a decade… Thus, world leaders may be planning for climate scenarios of global warming that are opposite to what might actually occur…
Peer-reviewed papers:
Lesson from the past: present insolation minimum holds potential for glacial inception (Science speak for we have the correct conditions for an Ice Age)
Solar energy reached a summer maximum (9% higher than at present) ca 11 ka ago and has been decreasing since then, primarily in response to the precession of the equinoxes. The extra energy elevated early Holocene summer temperatures throughout the Arctic 1-3° C above 20th century averages….
So what if, as these papers show, the only thing PREVENTING a return to full blown Ice Ages conditions is mankind’s increasing CO2????
During the 20th century the sun has been very active according to this paper and NASA However in the 21st century this is no longer true according to the Solar Dynamics Observatory Mission News
This shows how temperatures in Greenland have gradually fallen during the Holocene (present on right) http://jonova.s3.amazonaws.com/graphs/lappi/gisp-last-10000-new.png
This shows how temperatures have fallen during the Holocene in the Antarctic -10,000 yrs of Vostock Ice Core data (present on right)
http://2.bp.blogspot.com/_cHhMa7ARDDg/SsVwd55PJ8I/AAAAAAAABKY/52SrhXN4C3c/s1600-h/Vostok-10Kd.jpg
And finally the real kicker, the Vostock Ice Core shows we are at the end of the Holocene time wise. The sharp pointy upspikes are the interglacials everything else is ice cube city. You will note we have had a long run compared to most of the rest of the interglacials. (present on the left)
http://cdiac.ornl.gov/trends/temp/vostok/graphics/tempplot5.gif
Don’t you think this evidence should also be considered before any decisions are made to eviscerate our present technological society? I think rapid conversion to nuclear power is the best solution for both risks, not wimpy solar and wind power.

George Steiner says:
August 6, 2010 at 5:31 pm
If a CO2 molecule encounters a photon at 15 nm then immediately emits a photon at 15 nm, did the CO2 molecule beacame warmer? Became colder? Became neither warmer nor colder?
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I know the answer to that one!
It became warmer, warmed adjacent N2 molecules, radiated back to Earth and sent what was left to the sun.

Interesting. But empirically, addition of carbon dioxide to the atmosphere simply does not change the transmittance of the atmosphere in the infrared as Ferenc Miskolczi has shown. He used NOAA weather balloon database to show that the global average annual infrared optical density of the atmosphere has not changed for 61 years and has the value of 1.87. This means that constant addition of CO2 to the atmosphere for the last 61 years has had no effect on how much infrared radiation the atmosphere absorbs. Where does this fit in with your theory?

RACookPE1978 says:
August 6, 2010 at 7:35 pm
“However, this graph also shows that O2 and O3 at 209460 ppm (537 times the amount of CO2!) have a combined absorbtion peak in the same range of outgoing radiated energy (between 9.8 and 10 microns).”
This would be entirely O3, which is of order 1-10 ppm in the stratosphere. It is quite an effective GHG too. As mentioned elsewhere O2 contributes almost nothing at these wavelengths.

So, the science isn’t really settled? Gosh, this earth is a complicated place. 😉

Part 2

Congratulations Jeff probably one of the best posts on the physics involving the interaction between CO2 and outgoing LW radiation and it clearly shows the competition between water vapour and CO2 in the 15um wavelength range. But since the outgoing LW radiation energy is all absorbed the heating effect on the atmosphere is the same irrespective of which molecule absorbs the energy.
The IPCC do however repeatedly talk about the reradiated energy which finds its way back to the surface and thus increases the radiation absorbed by the earth.
Your post does not cover this claim by the IPCC and I realize one can not cover all the bases in one post so this is not a criticism.
In actual fact the absorption of IR by a molecule if looked at in detail is considerably greater at the actual spectral line frequencies and decreases at the frequencies on either side of the spectral line, thus you have a mini Planck curve around each spectral line. There are many spectral lines in the absorption zones shown in your diagram and as the concentration of the gas increases the Planck curve gets wider which is known as line broadening. It is this line broadening effect which forms the theoretical basis for the IPCC formula relating CO2 increase with increased temperatures I believe the forcing factor due to increased water vapour is strictly empirical. However at the current levels the Planck curves all overlap so the line broadening effect has no impact.
With regard to the reradiation back to earth the CO2 molecule will only reradiate energy which is exactly at the spectral lines so although the intermediate wavelengths travel further vertically since their absorption rate is less the resonant frequencies travel a much shorter distance downwards before they are absorbed. Thus a minuscule amount of reradiated energy gets back to earth and the concentration of CO2, once the mini Planck curves have overlapped, has no effect on the energy absorbed and therefore temperatures.

At first I thought this was a straightforward post. Michael Dunn has me thinking about this a bit more. I think I’ll want to read Tom’s post before commenting further.
George Smith, I thought that I should argue a point with you regarding intensity of incoming solar radiation:
“I disagree with those who want to divide this number by 4 after applying some albedo reduction to get some puny 240 W/m^2 all over the earth surface.”
It seems to me that the divide by 4 is straightforward. Solar radiation is averaged over the surface of the earth (area 4 pi radius^2). Projection of solar radiation onto earth is (pi radius^2) (ie. this is the area of space that Earth blocks the solar radiation). So I think that you need to divide by 4.

As much as I dislike aggressive and ignorant AGW climatards, I hate when the opposite side makes authoritative but wrong or half-accurate statements. Let’s see:
“What you need to understand about Tom Vonk’s post is that he was explaining that the atmosphere does not warm by any radiative absorption process. (And it doesn’t.”
Oh yes it does. What we need to understand that the term “warm” is usually consonant with “up” (and “cool” with “down”), which emphasizes some directional process. Therefore, if we start with a cool gas mixture and begin to shine the 15um laser, the mixture will warm up. Period. Obviously, when/if the system reaches a STATIONARY STATE, it stops warming up, and stays flat. Only then we can say that radiation does not warm it, which is kind of trivial. Even then we need to understand that Tom Vonk is wrong, he does not realize that LTE is not an absolute equilibrium, but is only a first-order approximation of mechanics of continuous medium at a mesosciopic level.
In second approximation, the media allows for temperature gradients, macroscopic motions, eddies, and diffusion transport. That’s exactly what happens with radiation in highly absorbing bands, where the media is “optically thick”. For this reason the propagation of radiation in this opaque media mathematically resembles diffusion, and is called “diffusion approximation”, or Rosseland approximation.
Therefore, it takes time to interact with temperature fluctuations of the size of mean free path of photons. Therefore, the other statements as
“So, temperature equilibrium is almost instantly established” and “Radiative equilibrium is established throughout the atmosphere faster than the air can gain temperature”
are highly inaccurate bunk, it is valid only for nearly transparent (“optically thin”) bands.
“And the air is worthless as a heat sink”.
Not if it flows at a speed. Every computer uses moving air to “sink” the heat from CPU and other parts. As a matter of paradox, the _effective_ thermal conductivity of atmosphere is about 100 times better than copper.
Also, transition from Fig.6 to Fig.7 will take quite a measurable time due to finite rate of diffusion of radiation and finite thermal capacity of air inside, so it does take time to warm up before starting to emit 1000W through that small window. Of course, the term “instantaneous” is quite stretchable…
More, the radiation from Jeff’s chamber might be pretty close to black body, because the can itself looks like a deep cavity, and inner surface of the cavity will experience multiple reflections, will warm up, and will emit close to black body. Hollow cavity is a standard model for blackbodies in physics.
It is also interesting that even with plain air at 375ppm of CO2 and the chamber length of 10cm, the chamber will have to absorb about 350W. Assuming the window area of 10cm2, it is equivalent to 350 kiloWatts/m2, such that the air (and chamber walls) will heat up to about 1500K before reaching a stationary state. Pretty stiff, is not it?
Cheers,
– Al

Hmmm… interesting article… how does Ferenc Miskolczi’s Saturated Greenhouse Effect Theory fit into this?
Ferenc Miskolczi’s Saturated Greenhouse Effect Theory: C02 Cannot Cause Any More “Global Warming”
http://pathstoknowledge.net/2010/01/13/ferenc-miskolczi%E2%80%99s-saturated-greenhouse-effect-theory-c02-cannot-cause-any-more-global-warming
It would really be great to have Ferenc Miskolczi or one of his collegues address the issues and points raised by Tom Vonk and Jeff Id.

My post doesn’t seem to have registered so here it is again. Mods please delete one if it comes up twice.
Bob Tisdale:
Some of these links may help you.
http://search.orange.co.uk/all?q=jet+stream+shifts+1970+to+2000&brand=ouk&tab=web&p=searchbox&pt=todayweb_hp4&home=false&x=21&y=15

I have read it but has he actually done the experiment? No! It was a thought experiment. There is one glaring error in that you cannot get a perfect insulator. An insulator will delay heat flow but will not stop it. ie. the 2nd law of thermodynamice holds true. What happens when something heat up quickly, ie it has a low specipic heat so requires less heat to raise its temperature through 1 degreeK than an object that heats slowly. This is easy to check- get two saucepans with the same weight of 1-water and 2 cooking oil and heat on the stove, check the time to raise the temperature from ambient to, say, 50C. The oil will take the shorter time. Now check cooling time and the oil will cool faster. This second part is important because it is a good example of the 2nd law- entropy must increase. The temperature must equal out so heat can only flow from hot to cold.
The atmosphere, containing some CO2 is heated by incoming solar radiation, the CO2 directly and the other air molecules by conduction/radiation from the CO2 and conduction with the ground and long wave radiation from the ground. Warm air rises and will cool adiabatically as it rises. So where is the back radiation commimg from? Not from the rising air because this is now cooler than the surface. We have established that hot to cold is OK but not the reverse.
This has been the problem with the Greenhouse Theory and the lost heat which Mann described as a travesty that it could not be found. The models, which believe the Greenhouse Theory and are embedded with it, show a warm lower troposphere which does the reradiation back to the surface but measurement by radiosonde or dropsonde cannot find it. If you cannot measure a temperature difference then that temperature difference is not there and the reradiation cannot take place.
In the atmosphere the rising air, though cooler than the surface, is still warmer than that above so it will radiate to the cooler zones. Cloud, which plays a vital part in temperature control in the atmosphere, is another story and one that we have yet to master and one that is not covered by any models which is one reason why they are always wrong.
Radiative adsorbtion and black body radiation is all very well but the theory of GHG’s must obey the two basic laws of thermodynamics. It does not.

I greatly appreciated the graphic showing the absorption spectra of various atmospheric gases as compared to the incoming and outgoing radiation. However there was no spectrum for methane. Here in New Zealand we are constantly told by warmists that we NZers have one of worst GHG emission rates per capita due to the levels of methane produced by our cows and sheep and because “methane absorbs 15x as much IR”.
This may be true, and if methane was a GHG in isolation might be important. But it seems to me that if methane’s absorption spectrum significantly overlaps those of the other gases, then then the argument about adding extra coats of paint on a window that is already largely opaque applies.
I have tried to search the web for a graph showing the absorption of methane compared to other gases; thus far I have come up with nothing. Has anybody seen a graph they can point me at.

Figure 2 seems to show that just about all the out-going radiation that CO2 can absorb is already being absorbed.

Sorry, I didn’t put that well.
The question is:
When IR is absorbed by CO2, what percentage of that IR is re-emitted as IR, what percentage is converted to vibrational & motion modes, and what percentage to other “pathways”.
Using my engineers rule of thumb, if the relative proportions of IR-IR to IR-‘heat’ is not greater than 100-1, (i.e. if more than 1% of events are converted to heat) then after 1000 absorption-re-emission events, the relative proportion of IR-quantised energy will be an order of magnitude less than that of motion energy (heat)

Thanks for your answer Kevin Kilty. You gave a detailed explanation, but I’d like to follow with some questions and clarifications.
The two tubes may be akin to blackbody cavities, where one is filled with CO2 (to some pressure) and the other with a transparent gas (or we can say it is empty). We can say that equilibrium can is achieved in each tube when the OLR at each window matches the incoming solar radiation.
Staying at the windows for a second, I assume that the tube full of CO2 has an emitting surface at the window, whereas the empty tube does not. I’m not sure whether that has any bearing on the matter.
So what do we expect to happen at the other end of the tubes according to GHG theories?
OLR emitted from the deep end of the empty tube gets free passage straight through the cavity and out the window. It can equilibriate in much the same way as the moon. Perhaps reaching a similar temperature to the surface of the moon in daylight.
This thread discusses CO2 as a resistive medium to OLR. The GHE effect appears to demand that equilibrium can only be achieved at the window of the tube full of CO2, if the temperature at its closed end is much higher. (We could almost decide what temperature we want by design of length of tube and maybe CO2 pressure?).
The argument of “OLR resistance” seems to suggest that the closed end of the tube full of CO2 could be sustained at higher temperature compared to temperature at its window. Certainly by radiative arguments – I’m not sure whether conduction will/could alter this.
Could we stick with a scenario where the sides are well insulated and conduction loss is negligible (incoming solar is quite powerful so we need not get too concerned if there is some leakage through the sides).
That leaves the question: when pointed into the sun, what are the temperatures at the closed ends of the tubes to radiate identical amounts of OLR at the windows?
If there is a significant temperature difference at the closed end of the tubes, we have potential to drive an engine and do work. Flow of heat through the engine helps the OLR to bypass the resistive medium in the tube full of CO2.
Why am I sceptical about this?

Derek B says: August 6, 2010 at 5:07 pm: “If the alarmists are even half right, that’s time we don’t have. So, much as we distrust them, we are reduced to depending on models and basing policy on risk minimisation. Meanwhile, we do know that there was significant surface warming over the 20th century as a whole. Yes, there are several candidate explanations, but none of them can claim to be more convincing than the known rise in CO2.”
I smell a troll! Still pushing the precautionary principle, Derek? We are only “reduced to depending on models” because the models have been so elevated to a level of respect that far exceeds their validity. Too many assumptions, too many unknowns, too many “what ifs,” too many ultra-wide error bars, too much cherry-picking. Just because the alarmists have been “reduced to depending on models” doesn’t mean the rest of us have to be.

“As it heats, emissions from the window increase in energy according to Planck’s blackbody equation. Eventually the system reaches a new equilibrium temperature where the output from our window is exactly equal to the input from our laser – 1000 watts. Equilibrium! – (Figure 7)”
questions, questions, always more questions:
What happens when the diameter of the chamber is increased ( keeping the 50% CO air mixture)? At what diameter will the laser beam “seen” on the out put side of the chamber? Or does (figure 7) the diameter of the chamber mater?
If you had “heat” sensor on the walls of the chamber would they always detect the same amount of “heat” on the walls as the diameter increased?
If the “heat” on the wall goes from X degrees to same degrees of “room” temperature on the outside of the walls wouldn’t indicate the 50% CO2 air mixture close to the walls not doing a lot of re radiation of “heat”?

Mr Id’s thought experiment is an assertion in drag. A bit like computer climate models.

The most fundamental underpinning of modern science is observation.
When there is uncertainty about the existance or non-existance of a phenomenon, scientists usually try to perform an experiment (i.e. fair test) or make an observation that will either refute or verify the existance of a phenomenon.
In the journal Energy and Environment Volume 21, Number 4 / August 2010
Dr. Ferenc M. Miskolczi has published an article:
“The stable stationary value of the earth’s global average atmospheric Planck-weighted greenhouse-gas optical thickness ”
http://multi-science.metapress.com/content/nm45w65nvnj3/?p=a52f8c4dc8a1411392c30af7d57b34f2&pi=1
which conclusively shows from observation that the mean infra-red opacity of the atmosphere has NOT SIGNIFICANTLY CHANGED over the last 61 years.
Hence, while it may be true that increasing levels of CO2 have increased the mean infra-red opacity of the atmosphere – it also true that some other infra-red absorber (most likley water vapor) has effectively counter-balanced the increase in opacity caused by CO2.
Any reasonable scientist who has read Dr. Ferenc M. Miskolczi’s paper would have no trouble dismissing CAGW on scientific grounds.

This is the important question:-
”
The question is:
When IR is absorbed by CO2, what percentage of that IR is re-emitted as IR, what percentage is converted to vibrational & motion modes, and what percentage to other “pathways”.
”
I read on another site that it has been calculated that it takes only about 0.4 second for an IR photon to leave the atmosphere from the surface. It is all the absorptions and re-emmissions by IRIG’s (Infra Red Interacting Gasses) that slow the IR photon down. At the speed of light, if you assume the atmosphere is 100miles thick, it should take only approx 0.0005376 of a second to leave the atmosphere.
All the IRIG’s do is scatter IR and warm the atmosphere a little. This scattered IR cannot warm the ground. See 2nd law.
The real greenhouse effect is due to the slowness of convection which is the main cooling mechanism.

Very few skeptics doubt that atmospheric CO2 is a source of warming. What they suggest is that, compared to other sources, its effect on Earth’s temperature is so minuscule as to be background noise. The insulating atmospheric effect (the term “greenhouse effect” is incorrect and misleading) created by water vapor is much more pronounced.
By the way, as Dr. Ference Miskolczi’s findings (which are routinely ignored) have shown, the total infrared optical thickness of the atmosphere, and its theoretical value is 1.87, has not changed, despite a 30 per cent increase in CO2 over the last 61 years.
(Says Miskolczi: “I performed these computations using observations from two large, publicly available datasets known as the TIGR2 and NOAA. The computations involved the processing of 300 radiosonde observations, using a state-of-the-art, line-by-line radiative transfer code. In both datasets, the global average infrared optical thickness turned out to be 1.87, agreeing with theoretical expectations.”)
His results “show an apparent warming associated with no apparent change in the absorption properties. Change in absorption properties cannot have been the cause of the warming.”
Please see:
http://www.examiner.com/x-32936-Seminole-County-Environmental-News-Examiner~y2010m2d12-Former-NASA-scientist-defends-theory-refuting-global-warming-doctrine
http://www.friendsofscience.org/assets/documents/E&E_21_4_2010_08-miskolczi.pdf

Radiation is not only governed by Plank theory, and it is very much dependent on View Factor, any body with radiative heat transfer course training, knows why the sun feels hot to earth at noon time than sunset time, the angle of sun radiation, or technically – View factor, is a key factor of radiative heat transfer
CO2, a 400 ppm quantity in the air – which means out of 100 gas molecule in the air, there is less than 0.04 molecule are CO2, so the effective radiation heat transfer due to such small View factor is questionable, need to be carefully calculated, no mention the physical parameter of absorptivity, emissivity of CO2 gas is highly temperature dependent, common knowledge is that it is significant of absoption at combustion temperature level, which is 3000 F range. atmosphere is far low temperature than combustion
by the way, the experiment of 50% CO2 in the can does not reflect the real air composition which only has 0.04% CO2 in volume. You have to compare apple to apple, right?

Jeff Id says:
At tAV, (comment 47) Pat Frank calculated the decay half life for radiative emission as 30 milliseconds, and the collision time between molecules at 10^-8 seconds – so almost none of the gas decays and re-emits (sorry to those who don’t like the word).
So basically, the IR given off by the warm earth is absorbed in around 10m (at peak absorption) and then the molecule doesn’t re-emit for around 30msecs, during which time it’s get banged 3million times which is far more than is necessary to convert the energy held by the excited electron into motion/heat energy.
Another interesting facet is that if the mean path of the IR is around 10m, then that IR energy takes around 30seconds to go through 10km of atmosphere. Or if we were to decide the really “thick” bit of the atmosphere was 30km, then within 100secs the IR will at a layer which has a relative “open window” into space.
Now, what is the effect of CO2 high in the atmosphere? It collides roughly every 10^-8 seconds, and in any one of those collisions, it can act as a vector to enable that heat energy to be lost via IR.
CO2 is a bit like sticking holes in a bag of dry, fine sand. The hole itself can be very small, but eventually (like a sand hour-glass), the conduit will allow the heat to escape.
So, one CO2 molecule in a vast array of gas can be like one small hole in a sand-bag, two – like two holes. Put enough CO2 in the atmosphere and you get a dramatic cooling effect.
PAUSE FOR REFLECTION
This is precisely the argument of the global warmers, but turned upside down. CO2 is a cooling gas, too much CO2 in the atmosphere will lead to catastrophic cooling of the atmosphere and “unless we all stop burning so much fossil fuel – it will inevitably lead to global cooling and we could see up to 6C warming, the sea level may fall making many ports unnavigable. The cooling temperatures would certainly lead to a rise of winter illnesses like flu (23,000 die in the UK each winter).
Global cooling by excessive CO2 is a real and imminent threat to national security and those who do not accept the simple truth of basic science that CO2 cools the atmosphere are clearly are in the pay of fossil fuel companies.
Moreover, the recent 21st century cooling clearly shows the CO2 induced global cooling effect is happening “faster than we had imagined” and …. etc.

It got too late to comment last night, but thank you everyone! There is a lot of great science in the comments above, too many names to mention. This is what makes WUWT the best site on the net.

RE: cal says: (August 7, 2010 at 8:21 am ) “The argument made by the Hadley centre is that an increase in CO2 increases the effective radiating altitude (as discussed above) and this implies a drop in temperature.”
I believe the argument they are making is that increased CO2 in the atmosphere will increase the depth of the CO2 ‘cloud’ around the planet in which CO2 photons cannot escape to outer-space. This, in *their* view, will necessarily force the tropopause to move a higher level to re-establish the previous radiative equilibrium and the natural adiabatic lapse rate will translate this increased altitude to higher temperatures on the ground.
However, if the level and temperature of the tropopause are now largely being determined by H2O, then I think there should be little change at all until we really add enough CO2 to the atmosphere to overwhelm the radiative significance of H2O.
I suspect that the temperature of the tropopause is determined primarily by the equilibrium established by the amount of incoming solar energy that can be absorbed primarily by H2O and CO2 at that altitude.

Stephen Wilde says:
Both the changes in the height of the tropopause and the changes in the latitudinal positions of the air circulation systems are direct evidence of a change in the speed of the hydrological cycle as I have said boringly often before.
Stephen, I was very interested in your assertion that the latitude of the air circulation systems may change. I agree with you that an increase in CO2 will lead to little change in surface temperature because the effect is to change the effectiveness of the convective cooling system. However, one possible outcome from that increased effectiveness is that we could potentially see a change in the structure of the Hadley cells (which I assume is the same as you said).
To put it so it is understandable: the sun heats the equators, causing air to rise, it then is forced out from the equator at high altitude until it looses enough heat (via infra-red emission into space) for that air mass to descend and repeat the cycle. In the process you get rising moist air over the equator and descending dry air over the Sahara, the Sahara being situated at a position where the air has been exposed to the IR window into space just long enough for the air to loose enough heat to start descending.
Similarly, over the poles, you get excess cooling. Air masses cool excessively forming a bulk of dense cold air which then spreads out from the poles. As it moves away from the poles it picks up heat until it rises (above the UK) – it then is sucked into the polar region by the cooling-descending air in that region.
The result is an area of high pressure at the sahara and low pressure over the UK, and we therefore get an intermidiate Hadley cell bringing air from the high pressure over the Sahara latitudes up to the UK latitudes. The result is the classic three Hadley cell (6 when you count the south hemisphere)
In theory, however, it is possible to have any number of Hadley cells. They are afterall only cooling convective currents and so long as there is an odd number in each hemisphere you will get the dominant rising air over the equator and descending air over the poles. (In theory you could get only one cell!). If however you change the rate of COOLING, so that the equatorial air mass looses heat quicker by some added vector (CO2), the result could be to shift the high pressure-dry zone of the Sahara further toward the equator. As each cell is really a convection cycle of heat-uplight-IR emission, the addition of CO2 would reduce the average time it takes for the air mass to cool, thereby tending to reduce the size of each convective cooling-cycle cell.
So, whilst CO2 is unlikely to have much effect on temperature, it could conceivably affect the number of Hadley cells. The result would be to move the Sahara Southward (and shrink it), to move the typical UK weather Northward (an area of continual weather fronts) around iceland. We would then see two further zones: one of typical dry climate with high pressure at the North of the Med, and another south of the med with continual weather fronts as hot southerly winds and colder northerly winds meet.
In reality, Hadley cells are not fixed, and more than likely at certain times, we already get a five Hadley cell structure to the atmosphere.

@winterkorn
‘The details are not important for understanding the simple existence of a greenhouse effect due to Earth having an atmosphere.’
But the details are of utmost import to understand why other planets, and some of their moons as well, in this same solar system also has warmed slightly just like earth the blue marble of the fried gaia.
And, personally, I’m getting pretty sure the other bodies around sol that has warmed slightly haven’t done so due to some thousands of a percentage increase of green house gases on earth. But of course, what if….

The abstract physics discussions about how insulators insulate (or not for those who somehow believe insulators don’t insulate) and quantum mechanical accounting for every particle and photon is interesting it must ultimately agree with the observations.
If we accept the temp record from 1880 to 2000 as reasonably accurate and break it into two 60 year intervals we find temperature rose 0.4c in each interval.
If we accept an anthropogenic CO2 driven increase of 75ppm during that time we find that it rose 25ppm in the first period and 50ppm in the second.
If we accept that CO2 acts as insulator and does raise surface temps but as with any other insulator it becomes exponentially less effective per unit of increase then everything makes sense and we can make some predictions for the next 120 years.
Let’s assume we don’t repent our wicked ways and continue doubling how much fossil fuel we burn every 60 years.
Years +CO2 +temp
1880-1940 +25ppm +0.4c
1940-2000 +50ppm +0.4c
2000-2060 +100ppm +0.4c
2060-2120 +200ppm +0.4c
As near as I can tell from the observations and by accepting the CO2 vs. temp correlations as causation (for the sake of argument) there will be a CO2 doubling to about 650ppm in 120 years and a 0.8c temperature rise because of it.
This is not inconsistent with IPCC projections. In fact it is their best case scenario and it happens to be right on the money for the ten years from 2000-2010 that we didn’t analyze above.
Now we must compare the upsides to the downsides.
If we examine all nations that underwent industrialization during this 1880-2000 period in history, compare their fossil fuel comsumption to gross domestic product, we find another correlation – growth in fossil fuel consumption goes hand in hand with economic growth.
Slowing economic growth is a huge downside but that’s what limiting fossil fuel consumption will do absent a comparably cost/effective alternative energy source.
As well, scientific and engineering advances are driven by growing wealth. If there’s less economic growth there will be less wealth available to fund research and development, including research and development of alternative energy sources.
There’s another big downside but it will happen if we strangle our growing energy needs.
A warmer earth with a higher CO2 content is a greener earth. This is just indisputable testimony from the geologic column. Personally I prefer green plants and animals to bare rock and ice so I consider this an upside to continued exponential increase in fossil fuel consumption.
We can expect sea level to rise about 12″ from thermal expansion. This is the only downside. 120 years to deal with it makes it seem almost insignificant.
So the CAGW crowd basically wants to throw civilization under the bus to stop a “problem” that’s actually a great benefit to both the biosphere and standard of living for each human member of it.
I suspect the CAGW crowd is suffering a mass “messiah complex”. They want to save the world and be recognized for it. But there’s a big problem for them if the world doesn’t need saving. Thus we get the climategate chucklemonkey writing in 2008 “We can’t explain the lack of warming since 1998 and it’s a travesty that we cannot”.
Actually the IPCC did explain it. It just happens to be their best case scenario where nothing scary happens – the world doesn’t need saving – in fact the world gets better by burning more fossil fuels.
So there. I feel much better now.

Continuing my conversation with myself….
Thinking about it more I’m thinking Tom may be right and Jeff (and I) might be wrong. Maybe additional concentrations of CO2 does not directly warm the surrounding air:
1) Presumably in actual atmosphere the air does not radiate like a blackbody because greenhouse gas concentrations are small (ie. If there were no greenhouse gases the atmosphere certainly would not radiate like a black body.)
2) The Energy Equipartition law suggests that statistically energy will be distributed evenly across the different kinetic modes available for a molecule. Air is a mixture of different molecules, and not all molecules have vibrational modes available to interact with radiation. Larger concentration of CO2 impacts the characteristics of the air mass as a whole since there is now larger proportion of available vibrational energy state relative to translational.
3) Therefore, an air mass with larger CO2 concentration and SAME equilibrium temperature would be expected to absorb and radiate a larger amount of radiation.
I’m sure someone can tell me if I’ve made errors in my logic above (ie. my interpretation of black-body/ energy equipartition law or otherwise). If not then it seems the argument I made earlier that the temperature of the air mass would have to increase in order to balance the change in absorbed radiation is wrong. Moreover, I don’t see why an injection of CO2 would result in a net transfer of energy from vibrational excitation to translational. Greater opportunity for vibrational to translational conversions would be equal to greater opportunity for translational to vibrational conversions.
Note: Even if Tom is correct, this does not mean that greenhouse gases have no warming effect on earth or atmosphere. The GHGs still warm the surface and warming of the surface results in atmosphere reaching higher equilibrium temperature. It’s just that higher absorption of radiation in atmosphere (due to higher CO2 concentration) does not DIRECTLY warm the surrounding air.