A reply to Vonk: Radiative Physics Simplified II

Radiative Physics Simplified II

A guest post by Jeff Id

Radiative physics of CO2 is a contentious issue at WUWT’s crowd but to someone like myself, this is not where the argument against AGW exists.  I’m going to take a crack at making the issue so simple, that I can actually convince someone in blogland.  This post is in reply to Tom Vonk’s recent post at WUWT which concluded that the radiative warming effect of CO2, doesn’t exist.  We already know that I won’t succeed with everyone but when skeptics of extremist warming get this wrong, it undermines the credibility of their otherwise good arguments.

My statement is – CO2 does create a warming effect in the lower atmosphere.

Before that makes you scream at the monitor, I’ve not said anything about the magnitude or danger or even measurability of the effect. I only assert that the effect is real, is provable, it’s basic physics and it does exist.

From Tom Vonk’s recent post, we have this image:

Figure 1

Short wavelength light energy from the sun comes in, is absorbed, and is re-emitted at far longer wavelengths.  Basic physics as determined by Planck, a very long time ago.  No argument here right!

Figure 2 below has several absorption curves.  On the vertical axis, 100 is high absorption.  The gas curves are verified from dozens of other links and the Planck curves are verified by my calcs here.  There shouldn’t be any disagreement here either – I hope.

Figure 2 – Absorption curves of various molecules in the atmosphere and Planck curve overlay.

What is nice about this plot though is that the unknown author has overlaid the Planck spectrums of both incoming and outgoing radiation on top of the absorption curves.  You can see by looking at the graph (or the sun) that most of the incoming curve passes through the atmosphere with little impediment.  The outgoing curve however is blocked – mostly by moisture in the air – with a little tiny sliver of CO2 (green curve) effective at absorption at about 15 micrometers wavelength (the black arrow tip on the right side is at about 15um wavelength).  From this figure we can see that CO2 has almost no absorption for incoming radiation (left curve), yet absorbs some outgoing radiation (right curve).  No disagreement with that either – I hope.   Tom Vonk’s recent post agrees with what I’ve written here.

Energy in from the Sun equals energy out from the Earth’s perspective — at least over extended time periods and without considering the relatively small amount of energy projecting from the earth’s core.  If you add CO2 to our air, this simple fact of equilibrium over extended time periods does not change.

So what causes the atmospheric warming?

Air temperature is a measure of the energy stored as kinetic velocity in the atoms and molecules of the atmosphere.  It’s the movement of the air!  Nothing fancy, just a lot of little tiny electrically charged balls bouncing off each other and against the various forces which hold them together.

Air temperature is an expression of the kinetic energy stored in the air.  Wiki has a couple of good videos at this link.

“Warming” is an increase in that kinetic energy.

So, to prove that CO2 causes warming for those who are unconvinced so far, I attempted a thought experiment yesterday morning on Tom Vonk’s thread.   Unfortunately, it didn’t gain much attention.  DeWitt Payne came up with a better example anyway which he left at tAV in the comments.  I’ve modified it for this post.

Figure 3- Experimental setup. A – gas can of air with all CO2 removed at ambient temp and standard pressure. B – gas can of air diluted by 50 percent CO2, also at ambient temp and standard pressure. C ultra insulated laser chamber with perfectly transparent end window and a tiny input window on the back to allow light in from the laser. Heat exit’s the single large window and cannot exit the sides of the chamber.

Figure 4 is a depiction of what happens when  C contains a vacuum.

Figure 4 – Laser passes straight through the chamber unimpeded and a full 1000 Watt beam exits our perfect window.

The example in Figure 5 is filling tank C with air from tank A air (zero CO2) at the equilibrium state.

Figure 5 – Equilibrium of hypothetical system filled with zero CO2 air from canister A.

Minor absorption of the main beam causes infrared absorption and re-emission from the gas reducing the main beam from the laser. This small amount of energy is re-emitted from the gas through the end window and scattered over a full 180 degree hemisphere.

What happens when we instantly replace the no-CO2 air in chamber C with the 50% CO2 air mixture in B?

Figure 6 – Air in C is replaced instantly with gas from reservoir B

From the perspective of 15 micrometer wavelength infrared laser, the CO2 filled air is black stuff.  The laser cannot penetrate it.  At the moment the gas is switched, the laser beam stops penetrating and the 1000 watts (or energy per time) is added to the gas.  At the moment of the switch, the gas still emits the same random energy as is shown in Figure 5 based on its ambient temperature, but the gas is now absorbing 1000 watts of laser light.

Since the beam cannot pass through, the CO2 gains vibrational energy which is then turned into translational energy and is passed back and forth between the other air molecules building greater and greater translational and vibrational velocities.  —- It heats up.

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)

Figure 7 – Equilibrium reached when gas inside chamber C heats up to a temperature sufficient to balance incoming light energy..

The delay time between the instant the air in C is switched from A type air to B air to the time when C warms to equilibrium temperature is sometimes stated as a trapping of energy in the atmosphere.

“CO2 traps part of the infrared radiation between ground and the upper part of the atmosphere”

So from a few simple concepts, two gasses at the same temp, one transparent the other black (at infrared wavelengths), we’ve demonstrated that different absorption gasses heat differently when exposed to an energy source.

How does that apply to AGW?

The difference between this result and Tom Vonk’s recent post, is that he confuses equilibrium with zero energy flow.  In his examples and equations, he has a net energy flow through the system of zero, which is fine. Where he goes wrong is equating that assumption to AGW.

What we have on Earth, is a source of 15micrometer radiation (the ground) projecting energy upward through the atmosphere, exiting through a perfect window (space) – sound familiar?   Incoming solar energy passes through the atmosphere so we can ignore it when considering the most basic concepts of CO2 based warming (this post), but it is also an energy flow.  In our planet, the upwelling light at IR wavelengths is a unidirectional net IR energy flow (figure 2 – outgoing radiation), like the laser in the example here.

Of course adding CO2 to our atmosphere causes some of the outgoing energy to be absorbed rather than transmitted uninterrupted to space (as shown in the example), this absorption is converted into vibrational and translational modes (heating). Yes, Tom is right, these conversions go in both directions.  The energy moves in and out of CO2 and other molecules, but as shown in cavity C above, the gas takes finite measurable time to warm up and reach equilibrium with space (the window), creating a warming effect in the atmosphere.

None of the statements in this post violate any of Tom’s equations; the difference between this post and his, is only in the assumption of energy flow from the Sun to Earth and from Earth back to space.  His post confused equilibrium with zero flow and his conclusions were based on the assumed zero energy flow.   The math and physics were fine, but his conclusion that insulating an energy flow doesn’t cause warming is non-physical and absolutely incorrect.

Oddly enough, if you’ve ever seen an infrared CO2 laser cut steel, you have seen the same effect on an extreme scale.

————-

So finally, as a formal skeptic of AGW extremism, NONE of this should create any alarm.  Sure CO2 can cause warming (a little) but warmer air holds more moisture, which changes clouds, which will cause feedbacks to the temperature.   If the feedback is low or negative (as Roy Spencer recently demonstrated), none of the IPCC predictions come true, and none of the certainly exaggerated damage occurs. The CO2 then, can be considered nothing but plant food, and we can keep our tax money and take our good sweet time building the currently non-existent cleaner energy sources the enviro’s will demand anyway.  If feedback is high and positive as the models predict, then the temperature measurements have some catching up to do.

Even a slight change in the amount of measured warming would send the IPCC back to the drawing board, which is what makes true and high quality results from Anthony’s surfacestations project so critically important.

This is where the AGW discussion is unsettled.

====================================

My thanks to Jeff for offering this guest post – Anthony

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Alex
August 6, 2010 10:01 am

A much better post than that of Tom Vonk.
1. It would be crazy (just endlessly stupid) to deny greenhouse effect as such.
2. The direct effect of CO2 is easy to calculate. It gives less than 1 degree C per doubling of CO2 concentration.
3. The central question is the feedback. Is it positive or negative and how large is it. If it is negative (it must be negative!), we are fine. However, according to IPCC it is positive and uncertain. The uncertainty may result in some warming between 2 degree C and infinity (sic!).

August 6, 2010 10:02 am

A clear dissertation which appears to be eminently rational. If others with more math than I posess (which wouldn’t take much!) agree with this, I can go along with it.
If my high school math and science teachers had been as clear and succinct as many of those who post essays on WUWT, I may have stayed at school a bit longer. In the early 1950s in New Zealand, with full employment and a booming post-war economy,(as one of our better-known poets put it) ‘many high school teachers couldn’t get a job in the Post Office’. This had a serious negative effect on the education attainment of my generation (less than 3% of school leavers went on to higher education) which 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!

Steve Keohane
August 6, 2010 10:02 am

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.

Bird Stewart Lightfoot
August 6, 2010 10:04 am

Well done, Jeff.

Steven mosher
August 6, 2010 10:06 am

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.

Pamela Gray
August 6, 2010 10:07 am

No argument here. I live in NE Oregon. I lurvs me some greenhouse gas.

Enneagram
August 6, 2010 10:09 am

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.

Enneagram
August 6, 2010 10:15 am
August 6, 2010 10:20 am

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.

PJP
August 6, 2010 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?

Scott
August 6, 2010 10:24 am

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

Tom in Florida
August 6, 2010 10:25 am

On behalf of the Peanut Gallery, thank you for an example that was easy to understand.
One of the problems in this debate is that scientists sometimes forget that most of the people in the world are not science oriented, (the Peanut Gallery). The ability to communicate positively with these people is very important yet often forgotten. The AGW crowd, specifically Al Gore, has been winning this part of the war for years. Unless that changes, nothing else can change. This post is a very good start.

Edward Bancroft
August 6, 2010 10:28 am

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

Layne Blanchard
August 6, 2010 10:29 am

Spencer also did a nice explanation on this at his site. It makes perfect sense that any barrier impeding the free flow of energy from a source will insulate that source and cause a higher temperature than a system without such insulation. Just as a cloud cover in winter holds warmth overnight, and a clear winter night becomes much colder. But our roiling convective atmosphere, heating during day, cooling overnight, facilitates the transfer of kinetic energy from CO2 to water vapor and then to relinquish that energy to space when water condenses. We live in a giant evaporative cooler.
I just traveled internationally a few days ago. I like to monitor parameters of flight on the seatback display. At the surface, temperature here was +63F. At 8000 ft it was near zero, and at 20,000 ft it was -50F. Yes, energy is being retained, but hardly what I would call a “hot spot”.

Stephen Wilde
August 6, 2010 10:30 am

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”

coaldust
August 6, 2010 10:30 am

An excellent illustration of the error in Mr. Vonks conclusion. Thank you.

Gail Combs
August 6, 2010 10:32 am

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.

Ed Caryl
August 6, 2010 10:37 am

Between Jeff, Tom, and Willis, the situation is getting clearer and clearer. I’m sitting here watching the thunderheads building over the Sacramento Mountains (NM), as they do nearly every day during the summer, pumping heat from the desert into the stratosphere. I’m looking forward to a rain shower this afternoon, which will bring the temperature down here from the mid-80’s (F) to the mid-60’s. The earth’s thermostat works just fine here. When it gets hotter, the rain is heavier and lasts longer.

CodeTech
August 6, 2010 10:37 am

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?

william Gray
August 6, 2010 10:42 am

Can someone post from Co2science Please? They have excellent papers on this subject.

joshv
August 6, 2010 10:44 am

“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?

Bomber_the_Cat
August 6, 2010 10:45 am

Anthony, it is not clear from what you write whether this is a real experiment or a thought experiment (describing what you expect to happen).
If it is a real experiment, there are other possible explanations for what is said to happen. For example, I could say that the infra-red beam at 15 micron is effectively ‘scattered’ by the CO2 (via absorption and re-emittance) and impinges on the sides of the insulated chamber. It thus warms the insides of the chamber which in turn warm the gas by conduction and convection (which is how the atmosphere gets heated anyway?) Any radiation you detect with a ‘blackbody’ spectrum characteristic of the chamber temperature is probably coming from the warmed material of the chamber itself, and not necessarily from the gas. How do you eliminate that possibility? I think you need to repeat the experiment with the whole chamber made of what you call “perfectly transparent” window material. The radiation will not then heat the chamber itself, but simply pass through it.
By the way, isn’t the emissivity of the gas so low that it would be hard to detect its emissions anyway? Surely it’s coming from the interior walls of the chamber?

Rhys Jaggar
August 6, 2010 10:46 am

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??

Richard Garnache
August 6, 2010 10:48 am

Jeff;
You are absolutely right, denying that CO2 contributes to the earth’s temperature weakens our position. Excellent post.

Warren in Minnesota
August 6, 2010 10:49 am

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.

Honest ABE
August 6, 2010 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?

Gail Combs
August 6, 2010 10:51 am

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.

Ken Hall
August 6, 2010 10:52 am

Spot on article Jeff. This is what I have been trying to explain to many AGW alarmists for a loooooooong time.
When they incorrectly assert that I do not believe in CO2 having any warming property and they try to lecture me about Planck and long time established basic physics I have to tell them that the atmosphere is not a flask. I ask them to show me a flask with approximately 32 million trillion gallons of liquid water in it and 5140 trillion tonnes of water vapour filled air and then they will have something with a closer resemblance to earth.
Of course CO2 has an absorption band, but an increase of CO2 with a logarithmic absorption from 380ppm even to 600ppm will not and cannot cause >2 degrees c of warming when the increase from 200ppm to 380ppm caused only part of the alleged 0.6 degrees witnessed during the 20th century.
The “sophisticated” computer models of a chaotic, non-linear system are incomplete and therefore wrong.

latitude
August 6, 2010 10:53 am

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

dearieme
August 6, 2010 10:53 am

The layman might find it helpful to know that long before the AGW fuss, combustion engineers routinely included the effects of CO2 and water vapour in their calculations of radiative heat transfer in furnaces. This is not contentious stuff, it’s bog standard physics.

Richard111
August 6, 2010 10:55 am

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

Enneagram
August 6, 2010 10:55 am

Scott says:
August 6, 2010 at 10:24 am Another fun thing I just realized is that CO2′s other main absorption band maxes out right around 666 cm-1…interesting.

Which is the “Perfect Fifth” 2/3 :: 3/2, a complete “quanta” (not the Planck’s incomplete constant=0.66252)
http://upload.wikimedia.org/wikipedia/en/2/20/Perfect_fifth_on_C.mid

August 6, 2010 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? 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!

Joss
August 6, 2010 11:00 am

Jeff wrote ” In our planet, the upwelling light at IR wavelengths is a unidirectional net IR energy flow (figure 2 – outgoing radiation), like the laser in the example here.”
Sorry. I do not agree.
On earth, every point source emits isotropically. The emitted field is NOT a vector field. No poynting vector here.
Idem for the CO2 molecule and air volumes in the atmosphere. Therefore , you may not add, substract , calculate energy flows , energy conservation laws etc. as if they were vector fields.

Enneagram
August 6, 2010 11:07 am

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.

Robinson
August 6, 2010 11:14 am

An excellent explanation, although not entirely relevant as the positive and negative feedbacks are where battle is usually joined.

A C Osborn
August 6, 2010 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 bandwith have such a large effect?

CRS, Dr.P.H.
August 6, 2010 11:16 am

Thanks for posting, Jeff! Right on the money, denying the physics of carbon dioxide in the Earth’s atmosphere completely is a losing game.
Where the CAGW crowd collapses is in the “catastrophic” aspect, particularly Hansen’s beloved runaway “Venus” effect. Please see p. 22 of his slides at this download:
http://www.columbia.edu/~jeh1/2008/AGUBjerknes_20081217.pdf
Until Earth gets clouds composed of sulfuric acid, moves several million miles closer to the sun, and gets an atmosphere generating a surface pressure of 90 atm, I’m not terribly worried about taking lessons in Venusian.

Enneagram
August 6, 2010 11:18 am

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 🙂

Julio
August 6, 2010 11:18 am

Jeff,
As a physicist, I appreciate your effort here, but I still think one needs to stress that the important point is that some of the energy reradiated by the CO2 in the atmosphere is sent downwards, that is, back to Earth. If all that happened was that the CO2 gets hot, while reradiating all the extra energy out to space (“forward”, like your figure 7 suggests), that would indeed have a negligible impact on the Earth’s temperature.

Jeff
August 6, 2010 11:27 am

I took his original point to be that CO2 can’t “create” new energy in the system, i.e. it can’t make it get hotter than the original energy input into the system would … that was the “heating” I thought he was talking about …
in a perfect black body one millimeter off the surface the temperature will be X depending on the amount of solar energy hitting said surface … X is the maximum value for air temperature … 20 millimeters above the surface it cannot and will not exceed X … 100% CO2 or 0% CO2 doesn’t change this …
how fast the heat transports is effected by the various gas or vapor concentrations …
so CO2 effects the speed of heat/energy transportation … it can’t “Heat” up anything … slow the loss, yes … so on a cronilogical basis you could say that the measured temp is hotter than it would have been with less CO2 …

August 6, 2010 11:27 am

In order to have a sane discussion about the theory of “global warming,” it is important for all camps to accept the fundamentals of science – which Jeff presents here well.
Neither side holds a monopoly on ignorance.

Jeremy
August 6, 2010 11:28 am

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”)

Tufty
August 6, 2010 11:32 am

Joss is right and in any event, the ‘basic physics’ of CO2 warming the atmosphere is not basic physics at all. The CO2 claim is not falsifiable by experiment because we can’t do the necessary experiments on the atmosphere. That is to say we obviously can’t control and monitor the effect of raising and lowering CO2 in the real atmosphere while keeping other variables constant. We don’t even know what those variables would be. In science (including basic physics) not falsifiable means not true. Or false for that matter. CO2 may or may not warm the atmosphere. We don’t know.
As for the implied suggestion that credible AGW skeptics must accept that CO2 warms the atmosphere to avoid accusations of extremism – well that isn’t science either. That’s politics.

Gail Combs
August 6, 2010 11:34 am

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/

August 6, 2010 11:36 am

CRS, Dr.P.H.
Thanks for the Hansen link.

Charles Higley
August 6, 2010 11:37 am

There is no doubt that CO2 absorbing IR does convert a small fraction of the energy to heat energy. However, this factor is small and too small to do anything about.
The IPCC in their great unfounded wisdom has multiplied this factor by 12 and then considered water vapor as a 30-fold positive forcing factor. This is the problem – they have artificially magnified the effect, which creates a false, much overblown warming in models which are full of critical flaws.

jorgekafkazar
August 6, 2010 11:41 am

I thought Tom Vonk’s post was intended to cover a very narrow, simple topic, one that sets aside certain significant factors (as mentioned in his caveats) in order to discuss the theoretical physics of molecular absorption of light. I did notice a few areas where he glossed over definitions, and it now seems that his narrow case doesn’t apply to the larger system of the real world. Still, I’d like to see Tom’s response to Jeff’s post, indicating where the two are in agreement, and what differing assumptions were made that resulted in different results. .

CRS, Dr.P.H.
August 6, 2010 11:43 am

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.

August 6, 2010 11:52 am

Julio says: “As a physicist, I appreciate your effort here, but I still think one needs to stress that the important point is that some of the energy reradiated by the CO2 in the atmosphere is sent downwards, that is, back to Earth. ”
That is why you can’t ignore the convective transport of heat through the atmosphere!
Hot air rises because it is hotter than the equilibrium temperature for such a gas at that level in the atmosphere. It therefore follows that rising air masses will emit radiation, it also follows that descending air masses tend (on balance) to absorb radiation.
In effect the whole atmosphere is just one great big heat engine. The heat source is the surface of the earth, and the heat sink is space. The heating causes the air to rise (now comes the fun bit) and because of the spin of the earth it begins to rotate IT IS LITERALLY LIKE AN ENGINE!!
Once the rising air has radiated heat into space by IR (or perhaps lost it by conduction), then it cools.
Warming: Now comes a bit that will confuse any global warmer
Remember those weather maps of low pressure areas with wind going into them? Well where does that wind go if all the air is heading inwards? You and I know that low pressures aren’t mysterious black holes, so we know it goes upward into the atmosphere, that upward movement is powered by the heat of the sun, and that heat is then lost to outer space – otherwise the fundamental thermodynamics of the heat engine are broken.
So, for each low pressure system at ground level, we can draw an equal an opposite outward going air system at highlevels. Likewise that air coming out of high pressure areas are part of the heat cycle of the atmosphere and similarly there are equal and opposite airflows going into high pressure areas.
HIGH PRESSURE = DESCENDING COOLED AIR
LOW PRESSURE = RISING WARMED AIR.
The whole system of atmospheric circulation will break down if you don’t have IR absorbing gases in the lower atmosphere allowing the natural cooling system of the planet to take that heat energy away from the surface where at higher levels, the same absorbing gases now act as equal an opposite cooling gases.
It’s all one big cooling cycle: the coolant (CO2) cools the surface of the earth, by absorbing IR, and then later on it cools itself by equal and opposite emission of IR at very similar wavelengths.
And, if you want to see how it works, go make a cup of black coffee, in a cold cup, then pour in milk DON’T STIR. If you’ve done it right, you’ll see cells of rising and descending liquid bounded by clearly defined lines just like our weather system … except they don’t rotate until you stir the coffee … add whisky and then drink.

ShrNfr
August 6, 2010 11:52 am

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).

Gail Combs
August 6, 2010 11:53 am

Bomber_the_Cat says:
August 6, 2010 at 10:45 am
…If it is a real experiment, there are other possible explanations for what is said to happen….. I think you need to repeat the experiment with the whole chamber made of what you call “perfectly transparent” window material. The radiation will not then heat the chamber itself, but simply pass through it.
________________________________________________________
A “perfectly transparent” window material is a plate of salt (NaCl) it is used in chemistry to hold the test sample in Infrared Spectrophotometers.
It was used by Woods in 1909 to show the true” greenhouse effect” found in greenhouses was from the normal glass allowing the sun’s energy (high wavelengths) to pass into the greenhouse but trapping the infrared energy (lower wavelengths) so it could not be re-radiated out. A greenhouse built with salt glass did not become warm.
An explanation of the experiment is here: http://hockeyschtick.blogspot.com/2010/06/greenhouse-theory-disproven-in-1909.html

UK John
August 6, 2010 11:54 am

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!

Spector
August 6, 2010 11:54 am

RE: Joss: (August 6, 2010 at 11:00 am) “On earth, every point source emits isotropically.”
That is quite true, however, in the upper atmosphere there is a conical segment about straight up in which radiation may have a good chance of escaping to outer space.
For each earthshine absorbing/emitting (greenhouse) gas it might be useful to define an altitude where perhaps all radiation emitted within 45 degrees of straight up has a 50 percent chance of escaping to outer space.

Crazydung
August 6, 2010 11:59 am

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 ^.^

Kevin
August 6, 2010 12:16 pm

What is the saturation point of atmospheric CO2 and at what point does the increase in CO have a negligible effect?
As there has been some warming, but none matching any of the models I think this is where the battleground truly exists.

1DandyTroll
August 6, 2010 12:22 pm

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

Roger Clague
August 6, 2010 12:27 pm

Steve Goddard says
In order to have a sane discussion about the theory of “global warming,” it is important for all camps to accept the fundamentals of science – which Jeff presents here well.
Who gave him the right to decide what is ‘fundamental science’. Science is process. Science is the sane discussion. That is science is the use of logic and numbers.
This complex thought experiment from Jeff Id does not at all resemble the earth’s atmosphere. So it can not show that CO2 causes it to heat up.
http://realplanet.eu/atmoseffect.htm
Here the author explains the effect using a thought experiment about the earth’s atmosphere. He does need to consider the chemistry of atmosphere

PSU-EMS-Alum
August 6, 2010 12:27 pm

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.

Jan K. Andersen
August 6, 2010 12:32 pm

Thank you Jeff, An excellent explanation of the natural greenhouse effect.

Ronaldo
August 6, 2010 12:33 pm

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.

stephen richards
August 6, 2010 12:35 pm

Scott says:
August 6, 2010 at 10:24 am
Can some back-of-the-envelope numbers using Beer’s Law and molar absorptivities/extinction coefficients be provided in this analysis?
Google it. There are plenty of responses

Pamela Gray
August 6, 2010 12:42 pm

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.

Ronaldo
August 6, 2010 12:42 pm

Drat, that should be demonstrated.

Roy Clark
August 6, 2010 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. 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.

Michael J. Dunn
August 6, 2010 12:48 pm

Misunderstandings are so unfortunate.
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. If you look at the temperature profile of the atmosphere with altitude, once it gets above the terrestrial boundary layer, there is only a weak relationship with surface temperature.) This is not identical with saying that a greenhouse process does not exist (which he wasn’t arguing).
In a nutshell, the picture is this: Sunlight heats the earth. The earth maintains the temperature of the atmosphere through convection. If certain gases are in the atmosphere, they function effectively as a spectrally-sensitive beam-splitter, scattering 50% of some outbound infrared spectra back to the earth, which can raise the temperature of the earth (greenhouse effect). The temperature of the atmosphere is unaffected by this beam-splitting process per se, because it is an equilibrium where input = output (no heat accumulation).
For those who are distracted by the “time lag,” it is negligible. Radiative equilibrium in an absorbing-emitting gas proceeds at the speed of light between molecules…very nearly the speed of light through open space, excepting for the random directions of the emitted photons. From a radiative heat transfer standpoint, the absorptive gases are like an opaque body with an internal heat conductivity that is thousands of times more rapid than normal conductivity. So, temperature equilibirum is almost instantly established, and the outbound radiation is unimpeded. (The substantial atmosphere is about 10 km deep. At 1/10 the speed of light, which is about a million times faster than molecular thermal velocities, the transit time is about 3/10 of a millisecond. Radiative equilibrium is established throughout the atmosphere faster than the air can gain temperature.)
And the air is worthless as a heat sink. We normally use it as an insulator. When nightfall hits the desert, it chills down rapidly. The air does not keep it warm. (The heat capacity of air is dominated by the condensibility of water vapor.)
My professional expertise includes performing detailed analysis of the radiative balance of high-energy laser beams engaging military targets. We have a definite interest in what happens to IR photons zipping through the air and how they affect solid materials. Tom is on firm ground. Try to understand it.
Jeff, your gedankenexperiment was okay except for two lapses of proper analogy. The first lapse is that the basic model should have been of a 15-micron laser hitting a black-body endwall (earth surface) and reflecting back out. But that doesn’t affect the experiment. The second lapse, critical to your argument—and which I have addressed above—is that the transition from Fig. 6 to Fig. 7 is essentially instantaneous. There is no heat accumulation. Also, there is no blackbody radiation! When we are speaking of molecular resonance absorption and emission, we are out of the realm of continuum radiation altogether. These are quantum mechanical processes for which (you guessed it) temperature cannot be defined. The earth emits as a black-body, but the atmospheric gases do not.
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. (Don’t worry about stratospheric heating; that is chemical recombination of atomic oxygen, a much different process.) Gotta go. I know there is at least one regular out there who doesn’t like lectures….

Brego
August 6, 2010 12:48 pm

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

Scott
August 6, 2010 12:50 pm

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 bandwith have such a large effect?

Hi AC Osborn – the reason these don’t match up is because the diagram is an absorbance diagram. Clouds reduce the incoming radiation intensity (mostly) via a scattering mechanism. This is also the reason that aerosols in the atmosphere have a net cooling effect. Finally, it’s also the reason why skeptics complain that changes in cloud cover aren’t included in climate models. IIRC, according to Roy Spencer, all of the supposed warming in recent decades can be accounted for with only a 2% change in cloud cover.
-Scott

Peter
August 6, 2010 12:59 pm

Joss, the keyword is net IR energy flow.

donald penman
August 6, 2010 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.If as suggested by tom vonk that the atmosphere does not warm up with outgoing infrared radiation from the earth then the atmosphere could still warm when h20 is evaporated from the ground and condenses in the atmosphere ,taking heat from the ground and adding it to the atmosphere,co2 does not condense in the atmosphere however it gets into the atmosphere .There could be infrared radiation going back to the earth from this as well as by backradiation caused by the absorption of h20 and co2.

Sandy
August 6, 2010 1:04 pm

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.

Robert of Ottawa
August 6, 2010 1:04 pm

Good article. This also doesn’t address how the doubling of CO2 doesn’t double the amount of IR absorbed by the CO2.
But for me always, the arguments pro/con AGW is historical. If the atmosphere was unstable, as the AGWers maintain (positive feedbacks ARE unstable) then the temperature would have run away billions of years ago.

Gail Combs
August 6, 2010 1:05 pm

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.

Robert of Ottawa
August 6, 2010 1:06 pm

As a thought experiment of the positive feedbacks that the AGWers claim, let’s model this feedback with some electric heaters in the above gas chamber. We will measure the temperature in the gas chamber and icnrease the electric heating proportionally to the increase in temperature. This is positive feedback.

Merrick
August 6, 2010 1:12 pm

I wouldn’t assume that Anthony would be particularly interested, and given my current load in professional and personal life I certainly can’t imagine finding the time, but when I read articles like this I’m glad that much of the basic physics required to understand the big picture is in place, but frustrated as usual that much of the important “physics” is left out.
As I alluded to in several posts under Tom’s article there’s a lot more to this than just the 15 um CO2 vibrational mode and translational energy. And, specifically, air temperature is NOT an expression of the average kinetic energy in air – despite what Wikipedia says – though it is related to the average kinetic energy. That definition completely disregards molecular internal energy, which is a little critical here, since light can only be absorbed into internal modes! One of the assumptions of Tom’s article, and tacitly in this one, seems to be that the way the 15 um CO2 vibrational excitation is relaxed non-radiatively is through V -> T (vibrational to translational) transfer from CO2 to N2. I haven’t taken the time to do a thorough analysis of this, but I suspect that’s a low-probability event. In general, V -> V and V -> R (rotational) energy are microscopically more likely. For a given type of transfer to take place it has to be energetically allowed and geometrically favored (through the impact parameter). The only impact parameters for strong V -> T coupling to N2 are those impact parameters near zero and along the axis of the N2 molecule. Given that there are a lot more impact parameters greater than zero than there are near zero and that there are a lot more approach angles off the N2 axis than near the axis this tends to result in it being much more likely for this particular energy transfer to be V -> R than V -> T.
Now, we’re talking about a lot of translational energy. The 15 um photon that is absorbed has an energy of a little less than 0.1 eV. At room temperature the available free energy is about 0.025 eV (k T). This means that the translationally excited N2 molecule (traveling at about 0.08 eV) running into any other molecule immediately after the CO2 collision which excited it, is generally going to run into a molecule with a lot less translational energy (about 0.025 eV). And therefore lose some translational energy.
We’re now back to the issue of energy transfer and the CO2 molecule. Very few N2 (or any other) molecules are going have sufficient translational energy to pass back to the CO2 molecule to excite a vibrational excitation when a subsequent collision occurs. And the very few molecules that still do have the required translational energy to transfer back must have alignment and impact parameter with the CO2 molecule such that essentially all of the energy is available to excite the vibration. And even then it’s still far more likely to excite a rotation or even just transfer the energy over as translation. All other alignments favor T -> R.
Now, in fairness, back-transfer DOES happen. One can get the order of magnitude of the fraction of excited state molecules in any *thermal* system from a simple Boltzmann calculation:
Ni / N = exp[-Ei / (k T)], where Ei is the excited state energy, T is the temperature, k is Boltzmann’s constant, and Ni and N are the excited state and ground state populations. [This is an oversimplification! – but of the right order of magnitude – there are partition function and degeneracy terms to account for]
For the 15 um CO2 vibrational state at 15C you get about 4% excitated state population of the CO2. So, as Tom suggested in his original article, there are definitely excited state CO2 molecules available to radiate 15 um radiation out in all directions. But it is the fact that the CO2 vibrational excitation, in general, cannot re-radiate before collisional cooling (as Tom originally stated in his article) and that it’s really hard to back-populate the CO2 vibrational excitation that makes you realize how much energy has to be placed into translational and internal molecular modes of all the other molecules before the back transfer starts to be likely to occur that gives you the appreciation for how CO2 is causing the atmosphere to heat up.
So, again, nothing in the article keeps the big-picture physics from being correctly understood, but the fine details leave out much of the more important chemistry that’s required for a more in depth discussion of the actual thermodynamics occurring.

Crazydung
August 6, 2010 1:14 pm

Mind blowing post by Michael J Dunn!
I hope he comes back ^.^

Gail Combs
August 6, 2010 1:14 pm

#
#
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/

August 6, 2010 1:14 pm

Well, it went better than I thought so far. 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. As far as I’m concerned, I’ve got no idea about the magnitude of the warming.
Michael J. Dunn
“The second lapse, critical to your argument—and which I have addressed above—is that the transition from Fig. 6 to Fig. 7 is essentially instantaneous. There is no heat accumulation. Also, there is no blackbody radiation! When we are speaking of molecular resonance absorption and emission, we are out of the realm of continuum radiation altogether.”
I understand what you are trying to say, but if you are right, your laser cavity won’t need that water cooling jacket or gas circulation pump anymore. Go ahead and blast a thousand watts at an absorbing medium the size of a coffee cup, I think you’ll find it might get warm. 😀 The blackbody radiation comes into effect when the vibrating molecular bonds collide with other particles and it turns into translational energy.

August 6, 2010 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 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.

Pamela Gray
August 6, 2010 1:17 pm

Mike, you have interesting points. CO2 is a pretty heavy gas. What equations do you have for its ability to rise once it has absorbed IR in this flow of rising warmed air? Or does it take a ride on water vapor and dust? Does it rise all by itself? Is water vapor the better mechanism for rising warmed air (it also absorbs IR)? How significant is CO2 compared to the other gasses in this process of rising air in order to cool the surface?

kuhnkat
August 6, 2010 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.

Steve in SC
August 6, 2010 1:37 pm

Your thought experiment is just so wonderful.
Trouble is, it can not be performed.
The world is fairly lossy, and will give you loads of trouble every time.
There is no perfectly transparent window and no material that will perfectly insulate a mass of gas.
As you add energy to the mass of gas the pressure will increase as it heats up.
That is where your new equilibrium will be established.
The other trouble is that at standard temperature radiation is not the primary mode of heat transfer and can not be neglected. The converse is probably more true.
I don’t think many people are disputing the basic physics. Its just that pesky everything else gets in the way in the real world. Nice try though.

Gail Combs
August 6, 2010 1:44 pm

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…”

August 6, 2010 1:47 pm

Kuhn,
It’s the shape of the graph that matters, if you follow the verification link you’ll see that I demonstrated it both ways.
Not so naughty.
Also, it matters exactly zero what’s going on in 1-4 microns, that’s a magnitude of the warming issue, not a basic physics issue.

Spector
August 6, 2010 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.

Gnomish
August 6, 2010 2:05 pm

Very elegant experiment and explanation, thanks!.
Now get out your 1000W sunlamp and a fan and a full swimming pool. We need to evaporate all that and get to the bottom of it.

Latimer Alder
August 6, 2010 2:12 pm

@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……)

Gail Combs
August 6, 2010 2:19 pm

Mike Haseler says:
August 6, 2010 at 11:52 am
Julio says: “As a physicist, I appreciate your effort here, but I still think one needs to stress that the important point is that some of the energy reradiated by the CO2 in the atmosphere is sent downwards, that is, back to Earth. ”
That is why you can’t ignore the convective transport of heat through the atmosphere!…
_________________________________________
Actually I like the idea of posts that take tiny bites out of the whole complex subject.
Tom Vonk’s recent post, even though it had problems gave me a very clear picture of the actual mechanism of infrared energy absorption by molecules and how the energy moves around and becomes “heat” (increased velocity)
This post takes the next step. A non-equilibrium state. Hopefully we will see other posts that build on the knowledge gained from these two posts until we have a decent picture of what is happening in a very complex system.

Tommy
August 6, 2010 2:25 pm

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?

August 6, 2010 2:26 pm

Jeff Id: Great post. Nice to have the greenhouse effect explained in a clear way.
Now consider that the three primary suppliers of long-term surface temperature measurements (GISS, Hadley Centre, and NCDC) only include surface air temperature measurements and extrapolations for approximately 30% of the Earth’s surface. The remaining 70% is ocean, the temperature of which is measured at the top “x” feet.
The oceans have their own “greenhouse effect”: they absorb downward shortwave radiation to depths of approximately 100 meters and absorb longwave radiation at only the top few millimeters, but the oceans can only release heat at the surface. The amount of heat released from the oceans varies due many factors. One of these includes the direct impacts of ENSO, which increases the surface temperature of the tropical Pacific through changes in trade wind strength and changes in the strengths of surface and subsurface ocean currents. Those changes cause warm waters to be drawn from the Pacific Warm Pool and spread across the surface of the equatorial Pacific. (This rise in temperature of the tropical Pacific SST directly impacts the measured global temperature, because “x” % of the ocean rose.) Also included are the indirect impacts of ENSO outside of the tropical Pacific, which are caused by changes in atmospheric circulation. Sea surface temperature rises when wind speed decreases, and vice versa.
Just a few things that always seem to be overlooked when there are discussions of greenhouse effect.
Regards

latitude
August 6, 2010 2:27 pm

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.

latitude
August 6, 2010 2:28 pm

Michael, I meant “all” of your post, not just the line I quoted.

Gail Combs
August 6, 2010 2:33 pm

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.

A Crooks of Adelaide
August 6, 2010 2:34 pm

Man, I’m way out of my comfort zone here but I thought the absorbtion was by photon capture by the electrons in the Carbon atom, and the energy went into boosting them into higher energy shells, not into kinetic energy of the molecule. Isn’t that what your absorbtion diagram is showing? They then re-emit the photon at the same energy level as they de-excite and this photon continues on its way either of into space, off to be captured by the next C atom or back down to the ground.
I have to admit I’m a geologist and so science isn’t my strong point.

Michael J. Dunn
August 6, 2010 2:37 pm

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.

jorgekafkazar
August 6, 2010 2:39 pm

Steven mosher says: “…Like you I believe in moving the discussion FORWARD….”
Amen!!
“…And just for good measure we will throw in some appeal to authority: Spenser….”
I particularly like his Faerie Queen.

August 6, 2010 2:49 pm

One thing which I mentioned on tAV was that the perfect insulating cylinder isn’t quite as non-physical as it might seem.
If you think of the atmophere which is basically in equilibrium and define a 1 meter cylinder boundary from ground to orbit. Energy which escaped from the side of the cylinder will come back in from adjacent air on the other side of the cylinder. (Infinite insulation).
If you think of energy re-striking the ground, an equal energy is coming back up, also infinite insulation.
So you have a perfectly insulated cylinder with a perfect emitting window at the top. — not so bad an example I think.
DeWitt Payne gets credit for it though.

Gail Combs
August 6, 2010 2:51 pm

Pamela Gray says:
August 6, 2010 at 12:42 pm
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….
____________________________________________-
As a victim of the reading method described I am glad it got trashed. However the historic facts of Dewey’s effect on the education of most of us who are now adults is still visible. It was for the history I linked to the article.
“For 10 years, William Schmidt, a statistics professor at Michigan State University, has looked at how U.S. students stack up against students in other countries in math and science. “In fourth-grade, we start out pretty well, near the top of the distribution among countries; by eighth-grade, we’re around average, and by 12th-grade, we’re at the bottom of the heap, outperforming only two countries, Cyprus and South Africa.”
http://www.enterstageright.com/archive/articles/0804/0804textbooks.htm
…the U.S. ranks 21st out of 29 Organization for Economic Cooperation and Development (OECD) countries in mathematics scores, with nearly one-quarter of students unable to solve the easiest level of questions….In 2000, 28 percent of all freshmen entering a degree-granting institution required remedial coursework
http://www.edreform.com/_upload/CER_JunkFoodDiet.pdf
Our education system is still crap and it traces back to John Dewey. If you have a better reference I would be happy to see it.

George E. Smith
August 6, 2010 3:00 pm

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.

Stephen Wilde
August 6, 2010 3:01 pm

Bob Tisdalr said:
“The oceans have their own “greenhouse effect”: they absorb downward shortwave radiation to depths of approximately 100 meters and absorb longwave radiation at only the top few millimeters, but the oceans can only release heat at the surface.”
Thanks Bob. That is my ‘Hot Water Bottle Effect’ in a nutshell and it’s hugely greater than the so called Greenhouse Effect.

Stephen Wilde
August 6, 2010 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.

A Crooks of Adelaide
August 6, 2010 3:06 pm

Further to my post above …
If it was as simple a transfer to kinetic energy as you imply, then why wouldn’t the atoms absorb at all wave lengths and just result in atoms with different speeds? Your explanation doesn’t explain the limits in the absorbtion bands. And if its not an energy transfer into kinetic energy but into molecular energy, does that mean the atoms actually dont increase in temperature?
My devil’s advocate position would say that the Carbon atoms would absorb all the photons they could until all the electrons occupy all the available higher orbits and then the rest would simply have to pass through.
I might add that intuitively, I think your system ought to warm, but I’m not too happy with your explanation.

p. solar
August 6, 2010 3:12 pm

@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 …
>>
If feedback is high and positive as the models predict, then …
>>
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
>>
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.

Stephen Wilde
August 6, 2010 3:12 pm

Gail Combs kindly referred us to this
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…”
I would be inclined to bet that the variations in Earthshine and the consequent albedo changes will eventually be found to be directly related to the average latitudinal positions of the cloud bands of the various jet streams and the ITCZ. The variations being due to changes in the angle of incidence of solar shortwave energy as those clouds move poleward and equatorward beyond normal seasonal variability over centuries.

Gail Combs
August 6, 2010 3:18 pm

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….
___________________________________________________________
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.

jorgekafkazar
August 6, 2010 3:24 pm

Pamela Gray says: “…While I understand that historically, whole language bec[a]me the preferred/only (and very unfortunate) method of reading instruction, it is no longer the case….“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.”
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.

Stephen Wilde
August 6, 2010 3:25 pm

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.

Stephen Wilde
August 6, 2010 3:35 pm

Scott said:
“according to Roy Spencer, all of the supposed warming in recent decades can be accounted for with only a 2% change in cloud cover.”
Well I reckon you could get that from the latitudinal shift in the cloud bands that we have actually observed over the period 1970 to 1995.
Since then the cloud bands have been going back equatorward again and hey presto albedo is increasing.
http://wattsupwiththat.com/2007/10/17/earths-albedo-tells-a-interesting-story/
This climate stuff looks to me like turning out to be quite simple after all. The only thing we need to ascertain is the precise cause of those latitudinal shifts and I’ve already set out my ideas on that here and elsewhere.

Gail Combs
August 6, 2010 3:37 pm

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….
______________________________________________________________
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/

August 6, 2010 3:40 pm

Gail Combs says:
August 6, 2010 at 11:53 am
A “perfectly transparent” window material is a plate of salt (NaCl) it is used in chemistry to hold the test sample in Infrared Spectrophotometers.
It was used by Woods in 1909 to show the true” greenhouse effect” found in greenhouses was from the normal glass allowing the sun’s energy (high wavelengths) to pass into the greenhouse but trapping the infrared energy (lower wavelengths) so it could not be re-radiated out. A greenhouse built with salt glass did not become warm.
************************************
Gail, this is completely untrue. Please read the old 1909 Woods paper. The greenhouse made with salt was almost identically warm as the greenhouse made with glass. Woods showed that the way a greenhouse works is by preventing convection – nothing at all to do with blocking IR radiation. The idea that, somehow the glass ‘blocks’ the infrared emissions, and that this is the mechanism that warms greenhouses, was utterly debunked by Woods in 1909. Unfortunately, the idea that, as you put it, greenhouses work by “normal glass allowing the sun’s energy (high wavelengths) to pass into the greenhouse but trapping the infrared energy (lower wavelengths) so it could not be re-radiated out” is a complete myth. The atmospheric ‘greenhouse effect’ is not in any way like the way greenhouses get warm: if find it incredible to think that people still believe this after its debunking over 100 years ago.

Jordan
August 6, 2010 3:41 pm

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?

Kevin Kilty
August 6, 2010 3:43 pm

Jeff has produced a good explanation of the basic physics, and my only complaint is that the diagram shows all radiation leaving via the distant end of the tube, which is not precisely what happens (it is what happens net after the tube reaches equilibrium).
However, there is the devil in the details still. People have already begun to add clouds, ocean surface, and other complications to the issue. Here are a couple of thoughts I have and if someone can add details to these I’d appreciate it.
1) Jeff’s diagram is probably based on calculations using MODTRAN. I assume MODTRAN has been validated with measurements, but maybe it has not. Undoubtedly it could be validated only in certain bands, or perhaps on average over large portions of spectrum. Does anyone know?
2) Jeff did not mention the detailed calculations which probably depend on the assumption of local thermodynamic equilibrium (LTE), a topic on Tom Vonk’s thread yesterday. LTE allows one to apply the Planck function to the distribution of radiation at any assumed temperature. However, the Planck function applies to cavity radiation, and in the case of the atmosphere there is no cavity. LTE does not strictly apply unless radiation is fully coupled to molecular states of translation, rotation, etc, and obviously this is not the case within the atmospheric window near 10um, and maybe is not the case in many other regions of the IR spectrum. Anyone know?
3) The window I mention in 2) is to some degree a thermostat. Discussion is generally limited to the impact of CO2, but water vapor dimers and trimers may have bands within the window. Thus a moistening of the atmosphere, and increasing polymerization of water vapor may have a big impact. I’ve alluded to this before in regard to El Nino. I’ve been looking for detailed info on the internet, but there is little. Anyone know of work along these lines?

David, UK
August 6, 2010 3:49 pm

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.

George E. Smith
August 6, 2010 3:59 pm

“”” Michael J. Dunn says:
August 6, 2010 at 2:37 pm
Can comment only briefly, so apologies.
Crazydung: Thanx and a Hatlo Hat Tip to Tom Vonk.
…………………………..
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. “””
Michael; while the spectrum of the solar radiation is approximately the 5780 K (or pick your own number) that Jeff postulates; the Stefan-Boltzmann emittance of course is attenuated by the square of the ratio of sun radius to earth orbit radius to finally yield thge 1366 W/m^2 at our orbit location.
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. That insolation level will never raise a desert surface temeprature to +60 deg C or even as high as +90 deg C for some black asphalt surfaces; and it is those much hotter than 288 K sureal surface temepratures that are responsible for the greatest earth cooling effect during the heat on the noonday sun.
Mother gaia does NOT wait till after sunste to start cooling her place down; she cools it 24/7 as the saying goes; in fact Mother Gaia probably invented the term 24/7 because she operates always in real time with real instantaneous vlaues and as I have said ; does NOT do statistical mathematics.
Working with average numbers instead of instantaneous values gets you on average that nothing ever happens.
It is the hottest dryest desert surfaces on earth that are cooling the planet via radiation; not the Arctic, and Antarctic wastelands that are puny radiators by comparison.

Gail Combs
August 6, 2010 4:01 pm

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…
_______________________________________________________
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”

Editor
August 6, 2010 4:04 pm

joshv says:
August 6, 2010 at 10:44 am

“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?

The detector doesn’t see the IR photons radiated by the ground – they’re absorbed but eventually IR photons from CO2 higher up are released and make it to the detector, so yeah white will do. If you could afford a broad spectrum color camera, then you’d see the Earth mostly okay, but covered with a yellow (or whatever color it displays for 15 um) haze – and a brighter haze in humid regions where H2O emissions join in.
Back to the laser – the laser shove photons in – they don’t make it out. The laser might call it black. However, the whole gas does glow in that IR yellow and gets brighter when the laser is on. Sort of translucent/milky, except that’s due to scattering photons, not absorbing and emitting photons.

George E. Smith
August 6, 2010 4:13 pm

“”” 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.

Gnomish
August 6, 2010 4:33 pm

Gail Combs says:
August 6, 2010 at 1:14 pm
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.
____________________________________________________________
Gail- you have it precisely backwards. It is important to be able to distinguish between heat and temperature. Please fix your idea. VELOCITY of the molecule is what we call TEMPERATURE.
Heat is something completely different and is NOT measured with a thermometer at all.

George E. Smith
August 6, 2010 4:35 pm

“”” 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.

Gnomish
August 6, 2010 4:40 pm

JeffID
Sometime chat with somebody in industry who actually uses lasers for delivering heat to materials (as for cutting shapes- maybe ask at Tap Plastics).
If you don’t remove the vaporized work material, the laser can not deliver the energy to the surface to do the desired work.
Therefore, blowers are used and the laser may be pulsed to allow vapor removal.
If this is not done, one is putting the watts into a cloud and wasting it.

Gail Combs
August 6, 2010 4:45 pm

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.
_____________________________________________________________________
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.

Scott
August 6, 2010 4:56 pm

Stephen Wilde says:
August 6, 2010 at 3:35 pm
Hi Stephen. Thanks for the link…I was unaware of that information. What I really liked was the first comment on the article you linked though…the perfect question to greenhouse gas warming. 🙂
-Scott

Derek B
August 6, 2010 5:07 pm

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.

Gnomish
August 6, 2010 5:07 pm

Heat is measured in :
joules
calories
BTUs
ergs
watt hours
dyne meters
electron volts
newton meters
poundal feet
NOT DEGREES

Gail Combs
August 6, 2010 5:15 pm

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.”
___________________________________________
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.
_______________________________
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)

Gnomish
August 6, 2010 5:17 pm

We don’t live in a thermometer. We live in a dynamic heat pump.

John Whitman
August 6, 2010 5:23 pm

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

August 6, 2010 5:27 pm

Derek,
Don’t misinterpret my post for an alarmist, believer or even we should do something about it one. It’s just the initial physics, the rest is up for disagreement.
This is one of the key’s to ‘settled science’. They use the line and revert to the basics, if skeptics don’t respond intelligently to the basics, their understanding is weak and not worth the time.
Once the basics are agreed to, the rest is up for discussion, because the rest of the physics are not certain. It’s called uncertainty in climate, but I call it unknowainty because there is a difference.

August 6, 2010 5:31 pm

John Whitman :
A quote from Tom Vonk’s post:
“CO2 absorbs the outgoing infrared energy and warms the atmosphere” – or –
“CO2 traps part of the infrared radiation between ground and the upper part of the atmosphere”
…you will be millionaire .
Even Internet sites that are said to have a good scientific level like “Science of doom” publish statements similar to those quoted above . These statements are all wrong yet happen so often that I submitted this guest post to Anthony to clear this issue once for all.
They are not ‘wrong’, but their magnitude and effects are definitely in question.

George Steiner
August 6, 2010 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?

NoMoreGore
August 6, 2010 5:48 pm

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.

Merrick
August 6, 2010 5:48 pm

Gail Combs:
Nope. Absorption of an IR photon causes a vibrational excitation. Electronic excitations require visible or ultraviolet photons.
And, no, velocity and heat are not interchangeable. Heat is rigorously defined only for systems in thermodynamic equilibrium. That means that not only is there energy in kinetic (external) energy of the atoms and molecules but that there is also energyin thermally available rotations and excitations.
Doesn’t anyone other than physical chemists understand this?

Kevin
August 6, 2010 6:04 pm

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.

Steve Fitzpatrick
August 6, 2010 6:21 pm

Kevin,
Steve Mosher’s comment (August 6, 2010 at 10:06 am ) was addressed to Jeff, but I think it was really written for you.

It's always Marcia, Marcia
August 6, 2010 6:21 pm

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.

August 6, 2010 6:21 pm

Stephen Wilde: You wrote, “Well I reckon you could get that from the latitudinal shift in the cloud bands that we have actually observed over the period 1970 to 1995.” And continued, “Since then the cloud bands have been going back equatorward again and hey presto albedo is increasing.”
And as always when you write this, I will ask, have you found a dataset that illustrates this latitudinal variation in clouds from 1970 to 1995 and back toward the equator since then?

August 6, 2010 6:28 pm

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.

John Whitman
August 6, 2010 6:34 pm

Jeff Id says:
August 6, 2010 at 5:31 pm
John Whitman :
A quote from Tom Vonk’s post:
“CO2 absorbs the outgoing infrared energy and warms the atmosphere” – or –
“CO2 traps part of the infrared radiation between ground and the upper part of the atmosphere”
…you will be millionaire .
Even Internet sites that are said to have a good scientific level like “Science of doom” publish statements similar to those quoted above . These statements are all wrong yet happen so often that I submitted this guest post to Anthony to clear this issue once for all.
They are not ‘wrong’, but their magnitude and effects are definitely in question.

——————-
Jeff Id,
I think there is a misunderstanding of the thrust of Tom Vonk’s post and the thrust of your reply to it. Maybe my solution is to read them both for the third time? OK. I will.
John

Gail Combs
August 6, 2010 6:38 pm

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.
______________________________________________________
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.

August 6, 2010 6:45 pm

Stephen Wilde wrote, “Thanks Bob. That is my ‘Hot Water Bottle Effect’ in a nutshell and it’s hugely greater than the so called Greenhouse Effect.”
No reason to thank me for my earlier comment about the oceans having their own greenhouse effect. That’s something I always keep in mind from an old John Daly post. Took me a few seconds to find it again. Here ya go:
http://www.john-daly.com/deepsea.htm
Scroll down to “DO THE OCEANS WARM THE PLANET?”

Merrick
August 6, 2010 6:48 pm

Wow. Now I know that solid state gain media get hot in lasers but gaseous gain media in laser doesn’t get hot – because the Einstein A and B coefficients ensure that the gaseous media radiate the photons oput as fast as they come in.
And laser media in a state of population inversion have a negative temperature.
Sorry. That’s just wrong. Please point me to any sources that state that gas lasers don’t require cooling and that lasing media in population inversiom are characterized by negative temperature. Negative temperature is an unrelated concept related to very cold materials with highly aligned spin states.

Gail Combs
August 6, 2010 6:58 pm

Merrick says:
August 6, 2010 at 5:48 pm
Gail Combs:
Nope. Absorption of an IR photon causes a vibrational excitation. Electronic excitations require visible or ultraviolet photons.
And, no, velocity and heat are not interchangeable. Heat is rigorously defined only for systems in thermodynamic equilibrium. That means that not only is there energy in kinetic (external) energy of the atoms and molecules but that there is also energyin thermally available rotations and excitations.
Doesn’t anyone other than physical chemists understand this?
_________________________________________
Doesn’t anyone other than physical chemists understand this?
Not many. Only physicists, physical chemists, a smattering of other chemists and the avid readers who devour anything connected to climate. That is why I suggest a few of these “simplified physics” articles were a very good idea.
SO thank you for the clarification. My chemistry teacher for physical chemistry (thermo) had a heart attack and we got stuck with an organic chemist who hated P chem and did not understand it. That class, my one and only, was forty years ago. That is why I asked in my first post for correction if I got stuff incorrect.
Hopefully others will learn from my putting both feet in my mouth.

August 6, 2010 7:02 pm

George Steiner,
At the Air Vent Pat Frank left a calculation which showed 30 milliseconds is typical before release of the energy. More than enough time for a collision to occur. This means most of the energy is released through kinetic interaction.

JimboW
August 6, 2010 7:06 pm

Jeff,
Thank you for this post.
As many others have pointed out above, it is very important for contributors here to call out sub-standard science /arguement, rather than remain silent and so leave the impression that the readership is in general agreement with something which is easily discreditted. Otherwise you end up looking like realclimate.

Oliver Ramsay
August 6, 2010 7:21 pm

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?
—————–
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.

Smoking Frog
August 6, 2010 7:27 pm

Gail Combs: I don’t see any chance of refuting Al Gore with “science that the majority of people can understand,” if that means science that isn’t oversimplified so far as to be incorrect. On the other hand, my alternative may be equally unrealistic. I think the majority of people should be skeptical (of both sides, or all sides) as any reasonable person would be of something he doesn’t understand.
I know that doesn’t answer the question of what happens when people vote; despite their skepticism, they may vote for the wrong side; but I just don’t see that a reasonable but ignorant person should have any attitude other than the skepticism I’m talking about. How could he? I know more science and math than the majority of people, and I’ve been following AGW for nearly 20 years, but I can’t swear that the warmists are wrong. I think they’re wrong, but if they’re right, that’s the way life is.
Don’t get me wrong. There are things that are within the reach of the majority, if the media would present them. They’re not all scientific. The majority don’t know beans.

August 6, 2010 7:35 pm

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?

Editor
August 6, 2010 7:35 pm

OK.
It appears there may be a problem with the recent-increase-in-CO2-causes-catastrophic-global-warming theory …
From the above graph, CO2 at 380 ppm has an absorption peak between 10.5 and 11 microns that will absorb some of the outgoing radiation from the earth. This absorbed energy is then assumed to increase the vibration (motion) of the (very few) CO2 molecules in the atmosphere, which then hit nearby air (O2 and N2 molecules) and cause them to increase the motion (temperature). Fine, an increase in CO2 would be assumed to cause an increase in net energy in the air (although that increased heat energy cannot be measured yet, and the increase will decrease logarithmically as CO2 increases linearly.)
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).
Why then, is CO2 is considered a massive threat towards heating the earth when O2 (being subject to the same heat exchange and radiation equations) is 537 times more prevalent? Is it because only CO2 can be used to control the world’s capitalist monies by taxation, restrictions, and international policies of government control?
(Yes, the ratio of peak absorption for CO2 is higher than that for O2/O3 … But it isn’t 537 times higher. Water – conventionally considered a greater green house gas than CO2 – is also conveniently ignored in this graph. Again, because the UN cannot tax water vapor.)
I add a caveat: Since 2003, the amount of O2 in ppm has decreased slightly. Since worldwide temperatures have reamined the same, the amount of volcanism has remained near constant, but CO2 has increased and O2 decreased, what is the net reflective and absorptive difference in the earth’s heat imbalance?
The CAGW alarmist cannot explain the cyclical changes in the earth’s tempeorature. It doesn’t fit their cherished, simplistic theory that REQUIRES the earth temperature respond linearly to a linear change in CO2 levels. Therefore, they had to invent – and still have to cling to – Mann’s-made global warming via the hockey stick and by ignoring changes since the depths of the LIA in the mid-1600’s.

August 6, 2010 7:42 pm

Arno,
Here is another reminder that the science is not settled:

The following article by Dr. Zbigniew Jaworowski, M.D., Ph.D., D.Sc., was published, after peer review, in March 2007. Dr. Jaworski was one of the first to point out the loss of scientific integrity in the field of global warming research.

Article and link.

Amino Acids in Meteorites
August 6, 2010 8:07 pm

stevengoddard says:
August 6, 2010 at 11:36 am
CRS, Dr.P.H.
Thanks for the Hansen link.

I hope you are going to make a post, or posts, on it!

Jim D
August 6, 2010 8:39 pm

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.

Alan McIntire
August 6, 2010 8:42 pm

George E Smith made a good point regarding the “average” 240 watts from the sun.
In fact, earth is receiving, and radiating away, heat at higher temperatures during the daytime than during the nighttime. As the earth heats up, earth’s radiation band shifts towards the left, and a smaller FRACTION of earth’s radiation is absorbed by CO2- negative feedback.
Regarding those greenhouse models, I checked out this article regarding multi
layer atmospheres,
http://www.geo.utexas.edu/courses/387H/Lectures/chap2.pdf
came across Newton’s law of cooling, and posted this at
“Science Of Doom”
http://scienceofdoom.com/2010/07/24/the-amazing-case-of-back-radiation-part-two/#comment-5086
My simple model assumed we get the same amount of radiation from the
atmosphere both day and night, and we get all our radiation from the sun during
the day, the same amount all day.
Obviously a lot of latent heat goes into the atmosphere during the daytime , otherwise the earth’s surface would get much hotter during the day than it actually does

JimF
August 6, 2010 8:47 pm

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

Amino Acids in Meteorites
August 6, 2010 8:54 pm

For those who still haven’t seen Roy Spencer’s talk on negative feedback here it is in 2 parts:
Part 1

Amino Acids in Meteorites
August 6, 2010 8:54 pm

Part 2

Jim D
August 6, 2010 8:55 pm

A point missed in the thought experiment is that the 1000 W coming out is all at 15 microns because that is the only wavelength CO2 could emit at (unless the temperature has pushed the envelope in Figure 2 far enough left to make other bands possible). This is an important point that gases emit only at their allowed wavelengths within their black-body temperature envelope, and with the intensity consistent with that envelope. It is like it is trying to be a black body but only has a few windows to output its photons. This is known as low emissivity (where perfect emissivity of 1 is a black body).
The intensity of the 15 micron emission of a region of gas is defined by the temperature and concentration of the CO2 in that region.

Barry Moore
August 6, 2010 9:02 pm

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.

Kevin Kilty
August 6, 2010 9:28 pm

Jordan says:
August 6, 2010 at 3:41 pm
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?

This is an interesting suggestion — i’ll give it a shot. The two objects as described are essentially blackbody cavities (The classical construction of a blackbody is a deep slender cavity drilled into any material–the specific material doesn’t matter). Radiation goes in and bounces around, and some gets absorbed, and what comes out can only come out the window in each case. Most of the radiation is absorbed in each cavity and only a little comes out the window at first. The cavity filled with CO2 will heat up more quickly than the empty cavity. However, at equilibrium what each is made of, and filled with, will not matter at all. As long as each can only view the sun through the window, each will achieve the same temperature, and as long as each is only exchanging radiation with the sun, each will reach the surface temperature of the sun. In short, each will be perfectly absorptive and emittive. There will be no temperature difference to exploit in an engine.
In the realistic case, of course, each tube will radiate into a large solid angle, as it isn’t possible to prevent conduction through a real layer of insulation. Then there may be a temperature difference at equilibrium, but this would be no different than the scheme of connecting a stainless steel panel to a white painted aluminum panel through a heat engine. The steel panel will get quite hot in sunlight, and the aluminum will stay cool. The heat engine produces work. You don’t even need to put this contraption in orbit.

Mike Blackadder
August 6, 2010 9:40 pm

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.

kuhnkat
August 6, 2010 10:40 pm

George E. Smith, and there is still more incoming in the near infrared than outgoing in the earth’s blackbody.
About 50% of the suns’ blackbody is in its infrared. About 45% is in the visible.
Maybe you can tell me if the Climate Models use the 1-4 micron range as visible energy? If not, their accounting is rather shoddy.

Al Tekhasski
August 6, 2010 10:43 pm

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

asmilwho
August 6, 2010 11:04 pm

Hallo,
I’m interested in other work that Tom Vonk has done as a physicist.
So if anyone can point me to his university, or papers he has had published , that would be great, thanks

pwl
August 7, 2010 12:47 am

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.

Stephen Wilde
August 7, 2010 1:47 am
Stephen Wilde
August 7, 2010 1:51 am

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

joletaxo
August 7, 2010 2:08 am

Great experiment but
What is the pressure in the “chambers” from whom will depend the rate off conductive occurence between the CO2 molecule, and the molecule off the other gazes?
We know for sure(maby) that the other molecule will not trap the laser beam, so the only way too exchange energy is let Us say”mecanical” and we foud again the “laps rate off transmission”.
An amount off energy is trapped by the CO2 molecule, and reemitted immediately,but a part is exchange with the molecule off the other gazes by conduction depending off the pressure in the chamber,and then reemitted as IR, in all directions,weekening the total beam.
The exemple off the cutting laser is perfect.Iron has a structural organisation off molecule that enchance the rate off transmission and the energy ,captured in surface odd the sheet is transmitted further by conduction,so the cutting effect
In the atmosphere, things are quite different:CO2 is a trace gaz, and the “mecanical” process is very week.And in the upper atmosphere, tings are going to be more critical, because pressure is very low.There in praticaly no chance off enchancing the t° off the other gazes there.
Back to the black board, because things appear to be unclear….

John Marshall
August 7, 2010 2:08 am

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.

P Wilson
August 7, 2010 2:13 am

It is difficult to justify this assertion. The wavelength at which c02 captures radiation is in the subzero region around its peak of 15microns and shoulders slightly less, and at the shoulders c02 has to compete with oxygen and nitogens’s wavelnths of heat absorption. These figures give around 7% heat absorption for c02 of outgoing radiation, and that is fixed according to saturation windows than quantity. C02 suspends heat loss to space a tiny fraction of IR, but nothing significant. It cannot send it back to terrestrial levels, as air presure, climate and other factors maintain a higher temperature at ground level than the regions of the troposphere where c02 is the most active in its heat absorbing height (where the troposphere is subzero). In other words, c02’s subzero active region cannot add heat below, where it is already warmer.
The experiment sends flags. Applied to AGW it would have to replicate air pressure, temperature and various other climatic factors, again. to be verifiable.
Its true that a c02 molecule’s stretching mode would allow it to transfer energy to other atmospheric molecules, such as the ghg water vapour, but this requires so much energy that it doesn’t occur even at 300K, with the c02 absorbtion bands, and there’s some 3,000 other molecules apart from c02 in a given volume of air, making collisions between thermally excited c02 molecules very unlikely.

Denis Purdy
August 7, 2010 2:36 am

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.

kwik
August 7, 2010 2:37 am

beegdawg007 says:
August 6, 2010 at 6:28 pm
Ah, yes! A very good post from Jeff Id. Now, next step is a real experiment with a laser, and 0.04% CO2. Then step up to 0.08%CO2. Measure.

Liam
August 7, 2010 2:38 am

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

August 7, 2010 3:05 am

Isn’t the main flaw in Jeff ID’s argument that we should look at what happens if we go from a 280ppm CO2 chamber to a 560ppm CO2 chamber? Or more general from a non-zero CO2 to a higher CO2 chamber? Anyone able to explain how that would alter Jeff’s “gedankenexperiment”?

Joe Born
August 7, 2010 3:26 am

To me the two disputants appear to argue past each other slightly, so I’m grateful for Merick’s comment above. To me, it goes to the heart of the matter.
But, knowing that as a layman I am easily led astray, I found Merick’s statement that “air temperature is NOT an expression of the average kinetic energy in air” disquieting. That statement doesn’t appear critical to his overall point, but, since I had always thought temperature is indeed the measure of average TRANSLATIONAL molecular kinetic energy, it makes me wonder whether something else in his comment is wrong, too. Has anyone detected anything?

August 7, 2010 3:35 am

Gail Combs says:
the CO2 laden air will absorb IR close to the ground, it will then heat up,
____________________________________________________________
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.
Gail, an interesting assertion, and whether I was right to miss this step depends on the relative conversion rate from energised electrons to vibrational modes.
My assertion was based on an article I read that IR given off by CO2 in the atmosphere travels only a few meters before being reabsorbed. The point of the article was that a change in CO2 levels meant a difference of a few meters in the distance CO2-IR travelled.
Now if we assume 10m average distance travelled, then 10km of atmosphere would represent 1000 average path distances.
The big question we have is: “would we obtain near enough to heat equilibrium in substance with 1000 average path distances to say” the IR causes the atmosphere to heat up. (for a 10km slice)
My hunch is that for all practical purposes you can assume the atmosphere heats up by IR, if however someone can puts some figures on that hunch I would be extremely grateful and if necessary start baking a humble pie.

August 7, 2010 3:43 am

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)

Spector
August 7, 2010 3:44 am

We are given that the concentration of gaseous water or free H2O molecules (I am avoiding the standard term ‘water vapor’ because in common usage a vapor is a fog) in the atmosphere ranges, according to the EPA, from 30,000 ppm to 40,000 ppm and the concentration of CO2 is about 390 ppm. Thus it seems reasonable to assume that for every single CO2 radiation photon that escapes to outer space or is received from the surrounding atmosphere in a given volume of atmosphere per unit time, there may be roughly 77 to 103 equivalent H2O radiation photon events.
Even considering the fact that the lower concentration of CO2 may allow CO2 photons to escape the atmosphere at lower altitudes, I would still think that H2O must be by far the most dominant greenhouse gas in the atmosphere and must play a primary role in determining the altitude and temperature of the tropopause.

Jordan
August 7, 2010 3:57 am

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?

Dave Springer
August 7, 2010 4:33 am

joshv says:
August 6, 2010 at 10:44 am
“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?

Yes, at 15um the detector sees “black”. This is because the optical depth of the atmosphere at 15um is far less than the actual depth of the atmosphere.
Astronomy 101: Composition of cold clouds of gas backlit by continuous spectrum have an absorption line (a gap where energy goes to zero) at the characteristic absorption frequency of the gas.

David, UK
August 7, 2010 4:34 am

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.

David, UK
August 7, 2010 4:36 am

Dang, why can’t this site have a “preview” button so we can check when the HTML hasn’t worked? Sorry.
[Fixed. Sorry, WordPress doesn’t support a preview function. ~dbs, mod.]

Merrick
August 7, 2010 4:55 am

Barry Moore on line broadening:
Barry, I haven’t read the IPCC report and doubt I’ll have time to do that soon. You seem to quote the IPCC report as claiming that the increased concentration of CO2 will result in line broadening. If so, the IPCC is incorrect and I hope you’ll look more closely at the actual science.
Many factors contribute to line broadening. Two of the most important effewcts are temperature (via Doppler) and *pressure* broadening. Not cencentration, but pressure. If a sealed vessel has it’s concentration of a gas increased so that the pressure also increases then you will see the effect. For non-polar molecules this is a pretty rigorous rule. In the same sealed vessel, if you added more N2 instead of CO2 to your original CO2 you’d still observe pressure broadening. It’s definitely not a concentration based effect
Since, even with increased CO2 in the atmosphere we are predicting no change in atmospheric pressure, the IPCC is simoly wrong if it in fact states this. Can you please point me to the section and page where this is discussed?

August 7, 2010 5:09 am

Mike Haseler says:
August 7, 2010 at 3:43 am
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”.

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).
I didn’t know it was that much difference myself.

Merrick
August 7, 2010 5:18 am

Liam – that is correct – all of the outgoing ~15um radiation that can be absorbed is. It’s the re-radiation by the warmed gas that matters. If there were 100 ppm less CO2 it would pretty much all still be absorbed by the atmosphere, but the altitude at which, say 90%, of the CO2 had been absorbed would be higher than at current concentrations. And if the concentration were 100 ppm higher than today that altitude would be lower. Does that make sense?
Now, go back to the point of this post: that warmed CO2 re-emits and *some* of it re-emits toward earth. Remember the inverse square law and that CO2 will be re-absorbing some of the re-emitted light on the way down and it’s easy to see that if on average the ~15 um radiation is absorbed higher in the atmosphere (low concentration case) then less of that reradiated energy makes it back to the ground and if on average the ~15 um radiation is absorbed lower in the atmosphere (high concentration case) then more of that reradiated energy makes it back to the ground.the difference might be small, but there clearly is a difference.
That part of the physics can be summarized just that simply. If people are going to argue over the finer details of how that reradiation happens I wish they’d be more careful about those details, but the conclusion of this very small part of the much more complicated picture can really be summed up that simply.
Many are going to immediately respond back regarding LTEs and forcings and negative feedbacks. Yes – of course they are all very important points to take into consideration. But this small portion of the topic seems still to be poorly understood by most of the folks here and it sure would be nice if we could get a significant plurality up to speed on at least this part.
A boy can dream, can’t he!

Roger Clague
August 7, 2010 5:28 am

John Marshall asks ‘has he actually done the experiment?’ The answer is NO!
IR exert R.W. Wood did something similar 100 years ago and showed that CO2 does not trap heat.
Philosophical magazine , 1909, vol 17, p319-320
A bottle of monatomic argon reacts to IR radiation the same as a bottle of CO2.

old construction worker
August 7, 2010 5:47 am

“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”?

August 7, 2010 5:50 am

This post is more acceptable to me then Tom’s and the experiment at least proves that there is a warming effect.
On the other hand, if it were not for the ozone and the water vapor and the CO2 and the oxygen in the air then we would all fry….the extra 30% radiation or so would make us toast….
The paper that confirmed to me that CO2 is (also) cooling the atmosphere by re-radiating sunshine is this one:
http://www.iop.org/EJ/article/0004-637X/644/1/551/64090.web.pdf?request-id=76e1a830-4451-4c80-aa58-4728c1d646ec
they measured this radiation as it bounced back to earth from the moon. So the direction of the radiation was:sun-earth-moon-earth. Follow info in fig. 6, bottom. Note that it already starts at 1.2 um, then one peak at 1.4 um, then various peaks at 1.6 um and 3 big peaks at 2 um.
So all gases other than nitrogen also cause a cooling effect!!My question was en is: what is the net effect of the cooling and warming of each the gases in the atmosphere other than nitrogen?
Where is the research on that? If you don’t have anything on that, then what is the use discussing any of these so-called theories?

Roger Clague
August 7, 2010 5:58 am

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

Dave Springer
August 7, 2010 6:08 am

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?

Very perceptive question. Alarmingly few people know enough to ask it.
The troposphere is opaque to 15um radiation upwelling from the earth’s surface in tens of meters. That is indeed vitally important. Adding more CO2 would have the effect of bringing total absorption closer to the surface – more kinetic energy in a smaller air mass makes the sensible temperature higher. The nub is that convection keeps the air near the surface well mixed at distances greater than tens of meters so at this point decreasing the optical depth of the atmosphere at 15um won’t have any effect – total radiated energy from the surface at 15um will be evenly distributed in the first few hundred meters of atmosphere regardless of how much more CO2 gets added.

Ninderthana
August 7, 2010 6:31 am

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.

John of Kent
August 7, 2010 6:44 am

Jeff, you can put what you want in your post but it still does not address the basic problem in physics that makes the alleged back radiation greenhouse effect impossible. A colder object (lower atmosphere) CANNOT heat a hotter object. Heat always moves from hotter to colder, this is like claiming you can make a river flow uphill. Not without a pump (i.e. WORK input you cannot).
Eventually sceptics/skeptics/realists, including Lindzen and Spencer are going to HAVE to accept that the greenhouse effect from back radiation is impossible.

John of Kent
August 7, 2010 6:56 am

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.

Jim D
August 7, 2010 7:27 am

A lot of people are fixated on the idea of photons coming in and going out of CO2 molecules, re-emission, etc. I am going to suggest a paradigm shift that leads to a more accurate way of thinking. CO2 intrinsically emits around 15 microns with a strength that depends on its temperature and concentration. The emission intensity only depends on these things, and is equal in all directions obviously.
Of course it absorbs too at those wavelengths, so you may ask what is the net effect. This depends on the background radiation. When you look up at CO2 against a cold sky, it is emitting more than absorbing, because it is warmer than the background. When you look down with the earth as a warm background, it is a net absorber. Either way it is absorbing and emitting at those wavelengths.
The important part is that from the ground perspective it is a net emitter, making for a warming effect.
From the space perspective it is a net absorber making for a reduction of outgoing radiation that also has consequences for the net earth energy budget.

August 7, 2010 7:29 am

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

John Whitman
August 7, 2010 7:37 am

Jeff Id, in your lead off post you say;
“None of the statements in this post violate any of Tom’s equations; the difference between this post and his, is only in the assumption of energy flow from the Sun to Earth and from Earth back to space. His post confused equilibrium with zero flow and his conclusions were based on the assumed zero energy flow. The math and physics were fine, but his conclusion that insulating an energy flow doesn’t cause warming is non-physical and absolutely incorrect.”

————————–
Jeff Id,
I did my homework and read both your post and Tom Vonk’s post one more time (3rd time).
Thank you for your excellent and educational post.
I find that your above paragraph from your post is not an accurate re-statement of what Tom Vonk said.
I liked your post immensely, except for it stating to be a reply to Vonk. Yours is a good educational tool for understanding our atmosphere by itself when all references to Vonk are removed.
I found that Tom Vonk explicitly addressed a specific narrow aspect concerning the interaction of gases in the atmosphere among themselves and also with IR radiation. His study did not pretend to address anything more widely of the whole earth system. His caveats explicitly stated processes and conditions in the whole earth system he did not address.
John

Wayne
August 7, 2010 7:47 am

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?

cal
August 7, 2010 8:21 am

Merrick’s last post is correct but I think his description is looking at the effect from the wrong perspective if one wants to be quantitative. I am sorry if I am boring anyone by repeating the same point I have made several times before but the key issue is not where the 15 micron photons are first absorbed (which is only a few feet off the ground) but where they are last absorbed before being radiated into space. If say the concentration of CO2 doubles the point where this final radiation takes place has to move upwards until the partial pressure of CO2 is half that at the original level so that the photon mean free path is the same.
This view is more informative because it is not possible to discuss the energy balance of the earth from bottom up. It is too complex. For this reason I did not find either Tom’s or Jeff’s papers very convincing. The only reasonable approach is to view the world (with its atmosphere) as a whole. It is then quite simple.
All the energy aborbed by the earth has to be radiated into space.
The earth’s albedo will change due to clouds and the disribution of land and water and as the earth rotates but if we neglect these (or averaged them over time) the energy absorbed and that radiated is constant, equal and opposite.
The absorbtion is mainly by land and sea because the atmosphere is a poor absorber of sunlight.
The radiation out is from three main agents. The earth’s surface, CO2 molecules in the atmosphere and H2O molecules in the atmosphere. These three account for 99% of the energy radiated into space.
The energy radiated will depend on the temperature of these radiating elements, and their concentrations in the case of CO2 and H2O.
The earth’s surface radiates directly into space at wavelengths around 10 micron where the atmosphere is nearly transparent. The temperature is therefore around 288K for these wavelengths. Photons between 13 and 18 micron are radiated by CO2 molecules from at or just below the tropopause (altitude 16km over the tropics and 8km over the poles). The tropopause is at 220K. Most of the remaining energy is radiated by H20 from various altitudes and temperatures depending on wavelength.
Thus is should be clear that photons emitted by CO2 and H20 are being radiated from molecules at a lower temperature than the surface temperature of the earth. If the atmosphere did not contain these molecules that energy would indeed be radiated from the surface. In this scenario the earths temperature would not have to be so high in order to radiate the same total energy. This is the unambiguous argument to show that the (badly named) greenhouse effect really does exsist.
However it does not follow that increasing CO2 will automatically increase surface temperature. 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. A lower temperature means less radiation and therefore the surface has to warm in order to restore the energy balance. However all the satellite data I have seen suggests that the radiating temperature is 220K which is the lowest temperature found in the atmosphere. Unless the tropopause is cooling ( it may be but I have seen no evidence) it could easily be argued that an increase in CO2 will lead to increased radiation due the higher CO2 concentrations and therefore the surface has to cool to compensate.
When it is not clear whether an effect is positive or negative it is hard to say that the science is settled!

August 7, 2010 8:23 am

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.

Stephen Wilde
August 7, 2010 8:39 am

Cal said:
“Unless the tropopause is cooling ( it may be but I have seen no evidence) it could easily be argued that an increase in CO2 will lead to increased radiation due the higher CO2 concentrations and therefore the surface has to cool to compensate.”
The tropopause doesn’t appear to cool . Instead it’s height changes. It moves up when the troposphere is warming and down when the troposphere is cooling.
Contemporaneously the air circulation systems move poleward when the tropopause is rising and the troposphere warming.
Similarly the air circulation systems move equatorward when the tropopause is falling and the troposphere is cooling.
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.
Thus a bit more energy in the atmosphere from more CO2 or any other GHG just provokes more ocean surface evaporation and a miniscule compensating increase in the speed of the hydro cycle for probably no change in surface temperature.
If a significant change in radiative balance could be caused then a higher equilibrium temperature would be achieved but if that happened there would also have to be a change in the optical depth of the atmosphere and Miskolczi seems to have shown as best we can discern from the available date that the optical depth has not changed for over 60 years despite more CO2 in the air.
AGW theory now has a serious case to answer.

Steve Keohane
August 7, 2010 9:03 am

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.

Bill Illis
August 7, 2010 9:06 am

People get caught up in the absorption and emission bands of CO2 and H20 and do not understand there is radiation ocurring all over the spectrum. CO2 has specific frequencies where it strongly interacts with EM radiation but there is also base black-body radiation (that is not as strong or intense sometimes) but there is two kinds of radiation to be concerned about – the strong Absorption and Emission bands and the more general black-body radiation.
Let’s take the Modtran results for the sensor at 50 metres high, the height we are concerned about since we live on the surface (no one lives at 20 kms high).
Here is the chart of the radiation “looking down” at 50M (for the tropics).
http://geodoc.uchicago.edu/tmp/rad.07105553.gif
It is nearly a perfect black-body curve at 20C, the average surface temperature in the topics. There are no bands, everything is radiating as if it were 20C.
The chart “looking up”. Now we see the same black-body curve again – no CO2 Absorption bands are evident here – except in the Atmospheric Windows, the intensity of the emissions has fallen (still “back-radiating” as some like to call it) but the intensity in the windows has now dropped to something like -20C.
http://geodoc.uchicago.edu/tmp/rad.07105841.gif
Let’s move the sensor altitude to 20 kms high where the temperature is -60C.
Looking up, we see that CO2 is still quite active here. There is some activity in the H20 and methane bands but nothing is going on in the window regions, The radiation at these spectra is already on its way to space.
http://geodoc.uchicago.edu/tmp/rad.07105142.gif
Looking down, we see the windows are emitting like the blackbody curve of 20C, CO2 is emitting as if it were -60C, and H20 is emitting as if it were -18C and so on.
http://geodoc.uchicago.edu/tmp/rad.07110031.gif
So one needs to consider there are a number of things going on here.

Spector
August 7, 2010 9:53 am

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.

Mike Blackadder
August 7, 2010 9:53 am

“The difference between this result and Tom Vonk’s recent post, is that he confuses equilibrium with zero energy flow.”
After reading Tom’s post I agree with Jeff that this illustrates where Jeff made an error.
I don’t know for certain that Michael Dunn is wrong arguing (basically) that radiation absorption/emission is so fast that it would be equivalent to scattering of radiation which would not alter the temperature of the atmosphere, however this is not the argument that Tom made in his original post and I suspect it is incorrect.
So essentially the surface is a source of LW radiation and some of that radiation will be absorbed by greenhouse gases and some will pass through atmosphere and escape to space. If we increase the concentration of greenhouse gases then the atmosphere will absorb more of the radiation passing through (unless concentrations are already high enough to impede radiation to an extend that convection dominates) and this extra energy absorbed by atmosphere will translate into higher temperature of the whole air mass through collisions. The response to more absorption is to reach higher equilibrium temperature and therefore higher rate of emission.

August 7, 2010 10:06 am

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.

Mike Blackadder
August 7, 2010 10:18 am

However, I suppose that this explanation is missing something from Tom’s post. Increasing CO2 concentration would have cooling effect until the point where the CO2 is sufficiently ‘excited’. During this transient period collisions would have the net effect of transferring energy from non-greenhouse gases to CO2 (in form of vibrational excitation) until these modes are in equilibrium. Still, I don’t think that this transient condition has any impact on the final equilibrium condition where the higher CO2 concentration must result in greater absorption of surface LW and higher equilibrium temperature to restore balance of radiation in and out of the air mass.

August 7, 2010 10:43 am

On the issue of the “greenhouse” effect, many are tying themselves in knots by unnecessarily delving into confusing details. Try thinking of the problem this way:
If it is easier for solar energy to reach the Earth’s surface than it is for heat energy to be irradiated away from the Earth, then it will be warmer at the Earth’s surface.
If the resistance to inflow and outflow of energy were equal, it would be cooler at the Earth’s surface (Eg. the Moon, on average, is cooler than the Earth.)
1. Solar energy is mostly non-infrared.
2. Heat radiated away from the Earth is mostly infrared.
3. The atmosphere allows non-infrared energy to pass through more easily than infrared. Energy gets in easier than out.
4. Therefore there is a “delay” in heat escaping the Earth as a whole system (planet including atmosphere), hence heat builds up near the surface until equilibrium between inflows and outflows are reached.
5. The more resistant the atmosphere is to the infrared flow away from the Earth, the higher the equilibrium temperature.
6. If greenhouse gases increase, the infrared outflow resistance increases, hence the heat content of the system rises to a higher equilibrium
(7. There are undoubtedly negative feedbacks in the Earth system. Otherwise, the Earth’s system would not have oscillated by only a few percentage point in temperature (in degrees Kelvin) over the last billion or more years. A system dominated by positive feedbacks is inherently unstable and gyrates wildly. A system dominated by negative feedbacks acts like the Earth has.)
The details of the mechanisms of radiation absorption, reemission, conversions to and from the kinetic energy of moving molecules and the potential energy of excited electrons, saturation effects, bandwidth broadening, etc. are critical to quantitative evaluation and predictions of the the equilibrium temperature for various changes in albedo, GHG concentrations, etc.
The details are not important for understanding the simple existence of a greenhouse effect due to Earth having an atmosphere.

Kevin Kilty
August 7, 2010 10:59 am

Let me clarify point by point.

#
#
Jordan says:
August 7, 2010 at 3:57 am
… 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.

Your original suggestion involved “ideal” things of all sorts and it is difficult to decide how these ideal things will work. In the case of the CO2 filled cavity the window will become hot through conduction with the CO2 gas. In the vacuum cavity it will become hot through contact with the structure of the tube, except the tube as stated has no conductivity (i.e. well insulated, you said) so what happens then? Look, it doesn’t matter because the window is ideal. It has perfect transmission, no reflection, and no absorption, so it has emissivity of zero. Doesn’t matter what its temperature is. It does not radiate.

So what do we expect to happen at the other end of the tubes according to GHG theories?

Distant end of the CO2-filled tube heats more rapidly, perhaps, but at equilibrium both have the same temperature, as I will explain in a moment.

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.

No, won’t be anything like the Moon. The sun is just a small object at the distance of the Moon, the materials of the moon do not absorb completely, absorptivity and emissivity are not the same value because the emission and absorption take place in different parts of the spectrum, and the moon radiates into a hemisphere.
The tubes, in contrast, as I have imagined them are perfectly insulated except for a small aperture. They gain and lose energy only through the aperture, and I assume the view through the aperture is only that of the Sun. So equilibrium will occur when the incoming and outgoing spectra are the same, and the tubes have reached a temperature equal to the sun. The OLR is not LR; it is thermal radiation at 5800K.

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).

I have assumed this scenario, except, as I tried to explain, it has some awful ambiguities.

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?

You are sceptical because you ought to be; the engine you describe would violate the second law. I have tried to explain why these two tubes, if allowed only interaction with the Sun, will reach the same temperature, and never be able to drive a heat engine. Each intercepts exactly the same energy from the Sun as does the other, at equilibrium each radiates back toward the sun the same energy, there is zero net to flow through the heat engine and no temperature difference to drive it.
If you want to make a heat engine, then you must allow the two tubes to exchange energy with more than just the Sun. This prevents them from reaching the same temperature, allows one of the two to supply net energy to the other through an engine, which the temperature difference will drive. As you have described this device, its CO2 filling doesn’t provide enough difference between the tubes to make much of an engine here even if you keep the two tubes from reaching equilibrium.
Now, if you really want a simple heat engine then make two radiating panels of different materials; one that gets very hot in the Sun and one that stays cool.

1DandyTroll
August 7, 2010 11:07 am

@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….

cal
August 7, 2010 11:08 am

Bill Illis says
People get caught up in the absorption and emission bands of CO2 and H20 and do not understand there is radiation ocurring all over the spectrum. CO2 has specific frequencies where it strongly interacts with EM radiation but there is also base black-body radiation (that is not as strong or intense sometimes) but there is two kinds of radiation to be concerned about – the strong Absorption and Emission bands and the more general black-body radiation.
I thought I had covered this clearly in my last post. The radiation from the surface approximates to a black body ( it is not exact – if it were the sea would not be blue!).
So of the three radiating elements I mentioned the surface is a near black body radiator and the gases are absorbing and radiating at their characteristic wavelengths but with intensities that are dependent on temperature.
I like your charts. I have not seen the ones “looking up” before. However I am not sure what your commentary is trying to say. You keep using the words “as if” it were such and such a temperature whereas that is exactly what it is.
For example when looking down from 50M all the radiation at all wavelengths will reach the sensor from the surface or from gas molecules in between which will be very close to the same temperature as the surface. This is exactly the point that Tom was alluding to. Any radiation absorbed by CO2 for example will be re radiated. Since the temperature decline within 50M is small you will not see that the re radiation is slightly lower. So no absorbtion bands are to be expected. Water vapour bands are even less likely to be seen.
Looking up from 50M you will see energy radiated downwards from excited molecules in the atmosphere above. There will be very little in the atmospheric window around 10 micron since these wavelengths are not absorbed and therefore cannot be re radiated downwards.
At the other wavelengths you will see energy radiated downwards mainly by H2O and CO2. Because they are such powerful absorbers the level at which they will radiating downward will ( on average ) be not far above the 50M where you have placed your sensor. So the fact that they are radiating at -20C seems entirely plausible to me.
If you look down from 20Km you will see exactly the picture I was descibing where all the radiation is either from the surface at about 288K ( higher during the day in the tropics) or from CO2 and H2O at the temperatures you quote.
Looking up you will mainly see radiation characteristic of CO2 since this is by far the dominant radiating gas above the tropopause.
All the data you showed seem exactly as one might expect.
Maybe I missed something that you were trying to say.

Dave Springer
August 7, 2010 11:20 am

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.

Stephen Wilde
August 7, 2010 11:26 am

Mike Haseler says:
August 7, 2010 at 10:06 am
Hello, Mike. Your post shows that you’ve got my point and that you see some of the implications.
As regards CO2 specifically though the fact is that we see quite large circulation changes from natural climate variability so any effect from CO2 is likely to be unmeasurable particularly since the response of the hydro cycle is highly scaleable by which I mean that the energy shifting efficiently of the latitudinal shifts would increase geometrically as the shifts become more extreme. After all over billions of years they have prevented permanent disruption of the system through ice ages and much warmer periods than we have now.
I haven’t yet thought through the precise consequences beyond the latitudinal movement of the jets but some of the possibilities are as you suggest.

Mike Blackadder
August 7, 2010 11:52 am

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.

Rob Z
August 7, 2010 12:14 pm

This is a valuable “Assume the horse is a perfect sphere” experiment. The blogger says: My statement is – CO2 does create a warming effect in the lower atmosphere.” is incorrect. The blogger merely proves that CO2 absorbs 15um wavelength radiation and relaxes. Whoop de doo. Congratulations!! The “physicist” fails in his “perfect sphere” experiment by failing to ask the question, “is there any way that CO2 would cause cooling to be faster or cause net cooling in general?” The answer is an emphatic YES! The second question is, “Will the cooling forces (excluding convection) overwhelm the radiative heating mechanism. The answer again is YES. How do we know this?
Convective cooling using air is substantially more effective than conductive cooling using air. It’s why we blow air on hot soup to cool it faster…more air…more cooling (CO2 at higher concentrations than 400ppm).
Conductive cooling using air is substantially better than radiative cooling with no air. Radiative transfers of energy are slow, it’s why things stay hot or cold in a vacuum. FOR A LONG TIME!!!
If you were to add a small amount of CO2 and only CO2 to the interstitial space (area between the surface contacting the coffee and the outside surface) of a thermos for your hot coffee… guess what …it get’s colder faster. Go do the experiment in a glass thermos or any thermos. Since your coffee is radiating at LWIR, the CO2 gas doesn’t keep the coffee warmer. That is basic physics and thermodynamics. Also, since there is more Oxygen than CO2 in the atmosphere…and replacing Oxygen with a CO2, a gas with a lower heat capacity at constant pressure, the atmosphere will be more conductive and cool faster.
Jeff hedges his bets…and says….”I’ve not said anything about the magnitude or danger or even measurability of the effect. I only assert that the effect is real, is provable, it’s basic physics and it does exist.”… This is disingenuous. The conductive effects of added CO2 to the atmosphere will outweigh the absorptive effects. The net effect is cooling. When the physical effect is not measurable in the real world, is it necessary to account for it? If a measured effect contains both mechanisms…and one outweighs the other, do you use the net effect in the calculation? If yes, do you make conclusions based on the net effect or the only one of the components? If CO2 can absorb heat and do conductive/convective cooling and the net result is cooling, do you claim that CO2 causes heating if the net effect is cooling?? The “green house effect” is bogus. Don’t believe me… convince a nursery to pump in CO2 (800ppm final concentration ought to be enough) to keep it warm at night in the green house instead of turning on the heat when the temperature approaches freezing outside. Should be able to bump the temp up by 5C. For good measure…have Jeff bring his laser.

Al Tekhasski
August 7, 2010 12:33 pm

Mike Blackadder says: “Therefore, an air mass with larger CO2 concentration and SAME equilibrium temperature would be expected to absorb and radiate a larger amount of radiation.”
Equilibrium temperatures of chamber “C” are not the same for different CO2 concentrations. Yes, at larger CO2 concentration an air mass will absorb larger amount of radiation. The parcel of air will warm up to a level of temperature when absorbed and emitted radiation are equal, regardless if it is a black body or not, at which point the radiation will stop warming the air. What might be so confusing in this simple schema?

Dave Springer
August 7, 2010 12:39 pm

@Cal
For what it’s worth the following is what you see in the infrared spectrum looking upward and downward:
http://www.sundogpublishing.com/fig8-2.pdf
It’s from the 2006 textbook “A First Course in Atmospheric Radiation” by Grant Petty.
All the figures from the textbook may be viewed at:
http://www.sundogpublishing.com/AtmosRadFigs.html

August 7, 2010 1:21 pm

Mike Blackadder
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.)”
Not true, the collisions are more numerous than radiation, you will get blackbody radiation.
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.”
This is just confusing. If the equilibrium temperature is dependent on the absorbed radiation, then what you are saying is that — if your air has the same energy input with or without CO2……
“I don’t see why an injection of CO2 would result in a net transfer of energy from vibrational excitation to translational. ”
C02 is far more likely to collide than radiate. So the CO2 will absorb the energy, the molecules vibrate and collide, and you get heat. More CO2 means more capture. Maybe only slightly more, but still more.
winterkorn says:
August 7, 2010 at 10:43 am
“If it is easier for solar energy to reach the Earth’s surface than it is for heat energy to be irradiated away from the Earth, then it will be warmer at the Earth’s surface. ”
Nice.

August 7, 2010 1:40 pm

Stephen Wilde: You replied, “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”
Thanks for the link. But I don’t need links to search engine outputs. I’ve researched that. Specific data upon which you rely was what I was asking for. On the page you offered, there was little to document the global latitudinal variations you commonly refer to.
I will again suggest you learn to use the KNMI Climate Explorer:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere
For example, it would allow you create Hovmoller diagrams of CAM-SOPI precipitation data from 10S-20N, at different ocean longitudes, from 1979 to present. The following are samples, using 12-month averages to eliminate seasonal variations. I’ve thrown some lines on them to make it easier to identify the variations. Here’s one that captures the ITCZ over the Pacific at 180 long (also catches the SPCZ on occassion):
http://i36.tinypic.com/sbnfcg.jpg
And the ITCZ at 120W:
http://i35.tinypic.com/qprp1v.jpg
And the ITCZ for the Atlantic at 30W:
http://i33.tinypic.com/k5324k.jpg
ENSO appears to be the cause of the greatest year-to-year variability, as one would expect.

sky
August 7, 2010 1:57 pm

Sanctus simplissimus! The thought experiment of passing a laser through gases in a container (which itself may absorb IR) confuses signal transmitivity with the flow of thermal energy in the atmosphere, which in the geophysical setting is demonstrably more through non-radiative mechanisms than through terrestrial IR radiation. In that setting there is no radiative algebra that can determine the temperatures throughout the atmosphere, as the AGW proponents invariably imply. Like temperature itself, radiative intensity is a NON-CONSERVATIVE state variable, and not a flow variable! For a solid physical understanding of the problem, the conservation of enthalpy under the inviolable direction of entropy needs to be mastered. This is almost never seen in discussions on either side of the climate debate.
Like all strong absorbers, CO2 is also a strong emitter. Its effect thus cuts both ways. It’s not a generator of any energy. Those who are inclined to believe that CO2 has a rare ability to trap or store thermal energy, squirelling it away like gold coins, forget that its specific heat is less than that of aluminum. For them, I suggest finding a large aluminum post on a cold winter day and see for themselves how much their temperature is increased by standing next to it. In fact, if they would put their tongues on said post they would never again attempt to argue that a colder body, unsustained by any independent power source, raises the temperature of the warmer body.

Mike Blackadder
August 7, 2010 2:52 pm

Jeff, thanks for the reply. Bear with me for a minute, I’m still trying to sort this out.
“Not true, the collisions are more numerous than radiation, you will get blackbody radiation.”
So you are saying that we will get a fixed amount of radiation from a mass of air at given temperature regardless of the CO2 concentration? Just to clarify. Say you have two packets of air in a vaccuum and both are at the same temperature, but one packet has concentration CO2 like earth and the other twice the amount; would the packet with higher CO2 not emit more radiation to space? Also I don’t see why many collision events have any impact except that it gives opportunity for the air temperature to reach equilibrium in response to radiation events. In other words a CO2 molecule would presumably transfer vibrational energy to translational and vice versa many times between absorbing or releasing a photon.
I said: ‘I don’t see why an injection of CO2 would result in a net transfer of energy from vibrational excitation to translational. ‘
Jeff: “C02 is far more likely to collide than radiate. So the CO2 will absorb the energy, the molecules vibrate and collide, and you get heat. More CO2 means more capture. Maybe only slightly more, but still more.”
My point (and I believe Tom’s point) is that the converse is also true. More CO2 means that there are more molecules with the additional vibrational degrees of freedom. CO2 that isn’t excited that collides with another particle will result in translational energy converted to vibration of the CO2. Therefore, if we increase CO2 concentration and we don’t increase the amount of energy in the air packet then the temperature is lower (ie. if CO2 has no vibrational excitation there would be a transient effect of net translational to vibrational conversion until reached an equilibrium).
I suppose that where this thinking goes wrong is in the event that there is a very large amount of radiation. If everytime a CO2 molecule transfers vibrational energy to another molecule that it immediately absorbs another photon that with the many collisions we are effectively pumping radiation into the system. I could see in that case why there would be a net transfer of energy from vibrational to translational. That seems to be the case in the example that you’ve given and perhaps is true in the atmosphere.

Stephen Wilde
August 7, 2010 3:08 pm

Thank you Bob, very helpful.
When I retire from the day job I’ll make a start. In the meantime I suspect that new observing techniques and closer attention to the relevant observations may make such work unnecessary.
Have you given more thought to extending your work to mesh in with global rather than regional events ?

cal
August 7, 2010 3:37 pm

Dave Springer
Thanks for the interesting links
Rob Z
I am sorry but I cannot agree with your view that conduction is more powerful than radiation. A few things are known for certain and one of these is how much energy would be radiated by the earth at its current surface temperature if there was no atmosphere. This is far more than it currently radiates. Therefore if there were no atmosphere it would cool until radiation balance is achieved. So despite what you may feel intuitively the nett effect of the atmosphere is not a cooling one.
Your example of the thermos flask is not valid. The thermos is designed to remove all forms of heat loss. So the there are two walls of poorly conducting material where the inner surfaces are silvered to reduce radiation and the gas is removed to reduce conduction. I am pretty sure that the thermos would work better with silvered surfaces and 0.0003 bar of CO2 in the gap than it would with blackened surfaces and a perfect vacuum.
More importantly we can do the sums for the real thing. The maximum temperature gradient across the atmosphere is 8K per kilometre.The conductivity of air is 0.024W/mK so the energy lost by conduction is only a tiny fraction of a watt per square metre compared with the hundreds of watts lost by radiation.
In any event the issue is not really what the atmosphere is doing now but what it would do if you added more CO2. As I have said previously this will never be answered using a bottom up analysis. The micro models used by climate scientists today may work when we study gross changes that occur for short periods during weather events they don’t work for subtle changes over long periods relating to climate. Indeed I suspect subtle effects like an increase in any trace gas or aerosol will not be understood using any type of analysis until we have hard data from satellites correlating actual emissions with actual temperatures as the earth responds over time to changes in clouds, wind, convection currents, ocean temperatures etc. Then we can do real science.

August 7, 2010 3:46 pm

Stephen Wilde says: “Have you given more thought to extending your work to mesh in with global rather than regional events ?”
ENSO and AMO are regional phenomenon with global effects. Have you forgotten my posts about OHC? I present and discuss things regionally because one can identify causes of variability–SLP, ENSO, etc. With global perspectives, one loses that ability, and assumptions made at the global scale may very well be incorrect, because of the noises created by the regional variations at different time scales.

Gnomish
August 7, 2010 4:22 pm

Rob Z says:
August 7, 2010 at 12:14 pm
You got it.
Any increase of heat capacity of the working fluid improves the efficiency of a heat pump.

August 7, 2010 5:33 pm

Mike,
from this link:
http://en.wikipedia.org/wiki/Planck%27s_law
you can see that intensity of emission I is based only on temperature. I really have a hard time following the rest of your post. Every time I think I’m getting it, I loose it.
Maybe an even simpler explanation.
The laser passes through clear stuff — it gets absorbed by black stuff. The CO2 is black stuff. If we consider all the other minor aspects of what happens, the black stuff is still black. The laser cannot pass — so it makes heat.
The rest of the consideration about re-emission time, how much light passes through and the rest only determines the level of heating, not whether it happens or not.
I hope that is helpful.

Spector
August 7, 2010 6:33 pm

RE: Gail Combs: (August 6, 2010 at 4:45 pm) “I guess I was not clear. I thought that is what I said.”
I am sorry, I thought that was an isolated general question…

Bill Illis
August 7, 2010 6:41 pm

There is another dimension to consider here – “Time”. How fast does the radiation exit the Earth system? How much time does it spend moving from molecule to molecule.
When the Sun sets each night, the average surface radiation level falls from 418 W/m2 at the peak to 364 W/m2 just at sunrise or a decline of 10C.
So over the 12 hours, an average 4.5 W/m2 is lost to space each hour (obviously slower in the CO2 and H20 bands and faster in the windows.)
But if the Sun did not come up tomorrow, at 4.5 W/m2 loss per hour, it would only take 80 hours – a little more than 3 days – before the surface temperature in the centre of the continents approached that of the Cosmic Background Radiation – give or take some lag from water bodies.
Or one could also say, the average time that the energy represented by a visible spectrum photon from the Sun spends in the Earth system before it is lost to space is 40 hours – either a surprisingly long number or a surprisingly short number depending on your perspective. But at the speed of light and the average relaxation time for excited molecules, this means the photons are spending an extremely long period of time bouncing around from molecule to molecule. Maybe someone wants to take those numbers and calculate how many molecules each photon ends up in before it escapes to space – lots of Zeros in that number.

Steve Fitzpatrick
August 7, 2010 7:35 pm

Jeff,
You and Willis are ‘the men’! Thanks for the post and comments.

Mike Blackadder
August 7, 2010 8:04 pm

Jeff,
I think I see the problem.
So we have a perfectly insulated chamber with windows at the ends to let radiation in and out, and I will add that it is surrounded by a vaccuum.
A 15um laser is firing through the gas in the chamber and we’ll consider how this effects the temperature of the gas depending on mix of N2 and CO2. Note: We’ll get to the case of no CO2 at the end.
Scenario 1) 1% CO2: Turn the laser on. With 1% CO2 we’ll assume that the gas does NOT appear completely black to the laser. So some laser light passes right through the chamber. The CO2 absorbs X photons/sec. Before being able to re-emit it gets in millions of collisions and will tend to transfer their vibrational energy to the cooler N2 gas (and also the collisions will result in translational energy of the CO2 molecules as well). So the air heats up. So the air is absorbing X photon/sec but is emitting less than X photon/sec. Eventually the gas will warm up to an equilibrium temperature where it is emitting X photon/sec and absorbing X photons/sec.
Here’s the important part. This only happens at the point when the following collision events are equally probable: CO2* + N2 -> CO2 + N2′, and CO2 + N2′ -> CO2* + N2. If this is not the case then a net amount of absorbed radiation is being translated into heating of the case or vice-versa.
Scenario 2) 2% CO2. Turn the laser on. Still some laser light passes through the gas without being absorbed but now a greater amount is absorbed: Y photons/sec. The same thing happens when the gas is cool, where there are more CO2* + N2 -> CO2 + N2′ than the CO2 + N2′ -> CO2* + N2, and so the CO2 doesn’t get a chance to release photons before transfering it to heating of the gas. We know that it will warm up and reach equilibrium when emitting Y photons/sec.
The problem is you assume this is a higher gas temperature than scenario 1, but it isn’t. In fact it is only when collision event CO2*+N2 -> CO2 + N2′ is equally probable to CO2 + N2′ -> CO2* + N2, which is the same temperature. The CO2 and N2 molecules involved in this collision have no knowledge of gas concentrations surrounding them. There is no reason why N2 suddenly has to be a higher temperature in order to energize CO2 as often as it deenergizes CO2.
Finally Scenario 3) 0% CO2. Turn on laser. Hopefully this helps clear things up. No laser light is absorbed by the gas, and all laser light passes right through. The gas doesn’t heat up.
Question: What’s the gas temperature? Before you say 0 K, remember the gas is in a perfect insulator surrounded by a vaccuum. The truth is the gas temperature could be anything. This illustrates how you’re only considering one side of the problem. In Scenario 1 & 2 we know the gas is cool when we start the laser because the gas contained CO2 which was emitting heat out of the chamber (net CO2 + N2′ -> CO2* + N2) transactions. Without the CO2 this can’t happen.
Where did I go wrong this time?

Mike Blackadder
August 7, 2010 8:09 pm

Re: 0% CO2 case. I forgot to mention. It has been suggested that adding CO2 to the chamber results in warming of the gas. This is not necessarily true since we don’t know what the temperature of the gas is without CO2. Adding CO2 could just as easily result in cooling of the gas, even with the 15um laser running.

Gnomish
August 7, 2010 9:06 pm

I find JeffID’s model quite good for the purpose of illustrating that radiation can be absorbed and converted to kinetic. Vonk examined in detail the mechanism of energy transfer and conversion.
The effect of an energy absorbing molecule is to absorb energy and quickly share it with everything else.
The study of the radiative physics is interesting and educational. It is the determinative property for heating something from above and it is the way heat is given up by a radiator.
In a heat driven system, however, it is really only significant at the end points because phase change and convection completely dominate the system between those terminals.
Neither Vonk nor JeffID are offering any explanation of conduction or convection.
The reason radiation has seized the field as the straw man of the argument is because the only thing that the taxable substance can do that distinguishes it in any way is be darkish in infrared. The fact that is has a profoundly underwhelming effect (and the opposite of what is claimed) on a convective system is obscured by the prestidigitation.
CO2 can’t hold a place on stage with water, but they’ve already got water meters.
You know that privately they are laughing like maniacs that they will tax your air and have succesfully guided the dialectic to elevate a trivial entity to the throne of a demonic pantheon at your expense.
By Avogadro, the ideal gas constant has the same value for all gases, so PVT = PVT regardless of the molecule.
1 mole of gas molecules, any kind = 24.45 litres at 298K ( 24.85C, 76.7F) and 101.325 kPa (14.696 psi, 1 atm)
In 1000 liters of air, at STP there are 1000/24.45 = 40.9 moles. As in a previous illustration, let the water component be 1% = 10 liters = 4.09 moles. It doesn’t matter what the other gases are for this.
At the critical temperature of water vapor, this 10 liters condenses and occupies 4.09 * 18g * 1g/cc = 736.20 cc.
So the 1000 liters of air would now be 990.74 liters.
Insofar as PVT = PVT for gases, if the pressure alone changes, it means (using 24.85C and 1 atm)
PVT start is 14.696 psi*1000*(24.85C+273.15K)
final P is
14.696 psi*0.990.74, or 1% pressure drop
To get a 1% pressure drop by changing the temperature alone you need to do from 298 to 292.04 = 5.96 degrees.
http://img534.imageshack.us/img534/4959/hadleypump.jpg
http://www.engineeringtoolbox.com/spesific-heat-capacity-gases-d_159.html
Gas or Vapor kJ/kg
Air 0.287
Carbon dioxide 0.189
Water Vapor 0.462
Steam 1 psia.
120 – 600 oF
That’s what it takes to change the temperature 1 degree K.
When CO2 changes from 1 to -1 C, a change of 2 degrees C, it radiates 2(0.189 kJ/kg) = 0.378 .
http://en.wikipedia.org/wiki/Enthalpy_of_vaporization
When water vapor changes from 1 to -1 (and condenses) it radiates 2257 kj/kg + 2(0.462 kJ/kg) = 2257.853776 kJ/kg.
It does this every single time you see a cloud.
But CO2 has no phase change so it carries no heat – the numbers:
All gases at the same temperature have the same number of molecules per unit volume. (Avogadro)
Water, being light, masses 18g/mole and CO2 masses 44 g/mole
Using 1 mole of air, just to make math easy:
We lowball the water in the atmosphere at 1% of the molecules
So, in a mole of atmosphere, we have 0.01 moles of water = 0.18g
now we highball the CO2 at 500ppm which is 0.0005, or 1/2000 of a mole of CO2.
1/2000 * 44g/mole = 0.000484 moles of CO2 = 0.021296g
So in our mole of air with but 1% H2O and a generous 500ppm CO2-
the water condensing radiates 0.18g * 2257.853776 kJ/kg = 406.41367968 J
while the CO2 radiates 0.021296g * 0.378 kJ/kg = 0.008049888 J
the ratio of 0.008049888/406.41367968 = .00001980712855516645290496438242332
or as much to say that water vapor in the example carries 50486.873814890343815963650674393 times more heat than the CO2 does.
And that’s just rain. If it turns to snow- multiply by 5-6.
Meanwhile, Venus is a ball of active volcanoes with a dry heat pump to radiate it poorly.
That is why Earth’s climate doesn’t resemble that of Venus.
Forget about CO2.
All things radiate as blackbodies (or maybe a bit grayish) and noting that while water does not change temperature as it changes phase, it radiates many hundreds of times more energy in the process than any other gas.
Therefore, the blackbody spectrum may not change a whit, but –
There are a number of things that water gas does which are scarcely mentioned. It seems to be considered nothing but a personal assistant to CO2.
However there are many things that water does which define the atmosphere, the lapse rate and the thermal equilibrium.
In the first place, it evaporates. When it does, 3.7 teaspoons of liquid becomes one liter of gas. This happens without temperature change. No change occurs in the black body spectrum.
The expansion increases the local pressure above what a dry gas can under the same conditions.
At the same time, water is much lighter than any other gas in our atmosphere (except the traces of He and H), , massing a measly 18g/mole – so it rises straight up, shifted by coriolis effect as it billows wider and wider.
When it finally condenses, at the same temperature as the surrounding gas, it radiates the one spectrum throughout its phase change, indicating no higher temperature while it radiates 406.41367968 J and changes back to 3.7 teaspoons from (a bit less than, now) a liter of gas, producing a local low pressure drop of 1% that draws the atmosphere below up to fill it. (To get a 1% pressure drop by changing the temperature in a dry gas you need to do from 298 to 292.04 = 5.96 degrees.)
If water is but one percent of the volume, (using a sample volume of 100 liters that started at STP) the constituents would radiate their share as well, depending on the specific heat-
um… well, the other gases don’t radiate any more than they gain from below or sideways, or the temperature would actually drop- but for a one degree drop:
N2 (89.3g = 78%) 1.039 kJ/kg = 92.J
O2 (13.1g= 20%) 0.915 kJ/kg = 12.0J
CO2 (0.02g = 500ppm) 0.189 = 0.008J
H2O (18g = 1%) 0.462 kJ/kg = 406.41367968J
Water does more work than everything else combined – without having to change its blackbody spectrum.
(Compared to the CO2, water moves 50,000 times more energy from surface to space.)

Gnomish
August 7, 2010 9:13 pm

Increasing the heat carrying capacity of the atmosphere improves the efficiency of the system. Adding CO2 helps convection cool mo bettah. I didn’t make up the physics.

Gnomish
August 7, 2010 10:21 pm

You see, our atmosphere is not in a tube. Any heat on the surface is just at one end of a constantly moving conveyor to the infinite heat sink of space.
It’s not sitting there gaining heat and the more heat you add, the faster the conveyor moves. A bigger differential from source to sink increases the flow rate.
Swapping one non-phase-change gas in the working fluid will only infinitesimally affect the heat capacity and flow rate.
It all ends up in space at the end of the conveyor unless it’s stored in the mass of the planet.
You have to actually increase input to warm the convection fluid. Everything is wrung out of it in a matter of days.

Jordan
August 8, 2010 3:34 am

Kevin Kilyy – thanks for sticking with my questions.
I tend to agree when you say the suggested machine would be a violation of the second law.
But I also want to test the consequences of the argument that GHG has a resistive medium to LWR, and (on that argument) what we might do if we allow SWR to enter a chamber with free passage, then resist the passage of outgoing LWR.
The empty/transparent tube is only included to drive this thought experiment to an extreme. To show that there is either something very different happening in the two chambers, or there is not.
I appreciate that the concept is highly idealised, but I wanted to remove confounding factors in order to test the principle when I described it here.
Please note the windows are only for containment. Your point about perfect tranmission is well made, but I did not wish to create the impression that the windows have any bearing on the tranmission of radiation. When I mentioned an emitting surface at the window of the chamber containing CO2 I meant the outer boundary of the CO2, not the window itself.
The main reason why I mentioned the window-end of the CO2 chamber is because the last molecules are the emitting surface for that chamber due to its optical depth to LWR. I mentioned it to emphasise the notion of a possible temperature gradient in that tube which would not exist in the non-GHG or empty space in the other tube.
I accept your comment about equilibrium temperature on the surface of the moon. But I was thinking more in terms of what SB would demand for incoming solar radiation at circa 1500 W/sqm. Even in the closed chambers mentioned and where the image of the sun fills the apeture (that’s a good point which I failed to mention), I did not expect this to cause a rise to the same temperatire of the surface of the sun becuase of the 1/r^2 “dilution” of solar flux. Doesn’t SB suggest something more like 400K?
I understand that there are some awful ambiguities in reaching for the idealised physics. And the machine does seem to be a viloation of the second law. But these points leave little room for the argument that CO2 is a resistive medium, which could result in a potential difference at the closed ends of the tubes.
It is also important to mention that the engine does not permit the CO2 filled tube to reach its own equilibrium. If there is a temperature difference at the closed ends, it uses that potentital to remove energy from the CO2 filled tube.
I’m not trying to deny the physics – just testing them. And thanks for the discusson, please stick with it.

August 8, 2010 3:39 am

Stephen Wilde says: Hello, Mike. Your post shows that you’ve got my point and that you see some of the implications.
As regards CO2 specifically though the fact is that we see quite large circulation changes from natural climate variability so any effect from CO2 is likely to be unmeasurable particularly since the response of the hydro cycle is highly scaleable

Stephen, whenever I see these radiation transmission graphs, I really should come down like a tonne of bricks on the idea that there is ONE such graph. Cloud cover is by far the biggest factor effecting heat loss. This is so patently obvious to anyone who has gone out on a cloudless night – for heaven’s sake even the Romans knew this as they used to use the clearness of the night sky in the Sahara to make ice in massive insulated pits they would open up on clear, still nights to let it freeze.
Anyone can check out the massive change in radiative properties by buying a cheap IR thermometer, going out on a cloudy and sunny day/starry night and noting the difference. The sky’s radiative temperature (as measured by the emissivity curve of the IR thermometer) about (winter) 4C and -40C. In fact it is so cold on clear nights it goes off the end of the scale (-40C).
Quite obviously, and never admitted by the global warmers, the single biggest factor effecting the climate is the extent of cloud cover.
What goes up comes down
By the laws of physics clouds should not exist. Afterall, water is heavier than air and so it will fall down to earth. Therefore, in a static model of the atmosphere there can be no cloud, because if the air were static, the water would fall out of it.
So, clouds are by their very nature part of the dynamic convective cooling system of the world. They are also have a dramatic effect on temperature. It’s not difficult to prove that if that effect were to cause temperatures to drift from “normal” then, we’d already have had run-away global warming or global cooling and none of us would be here.
So, clouds are part of the heat regulatory system of the atmosphere, and so the key measurement I personally would use to monitor so called “climate change” (yuck) would be the extent of cloud cover.
That is to say, that in a self-regulatory system like the atmosphere, the best way to measure a change is not in the variables being regulated (temperature), but in the variable doing the regulation (cloud cover). Depending on the quality of that regulation, you could have imperceptible changes in temperature but the system could be under huge stress, because the regulation was highly effective. So, the place to look is at the thing doing the regulation of temperature not the temperature itself.
And, then when you start to think about human’s influence of the cloud cover, you begin to see where the real problems can lie:
1. Soot and dust from smoke
2. Aircraft con trails
3. And the level of high energy ionising particles which can form the nucleus on which water droplets can form.
And where is the biggest change? It has been the dramatic rise in smoke levels during the industrial revolution, followed by dramatic reductions in smoke levels from clean air legislation in the 1970s.
I would strongly suggest that the main reason for “global warming” is the environmentalists who (rightly) insisted that we stop pouring so much soot into the air in the 1970s – after which we appear to see a clear rise in temperature which so scared the warmers
Ironic isn’t it. We are all suffering from this global warming hysteria because the world had the good sense to remove smoke from the atmosphere which appears to have resulted in apparent warming.
And, If you want proof that dust can cool the planet, JUST MENTION TO A GLOBAL WARMER THEIR LAST SCARE REGARDING THE NUCLEAR WINTER!

Ulric Lyons
August 8, 2010 3:50 am
Jordan
August 8, 2010 3:51 am

Ouch! Sorry for the typo, that last post from me should have been to Kevin Kilty

Gnomish
August 8, 2010 4:45 am

http://pielkeclimatesci.wordpress.com/2010/08/06/comments-on-a-new-paper-on-climate-sensitivity-by-lin-et-al-2010/
“Until the climate community moves away from the surface temperature trends, with its inaccuracy and unnecessary complexity, and replaces it with the diagnosis of ocean heat content changes in Joules over time, the policy community will continue to be misled as to the actual warming and cooling of the climate system.”

stephen richards
August 8, 2010 7:22 am

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).
Presumably at 1ATMOs

stephen richards
August 8, 2010 7:26 am

This has been the best thread on any site for some long time. Very few trolls have bothered to contribute so the flow of the thread has been maintained and the contributions have been intelligent, informed and very useful.
Thanks from an old physicist.

August 8, 2010 7:29 am

Jeff Id:
My statement is – CO2 does create a warming effect in the lower atmosphere.

WHEN a known greenhouse gas whose percentage can and does vary daily and weekly and with that variance _does_ cause noticeable local, overnight and daily temperature variances which vary proportional to that GHG, a veritable living experiment observable with minimal cost, time or equipment avails itself and supports the above JI statement.
What? Has no one else has observed basic outdoor temperatures in a meteorological context while also observing humidity/moisture/water content of the surrounding air mass and noted some correlation? … and now I have to ask the question, would these conditions in the longer term affect an observed average?
There is also another concept simply involving energy ‘flux density’ as it relates to the electromagnetic exchange of incoming (solar) energy to outgoing (earth LWIR) energy; the introduction of any mechanism which delays, temporarily ‘stores’ via low percentage reflection or re-radiation or ‘back’ radiation or ‘back’ scatter to use a radio/RADAR term is going to necessarily increase the ‘energy flux’ density in said system, and, in this case, it will cause some small increase in a metric we call temperature
No?
.

August 8, 2010 8:36 am

This is a great post and I thank Jeff and Tom for presenting things so clearly. To me the whole human-caused warming theme boils down to Figure 5 which is filled with oxygen. Clearly, the tank case will get warmer due to convection and radiation (photons scattering as shown at the exit). There should be a Figure 5b where 390PPM of CO2 is added and allowed to displace some oxygen. Now, will the case get warmer still? Yes, it will. Will the warming be measurable? I very much doubt it…even with extremely accurate equipment and very careful procedures. If you can’t measure it in this lab experiment, then you’ll never measure it in our atmosphere. Sorry, Dr. Mann, this case is closed.
As a correction to John Marshall above, it’s Kevin ‘Travesty’ Trenberth (not Mann).

August 8, 2010 8:53 am

Henry@Mike Haseler
I must say, I liked your last post. It is good. It is what I had been thinking also. Can I quote you?
Henry@wintercorn
Due to the elimination of CFC’s and many human activities, there has been an increase in ozone. Ozone eliminates a large portion of UV radiaton, where the sun’s intensity is very high.
So, don’t you think global cooling is imminent?

Dave Springer
August 8, 2010 8:59 am

Jeff Id says:
August 7, 2010 at 1:21 pm
C02 is far more likely to collide than radiate. So the CO2 will absorb the energy, the molecules vibrate and collide, and you get heat. More CO2 means more capture. Maybe only slightly more, but still more.

Only if all the energy isn’t already being absorbed. The effective optical depth of the troposphere at 15um is far less than the actual depth so it is indeed all being absorbed. It can’t absorb more than 100% of the emission.
Atmospheric transmission at sea level (1000mb) of 15um is nearly 0% across a distance of just one meter. At 20 kilometers (100mb) across 1 meter of air transmisson rises to 50%. textbook reference: http://www.sundogpublishing.com/fig9-13.pdf
Now compare to zenith transmission (entire CO2 column from sea level to 20 kilometers) where absorption is 100% across a much broader swath centered on 15um.
http://www.sundogpublishing.com/fig9-12.pdf
This is the “shoulder broadening” that is often talked about that happens with increased CO2.
Now, near as I can tell from actual observations, if we accept those and accept the correlations as causations, each CO2 doubling beginning at 280ppm effectively raises the average temperature at the surface (absent positive or negative feedbacks) pretty darn near to the IPCC published number of 1.1c.
While I can’t prove it, because correlation is not causation, it appears to be credible enough. CO2 does act as an insulator. That’s just basic classical mechanics. Explaining the exact mechanism at the quantum scale is interesting, evidently quite controversial, but ultimately irrelevant because we’re dealing with scales far outside the quantum realm and at that scale classical mechanics explains things quite well.
So if, for the sake of argument, if we accept the 1880-2000 data:
1) temperature rise of 0.8c
2) CO2 rise of 75ppm
then accept
3) the CO2 increase was due to anthopogenic emission
4) correlation between more CO2 and rising temp is actually causation
and then note (H/T to Vonk)
5) the temperature rise was 0.4c for the first 25ppm added from 1880 to 1940
6) the temperature rise was 0.4c for the next 50ppm added from 1940 to 2000
then it is reasonable to reach a tentative conclusion that the shoulder broadening effect of adding more CO2 follows (like many other energy distribution phenomenon) and inverse square law – i.e. for each incremental temp increase of 0.4c it requires twice as much additional CO2 as the previous increment.
This makes sense in many different ways from the basic physics of insulators straight on through to the observations of increasing CO2 correlating with rising temperature through in inverse square rule.
Whatever positive or negative feedbacks are associated with rising or falling CO2 must be presumed to have been operating over the entire period of 1880 to 2000 so while arguing about them might be interesting the net effect is included in the actual observations.
We can also look much further back in history when atmospheric CO2 was 10 to 20 times greater than today yet temperatures during those periods was only several degrees C higher. This is yet more observational evidence that we have an inverse square law governing the relationship between CO2 and temperature.
We can’t possibly burn enough CO2 to reach those prehistoric levels and even if we could it would only make the earth green from pole to pole as it was during the Eocene thermal optimum 50 million years ago. I prefer plants and animals to rocks and ice so when it comes to fossil fuels I say “Burn baby, burn! And in the meantime have a plan to find and develop an economical alternative energy source for day when the fossil reserves become economically unrecoverable”.

Dave Springer
August 8, 2010 9:13 am

I wish I could edit these things. Where I referred to CO2/temp correlation following an inverse square rule I should have written that was an exponential rule. Double the CO2 ppm to get the same incremental rise in temperature not square the ppm.

Dave Springer
August 8, 2010 9:22 am

stephen richards says:
August 8, 2010 at 7:22 am
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).
Presumably at 1ATMOs

Even if it does re-emit it’s irrelevant because near total absorption of 15um at 1ATMOS occurs in a distance of 1 meter. Even at 0.1ATMOS absorption is 50% across a distance of 1 meter:
http://www.sundogpublishing.com/fig9-13.pdf

cba
August 8, 2010 9:25 am

Jeff,
great explanation. Also hats off to Dewitt P and his contributions to your effort. He was of great help to me a couple of years back while getting my feet wet.
I think though that the problem with Tom’s explanation was a little different, having to do with difference of temperatures of the BB curve versus the temperature of the LTE example. In any case, it leads to a conclusion that is problematic in that if co2 did not transfer energy to other molecules in the sample after and change in conditions, then the LTE condition would become lost and one could end up with different temperatures for the various types of molecules present. I think part of Tom’s purpose for writing the post was that there seems to be a delusion among some CAGW fanatics that there is some big energy reservoir in the sky just like the oceans where energy is sucked up over time and getting ready to pop out in some deluge of heat.

cba
August 8, 2010 9:36 am

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?
——————–
Actual attenuation is going to be directly related to the total number of the co2 molecules in the air column. Other effects are going to be secondary and involve the width of each spectral line and that is controlled by such things as the concentration of co2 in the gas (co2 partial pressure), temperature of the gas and pressure of the gas. As the total pressure drops, one has narrower line widths. The line width and height can be thought of as the effect at each wavelength and in order to capture any significant amount it must be over some range of wavelength. The 15 um band is composed of thousands of individual lines that overlap. At much lower pressures there may be little to no overlap and one winds up with portions of the band that are transparent.

cba
August 8, 2010 10:12 am

Scott says:
August 6, 2010 at 10:24 am
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).
—————————————
Something like the HITRAN database can provide raw information but it’s a tremendous effort to get something fairly complete out of that. One can also get fair mileage out of Archer’s online modtran calculator. Some lines will have extinction path lengths measured in the cm distances. A short distance away in the wavelength, one can have path lengths of 1km or more.
This area tends to not be where the problems and arguments (and errors of the warmers) with the warmers resides. It is also only valid for clear sky conditions which is less than half of the Earth’s surface at any one time. The problem lie in the nature of cloud effects, albedo and absorption, in the total sensitivity effect present today in the amount of how much change in power results in how great a change in temperature, and ultimately, just how much change in temperature get’s conveyed into feedback that affects the amount of power getting through the atmosphere. There’s plenty there to indicate in a fairly robust fashion just how little effect occurs and there’s plenty there to suggest where the errors and fallacies of the co2 warmers exist.

Doug McGee
August 8, 2010 10:36 am

Wow, it seems only yesterday this site was promoting G&T’s alleged refutation of CO2 as a GHG. I guess this is how blog science works – baby steps towards what most everyone already knows.

Roger Clague
August 8, 2010 11:09 am

Doug McGee says
‘Wow, it seems only yesterday this site was promoting G&T’s alleged refutation of CO2 as a GHG. ‘
This site does not promote points of view. It allows discussion. There are plenty of contributers, including me, who agree with G and T. There are those who disagree with them.
No consensus here, thankfully, only civilised debate. Join the fun.

Foley Hund
August 8, 2010 11:16 am

I see it like this: Diluting the atmosphere H2O with a minimal green house gas as is CO2, then the concentration of retained heat should therefore decline with the declinge H2O concentration.

wayne