Explaining misconceptions on "The Greenhouse Effect"

Guest post By Ben Herman and Roger A. Pielke Sr.

Image: University of Arizona

During the past several months there have been various, unpublished studies circulating around the blogosphere and elsewhere claiming that the “greenhouse effect” cannot warm the Earth’s atmosphere. We would like to briefly explain the arguments that have been put forth and why they are incorrect.  Two of the primary arguments that have been used are

  1. By virtue of the second law of  Thermodynamics, heat cannot be transferred from a colder to a warmer body, and
  2. Since solar energy is the basic source of all energy on Earth, if we do not change the amount of solar energy absorbed, we cannot change the effective radiating temperature of the Earth.

Both of the above statements are certainly true, but as we will show, the so-called  “greenhouse theory” does not violate either of these two statements. (we use quotation marks around the  words “greenhouse theory” to indicate that while this terminology has been generally adopted to explain the predicted warming with the addition of absorbing gases into the atmosphere, the actual process is quite a bit different from how a greenhouse heats).

With regards to the violation of the second law, what actually happens when absorbing gases are added to the atmosphere is that the cooling is slowed down. Equilibrium with the incoming absorbed sunlight is maintained by the emission of infrared radiation to space. When absorbing gases are added to the atmosphere, more of emitted radiation from the ground is absorbed by the atmosphere. This results in increased downward radiation toward the surface, so that the rate of escape of IR radiation to space is decreased, i.e., the rate of infrared cooling is decreased. This results in warming of the lower atmosphere and thus the second law is not violated. Thus, the warming is a result of decreased cooling rates.

Going to the second statement above, it is true that in equilibrium, if the amount of solar energy absorbed is not changed, then the amount of IR energy escaping out of the top of the atmosphere also cannot change.  Therefore the effective radiating temperature of the atmosphere cannot change. But, the effective radiating temperature of the atmosphere is different from the vertical profile of temperature in the atmosphere. The effective radiating  temperature is that T that will give the proper value of upward IR radiation at the top of the atmosphere  such that it equals the solar radiation absorbed by the Earth-atmosphere system.

In other words, it is the temperature such that 4 pi x Sigma T4 equals pi Re2 Fso, where Re is the Earth’s radius, and Fso is the solar constant. Now, when we add more CO2, the absorption per unit distance increases, and this warms the atmosphere.  But the increased absorption also means that less radiation from lower, warmer levels of the atmosphere can escape to space. Thus, more of the escaping IR radiation originates from higher, cooler levels of the atmosphere. Thus, the same effective radiating temperature can exist, but the atmospheric column has warmed.

These arguments, of course, do not take into account feedbacks which will  kick in as soon as a warming (or cooling) begins.

The bottom line here is that when you add IR absorbing gases to the atmosphere, you slow down the loss of energy from the ground and the ground must warm up. The rest of the processes, including convection, conduction, feedbacks, etc. are too complicated to discuss here and are not completely understood anyway.  But the radiational forcing due to the addition of greenhouse gases must result in a warming contribution to the atmosphere. By itself, this will not result in a change of the effective radiation temperature of the atmosphere, but it will result in changes in the vertical profile of temperature.

The so-called “greenhouse effect” is real. The question is how much will this effect be, and this is not a simple question. There are also questions being raised as to the very sign of some of the larger feedbacks  to add to the confusion.  Our purpose here was to merely point out that the addition of absorbing gases into the atmosphere must result in warming, contrary to some research currently circulating that says to the contrary.

For those that might still question this conclusion, consider taking away the atmosphere from the Earth, but change nothing else,  i.e., keep the solar albedo the same (the lack of clouds would of course change this), and calculate the equilibrium temperature of the Earth’s surface. If you’ve done your arithmetic correctly, you should have come up with something like 255 K. But with the atmosphere, it is about 288 K, 33 degrees warmer. This is the greenhouse effect of  the atmosphere.

5 1 vote
Article Rating
632 Comments
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
Vince Causey
July 23, 2010 8:15 am

Good article Dr. Pielke. It is unfortunate that this needs saying at all, but I fear the infamous G&T paper has done a bit of damage to the credibility of sceptical science.

Alberto
July 23, 2010 8:16 am

Greenhouse Gases emitted in all directions. Also into outer space. Seems to forget this detail.

Laws of Nature
July 23, 2010 8:16 am

Hi there,
well .. I usually describe it the following way:
It is a fact, that with increasing CO2 the characteristic CO2 emission into space comes from a greater atmosphere layer (measured by the temperature of the emitting molecule via the spectrum width).
In layman terms this means the lower layer losses one way to transport energy and thus has a lower thermal conductivity (which means it warms)
This effect is well understood and can be calculated to the 3.7 W/m^2 cited by IPCC, the question reamins, what this means to the temperature.
All the best regards,
LoN

July 23, 2010 8:17 am

The amount of warming from the greenhouse effect varies by a large amount between the tropics and the poles, due to the amount of water vapour in the atmosphere. The tropics experience much more more greenhouse effect than the south pole, because there is almost no water vapour in the atmosphere over the south pole.

trbixler
July 23, 2010 8:18 am

My guess is all of the feedback ‘constants’ are driven by the variables “The rest of the processes, including convection, conduction, feedbacks, etc. are too complicated to discuss here and are not completely understood anyway.” Without understanding those variables ones instrumentation is left to quantify the dynamics. Empirical prediction?

July 23, 2010 8:18 am

The conditions forcing the escape of radiation the atmosphere must also force the escape of atmospheric gases. As such, wouldn’t the conditions for escape of those gases be the determinant of the rate of the greenhouse effect
….There is dusted together water on the moon and mars………

AdderW
July 23, 2010 8:18 am

Rubbish…

Trev
July 23, 2010 8:19 am

Surely the ultimate question is – Is the Earth sensitive to changes in CO2 levels?
The earth has had much higher levels of CO2 in the past so the knee jerk reaction to this must be NO, or else we would not be here to talk about it.
Is industrialisation altering our atmosphere to such an extent that we face imminent virtually immediate doom?
Again looking at the last 20 years I would say NO. So whatever we need to do whatever we need to measure and calculate we can do rationally and sensibly and slowly and openly.
Is this happening? NO ….

Leonard Weinstein
July 23, 2010 8:19 am

You have to add the trapping effect of the clouds and you have the basic story complete.

DirkH
July 23, 2010 8:20 am

Anyway, it looks like Kevin Trenberth’s backradiation hop (up, down, up, down) as described here
http://johnosullivan.livejournal.com/19541.html
vastly overestimates back radiation because they just didn’t follow the established vector calculus rules (subtracting energy that goes into the opposite direction).
http://hockeyschtick.blogspot.com/2010/07/new-unphysical-agw-simulator-available.html
The atmosphere is due to the density of CO2 a dense fog for the absorption bands of CO2 even where there is no water vapor, and this was so even before the increase in CO2 emissions. The light (or LWIR) from a diffuse surface like the Earth’s surface must be diffuse. The fog will re-emit the light into all directions equally. What does it matter whether a ray from the surface is intercepted after 23 m on the average or after 15 m the first time, to be re-emitted? Nothing at all when the atmosphere is 10,000 times as high.

Jeff
July 23, 2010 8:20 am

slowing down the cooling of an object cannot cause it temperature to rise … THAT would violate the 2nd law …
if a black box is warmed to x degrees by the sun then its temperature cannot rise above x no matter how much greenhouse gas it is surrounded by …
x becomes the upper threshhold of the objects temperature (assuming no other energy inputs …)
yes, it may REMAIN at some temperature between x and zero longer than it would but it can never rise above x … it may be relatively warmer because of slowed cooling but it has certainly not “warmed” up …
if you say something has warmed you are implying that its temperature has RISEN … not cooled slower …

J. Bob
July 23, 2010 8:21 am

Good article. In a way it reminded me of another item I read today, not exactly on the subject, but interesting, about Enrico Fermi, and connections.
This connection is CO2 causing GW simply because CO2 was increasing and some recent warming. This idea was noted in similar to a train of thought that Enrico Fermi discussed with his friends Teller, John von Neumann, and others over lunch at Los Alamos. The subject was the recent disappearance of NY trashcans and increased appearance of flying saucers. The logical, but not necessarily correct, conclusion was aliens were stealing NY trashcans.
http://www.firstthings.com/onthesquare/2010/07/et-phone-here

July 23, 2010 8:22 am

“The rest of the processes, including convection, conduction, feedbacks, etc…. are not completely understood anyway. … There are also questions being raised as to the very sign of some of the larger feedbacks to add to the confusion. ”
Dr Pielke, I note you talked about warming the ground, but carefully avoided reference to the ocean, the really big dog on the climate block. Since longwave radiation can’t penetrate the ocean, but only causes increased evaporation at its surface, and since as you note, there’s lots we don’t know about convection etc, what makes you so sure adding more co2 will cause warming? Is Miscolzci to be ignored forever?
http://tallbloke.wordpress.com/2010/01/04/why-the-sun-is-so-important-to-climate/
Earth warmed while solar activity was high, and cloud albedo diminished, and ocean heat-energy content has been dropping since 2003 when the sunspot count dropped below its long term average of 40, and cloud increased again.
http://tallbloke.wordpress.com/2010/07/21/nailing-the-solar-activity-global-temperature-divergence-lie/

July 23, 2010 8:26 am

I guess I have a problem with the over simplistic model. Yes, absorbing gasses in the atmosphere ‘slow’ the cooling because the radiated heat bounces a like a pinball from molecule to molecule before it actually radiates to space.
However, the movement of air columns can shorten or lengthen that wayward path, as can precipitation which tends to absorb heat and drop it back into the oceans.
When air heats it rises, but the atmosphere also expands (something easily detected in satellite orbits, which experience changes in atmospheric drag constantly as the atmosphere expands and contracts – sometimes regionally). An expanding atmosphere lowers the density as volume increases. Already ‘thin’ air becomes even thinner, which means the chances of IR radiation bouncing back into the atmosphere should decrease and radiation rates escaping should increase.
If the Earth’s atmosphere actually has built in thermal balancing – which must be the case given it has survived for billions of years – then the combination of precipitative cooling and increased radiative cooling because of lower density and greater surface area to space would seem to more robust than many climate alarmists would consider.
This becomes even more true if recent human actions on climate are driven by the UHI and expanding population centers (changing the basic reflective/absorptive characteristics of the Earth’s surface). I seriously doubt CO2 or any GHG can go into a ‘runaway’ mode. If you look at Mars, Earth & Venus it is not the GHG gas necessarily that drives their climate, but the distance from the Sun (i.e., solar flux intensity) and their mass (how much atmosphere they can hold gravitationally) which dictated their atmospheric stability point.
No one has proved reducing GHG on Venus or increasing it on Mars would change a damn thing. These kinds of theories border on the science fiction concept of terra forming – something never proved even slightly.
The billion year stability of our atmosphere, through massive eruptions, massive (but slow) changes in content, though large impact events, would indicate the cross-checking balancing mechanism always bring the system back to a nominal range of climate. A range we have seen for millions of years and a wide range of CO2 and GHG concentrations.

EDT
July 23, 2010 8:27 am

While it doesn’t refute your argument, I want to point out that assertion #2, technically, is not correct. There are many sources of energy on Earth that are not sun related. Simply because it has mass, the Earth contains ~5^41 J of energy. It creates a vast gravitational well that imparts energy on all objects on the planet. Additionally, a lot of our energy sources have no ties to solar energy (e.g. fission reacts on Uranium which is, most likely, a remnant of a distant supernova).
However, if you were to say that the sun is the source of all BIOLOGICAL energy, I wouldn’t argue.

July 23, 2010 8:28 am

“The rest of the processes, including convection, conduction, feedbacks, etc. are too complicated to discuss here and are not completely understood anyway.”
But that’s the crux of the matter. For starters, there cannot be a proper greenhouse effect in the presence of constant convection. And the biosphere is a temperature regulating mechanism that constantly changes the chemical composition of atmosphere, therefore defining, where the equilibrium will be.
Therefore, all this talk about “greenhouse effect being real” is nonsense. No, it’s not “real,” it exists only within the simplistic framework of intentional misunderstanding.

Dr David
July 23, 2010 8:29 am

How much of the 33 degrees is due to heat escaping from the Earth’s core and tidal forces?

anna v
July 23, 2010 8:32 am

For those that might still question this conclusion, consider taking away the atmosphere from the Earth, but change nothing else, i.e., keep the solar albedo the same (the lack of clouds would of course change this), and calculate the equilibrium temperature of the Earth’s surface. If you’ve done your arithmetic correctly, you should have come up with something like 255 K. But with the atmosphere, it is about 288 K, 33 degrees warmer. This is the greenhouse effect of the atmosphere.
A bit misleading, this last paragraph.
The dry atmosphere consists of:
N2 78.084%
O2 20.946%
Ar 0.934%
rest 0.03768%
and if there is humidity around, H2O 0.4% and more near the surface.
The trouble is not with whether the atmosphere keeps temperatures temperate, but whether the tiny amount of CO2 can contribute significantly to this, considering also that H2O covers most of the spectrum and CO2 only some windows.
I am curious if anybody has calculated a toy earth with only N2 and O2 as an atmosphere. Deserts do get cold at night and hot in the day, but on average would not be too far off current global averages.

July 23, 2010 8:35 am

I question the analysis by Herman and Pielke in
http://claesjohnson.blogspot.com/2010/07/blackbody-radiation-by-ockhams-razor.html
Comments from Herman and Pielke are particularly wellcome.

Michael
July 23, 2010 8:35 am

“If you’ve done your arithmetic correctly, you should have come up with something like 255 K. But with the atmosphere, it is about 288 K, 33 degrees warmer. This is the greenhouse effect of the atmosphere.”
Um, what about an atmosphere devoid of greenhouse gases? What about the dry adiabatic lapse rate?

Bob Kutz
July 23, 2010 8:35 am

That is a very good simple explanation of the greenhouse effect.
Can you tell me, does atmospheric CO2 currently absorb 100% of the longwave IR in the bandwidths which apply?
If so, at what altitude is the saturation achieved?
Assuming that additional CO2 would lower that altitude, what sort of effect would this actually have on surface T? I mean, given what we know about the atmosphere I would think convection would distribute this additional atmospheric heat well enough to prevent a significant increase to the ground temp and probably keep the increased surface atmospheric temp from increasing a great deal as well. I guess what I’m really asking is, if all of the IR that CO2 can absorb is already being absorbed by CO2 within the first several tens of meters above the surface (to my understanding), what additional impact can more CO2 have on the overall heat content of the atmosphere, and does it really make a difference if that heat is added in the first 50 meters or the first 5?
Maybe this isn’t so, I do not know for a fact if the CO2 is currently absorbing 100% of the IR it is capable of, though I’ve read and been told that this is true. Maybe science doesn’t yet know the answer to these other questions, which would seem plausible as this is almost bordering on chaos theory; (everything’s just so, you have all of the measurements and can accurately predict what will happen forever, then a butterfly flaps it’s wings and all of your calculations go awry.)
Or maybe I’m just way off base in my line of thinking here.
Please let me know your thoughts.
And again, this is a really good article in describing the greenhouse theory of global warming to someone (like me) who hasn’t the scientific background to do the math, but is really trying to understand and keep up with the debate.

July 23, 2010 8:37 am

Dr. Pielke
For your demonstration of the greenhouse effect WUWT has used the Arctic part of the globe, which is currently very popular with many researchers. In a way of a modest contribution, I think I may have found an important correlation as shown here.
http://www.vukcevic.talktalk.net/NFC1.htm
You may not agree with the explanation for this unusual phenomenon, but in the interest of science and the readers of WUWT (well over 3000) who viewed this graph, I would very much appreciate your comment.
Thank you.

Pamela Gray
July 23, 2010 8:38 am

This is entirely reasonable. For me, that we have greenhouse affects on the planet is rather boring (not that your presentation was). It’s kind of a stable thing and of not much complexity relatively speaking.
It’s the feedbacks and turbulent nature of the thermosphere that fascinates me. Much harder to simply explain and therefore endlessly fascinating to me. If each of our gasses and particulates in our overturning thermosphere (warm to cold in height so it wants to be turbulent) were colored, it would be a right pretty ever changing kaleidoscope of swirling color topped with a ribbon-like fairly stable stratospheric layer (cold to warm in height so those layers don’t want to be turbulent), and so on. If one were to try to demonstrate AGW increases in any one color in that thermosphere, stratosphere, etc, you would be hard pressed to do so. But regardless I could stare at such a presentation for hours.

DirkH
July 23, 2010 8:40 am

DirkH says:
July 23, 2010 at 8:20 am
“[…]The atmosphere is due to the density of CO2 a dense fog for the absorption bands […]”
Such a re-emitting fog must tend towards an equilibirum, and that’s why its exact density does little to change the overall distribution of re-emittance towards the ground or space; just like adding another 15m of atmosphere does not change the distribution. I’m assuming a 100% re-emittance here. If the re-emittance is smaller, energy will just be distributed to non-LWIR-emitting molecules like O2 which results in heating where we enter the area of “not well understood anyway” convection and conduction so that would steal some more energy from Kevin Trenberth’s beloved backradiation, torpedoing his assumptions further.

Leonard Weinstein
July 23, 2010 8:40 am

I don’t think that most of the arguments circulating (such as Lubos’s or mine) are contradicting what you said. Their point is that, at least for Venus, it is mainly the fact that the atmosphere is very tall due to much higher mass of the atmosphere that causes the very high surface temperature. There still needs to be greenhouse gas and clouds, but they could be a far lower percent of the composition and still get most of that high temperature as long as the mass of the atmosphere is high enough to maintain the approximate altitude where outgoing radiation leaves the atmosphere. If the Earth had 100,000 ppm CO2 rather than 390 ppm, the temperature would only be a few degrees higher that at present, due to the limited size of our atmosphere. In other words, it is the COMBINATION of mass of the atmosphere that is resulting in it’s thickness combined with the trapping effect of greenhouse gases and clouds that result in the ground temperature. The concept that had been often stated, of a “runaway” greenhouse effect, is what brought that point up. There is no runaway, just straightforward fluid dynamics and radiation heat transfer.

EDT
July 23, 2010 8:43 am

bah. I pounced on the sentence without reading the context. You were quoting other sources. Nevermind. I guess I’m the troll here. 🙂

Mike Davis
July 23, 2010 8:44 am

This shows a lack of understanding of how a green house works. A green house restricts transfer of energy it does not heat or cool. By claiming that green house gasses that restrict energy transfer result in warming you are missing half the equation because they also restrict the increase in warming to start with. The restriction leads to less extreme temperatures both warm and cold. If the globe was experiencing an increase in Green House Effect we would see a reduction of extreme weather events because of the restrictive nature you claim. There is no evidence of that! Climate continues within the range expected for an interglacial period as displayed by historic interglacials.

John A
July 23, 2010 8:45 am

Dear Dr Pielke:

The bottom line here is that when you add IR absorbing gases to the atmosphere, you slow down the loss of energy from the ground and the ground must warm up.

What are “IR absorbing gases”? As far as I am aware, gas molecules can absorb light quanta but by becoming excited, they give up the energy just as quickly. There is a slight loss of energy because of increased entropy on the release of that energy, because some of that motion is converted into molecular oscillation and some into translational energy.
You appear to reject the nomeclature of “greenhouse theory” because that isn’t how greenhouses warm up, but you describe the warming of the lower atmosphere as if there was a sheet of glass high up there which heats up and then magically re-radiates the energy to the ground and then slows down the re-emission of the heat back into space. This is a false model.
Real greenhouses don’t work like this either – they warm because they restrict the convectional motion of the air, something demonstrated one hundred years ago by Robert Wood.
The atmosphere also has massive convectional motion driven by the Sun which (somewhat to my surprise) is completely ignored in those idiot cartoons by Trenberth which treats the Earth’s atmosphere as if it was made of lucite. The circulation of the oceans is an even bigger thermodynamic engine driven by the Sun.
I’m afraid you have failed to grasp the main criticism of the greenhouse gas hypothesis – the atmosphere is not restrained from convecting.
Why does it not get so cold at night? Because of water vapour in the atmosphere. Not because water vapour is “a powerful greenhouse gas” whatever that means, but because in the atmosphere water vapour changes state from gas to liquid as it cools and liquid to gas as it heats up. Thus some of the energy from the sun is captured in the latent heat of vaporization (NOT “re-radiated”) of water backwards and forwards from gas to liquid to gas. The heat captured by water condensing in the atmosphere during the day is transported to the nightside (by the rotation of the earth) where the loss of the Sun is compensated by emission of heat as water evaporates and re-emission of heat as water condenses higher up.
It is the water vapour effect of retaining heat by constant cycling from liquid to gas to liquid that slows the re-emission of heat energy back into space, not “re-radiation”. Water vapour clouds glow in IR because of this effect, which is why they can be pictured at night from satellites.
The more water vapour in the atmosphere (as in the tropics) the greater this heat trapping in clouds becomes.
It explains why the greatest difference between day and night temperatures occurs in the major deserts where water vapour in the atmosphere is scarce. It also explains why the difference between day and night on Mars is even more extreme than the Earth despite having eight times the partial pressure of CO2 at the surface than the Earth – its the lack of heat energy “trapped” by water vapour of which Mars has very little, from changing state in the atmosphere in the form of clouds.

Richard Garnache
July 23, 2010 8:49 am

While I agree that so-called greenhouse gases reduce the cooling rate of the earth, the degree that CO2 affects that cooling rate is in question. Ibelieve the formula used by IPCC is in serious error.
The IPCC contends that doubling the co2 concentration will cause a forcing of 3 to 6 degrees C. Unfortunately they seem to be better at fudging data than applying physics. Their standard calculation is shown below.
∆T=4.7ln(c/co)=4.7ln(836/368)=4.7*.69=3.2Deg C
However, H20 also absorbs 15 micron radiation. Since water vapor concentration is 1 to 4% of the near earth atmosphere, it would be more accurate to include all gasses that absorb 15 micron radiation. To be clear, c should include 10000ppm water vapor plus 836 ppm co2, and co should be 10000 ppm water vapor plus 386 ppm co2.
∆T=4.7*ln(10836/10386) = 4.7*.044 = .2 degrees C
I can live with that.

Leonard Weinstein
July 23, 2010 8:54 am

I need to add another point mainly related to Venus. Absorption of the radiation from the ground is important so that back radiation nearly equals radiation up as a trapping mechanism. However, this DOES NOT significantly directly change the atmospheric temperature. The main factors that determine the atmospheric temperature are the effective location of outgoing radiation (which sets the value of temperature in the atmosphere at that location) and lapse rate, and the lapse rate will (on the average) be the wet or dry lapse rate. The atmospheric convection totally dominates in retaining that lapse rate level (it transports much more energy that the radiation flux). The trapped heat was important is setting the location of the outgoing radiation, and for Venus, that is its only important function. Earth is much more complicated due to the fact that the outgoing radiation leaves from all altitudes from the ground up, so that can’t be treated as simply as Venus.

DirkH
July 23, 2010 8:59 am

The radiation density in my idealized CO2 fog must, when it reaches equilibrium with the LWIR-radiating Earth surface, have the same radiation density as the Earth’s surface. It cannot exceed this radiation density. The CO2 concentration is not a variable that can manipulate this. The fog model only breaks down with extremely low CO2 concentrations; but the variation in CO2 concentration from 270 ppm to 390 ppm does absolutely NOTHING to the radiation density in this fog.

Nylo
July 23, 2010 9:01 am

tallbloke, the GHE will by itself (i.e. without feedbacks) cause warming. However as it happens, other collateral effects may cause the warming to be increased, decreased or perhaps even reverted into cooling. Roger is only talking about the GHE, alone, without considering feedbacks.

DirkH
July 23, 2010 9:03 am

So any measured INCREASE in downwelling CO2-caused LWIR radiation must be caused exactly because this fog model is idealized and the real atmosphere behaves differently. IOW, CO2 moelcules collide with O2 etc and heat the gas mix up via conduction. Where, again, energy leaves the radiation model and turns into plain old kinetic energy, heats the atmosphere up, leading to convection. As Abdusamatov has said “Heat rises up, not down”.

Enneagram
July 23, 2010 9:03 am

Tallbloke is right. Do you prepare your breakfast with a hair dryer? “Your are going against the wind”. Have you already found that atmosphere’s heat piggy bank you dreamed of?. You integrate from 0 to infinite, that’s like asking, how much will I warm up by putting on my bed an infinite number of covers?. Add all the warm you can to the atmosphere and it won’t warm up sea water. Please, let us not cheat people: The heat capacity of the air is 3227 times less than water. Would you warm your feet, when cold, with a bottle filled with hot air, or instead with hot water?

July 23, 2010 9:06 am

“If you’ve done your arithmetic correctly, you should have come up with something like 255 K. But with the atmosphere, it is about 288 K, 33 degrees warmer. This is the greenhouse effect of the atmosphere.”
I politely disagree. That 255K has been obtained by blackbody calculation, but confusingly with present Earth’s albedo (which is predominantly made by clouds and snow/ice). Look at the nearby Moon with albedo 0.11 (Earth has ~0.3): its average temperature is 270K.
http://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html
So for start, 288-270K = 18K is more correct.
Second, this temperature difference is because of existence of ATMOSPHERE, not greenhouse gases. It is easy to show, that on Earth, the main “greenhouse gas”, water vapor in various states, effectively cools the Earth: a) by clouds, creating major part of albedo, b) by evaporative cooling, preventing all Earth being hot as dry deserts, c) by ice/snow, participating on albedo.
Mere greenhouse gases in a thin atmosphere create no “greenhouse” effect. Mars atmosphere consists of 95% CO2 – but Mars blackbody T = Mars actual T = 210K.
http://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html
You need a bulk atmosphere (in our case composed of N2 and O2) and water in liquid/vapor state to get habitable conditions with mild diurnal cycle and pleasant average temperature. Our nights are warmer than on the Moon not because of “backradiation”, but mainly because the atmosphere holds the daily heat. “Backradiation” on Mars does NOTHING, and the effective concentration of CO2 there (6,000 ppm) is that of CO2+water vapor on Earth (if water vapor creates 90% of GHE).
In my chemist opinion, the greenhouse theory confuses the simple heat storage in the atmospheric mass with hypothetical arrows in radiation diagrams.
Not to forget, how do I know the IR radiation is coming from IR active gas, and not from nitrogen/oxygen bulk atmosphere? That forgotten 99% of the atmosphere radiates in IR spectrum, as every material with its temperature above zero K.

Ibrahim
July 23, 2010 9:08 am

Could you tell me how much IR-radiation is coming straight from the sun to the earth?

Ralph Dwyer
July 23, 2010 9:08 am

Speaking for the simple-minded among us, I think we are very fortunate to have an atmosphere that “behaves/responds” as well as it does supporting life as we know it. Keeping it simple, I don’t think anyone would argue that the atmosphere is in equilibrium. But it is “responding” to something. Right? Could it be the sun above and/or the oceans and land mass below or volcanic emissions or even the pesky humans? I’ll stick with Ian Plimer on this one and say the pesky humans are the least of out worries.

Mac
July 23, 2010 9:09 am

….. but the atmosphere is not a perfect blanket around this planet. Additionally CO2 only constitutes a small fraction of the atmosphere’s composition. So the % of IR radiated directly back to Earth is small.
Also the oceans, which covers 70% of this planet’s surface, lose most of its heat thru evaporation, which involves a completely different physical process.
If this planet had no oceans and a thick atmospheric blanket of CO2 then I would agree that there would be a significant rise in surface temperatures ……….. but this planet doesn’t.

SeSci
July 23, 2010 9:13 am

What is Governing the Temperature of the Earth?
The surface of Planet Earth is heated by the incident short-wave electromagnetic radiation from the sun. In order to balance the temperature of the earth, most of this incident radiation energy is, contrary to the assumption made in the AGW hypothesis, removed from the surface by convective cooling by a flowing atmosphere and by evaporation (removal of latent heat) from the surfaces of the seas, lakes and moist soil; and by transpiration of plants. Only a small fraction of the incident energy is radiated by the surface towards space in the long-wave infra-red (IR) part of the electromagnetic spectrum [1]. Consequently, the lower atmosphere, is heated by convective heat transfer from the surface of Earth; by release of latent heat during condensation of water vapour (formation of clouds) and; to a small extent, by thermalisation of excited GHG molecules. The so heated air parcels increase in volume (reduce their density) and rise towards higher altitudes, while their temperature reduce along the lapse rate function. The rising warm air is replaced by cooler air, thus maintaining a continuous convective churning/stirring of the atmosphere that we call wind.
In the upper part of the troposphere and in the stratosphere, IR energy can more efficiently be emitted towards space to achieve the required radiation balance of Earth’s. That is, the estimated effective radiation balance temperature for the earth, ‑18°C, is established in the upper portion of troposphere and in the stratosphere and not at the surface of the earth, as anticipated by IPCC and the AGW proponents.
The bottom portion of the troposphere and thereby also the surface of the earth, exhibit an average temperature of +15°C. This is approximately 33 K higher than what can be estimated based on the radiative balance with space. This temperature increase is the direct result of the presence of an atmosphere, with its given mass, within the gravitational field of the earth (see contributions by Jelbring and Thieme below). The atmosphere (the air), with its mass, is attracted towards the surface of the earth by the gravitational field. Most of this atmospheric mass will thus reside close the surface of the earth where it is compressed to a higher pressure (on average 1.013 bar) and obtains thus a higher temperature. Correspondingly, the atmosphere becomes thinner (less compression and thus lower pressure) and cooler, the higher the altitude is. This pressure and temperature distribution is governed by a restricted thermodynamic equilibrium, so-called adiabatic condition. Such a condition prevails when the size of the air parcels is large in comparison to the length scales for heat conduction and diffusion during the time interval pertaining to the state change. Adiabatic changes in temperature thus occur due to changes in pressure of a gas while not adding or removing any heat from or to the surrounding. This entails that the total energy content in an air parcel with a given mass remains constant when it moves vertically, that is, the sum of potential and thermal energy remains constant, independent of the altitude.
The (vertical) circulation of the air is a continuous process that is driven by the sun and the dynamics of the planetary atmosphere. At high altitude (high potential energy), a parcel of air of given mass has a large volume and low temperature (low thermal energy). When brought to lower altitudes (low potential energy and high thermal energy) it becomes compressed and thus heated. Again, the temperature of the air parcel will be governed the lapse rate function, which is a consequence of the prevailing thermodynamic equilibrium under adiabatic conditions.
The mathematical description of this mechanism has been called the adiabatic model of atmospheric temperature (see papers by Khilyuk and Chilingar) and can closely (within 0.1%) describe the long-term average temperature distribution as function of altitude in the troposphere. The normal atmospheric pressure (1.013 bar) near the surface of the earth will bring the air temperature to around +15°C, or TEarth  33 K higher than the temperature determined from the radiation balance between incident (short-wave) radiation from the sun and outgoing (long-wave) radiation from the upper part of the atmosphere towards space.
The cyclic heat input from the sun (over day and night; seasonal variations at different latitudes, etc.) provides the driving forces behind the continuously circulating atmosphere and its vertical transport of heat from the surface of the earth to higher altitudes, where heat balance can be established by long-wave radiation towards space. Well proven, basic physics considerations (radiation balance and adiabatic compression) therefore directly explain the observed temperature of Earth’s atmosphere, without the need to revert to obscure and unverified greenhouse effects from greenhouse gases.
The Hothouse Venus
Planet Venus, with its CO2 rich atmosphere (96.5% CO2) has a very high surface temperature, in the order of 462°C (735 K). This high surface temperature is often claimed to be the result of a runaway greenhouse effect due to the high CO2 concentration, evaporation of the surface water and subsequent rise of the levels of other GHGs. This, of course, sounds plausible in the ears of the AGW proponents, who want to scare the inhabitants of Planet Earth that similar dramatic temperature increases (beyond the tipping point) may develop also here, if we do not take appropriate measures to curb the emission of GHGs.
There exists, however, a physically well-founded, explanation for the high surface temperature on planet Venus, namely the adiabatic model of atmospheric temperature (see papers by Khilyuk and Chilingar), mentioned above. Not only is the concentration of CO2 much higher at Venus than on Earth, but also the atmospheric pressure at the surface of Venus is much higher, approximately 90 bar. While the gravitational effects on the mass of the (dynamic) planetary atmosphere heats the bottom of the atmosphere and the surface of Earth by TEarth  33 K above the effective temperature expected from radiation balance alone, the same effect on Venus heats its surface by TVenus  507 K above its effective radiation balance temperature, which is ‑45°C (228 K). The adiabatic model of atmospheric temperature also well describes the temperature of the Venusian atmosphere as function of altitude, within 1%. Again, there is no need to revert to an (unverified) runaway greenhouse hypothesis to explain the high surface temperature of Venus. Plain, well established, physics suffices. Consequently, the (runaway) greenhouse effect does not exist.
Suggested Reading:
H.R. Jelbring. The Greenhouse Effect as a Function of Atmospheric Mass, Energy & Environment, Volume 14, Number 2 – 3, May 2003, pp. 351-356, http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/FunctionOfMass.pdf
Hans Jelbring, Politics and the Greenhouse Effect, http://www.tech-know.eu/NISubmission/pdf/Politics_and_the_Greenhouse_Effect.pdf
Heinz Thieme, The Thermodynamic Atmosphere Effect – explained stepwise, http://realplanet.eu/atmoseffect.htm
L. F. Khilyuk, G.V. Chilingar, On global forces of nature driving the Earth’s climate. Are humans involved? Environmental Geology, Volume 50, Number 6 / August, 2006, pp. 899-910, http://www.springerlink.com/content/t341350850360302/ (behind pay-wall)
G.V. Chilingar, L.F. Khilyuk, O. G. Sorokhtin. Cooling of Atmosphere Due to CO2 Emission. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, Volume 30, Issue 1, January 2008, pages 1‑9
http://www.mitosyfraudes.org/Calen9/Chillingar_Atm_Cooling_due_to_CO2.pdf

Monckton of Brenchley
July 23, 2010 9:13 am

I am delighted that this simple and clear but authoritative statement of the reality of the “greenhouse effect” has been posted here. Too many inaccurate statements to the effect that there is no greenhouse effect have been published recently, and they do not deserve to be given any credence. The true debate in the scientific community is not about whether there is a greenhouse effect (there is), nor about whether additional atmospheric CO2 causes warming (it does), nor about whether CO2 concentration is rising (it is), nor about whether we are the cause (we are), but about how fast CO2 concentration will rise (for a decade it has been rising at a merely-linear 2 ppmv/year, against the IPCC’s projection of an exponential increase at today’s emission rates), how much warming a given increase in CO2 concentration will be expected to cause (around a third of what the IPCC projects), whether attempting to mitigate future “global warming” will make any real difference to the climate (it won’t: remember Canute), whether the cost of forestalling each degree of “global warming” will be disproportionate to the climatic benefit (it will), and whether focused adaptation to any change in the climate, where and if necessary, will be orders of magnitude cheaper than trying to prevent that change from occurring in the first place (yes).

Dave Dardinger
July 23, 2010 9:15 am

Thus, the warming is a result of decreased cooling rates.

This is a bit misleading. As you point out later, the total heat released to space is going to be the same eventually. And the amount of radiation released by the surface will actually increase to include the increased amount of long-wave radiation downward. What’s really changed is the ability of the atmosphere to absorb additional heat because of the increased amount of GHGs in it. This means both the surface and the lower atmosphere will warm (if feedbacks are ignored.)

dp
July 23, 2010 9:17 am

Is it possible to discuss briefly the effects of changes in the night sky temperature? (I say night sky only because it is easier to visualize, but it is in fact a twenty four hour effect).
As a side note to my interest in studying night sky radiation as an energy source for heat engines is that the temperature of the sky at the galactic plane is quite different than what it is away from the plane, and that the alignment of this plane with the earth’s equator is cyclical over time. This periodic alignment (and other celestial alignment variations) exposes the equatorial earth to longer periods of warmer areas of space and of course the poles to cooler areas, and this, it seems, should affect the ability to cool by radiation.
This question occurred to me because the article discusses the thermal properties of the sky as an unchanging component of the process. Surely in my lifetime it will be, but over the period of time important to climate this may be non-trivial.

Josh Grella
July 23, 2010 9:17 am

Though I agree with the general idea written about here, I still have a few questions about the greenhouse effect that I haven’t seen addressed anywhere yet (perhaps I just missed it along the way). If greenhouse gases increase, would they not absorb incoming IR as well as outgoing IR? If they do, how do we determine which IR they abosorb at what rate? Also, since CO2 and other gases can/do emit IR in all directions, how do we determine where the radiation emitted goes or is it just assumed that it is emitted in all directions at the same rate/proportion? Is it easier to emit IR outward, sideways, down, any other direction depending on which layer of the atmosphere said greenhouose gas is in? Is all or some of this part of the great unknown at this point?

GabrielHBay
July 23, 2010 9:17 am

The weakness in all this seems to me to be the impression I gain that this is all just theory… there MUST be warming because, based on the line of reasoning, it seems to make sense. Is there any experimental method or data that actually confirms that the theory is valid? Yet some of the other theories that have been circulating have also seemed to make sense. Frankly, having spent countless hours reading on this (excellent) site, I have come to the conclusion that even the most sincere analysts and philosophers here are still dealing out opinions and theories that, while interesting, still fail the test of hard science in that nothing can yet be proven. My own skepticism goes beyond just AGW to encompass the entire field of the related science. The actual reliable knowledge here is still dwarfed by the vast unknown. Sorry guys..

Theo Goodwin
July 23, 2010 9:19 am

Is it not true that your explanation is based on the assumption that CO2 molecules are distributed randomly in the atmosphere? Is it not true that there have been no experiments to test the assumption that CO2 molecules are randomly distributed throughout the atmosphere?

John Prendergast
July 23, 2010 9:20 am

Lord Kelvin’s second Law lof Thermodynamics paraphrases as heat flows from a hotter body to a colder body. Thus heat from earth’s surface and lower atmosphere must flow to a colder body, perhaps the 0.389 parts per million of CO2 in the atmosphere. However CO2 does not radiate heat to space or back to earth in certain fairly narrow wave lengths. This means we have lot of hot CO2 floating around in the atmosphere, don’t we? No we don’t, becuase hot CO2 molecules pass on their heat to cooler fuller spectrum radiating nitrogen and oxygen molecules. The very slightly heated Oxygen and Nitrogen molecules radiate more energy to space than they did before. Thus CO2 may have an effect but it is going to be very very small until the atmosphere gets to about 13% Co2 when CO2 molecules will start to have to try harder to pass on heat to oxygen and Nitrogen and Helium and Argon molecules.
Of course water vapour mucks things up, there are about 2790 times more water vapour molecules in the atmosphere than there are CO2 molecules and water vapour acts both as a solar sheild/reflector as well as an emitter when not in clouds formation. Water vapour also blocks heat radiation in same frequencies as CO2, again a very small part of the radiating spectrum.
Please stop knocking CO2 – it is free plant food. We need every bit of growing power as earth gets fuller of people.

CodeTech
July 23, 2010 9:22 am

And then… then there’s night. That would be what half of the planet is experiencing at any one time.
Has anyone tried using a satellite to measure IR radiation on the night side? If night time IR emissions are dropping, then I’d accept that “something” is happening. But as it is, “nothing” out of the ordinary is happening.
Any attempt to show “something” will continue to fail as long as heat continues to radiate away on the night side. That would be the major mechanism of the planet’s temperature self-regulation.
Of course the “greenhouse effect” is real, and of course H2O is the overwhelmingly dominant factor. The currently popular fantasy about CO2 “tipping” the balance in some dramatic fashion is ludicrous, and ignores historically significant CO2 levels that did not (and can not) cause any of these “tips”.
If only some of these people would stand back and see how insane the concept of runaway “feedbacks” is at the gas percentages we’re talking about… especially in the context of an atmosphere that has remained relatively stable for BILLIONS of years.

July 23, 2010 9:22 am

I think this old article by me holds up pretty well to date :
http://climaterealists.com/index.php?id=1562
“Greenhouse Confusion Resolved”
and this is especially for Enneagram:
http://climaterealists.com/index.php?id=1487&linkbox=true&position=3
“The Hot Water Bottle Effect”

DirkH
July 23, 2010 9:24 am

Claes Johnson says:
July 23, 2010 at 8:35 am
“I question the analysis by Herman and Pielke in […]”
Great to see you here, Prof. Johnson! I guess your argument (ignoring the low frequency backradiation) is the classical thermodynamics position. My model of a “CO2 fog” that redistributes the “backradiation” around until an quilibrium is reached practically has the same effect: As the radiation in this absorption band goes back and forward in all directions, it practically cancels out, and that is exactly what your argument says (that it’s irrelevant).
Yours is the general view of energy balance, mine – or Dr. Pielke’s – looks at individual rays and tries to figure out the system dynamics.

drams1
July 23, 2010 9:26 am

Reading some of the comments suddenly makes me feel sympathetic with the few warmists that read sceptical blogs.
…and that is an amazing feat…

Enneagram
July 23, 2010 9:27 am

There is no such a thing as the greenhouse effect, greenhouse gases are gases IN a greenhouse, where heated gases are trapped and relatively isolated not to lose its heat so rapidly. If greenhouse effect were to be true, as Svante Arrhenius figured it out: CO2 like the window panes in a greenhouse, but …the trouble is that those panes would be only 3.8 panes out of 10000, there would be 9996.2 HOLES.
See:
http://www.scribd.com/doc/28018819/Greenhouse-Niels-Bohr
No CO2=No life on earth=No YOU.
BTW: CO2 it is not black, ya know, it’s what you exhale (900 grams a day)and plants breathe.

DirkH
July 23, 2010 9:31 am

John Prendergast says:
July 23, 2010 at 9:20 am
“[…]cooler fuller spectrum radiating nitrogen and oxygen molecules. The very slightly heated Oxygen and Nitrogen molecules radiate more energy to space than they did before. ”
One objection, John: O2 and N2 don’t radiate in the LWIR range. What they can do is rise, give the heat back to CO2 molecules higher up in the atmosphere via collisions, and CO2 is a good radiator in the LWIR range – namely in its absorption band. That is why CO2 and water vapor act as coolants in the stratosphere because these molecules are best suited to radiate LWIR to space.

Bill Yarber
July 23, 2010 9:32 am

I disagree completely with the 3rd and 4th paragraphs because they refer to a step change in absorption and not the resulting steady state condition after the system returns to equilibrium! The temperature of theEarth is controlled by the radiation received from the sun. If that radiation is held constant, the changes in the CO2 concentration will not deduce the energy out, only slow the transit time temporarily until the new equilibrium condition is achieved. Energy in was balanced with the energy out prior to the step change and if the energy in does not change, the energy out will again balance the energy in at the new equilibrium level. The only change is the temporary change to the radiation transit time.

RuhRoh
July 23, 2010 9:35 am

Mr. Juraj V;
Are you saying there is more CO2 on Mars than on Earth, yet there is no discernible ‘greenhouse warming’ on Mars? Yikes!
From those very handy links,
Mars atmosphere is ~2.5 x 10**16 kg, @950,000 ppm CO2, yes?
Earth atmosphere is ~5 x 10**18kg, @ 400ppm CO2.
This seems to be a very potent issue for the greenhouse advocates.
Maybe RC can answer this one.
RR

July 23, 2010 9:39 am

What is patently obvious is that there are too many processes going on in the atmosphere, including daytime/nighttime effects, seasonal effects, land versus ocean effects, conduction, convection, radiation etc etc for simple explanations to answer the question. It is because “climate scientists” try to oversimplify what is a very comples process and include “back-radiation” that non-experts in thermodynamics get very confused.
Perhaps it is the purpose of “climate scientists” to spread confusion because they do not understand it themselves.

DirkH
July 23, 2010 9:40 am

Explaining misconceptions on “The Greenhouse Effect”
Posted on July 23, 2010 by Anthony Watts
Guest post By Ben Herman and Roger A. Pielke Sr.
“[…]decreased, i.e., the rate of infrared cooling is decreased. This results in warming of the lower atmosphere and thus the second law is not violated. Thus, the warming is a result of decreased cooling rates.”
Wait. If a cooling rate decreases, but, as you say, the overall radiation emitted by the planet stays the same, this means that the heat transport becomes slower. This is in line with my CO2 fog argument.
BUT, if the TRANSPORT RATE decreases, this will lead to an increase in “trapped heat” only as long as the transport rate keeps decreasing. IOW, the temperature anomaly must be the first derivative of the CO2 increase as recognized by Beenstock and Reingewertz
(in
http://economics.huji.ac.il/facultye/beenstock/Nature_Paper091209.pdf
)
and as predicted by Miskolczi’s theory.
So i guess we have a new consensus here even though we approach the argument from different angles.

DirkH
July 23, 2010 9:42 am

DirkH says:
July 23, 2010 at 9:40 am
“IOW, the temperature anomaly must be the first derivative of the CO2 increase ”
Correction : “the temperature anomaly must be the first derivative of the CO2 concentration”
We must be nit-picky here.

mkelly
July 23, 2010 9:43 am

If you’ve done your arithmetic correctly, you should have come up with something like 255 K. But with the atmosphere, it is about 288 K, 33 degrees warmer. This is the greenhouse effect of the atmosphere.
Some comments:
1. The weight of the atmosphere adds heats. PV=nRT. STP indicates without “GHE” temperature is 273 K. So “GHE” can account for 15 K at most.
2. The second law is about the increase of entropy. dS = dQ/T. You seem to be saying entropy can decrease. Please be clearer. Every exchange of a IR photon must increase entropy and thereby not allowing an increase in temperature.
3. If you are going to use blackbody radiation then include Wein’s Law. T = 3000/micro. The absorbtion line for CO2 is 15 micro. That is a temperature of 200 K. We live is a 300 K world. Any IR absorbed by a molecule of CO2 would be at the temperature energy level of 200 K. How does this heat anything? Further, let’s be clear black body is for a two dimensional cavity. The soil, rocks, etc absorb energy down to depth which is a violation of the use of black body theory.
4. All atmospheric gases dissipate heat. None add heat on there own. Adding CO2 in my living room will not increase the temperture as long as my heater puts out the same heat. CO2 in not an insulator.
5. O2 or N2 that absorbed conducted heat or convected heat from the ground will not be effected by anything a CO2 molecule does having absorbed an IR photon.
Thank you for the post.

Tom Rowan
July 23, 2010 9:45 am

Omitted is the fact that the overwhelming greenhouse effect is caused by water vapor and not CO2.
I do not know of any serious student of climate study refuting the fact that water vapor literally blankets the planet and keeps it warm during nighttime.
This fact is evident whenever cloud cover at night blankets us even in colder weather.
Everyone who is alive recognizes that fact and it has never been in any serious dispute.
A crystal clear night cools more rapidly than a cloudy one. What is always lost on the warmest, and apparently the authors of this piece, is that CO2 remains relatively constant whether or not the night sky is cloudy or clear.
If CO2 were a dominate greenhouse gas, then every night would remain warm regardless of cloud cover.
Thus endeth the obvious. Why not point it out?

July 23, 2010 9:49 am

Ben Herman and Roger A. Pielke Sr: NODC Ocean heat content (OHC) data shows no sign of the effects from a rise in anthropogenic greenhouse gases. Tropical and southern hemisphere OHC show flat to declining trends that are occassionally shifted up by multiyear La Nina events. See:
http://bobtisdale.blogspot.com/2009/09/enso-dominates-nodc-ocean-heat-content.html
North Pacific OHC declined until the late 1980s, then shifted upwards with a change in the NPI. Refer to:
http://bobtisdale.blogspot.com/2009/12/north-pacific-ocean-heat-content-shift.html
And North Atlantic OHC is impacted by AMO/AMOC, sea level pressure and ENSO. See:
http://bobtisdale.blogspot.com/2009/10/north-atlantic-ocean-heat-content-0-700.html

DirkH
July 23, 2010 9:50 am

Vince Causey says:
July 23, 2010 at 8:15 am
“Good article Dr. Pielke. It is unfortunate that this needs saying at all, but I fear the infamous G&T paper has done a bit of damage to the credibility of sceptical science.”
Not at all! It is the same argument as formulated by Prof. Claes Johnson and classical thermodynamics! It is just that we mere mortals often have a hard time following the physicists because they tend to make rather large steps in their arguments. It’s not a contradiction at all.

July 23, 2010 9:51 am

Trouble with carbon dioxide greenhouse effect is that it requires carbon dioxide to absorb infrared radiation and thereby get warm. This simply does not happen because the infrared band of the atmosphere is saturated and no further additions of carbon dioxide to air can change the already-existing greenhouse effect. This follows from the empirical observation based on NOAA’s weather balloon database that the global average annual infrared optical thickness of the atmosphere has been unchanged for 61 years, with a value of 1.87. This means that constant addition of carbon dioxide to the atmosphere for the last 61 years has not had any influence on the transparency of the atmosphere in the infrared or the optical thickness would have increased. And it didn’t. See Ferenc Miskolczi E&E 21(4):243-262 (2010). His is the first determination of the actual optical thickness of the atmosphere in the IR despite the billions spent on “climate research” by “climatologists” who spew out thousands of “peer reviewed” papers every year.

PolyisTCOandbanned
July 23, 2010 9:52 am

1. It’s kind of sad that Pielke needs to put this kind of thing forward and that hoi polloi are/were/continue to be so wishful thinking as to believe the greenhouse effect can not exist or the like.
2. There are a lot of good insights from nuclear reactor design that are useful in giving insights into why greenhouse effect occurs. Things like understanding heat transfer accross plates of multiple cladding content. Things like how a material may be non-absorbing of fast neutrons, but absorbing of thermal neutrons. how water can act as a “reflector” despite isotropic nature of the liquid itself, how power can remain the same, but centerline temp change as a result of gradient across the plate. Etc. etc.

Ryan
July 23, 2010 9:53 am

“The bottom line here is that when you add IR absorbing gases to the atmosphere, you slow down the loss of energy from the ground and the ground must warm up. ”
Whoa! Big logical leap right there. The atmosphere may on average warm up. That does NOT mean that the ground warms up.
The absorbtion could be in the upper layers of the atmosphere leaving less energy to reach the ground. This will be particularly true if the angle of incidence of incoming radiation is such that the energy reaching the ground has had to travel through a great deal of atmosphere to reach the ground – since much of the warming of the (upper) atmosphere will in such cases occur further south.
Imagine a duvet touching your body – the inner layers of the duvet tend to get as warm as your skin temperature but the outer layers do not, and neither do the parts of the duvet not in contact with your skin.
And all this is before we get into the complexities of energy being absorbed by evaporation creating cloud cover and therefore less incident radiation reaching the ground, in the manner of a giant air-conditioning system.

July 23, 2010 9:57 am

Thank Dr. Pielke,
One of the difficulties the sceptical community has in making any headway is the large collection of nonsense that certain people insist upon. Luckily, Christy, Spenser, Lindzen, Pielke, Monkton all rightly understand that the key scientific questions is
How much warming.
GHGs will not cool the planet.

July 23, 2010 9:59 am

“When absorbing gases are added to the atmosphere, more of emitted radiation from the ground is absorbed by the atmosphere”
Can I just point out the CO2 is not just an absorbing gas, it is also an emitting gas.
A gas which absorbs at a particularly frequency is also a gas which emits at that frequency (at least when that frequency is near black body temperature).
Adding CO2 to the atmosphere therefore can also tend to make it cool down by creating a pathway for heat to be emitted by the CO2 if the CO2. This is basic physics and it is about time the cooling effects of CO2 were more widely known.

RuhRoh
July 23, 2010 9:59 am

Wow, this is a popular thread!
As few are likely to connect my first post back to Juraj V insightful comment,
I herewith try to make a self-contained post.
What about the application of ‘greenhouse gas’ theory to Mars?
The (thin) Martian atmosphere is >95% CO2.
Unless I’ve blown the math, Mars atmosphere has much more (total) CO2 enveloping Mars than our Earth enjoys.
Yet the atmospheric temperature of Mars is the same as the BlackBody temperature, at 210K.
So, it seems that ‘greenhouse gas’ theory should apply with equal vigor to warm Mars as to more complex planets like Earth.
Is it wrong to expect that a planet with more total CO2 than Earth would have such a negligible ‘warming’ by all of that CO2?
Perhaps Dr. P will run the GG math on this nice clean example planet, which lacks the complexity of oceans, clouds and highly variable albedo feedbacks.
TIA
RR

R. Gates
July 23, 2010 10:00 am

Very nice and straightforward article. Easy to understand. I’m certain that despite the clarity and scientific rigor of this and countless other articles, a certain class of skeptics will continue to spew forth their own unfounded nonsense.

DirkH
July 23, 2010 10:04 am

Steven Mosher says:
July 23, 2010 at 9:57 am
“[…]GHGs will not cool the planet.”
CO2 in upper atmospheric layers does cool the planet.
“The planet’s temperature is regulated by the thin upper layers where radiation does escape easily into space. Adding more greenhouse gas there will change the balance.”
from:
http://www.aip.org/history/climate/co2.htm
See also:
“Earth’s upper atmosphere cooling dramatically ”
http://www.msnbc.msn.com/id/34479085/

kwik
July 23, 2010 10:07 am

Dr. Pielke et al, do you disagree with these numbers;
http://www.geocraft.com/WVFossils/greenhouse_data.html
It would be nice to know whether you agree. Because if you do, we can further agree that the effect from human induced CO2 can only be insignificant noise in the big picture.

Jeff P
July 23, 2010 10:08 am

Enneagram says:
July 23, 2010 at 9:03 am
“Tallbloke is right. Do you prepare your breakfast with a hair dryer?”
No, but I do put water in the freezer and after a while I get ice cubes.

John Phillips
July 23, 2010 10:09 am

“By virtue of the second law of Thermodynamics, heat cannot be transferred from a colder to a warmer body”
A minor quibble with that statement. Heat cannot be transferred from a colder to a warmer body via conduction, but it can via radiation. IR from a colder body can be absorbed by a warmer body. I don’t think that invalidates anything else in the post though.

Nuke
July 23, 2010 10:09 am

Perhaps we need to rename the “greenhouse effect” to something that is more descriptive? After all, that’s not how greenhouses work.

Theo Goodwin
July 23, 2010 10:09 am

I want to thank Richard Garnache for his very illuminating post. Do you have a website, Richard?

latitude
July 23, 2010 10:13 am

After all these decades, how in this world can anyone talk about greenhouse anything and not be talking about water?
We’re still trying to come up with some plausible explanation of CO2.
A person would think, after all this time, and all the horrible things that are going to happen to us all, we might have some sort of clue.

Michael
July 23, 2010 10:18 am

I just had to share this from another blog with you.
DirkH Says:
July 22, 2010 at 9:55 pm
“To see what will happen, here are some pictures of the snow catastrophy of 1978/79 in Northern Germany.
This is what awaits many people when the winters get harder.”

DirkH Says:
July 22, 2010 at 10:05 pm
“One more word: 12 people died in Western Germany. Intense rescue efforts by the army freed most of the people lost in villages from their peril.
In Eastern Germany, Communist at that time, the entire energy production shut down. Shortly before they had decided to use only home-grown brown coal power plants to become independent. The cold meant they were no more able to dig the humid brown coal so they had to shut off all power plants.
How many people died in Eastern Germany was never communicated. It must have been far more than the 12 in the west – it was a country with 14 Million inhabitants under a total blackout in winter!
So the technology of the West saved our asses. The run-down technology of the East failed spectacularly.
The West immediately offered help. The West asked the communists what they needed; rotary hammers they said, and within 3 hours some trucks with a few hundred rotary hammers were at the border so they could hammer some brown coal out of their pits to restart energy production.
Technology saves your ass. And only technology.”
http://pgosselin.wordpress.com/2010/07/22/noaa-models-predict-big-arctic-deep-freeze/

AllenC
July 23, 2010 10:20 am

All climate forecasts need to take a lesson from economics. There is a Latin phrase which is used (not over used) in economics. That phrase is: Cēterīs paribus.
Unfortunately in climatology, as in economics, one cannot hold all other things equal (constant). This is where the “rub” is. The AGW concept may be right in theory, but it will never be useful in forecasting the earth’s climate because there are so many many other factors in play. I doubt that no one really knows what all those factors are; nevermind being able to model their effects and the interplay amongst all of those factors.
This is amongst my biggest complaints about the AGW concept (that controlling ONLY the relative amount of CO2 in the atmosphere will greatly impact Global Warming). What is also so remarkable about the AGW concept is that such an infintesimally small change in the relative amount of CO2 in the Earth’s atmosphere can have such an enormous impact on the Earth’s average temperature (assuming that anyone can accurately calculate what it is).

Enneagram
July 23, 2010 10:21 am

Stephen Wilde says:
July 23, 2010 at 9:22 am
Thanks Stephen; that’s it.
My great grandmother used a hot water bottle, now she would use instead a hot water bag. One more curious thing: She used, also, water bottles made of glass of different colors, which she put under the sun light to drink that for different ailments.

Roy Clark
July 23, 2010 10:21 am

The surface warming part of the ‘greenhouse effect’ is just the downard IR radiation from the atmosphere to the surface. Most of this originates in first kilometer layer above the surface. However, there is no equilibrium. The temperature of this layer is mainly set by convection from the surface. The idea that CO2 can cause any kind of climate change is incorrect.
The surface heating is dynamic. The daily heat load hitting the surface can be up to 30 MJ/day – varying continuously during the day. At night the cooling is between about zero and 360 kJ per hour depending on humidity and cloud cover. Over the last 200 years the 100 ppm increase in CO2 has produced an increase in downard ‘clear sky’ LWIR flux of 1.7 W.m-2. That is 6 kJ/hour or 0.15 MJ perday. Add this to the rest of the surface surface flux and it is buried in the noise. The surface flux is also coupled into the surface and heats the ground down to about 1 meter.
IT IS IMPOSSIBLE FOR A 100 PPM INCREASE IN ATMOSPHERIC CO2 CONCENTRATION TO CAUSE ANY KIND OF CLIMATE CHANGE
There is no CO2 ‘signature’ in the meteorological surface air temperature (MSAT) record. This has been created from the ocean surface temperature changes along the path of the weather systems that show up in the MSAT. In the US it is just the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation. The hockey stick itself is not the major fraud. It is the use of the hockey stick to ‘calibrate’ the climate simulations that is the real fraud. The climate results are then used to perpetuate the rest of the ‘environmental disaster’ fraud. The increases in ocean surface temperatures from about 1960 onwards have been reprocessed into a ‘CO2 signature’ in the meteorlogical surface temperature record. The ocean surface temerpatures are now cooling so the fraud is finally being revealed. The oceans won’t ‘hide the decline’.
For more info go to Energy and Environment 21(4) 171-200 (2010) ‘A Null Hypotheisis for CO2’
http://multi-science.metapress.com/content/9p72043270187318/?p=186148f7bd6a4c1681163d19daa8aea0&pi=2
[Paywall, unfortunately – if WUWT sends me an e-mail address I can send a copy of the paper]

July 23, 2010 10:24 am

The altitude of a CO2 molecule makes a difference. The higher up it is, the larger percentage of re-radiated LW goes out into space due to the curvature of the Earth.
This shows what happens.

Enneagram
July 23, 2010 10:29 am

The fastest way to lose your soul: Change your creed to GWR religion.

the fritz
July 23, 2010 10:30 am

Green house effect is not a source of energy; if it warms the surface, something else must cool; the cooling of the stratosphere can give an idea of how much the surface must warm, or how much heat is in the pipe (oceans)

MartinGAtkins
July 23, 2010 10:34 am

With regards to the violation of the second law, what actually happens when absorbing gases are added to the atmosphere is that the cooling is slowed down. Equilibrium with the incoming absorbed sunlight is maintained by the emission of infrared radiation to space. When absorbing gases are added to the atmosphere, more of emitted radiation from the ground is absorbed by the atmosphere.
I have problems with this. You cannot absorbed more energy than is available to the receptive molecule. Perhaps Ben Herman and Roger A. Pielke Sr would like to quantify the amount of surface
emitted LWR that CO2 is receptive to that escapes directly into open space.

simpleseekeraftertruth
July 23, 2010 10:34 am

A greenhouse effect and a green house gas are different things. Greenhouse effect is caused by the fact that glass is semi-transparent to IR in both directions which causes IR to be trapped on the side away from the primary IR source. Thus the inside of a greenhouse (glass house) then becomes warmer.
A greenhouse gas which is often pumped into a greenhouse is CO2. This is done by commercial growers to increase plant growth (yields), not because it warms but because it feeds the plants by making the scarce CO2 more readily available for photosynthesis.
CO2 increases in temperature when exposed to sunlight. It does this by absorbing IR. This is neither due to a greenhouse effect nor is it a greenhouse gas when it is not in a greenhouse.
Can we drop the ‘greenhouse’ as either an adjective or adverb and find word(s) which correctly describe the phenomenon of its IR absorption properties and its effect on the atmosphere then planet in that order. The search for the correct descriptives may assist in critical thinking about the subject which is demonstrably sadly lacking in some quarters.

Jim G
July 23, 2010 10:42 am

Monckton says:
“whether attempting to mitigate future “global warming” will make any real difference to the climate (it won’t: remember Canute), whether the cost of forestalling each degree of “global warming” will be disproportionate to the climatic benefit (it will), and whether focused adaptation to any change in the climate, where and if necessary, will be orders of magnitude cheaper than trying to prevent that change from occurring in the first place (yes).”
If some of the ice core data is correct, co2 and methane started increasing about 6 or 8 thousand years ago, about when men, due to a more beneficial climate, crawled out of their caves and began to farm and icrease their population. Can’t quote the study, but it was in “Scientific American” years ago when I still subscribed to that rag. The chart actually picked up the drop in c02 and methane that occured about the time of the two great plagues which substantially reduced populations around 450? and 1450? AD. Makes sense given what we do to warm ourselves (build fires), irrigate crops (rotting vegetation), raise livestock which defecate, as do we, etc. It would appear from that analysis that the only real reductions in these gasses which we could cause would require drastic depopulation of our planet. Of course I am doing what I hate here by implying cause and effect from a simple Algore type of chart.
As far as the cost of any potential change in our production of greenhouse gasses, I totally agree with your comments. Not going to the extreme of drastic population reduction, there will be little effect by other actions and significant socio-economic negative impacts as a result. We must, after all, continue to heat and eat. One can see it coming here with the various carbon tax schemes being planned by the US federal government which all will be detrimental to our economy and way of life while giving more control to the government. But that is the real goal in our particular situation.

richard telford
July 23, 2010 10:44 am

Enneagram says:
July 23, 2010 at 9:27 am
There is no such a thing as the greenhouse effect, greenhouse gases are gases IN a greenhouse, where heated gases are trapped and relatively isolated not to lose its heat so rapidly. If greenhouse effect were to be true, as Svante Arrhenius figured it out: CO2 like the window panes in a greenhouse, but …the trouble is that those panes would be only 3.8 panes out of 10000, there would be 9996.2 HOLES.
———————
This is, of course absolutely, correct if you are considering a planet with an atmosphere a single molecule thick. In an atmosphere two molecules thick, the number of holes would be 10000*0.9962^2 = 9924. Now consider how many holes there would be in an atmosphere only a million molecules thick (<<1mm). (10000*0.99962^1000000

July 23, 2010 10:50 am

PTCO.
It’s more than sad that people continue to fight against the basic physics. Physics that working engineers understand and use on a daily basis. The problem is this: The warmists have been very successful in lumping those of us who understand how GHGs work to warm the lower portion of the atmosphere, with those who deny this fundamental physics. They lump those who deny the science of GHGs with those who question the accuracy and completeness of our understanding of sensitivity.
GHGs will not cool the planet. There no science to suggest they will. C02 will warm the planet, up to limit. That limit has not been reached and the questions are:
1. how fast will we reach that limit
2. will it be damaging
3. Can and should we do anything about it.

Casper
July 23, 2010 10:51 am

Anthony,
you should read this article:
“[b] Falsi fication Of The Atmospheric CO2 Greenhouse E ffects Within The Frame Of Physics[/b]”
[b]Abstract[/b]:
The atmospheric greenhouse e ffect, an idea that many authors trace back to the
traditional works of Fourier (1824), Tyndall (1861), and Arrhenius (1896), and which
is still supported in global climatology, essentially describes a fictitious mechanism, in
which a planetary atmosphere acts as a heat pump driven by an environment that is
radiatively interacting with but radiatively equilibrated to the atmospheric system. Ac-
cording to the second law of thermodynamics such a planetary machine can never exist.
Nevertheless, in almost all texts of global climatology and in a widespread secondary
literature it is taken for granted that such mechanism is real and stands on a rm sci-
enti c foundation. In this paper the popular conjecture is analyzed and the underlying
physical principles are clarified. By showing that (a) there are no common physical laws
between the warming phenomenon in glass houses and the fictitious atmospheric green-
house eff ects, (b) there are no calculations to determine an average surface temperature
of a planet, (c) the frequently mentioned difference of 33 C is a meaningless number
calculated wrongly, (d) the formulas of cavity radiation are used inappropriately, (e) the
assumption of a radiative balance is unphysical, (f) thermal conductivity and friction
must not be set to zero, the atmospheric greenhouse conjecture is falsified.
Electronic version of an article published as International Journal of Modern Physics
B, Vol. 23, No. 3
http://arxiv.org/PS_cache/arxiv/pdf/0707/0707.1161v4.pdf

Dr. Dave
July 23, 2010 10:52 am

Good article. Second time I read it today. I’ve always accepted the greenhouse effect because it just seems intuitive. However I have recently been reading some of the work by some of those who are skeptical of the greenhouse effect theory and they make compelling arguments.
So let’s just assume the greenhouse effect is real and it is responsible for the planet being about 33 degrees K warmer than it would be without it. If water is responsible for 95% of the effect, does that suggest that all the remaining GHGs are responsible for only about 1.6 degrees K of the total effect? I suppose this is the central question. Just how much warming (or reduced cooling) is likely to result from a doubling of atmospheric CO2 concentration? As I understand it, a doubling would theoretically result in about 1.2 degrees K of apparent warming. Is this even significant?

John Eggert
July 23, 2010 10:52 am

An excellent article. It is not an easy thing to make the complicated understandable.
The absorption of radiant heat in the atmosphere was studied in detail long before climate scientists began getting involved. As an example, those who question Dr. Pielke’s explanation must explain why it is that blast furnace calculations work. These too account for the amount of heat absorbed by the atmosphere and the subsequent increase in temperature of the atmosphere.
The blast furnace calculations for radiant heat transfer are identical in form to those used to estimate the absorbance of radiant heat in climate research. Climate science is not the only area where these calculations are performed. In other areas, there is little disagreement with Hansen / Ramanathan.
My only issue is that in other areas, the impact of CO2 is asymptotic, parallel to the x axis to a line at about 500 bar.cm with nearly 0 increase after 100 bar.cm. (See “Heat Transfer Handbook, Bejan And Kraus, Pg 618). Using the methods taught me, I come up with a curve nearly identical to F=5.35ln[CO2], diverging at about 100 ppm CO2 and basically F=0 after 200 ppm CO2.

Theo Goodwin
July 23, 2010 10:54 am

The graphic accompanying the article is not helpful to those of us who need education because it does not show the relevant mechanisms. Could someone please post a graphic that covers the molecular level, sort of a “Radiation’s Quest for Space” graphic that shows radiation leaving the cooling black asphalt and all the adventures it might have, especially encounters with CO2 molecules, as it heads for space?

Alexander Davidson
July 23, 2010 10:56 am

There’s a basic physics’ problem. To state “The bottom line here is that when you add IR absorbing gases to the atmosphere, you slow down the loss of energy from the ground and the ground must warm up.” is only correct if the extra CO2/CH4 etc. does not trigger a reduction of water vapour concentration. The evidence here [ http://docs.google.com/leaf?id=0B74u5vgGLaWoNDFjODAwMWMtNmNmYS00NDhmLWI3NjItMTE0NGMwNWMxYjQ2&sort=name&layout=list&num=50 {sorry, needs Google Mail account to read}] indicates that over the past c. 60 years, as CO2 has increased, the water average vapour concentration in the atmosphere has decreased. So, whilst the land/water/lower atmosphere have warmed, there has been no apparent change of the integrated atmospheric IR absorption properties. If true, this indicates that the extra CO2 has not caused the warming so the latter may have been due to a natural process(es).
The above paper by ex-NASA scientist Miskolczi should be read in conjunction with his 2006 paper which suggests a thermodynamic equilibrium argument for this control mechanism. If true, it indicates a Gaia-type mechanism with an interaction between the IR adsorption column properties, the transport of latent heat upwards, liquid/solid water downwards.
So, no argument about higher temperatures, just be careful about the claim that this is firm evidence of global warming!

George E. Smith
July 23, 2010 10:58 am

“”” Jeff says:
July 23, 2010 at 8:20 am
slowing down the cooling of an object cannot cause it temperature to rise … THAT would violate the 2nd law … “””
Jeff, if only you knew just how much, a statement such as you just made lowers YOUR credibility (as to knowledge of thermo-dynamics.)
Let us take as the (your) “object” a small spherical “Blackbody”; might as well make it the size of a tennis ball, say about 5 cm diameter. I choose a “blackbody”, simply because you did not exclude it from your “object” category; and other than that it is a simple thing to understand. In the end though, it matters not that I choose a blackbody. And since we are doing this; stick in the sand wise, I will also make the body to have infinite thermal conductivity; well very high anyway; and it is a thin shell like a ping pong ball so that it is of very low mass and heat capacity.
So we put our ball out in space in earth’s orbital position (from the sun) to soak up solar radiation at 1366 W/m^2 of intercept are exposed to the sun. All that incident energy gets absorbed; and since the ball is highly thermally conductive; it spreads uniformly throughout the ball, so the Temperature of the ball is the same all over the surface. BB radiation theory tells us that the ball will radiate uniformly (W/m^2) from all over the surface, as soon as its Temperature moves above zero Kelvins (absolute zero). With this loss of energy through radiation, the rate of increase of temperature with the incoming solar radiation, will slow down, since the energy arrives from the sun at a constant 1366 W/m^2, but leaves at a sigma.T^4 W/m^2 rate based on the Temperature. Since the total surface area of our uniform Temperature ball is four times the intercept area collecting solar energy, the uniform rate of energy loss from the ball, cannot exceed 1366/4 or 341.5 W/m^2 (Trenberth uses 342).
We know from our compendium of useless facts that must be remebered; that at 288 K; the mean earth Temperature; the rate of black body radiation is 390 W/m^2. So we are less than that. 0.875641 of that to be more specific; and we know from BB theory that that number varies as T^4.
So 4th root of 0.875641 is 0.967345, and we multiply that by the 288 Kelvins of earth Temperature and we get 278. 6 Kelvins, or about 5.45 deg C.
Well our authors above said 255 Kelvins; but they don’t have a black body; theirs has an albedo equal to Earth’s, and that is what lowers us to 255 K.
Ok so far so good. I deliberaterly chose a low thermal mass ping pong like ball so that it heats and cools very rapidly; if I make it thin enough it would change temperature in milliseconds or less, adjusting its Temperature so that incoming energy RATE always equals outgoing energy RATE (Watts).
Now you have declared that the cooling rate does not change the Temperature. Well specifically you said “”” slowing down the cooling of an object cannot cause it temperature to rise “””
So now I want to modify our ball to “slow down its cooling rate.” Well just to see if you are correct.
I’m not going to add an atmosphere to our ball; that just complicates things with hurricanes; and tornadoes and things.
So now I am going to fill our nearly massless ping pong ball with lead to increase its mass by a huge amount, and with a material that isn’t too great a thermal conductor either (for a metal).
Now a Maxwell’s Demon sitting on the surface of the sun looking at our new ball, is not going to “see” ANY difference in the appearance of the ball; but its gravimeter is going to detect that the gravitation pull of our modified ball on the sun has increased by a huge factor so it does know the ball is different; but not in external visual appearance.
Now the radiation impinging on our heavy ball is still totally absorbed; but now the ball is not infinitely thermally conductive, so the rate at which heat travels through the ball to the unradiated isde slows down as most of the heat has to propagate through the lead core, which isn’t such a great conductor.
Now notice that the thermal black body radiation being emitted from the surface of the ball, encounters NO impediment of any kind; it simply leaves as before, but the presence of the lead core slows down the rate that heat is moved from the sun side to the night side, which slows the rate at which the sun side can cool.
Since the night side can only radiate energy that comes to it from the sun side, by conduction through the ball, that heat can only flow, if there is a Temperature gradient through the ball to drive the heat. It is quite like Voltage across a Resistor driving a current through the resistor. No Voltage difference; no current flow.
So our ball can no longer be isothermal like it used to be. The sun side must get hotter since heat is arriving faster than it is being radiated (1366 W/m^2 in and 341.5 out) to that extra 1022.5 W/m^2 has to travel through the ball to get radiated from the rest of the surface.
The sun side Temperature increases above 278 K setting up a temperature gradient which starts to drive heat through the ball; but the night side must cool down since it waqs also radiating at 341.5 W/m^2; but we have slowed down the rate of supplu of that energy from the sun side, so the night side temeprature must fall, as well as the sun side heating up; and all this happened simply because we slowed down the rate of heat flow.
Eventually the situation will stabilize; with the sun side somewhat hotter than 278 K, and the night side somewhat cooler than 278 K and the Temperature difference is driving 1022.5 W/m^2 through the ball to other parts (on average).
Since the rate of loss of energy goes as T^4; so it is non-linear with temperature, the colder parts of the ball, are not doing their fair share of cooling, and the hotter parts are being overworked, and if we average the Temperature all over the ball surface that average will ALWAYS be hgher than the original case of an isothermal ball at 278 K all over.
Now I didn’t put any atmospheric impediment in the way of energy loss from the surface; I simply slowed down the rate at which that energy can be lossed; in this case by raising the thermal mass and hence thermal time constant of the ball.
We have such a ball in the solar system. The Planet Mercury keeps one face facing the sun almost all the time; and it isn’t highly thermally conductive, and has no impeding atmosphere and the sun side is much hotter than the night side.
You get into real trouble trying to apply Second Law concepts to Electromagnetic Radiation. EM radiation IS energy; but it is NOT HEAT; and the second law applies to HEAT transport; NOT energy transport.
A photon emitted from some interstellar molecule at a Temperature of say 3 Kelvins; the background Temperature, can easily impinge on the surface of the sun and be absorbed; or for that matter on the surface of some Neutron star at some totally enormous Temperature. Photons don’t know ANYTHING about Temperature; they can come from anywhere and go anywhere without impediment.

Robert of Ottawa
July 23, 2010 11:02 am

Well, hold on. A planet without an atmosphere would be at a certain surface temperature defined by surface albedo and stephan-botlzmann’s law. Would the surface temperature of that planet be the same with a massive atmosphere that was completely transparent to all radiation? No, because the atmosphere would still affect the temperature of the planet through conduction and convection, to the point thatthe same radiative balance would exist at the top of the atmosphere, the surface being at a higher temperature than without an atmosphere, due to the physics of the lapse rate.
Remember, this test assumes an atmosphere completely radiativeely transparent to all wavelengths, but allows for convection and conduction.
My point is, radiative processes are not the only ones governing the temperature of the plane. Conduction and, especially, convection and evaporation, are not understood, complex and ignored.

Patrik
July 23, 2010 11:06 am

How much of the 33 k is due to clouds?

George E. Smith
July 23, 2010 11:16 am

I’m not a fan of (too) simple models of the type presented here.
It is no easier for lay persons to understand this type of model than it is for them to understand ones that are considerably closer to the reality (Mother Gaia’s model).
The idea that somewhere in the earth’s atmosphere there is a layer that has some “effective Temeprature” and from that layer ALL of the radiation of the planet is emitted to space in some black body like radiation spectrum at that characteristic Temperature; is quite incorrect; and quite misleading to the lay reader.
YES the earth’s atmosphere at ALL levels is emitting a thermal radiation spectrum IN ALL DIRECTIONS; and some of that returns to earth which DELAYS its loss to space (but DOESN’T prevent it); and some of it is directly lost to space. Some of it also is RE-ABSORBED by other atmospheric layers (and their GHG molecules).
The earth’s surface itself (solid and liquid) is a majort source of thermal EM radiation with a spectrum that is characteristic of the surface temeprature (principally); and a good deal of that radiation goes right through the atmosphere unimpeded to be lost to space with a spectrum characteristic of the surface temeprature of that particular surface element.
As a result; the earth’s external emission spectrum is not a simple Black Body spectrum of an isothermal body at 288 K or any other single Temperature.
But other than that, I’m supportive of the authors. The Second Law of Thermodynamis is a dog that won’t hunt in this field; and the “Greenhouse” effect; as well understood in climate science as opposed to agriculture IS A VERY REAL EFFECT.
The important point is that although the greenhouse effect is real, and does raise earth’s temperature above some BB theoretical equilibrium Temperature; THAT IS NOT WHAT IS CONTROLLING THE EARTH’S TEMPERATURE RANGE !!!
HEY ! IT’S THE WATER !!! (ever heard of clouds ?)

Alexander Davidson
July 23, 2010 11:18 am

PS I have also been working on the validity of the claim in many of the IPCC models that high AGW/high feedback has so far been partially masked by man-made cooling via aerosols decreasing cloud droplet size thereby increasing albedo. This greatly worries the modellers because of the uncertainties of cloud physics although the direct aerosol effect has been verified by Mt. Pinatubo.
The problem is the cloud theory [Twomey 1974] uses a very simplistic approximation to the physics. Whilst it does successfully predict increased albedo for thin clouds with smaller droplets [e.g. ship’s track clouds], it cannot apply to thick clouds. Also, if you think about it, once the light entering a cloud becomes fully diffuse, the maximum albedo is 0.5; 0.7 is common, I’ve seen 0.9 quoted, there’s an unpredicted angular dependence and no apparent difference of albedo between thick polluted and thick unpolluted clouds.
So, there’s probably another optical process giving enhanced back-scattering at the tops of clouds: I think I’ve worked out why but the maths is horrific. No man-made cooling from polluted clouds means either the assumptions about AGW in the models are wrong, they’ve been wrongly calibrated, or both. I prefer the combination.

RockyRoad
July 23, 2010 11:20 am

Steven Mosher says:
July 23, 2010 at 10:50 am
(…)
GHGs will not cool the planet. There no science to suggest they will. C02 will warm the planet, up to limit. That limit has not been reached and the questions are:
1. how fast will we reach that limit
2. will it be damaging
3. Can and should we do anything about it.
———————Reply:
It gets far more complicated than that. First you must defend your term “damaging”. Many (like myself) see far more benefits to an increase in CO2 than the problems, hence one might argue that “damaging” is an unfortunate choice of words; perhaps switch #2 with the statement “What will be the impacts, if any”. Then it gets even worse (if that’s possible), since your #3 gets to the truly messy part of balancing interests regarding a subject for which there is precious little concensus.
What may be of great interest (and a source of substantial grant funding) to a scientist may be conveyed as horribly unsettling by someone ideologically driven for political purposes yet, if left alone, could be beneficial with an overall improvement in society as a whole. Everybody with an opinion needs to be asked simply: “What is your vested interest?”

July 23, 2010 11:21 am

“Patrik says:
July 23, 2010 at 11:06 am
How much of the 33 k is due to clouds?”
A good question but even more to the point how much of that 33K is due to liquid water oceans.
The air even in it’s entirety could well be a total irrelevance in comparison.

MartinGAtkins
July 23, 2010 11:22 am

Dr David says:
July 23, 2010 at 8:29 am
How much of the 33 degrees is due to heat escaping from the Earth’s core and tidal forces?
It’s not necessary to calculate this as we are talking about climate variables and not energy constance.

Layne Blanchard
July 23, 2010 11:27 am

Dr Pielke,
Has anyone looked at the spectra of C02, and the spectrum of IR radiated toward space from earth’s surface, and quantified how much IR is even available to CO2? If CO2 is in trace concentrations, what becomes the probability that this IR from earth’s surface will find a CO2 molecule to energize, and then, even if ALL of it were captured by CO2, what percentage of total re-radiated IR could this even contribute, given those bands of absorption peculiar to CO2? Would not any single humid day be orders of magnitude greater? And after C02 kinetically hands off that energy to water vapor, what mechanism is to prohibit higher energy water vapor from rising and COOLING further?

R. Gates
July 23, 2010 11:30 am

Steven Mosher said:
“C02 will warm the planet, up to limit. That limit has not been reached and the questions are:
1. how fast will we reach that limit
2. will it be damaging
3. Can and should we do anything about it.
______________
Best repsonse to this thread that I’ve seen.

Peter
July 23, 2010 11:35 am

Robert of Ottawa:

Would the surface temperature of that planet be the same with a massive atmosphere that was completely transparent to all radiation? No, because the atmosphere would still affect the temperature of the planet through conduction and convection, to the point thatthe same radiative balance would exist at the top of the atmosphere, the surface being at a higher temperature than without an atmosphere, due to the physics of the lapse rate.

Not quite. If the atmosphere was completely transparent to all radiation then the surface would be the (main) effective radiating surface, not the TOA. The surface temperature would actually be a bit lower than it would be if there were no atmosphere, as some of the energy from the surface would go into warming the atmosphere through conduction and convection, but the total energy radiated by the surface plus the whole of the atmosphere (not just the TOA) would equal the incoming energy at equilibrium.
The atmosphere would still be warmer at the bottom than at the top, due to the lapse rate, but it would still be a lot colder than would be the case if greenhouse gases were present.

anopheles
July 23, 2010 11:37 am

Surely to goodness this can be measured? On a clear night, let’s see the radiation profiles. Lets cover some of the ground and see how different the radiation is. If there is scattered longwave IR running around in the atmosphere, it can be measured, can’t it? How hard could it be to prove this once and for all? By experiment. Not only the right way, but the only right way. What does the theory predict? Can we observe it?

kwik
July 23, 2010 11:39 am

Juraj V. says:
July 23, 2010 at 9:06 am
I agree with Juraj here.

P Wilson
July 23, 2010 11:43 am

the two dominant climatic forces and the effect they have on climate, despite there being a large amount of research on them are: oceans and clouds/water vapour, which comprise 98% of the climate, (Oceans have over 1000 times more ability to retain shortwave heat than air does longwave, and a much greater heat capacity, and 70% of the earth surface is ocean) and then go onto make pronouncements about what it will be like in years to come. However, vapour overlaps c02 by a magnitude of 100 times, in quantity, and over three times in its spectral bandwidth, (300 times the ghg as c02) so a change in cloud or vapour of 1%, which is very common, is the equivalent of a change in c02 of several hundred ppm. IE. It swamps the entire “effect” of c02, and can be a negative “feedback”. Re-radiated longwave radiation doesn’t penetrate oceans, as it takes a great amount of energy to heat them by 1C. Far more so than solid mass and air. Water is penetrated to depths of 100 metres or more by incoming solar energy in the ultraviolet and visible wavelengths but is not penetrated by infrared (longwave) wavelengths.
One notices at the beach that when the sand and paving is hot, water waves are still cool. That means no amount of greenhouse effect can cause either thermal expansion of water, or water vapour “feedback”. Certainly, since c02 intercepts heat at 15 microns, then re=emits it in less than a billionth of a second, to oxygen and nitrogen, when its saturation window closes. This wavelength on the spectroscopic band is already in the subzero region. In other words, the energy absorbed by c02 is dependent on freezing regions, such as Antarctica. Normal IR radiation leaving the earth is around 10 microns, 0r 7-14, incidentaly at the bandwidths where water vapour intervenes which co-incides with an average 288k (15C), and which is invisible to c02. That leaves very little energy for c02 to delay – around 3-4% of subzero energy. It is so miniscule that the effect cannot, and has not been measured. In tropical deserts where temps are 45C plus, radiation leaves at 8.5 microns, which puts it even further out of the c02 micron band.
So c02 absorbtion is a rare event in the atmosphere. Its also forgotten that most heat leaves by convection and evaporation, and not from re-radiation.
the only way that global warming via ghg’s (lets take only c02)could be justified would be by Boyle’s law, or the ideal gas law. However, temperature change through air pressure depends on a closed system – if the atmosphere gains more density it expands, than increasing partial pressure – the so called Iris effect. Given the limited spectroscopic bands of c02 on the other hand, an argument can’t be developed for c02 increasing the temperature or retaining heat. In the mid to upper troposphere where it goes to from -20-45C, or 228K, that does coincide with heat absorbtion from c02. However, there is no physical mechanism by which such mid tropospheric subzero temperatures can send heat back to earth, as temperature falls with altitude. (The notion indeed violates the 2nd law of thermodynamics)

R. Gates
July 23, 2010 11:44 am

the fritz says:
July 23, 2010 at 10:30 am
Green house effect is not a source of energy; if it warms the surface, something else must cool
__________
This is the worst response I’ve seen to this thread.
No one is talking about the the GH properties of CO2 and other GH gases as being “sources” of energy. The primary (but not only) source of energy on earth is the sun. It is the sun that loses energy that is received by earth, but the net energy of the system (sun-earth) of course stays the same, however, the total entropy of the solar system increases as useful energy is lost.
Ultimately of course, the source of all energy in our region of the universe is gravity, for without it, we’d be just another cold region like the majority of the universe where not much (in fact nothing at all) exciting happens.

Dave Dardinger
July 23, 2010 11:49 am

Robert,

the atmosphere would still affect the temperature of the planet through conduction and convection, to the point that the same radiative balance would exist at the top of the atmosphere, the surface being at a higher temperature than without an atmosphere, due to the physics of the lapse rate.

I think you’re incorrectly assuming that this atmosphere which is transparent to all radiation could still emit radiation. This is a contradiction. If it can emit LWIR then it must also absorb LWIR. Which brings up something I’ve asked about a few times without getting an answer. I assume that if molecules like O2 and N2 were to interact in a collision, there’s a small possibility they could emit IR (or absorb it). The reason that O2 and N2 don’t normally absorb or emit IR is that they’re symmetric molecules and thus can’t interact with an electromagnetic field. But while they’re in the process of collision, there will be some asymmetry set up which could lead to emission. The question is just how likely this is? My guess is that it’d be quite rare since the interaction time would be much quicker than the average time it takes for a quantum of IR to be emitted from a GHG (for instance). But the math to do the calculation is likely to be quite hairy and beyond my abilities. But surely there’s someone here who’s a wizz at QM who could solve the problem?

cedarhill
July 23, 2010 11:51 am

The Moon is without an atmosphere. It’s daytime temperature is around 400K (+/-) and it’s night time temperature is about 120K (+/-). So how does one arrive at a temperatiwhere does the 255K temperature of the Earth without an atmosphere. Actually this would be really cool sine the oceans would freeze during the night and boil during the day. Nice model.

Reed Coray
July 23, 2010 11:56 am

I want to thank Anthony, Ben Herman, and Dr. Pielke for this post. It has increased my knowledge of the popularly named “greenhouse effect”.
I believe, however, that lacking from this discussion are formal definitions of “a greenhouse gas” and “the greenhouse effect” Without such formal definitions, there is little common ground for discussion. For you electrical engineers, it’s kind of like discussing Signal-to-Noise Ratio (SNR) without a formal definition of “Signal Power” and/or the bandwidth in which the “Noise Power” is defined.
Therefore, I request that Ben Herman and Dr. Pielke provide formal definitions of these entities. Something like:
A greenhouse gas is a gas whose molecular electron structure is such that (a) it possesses electron energy states whose energy difference is in the IR band, and (b) when excited from a lower energy state to a higher energy state by an IR photon, a portion of the stored energy when released will be transformed into thermal energy of the molecule and/or the surrounding gas molecules.
For a body whose rate of thermal energy input is fixed, the greenhouse effect is the phenomenon by which a greenhouse gas solely by virtue of its ability to transduce IR photon energy into molecular thermal energy will induce a rise in the temperature of the gas surrounding the body.
I make no claim that the above are valid definitions. They are meant only to be examples. But before I can decide if the “greenhouse effect” is real or figment of the imagination, I need explicit definitions of these two entities.

Larry Barnes
July 23, 2010 11:56 am

The statement that taking away the atmosphere and calculating the expected temperature keeping the albedo the same is nonsense. Most of the albedo effect is the result of the oceans and the atmosphere. Without the atmosphere there can be no ocean and without them the earth would look like the moon with an albedo in the range of 10-12 percent. If you then calculate the expected equilibrium temperature you will get something about 273-278 degrees Kelvin. Thus the “greenhouse effect of 33 degrees” is utterly false. The best that can be said is that the ocean-atmosphere system causes the earth to be 5-10 degrees warmer that it would otherwise be. The term greenhouse is also a nonsense as no greenhouse works in the way suggested by the proponents of the term.

Bill DiPuccio
July 23, 2010 11:58 am

If those who oppose the greenhouse theory are right, then we not only must reinvent climate theory, but meteorology itself. On a clear calm night, temperatures drop rapidly at the surface boundary layer as IR heat radiates into space. On a calm cloudy night, the temperatures drop more slowly because that IR heat is re-radiated downward by water droplets in the clouds.
Now apply this concept to daytime heating: Greenhouse gases don’t add heat, but retard its loss by reradiating. During the day the ground temperature may easily exceed 100F in the summer while the air temperature may only 75F. We rely on radiation and convection to transport this heat away from the surface. Additional greenhouse gases will retard surface cooling (though ever so slightly in my view) causing the air temperature to be closer to the ground temperature. So the surface air temperature increases without adding any heat to the system. All the heat needed to do the job is already present.

Gnomish
July 23, 2010 12:02 pm

“The bottom line here is that when you add IR absorbing gases to the atmosphere, you slow down the loss of energy from the ground and the ground must warm up. ”
crazy. backwards.
improve the heat capacity of a convective heat exchange system and you increase efficiency.
2 words:
phase change

stephen richards
July 23, 2010 12:03 pm

I’ve got problems with all of this.
What follows is a question and not a statement;
CO² 0.04%
H²O 5%
They both absorp at the same hµ (approx). H²o dominates and as a probability must absorp 100 times more IR ?
When a mole absorps it raises its’ instability and wants to reradiate the energy and return to the ground state a.s.a.p. This reradiation is never uni-directional? Why would it radiate in a downward direction ?
The reradiated energy is at the same hµ (nu) as the absorped unless some form energy conversion has occured (conservation of energy law)? so will be absorped by another mole at ground state.? If the other moles are already at the higher quantum level, it will radiate to space?

stephen richards
July 23, 2010 12:07 pm

Bill DiPuccio says:
You are of course correct. The problem with the greenhouse theory is that the planet is not a greenhouse. The greenhouse theory just is no applicable. The big question is what happens to the energy absorped by a CO² molecule in a system as complex as this planet (not just the atmos).

Peter
July 23, 2010 12:07 pm

RockyRoad:

First you must defend your term “damaging”

I guess you must have missed the preceding bit which said:

…and the questions are:

(my bold)

phlogiston
July 23, 2010 12:10 pm

Reed Coray says:
July 23, 2010 at 11:56 am
An intelligent question. The more you try to make a precise mechanistic definition of a “greenhouse gas”, the clearer one will see the holes in the hypothesis, what seemed intuitively simple proves more complex and elusive.

Alex
July 23, 2010 12:10 pm

Dear Ben and Roger,
In principle, your article is correct.
However.
1. It is unclear why you should compare the <> temperature of the Earth with and without atmosphere and claim this should be the “greenhouse effect”. Most of the Earth albedo results from clouds. So, you <> compare the temperature somewhere around clouds. And it is around 233 K, as it should be according to the albedo!
2. The temperature below the clouds (actually in the whole troposphere) is simply the adiabate. The higher pressure = higher temperature. Nothing with “greenhouse”.
3. If you descent down into a deep shaft, you know the temperature increases. Do you think this is “greenhouse effect”, or may be, rather the adiabatic temperature lapse?
One must be very careful with the so called “greenhouse”.
Your tried explanation is too naive!

phlogiston
July 23, 2010 12:12 pm

R. Gates says:
July 23, 2010 at 11:44 am
the fritz says:
July 23, 2010 at 10:30 am
Green house effect is not a source of energy; if it warms the surface, something else must cool
__________
This is the worst response I’ve seen to this thread.
Climate is a zero sum game – didn’t you read the memo?

Patrik
July 23, 2010 12:13 pm

Bill DiPuccio>> You use clouds as observational evidence for the validity of the GHG theory, but your example actually reinforces the notion that GHG:s are poor isolators compared to for example clouds.
The air humidity can be identical on the two nights you mention, but the one with clouds will always be the warmest – by far…

stephen richards
July 23, 2010 12:15 pm

R. Gates says:
Another of your cracked replies courtesy of the Gavin Schidt school of answers.
Gravity does not generate energy. Energy cannot be made or destroyed einstein.
Sure, gravity is a force which creates the conditions for the creation of stars and the nuclear energy in those stars is started by the force of gravity compressing the gases.

Phil.
July 23, 2010 12:15 pm

RuhRoh says:
July 23, 2010 at 9:35 am
Mr. Juraj V;
Are you saying there is more CO2 on Mars than on Earth, yet there is no discernible ‘greenhouse warming’ on Mars? Yikes!
From those very handy links,
Mars atmosphere is ~2.5 x 10**16 kg, @950,000 ppm CO2, yes?
Earth atmosphere is ~5 x 10**18kg, @ 400ppm CO2.
This seems to be a very potent issue for the greenhouse advocates.
Maybe RC can answer this one.

No need to go there, the absorption of CO2 (or any absorber) depends on it’s temperature, concentration and pressure. On Mars the absorption lines of CO2 are very narrow ( a bit like a picket fence with relatively large gaps) whereas the conditions on Earth broaden the lines (so the gaps in the fence narrow). This means that the same mass of CO2 is more effective absorber on Earth. I have compared the partial spectra below at the respective surface conditions.
http://i302.photobucket.com/albums/nn107/Sprintstar400/Mars-Earth.gif

stephen richards
July 23, 2010 12:15 pm

P Wilson says:
July 23, 2010 at 11:43 am
the two dominant climatic forces and the effect they have on climate, despite there being a large amount of research on them are: oceans and clouds/water vapour, which comprise 98% of the climate
Which aspect of climate ??

Monckton of Brenchley
July 23, 2010 12:18 pm

In reply to Cedarhill, the effective radiating temperature of the Earth is the temperature that prevails at what is called the characteristic-emission altitude, defined as the altitude (varying with latitude) at which the ingoing and outgoing fluxes are equal. If we remove the atmosphere, biosphere, hydrosphere and cryosphere, and retain only the lithosphere, also artificially retaining today’s Earth albedo, then the mean characteristic-emission temperature will be as follows:
[(S/4)(1-a)/s]^(1/4) = 255 K,
where S = 1368 W/m2 is the total incoming solar radiation, which is divided by 4 to allow for the ratio of the surface area of the disk presented to the Sun’s rays by the Earth and the surface area of the rotating sphere; a = 0.3 is the albedo, artificially held at today’s value; and s = 5.67 x 10^(-8) is the Stefan-Boltzmann scaling constant.
The effective radiating temperature of the Earth today is of course exactly the same, but the characteristic-emission altitude is no longer at the surface but several miles up, and the surface is some 33 K warmer than the characteristic-emission altitude.
To calculate the mean surface temperature of the lithosphere without artificially pretending that clouds and ice are still present, halve the albedo to 0.15, about the same as that of Mars today. Then the true surface temperature of the naked lithosphere today would be 268 K, or around 20 K cooler than today’s measured mean surface temperature. Hope this helps.

Physics Major
July 23, 2010 12:19 pm

If you’ve done your arithmetic correctly, you should have come up with something like 255 K. But with the atmosphere, it is about 288 K, 33 degrees warmer. This is the greenhouse effect of the atmosphere.

This implies that the presence of the atmosphere causes 33 degrees of warming, but it doesn’t imply that IR absorbing gases are responsible for all (or any) of the 33 degrees.
The atmosphere of Mars contains about 12 times as much CO2 compared to Earth’s atmosphere and there is very little atmospheric warming on Mars. The amount of warming seems more related to the total amount of atmospheric gas and hence pressure.
Mars=low pressure, low warming
Earth=moderate pressure, moderate warming
Venus=very high pressure, very high warming

bob
July 23, 2010 12:22 pm

P Wilson,
“In tropical deserts where temps are 45C plus, radiation leaves at 8.5 microns, which puts it even further out of the c02 micron band.”
This is incorrect, the peak may be at 8.5 microns, but the radiation is emmitted in a wide band which does indeed incompass the absorption bands of CO2.

jorgekafkazar
July 23, 2010 12:23 pm

“When absorbing gases are added to the atmosphere, more of emitted radiation from the ground is absorbed by the atmosphere. This results in increased downward radiation toward the surface…
Poorly put. This seems to repeat the original canard of heat flowing from cold to hot, as opposed to a reduction in heat loss rate from hot to cold.

stephen richards
July 23, 2010 12:25 pm

stephen richards says:
July 23, 2010 at 12:15 pm
R. Gates says:
Another of your cracked replies courtesy of the Gavin Schmidt school of answers.
Gravity does not generate energy. Energy cannot be made or destroyed einstein.
Sure, gravity is a force which creates the conditions for the creation of stars and the nuclear energy in those stars is started by the force of gravity compressing the gases.
E=mc² not F.r²/m1.m2

simpleseekeraftertruth
July 23, 2010 12:25 pm

@ Read Coray 11:56am
Please see my post at 10:34. The terms Greenhouse Effect & Greenhouse Gas have meanings and definitions other than those now generally used. The terms have been hijacked because of their ability to convey a message and at the same time, convey it in a perjorative way. We need terms for the effects of CO2 in the atmosphere that convey the true meaning of those effects & ‘Greenhouse Anything’ just does not do that.

bob
July 23, 2010 12:27 pm

I think physics major is on to something!
“The atmosphere of Mars contains about 12 times as much CO2 compared to Earth’s atmosphere and there is very little atmospheric warming on Mars. The amount of warming seems more related to the total amount of atmospheric gas and hence pressure.
Mars=low pressure, low warming
Earth=moderate pressure, moderate warming
Venus=very high pressure, very high warming”
Maybe it is pressure broadening of the CO2 absorption bands?

Phil.
July 23, 2010 12:31 pm

Reed Coray says:
July 23, 2010 at 11:56 am
I want to thank Anthony, Ben Herman, and Dr. Pielke for this post. It has increased my knowledge of the popularly named “greenhouse effect”.
I believe, however, that lacking from this discussion are formal definitions of “a greenhouse gas” and “the greenhouse effect” Without such formal definitions, there is little common ground for discussion.

Such molecules need to have bonds which can be made to vibrate or rotate by absorbing light. To do that they need a permanent dipole, i.e. a different atom at each end of the bond. (this is a simplification but as reasonable one)
This means O2 and N2, the vast majority of the atmosphere can not do this. (This is where the trace gas argument breaks down, in a dry atmosphere CO2 and O3 contribute all of the absorption, thus a spacecraft approaching a desert Earth looking at the emission spectrum would to a first approximation see an atmosphere entirely composed of CO2 and O3). At first glance you’d think that O3 couldn’t absorb, but it’s a bent molecule and does possess a dipole. Most of the ‘greenhouse gases’ in the Earth’s atmosphere are triatomic or larger i.e. CH4.

July 23, 2010 12:32 pm

I can’t see any text by way of explanation on my computer, only the graphic on this site and the link to thye other blog page. That page just links back to this with no text. What gives?? Where is the article?? It seems to have gone missing on my computer.

July 23, 2010 12:33 pm

Alas, very superficial and not well done.
I recommend:
Heat Transfer by Infrared Radiation In the Atmosphere: Walter Elsasser, Harvard Meteorology Studies, 5-8, 1948 Pages 1-107.
Pay particular attention to page 23, discussing his general radiation chart for the Troposphere Dr. Elsasser says:
“It may be noted that since the flux in the carbon dioxide band is EQUAL, at any level, to a definite fraction of the black body radiation corresponding to the temperature of that level in BOTH the upward and downward directions, the RESULTANT flux of the CO2 vanishes in the approximation of the chart. This is a fair approximation to the truth in the lower atmosphere (for the upper atmosphere, see Section 12).”
Section 12, as with Plass, et.al, in 1955, notes the CO2 to be a net “upflux” agent in the stratosphere.
I would like to know how the basic physics changed since 1942.
Yours, stubbornly insistent on resolution…
Max Hugoson

wws
July 23, 2010 12:38 pm

R. Gates wrote: “Ultimately of course, the source of all energy in our region of the universe is gravity,”
You must have missed being taught that “It’s better to keep quiet and be thought a fool than to open your mouth and prove it beyond all doubt.”

July 23, 2010 12:40 pm

THE “GREENHOUSE EFFECT”
AS A FUNCTION OF ATMOSPHERIC MASS
http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/FunctionOfMass.pdf

Phil.
July 23, 2010 12:42 pm

jorgekafkazar says:
July 23, 2010 at 12:23 pm
“When absorbing gases are added to the atmosphere, more of emitted radiation from the ground is absorbed by the atmosphere. This results in increased downward radiation toward the surface…”
Poorly put. This seems to repeat the original canard of heat flowing from cold to hot, as opposed to a reduction in heat loss rate from hot to cold.

This is a common fallacy, radiation from cold to hot takes place all the time and is not a violation of the 2nd Law. Your interpretation would have the night side of the earth radiating into outer space but when it’s at noon it would stop radiating back towards the Sun! No net heat can be transferred from the cold body to a hot via radiation but the radiation is always going both ways.
Suppose you have an isolated black ball which you heat so that it eventually equilibrates at a certain temperature, introduce another ball nearby at a lower temperature, the hotter one will get hotter (as will the cooler).

mkelly
July 23, 2010 12:47 pm

P Wilson says:
July 23, 2010 at 11:43 am
Re-radiated longwave radiation doesn’t penetrate oceans, …
Re-rediated IR does not penetrate leaves, people, snow, corn, etc. It “disappears”. So all the warming that is supposed to be caused by IR is happening on less than 30% of the earths surface.
Let’s see if I have the numbers correct.
CO2 input from humans roughly 3%. (slightly less)
IR band 5 micro to 75 mirco. (pick a low to high as you see fit)
CO2 band at 14-16 micro. Allowing for bandwidth broading due to statuation.
75-5 = 70
14,15,16 are 3 numbers
3/70 = .0428
So CO2 occupies 4.28% of IR.
3% of 4.28% = .00128
Humans can only be responsible for this part of any warming etc caused by CO2.
Good post PWilson.

Theo Goodwin
July 23, 2010 12:48 pm

Herman and Pielke, Sr. write:
“With regards to the violation of the second law, what actually happens when absorbing gases are added to the atmosphere is that the cooling is slowed down. Equilibrium with the incoming absorbed sunlight is maintained by the emission of infrared radiation to space. When absorbing gases are added to the atmosphere, more of emitted radiation from the ground is absorbed by the atmosphere. This results in increased downward radiation toward the surface, so that the rate of escape of IR radiation to space is decreased, i.e., the rate of infrared cooling is decreased. This results in warming of the lower atmosphere and thus the second law is not violated. Thus, the warming is a result of decreased cooling rates.”
Though scientists might be quite familiar with these claims and have no trouble understanding them, the actual statements in English, above, contain ambiguities. Consider the following:
“This results in increased downward radiation toward the surface, so that the rate of escape of IR radiation to space is decreased, i.e., the rate of infrared cooling is decreased.”
Increased downward radiation toward the surface is one thing but the fact that the rate of escape of IR radiation to space is decreased is another thing. I take it that there are two things going on here. One is that radiation has been intercepted by a CO2 molecule and, for that reason, the rate of escape of IR radiation to space is decreased. Got it. That is clear. The other thing is that there is radiation that has its source in the capturing CO2 molecule and this radiation warms the Earth. Given this radiation warming the surface of the Earth, why do the good doctors describe it all as a slowing of the cooling process. Part of the process heats the surface of the Earth. I believe that the surface of the Earth does not know or care whether the radiation comes from the Sun or elsewhere. So, why is this radiation from the CO2 molecules not treated as radiation from the sun, for the purpose of calculating Earth’s heat budget?
With all due respect, professors, if you are setting about to educate us in these matters, would you please undertake it seriously? What you have given us raises far more questions than it answers.
By the way, Trenberth (yes, that one) created a book for NASA that attempted to explain all these matters to high schoolers and he attempted to calculate all the heat added by radiation bouncing up and down between CO2 molecules and Earth. He came up with a multiplier effect of three, I believe. After some rather heavy criticism, that section of the book was removed by NASA. Check here:
http://www.climatechangefraud.com/climate-reports/7055-nasa-charged-in-new-climate-fakery-greenhouse-gas-data-bogus

Richard
July 23, 2010 12:50 pm

Back to the basic comparison. What do you do when your greenhouse gets to hot?
And what whould mother nature do? You open the vents!

Theo Goodwin
July 23, 2010 12:53 pm

Herman and Pielke, Sr. write:
“With regards to the violation of the second law, what actually happens when absorbing gases are added to the atmosphere is that the cooling is slowed down. Equilibrium with the incoming absorbed sunlight is maintained by the emission of infrared radiation to space. When absorbing gases are added to the atmosphere, more of emitted radiation from the ground is absorbed by the atmosphere. This results in increased downward radiation toward the surface, so that the rate of escape of IR radiation to space is decreased, i.e., the rate of infrared cooling is decreased. This results in warming of the lower atmosphere and thus the second law is not violated. Thus, the warming is a result of decreased cooling rates.”
Though scientists might be quite familiar with these claims and have no trouble understanding them, the actual statements in English, above, contain ambiguities. Consider the following:
“This results in increased downward radiation toward the surface, so that the rate of escape of IR radiation to space is decreased, i.e., the rate of infrared cooling is decreased.”
Increased downward radiation toward the surface is one thing but the fact that the rate of escape of IR radiation to space is decreased is another thing. I take it that there are two things going on here. One is that radiation has been intercepted by a CO2 molecule and, for that reason, the rate of escape of IR radiation to space is decreased. Got it. That is clear. The other thing is that there is radiation that has its source in the capturing CO2 molecule and this radiation warms the Earth. Given this radiation warming the surface of the Earth, why do the good doctors describe it all as a slowing of the cooling process. Part of the process heats the surface of the Earth. I believe that the surface of the Earth does not know or care whether the radiation comes from the Sun or elsewhere. So, why is this radiation from the CO2 molecules not treated as radiation from the sun, for the purpose of calculating Earth’s heat budget?
With all due respect, professors, if you are setting about to educate us in these matters, would you please undertake it seriously? What you have given us raises far more questions than it answers.
By the way, Trenberth (yes, that one) created a book for NASA that attempted to explain all these matters to high schoolers and he attempted to calculate all the heat added by radiation bouncing up and down between CO2 molecules and Earth. He came up with a multiplier effect of three, I believe. After some rather heavy criticism, that section of the book was removed by NASA. Check here:
http://www.climatechangefraud.com/climate-reports/7055-nasa-charged-in-new-climate-fakery-greenhouse-gas-data-bogus

July 23, 2010 12:53 pm

OK gentlemen. Whats wrong with this scheme?
http://i480.photobucket.com/albums/rr165/magellansc24/hansen_oven.jpg
😀

Phil.
July 23, 2010 12:58 pm

stephen richards says:
July 23, 2010 at 12:03 pm
I’ve got problems with all of this.
What follows is a question and not a statement;
CO² 0.04%
H²O 5%
They both absorp at the same hµ (approx). H²o dominates and as a probability must absorp 100 times more IR ?

In general they don’t actually, here’s the spectrum of water and CO2 in the 15 μm band.
http://i302.photobucket.com/albums/nn107/Sprintstar400/H2OCO2.gif
When a mole absorps it raises its’ instability and wants to reradiate the energy and return to the ground state a.s.a.p. This reradiation is never uni-directional? Why would it radiate in a downward direction ?
The reradiated energy is at the same hµ (nu) as the absorped unless some form energy conversion has occured (conservation of energy law)?

On absorption it will cause a change from one rotational/vibrational state to another, there is no requirement that an emitted photon would fall back to the same state so the emitted photon will usually be a different energy (hν). In fact for CO2 the time it takes to emit a photon from the excited state is much shorter longer than the mean time between collisions in the lower atmosphere so the most likely fate of the excited state is to transfer kinetic energy to the surrounding gases via collisions. Higher up in the atmosphere collisions become less likely and therefore emission of radiation more likely.
so will be absorped by another mole at ground state.? If the other moles are already at the higher quantum level, it will radiate to space?

Peter
July 23, 2010 1:00 pm

I think that one area of misunderstanding is that, although the presence of greenhouse gases permits the surface to be warmer than otherwise, it does not necessarily cause the surface to be warmer.

Andy J
July 23, 2010 1:01 pm

Well the Herman Pielke note, as clearly stated, does not invite controversy and simply and clearly gives the basis for (informed) AGW statements about “greenhouse gas” warming. Some of the ensuing comments demonstrate that this is needed and that this very basic assertion is misunderstood. In particular they note that this is not the full story of very complex processes.
However, I note that the Stefan-Boltzmann formula for thermal radiation is somehow misquoted lacking R^2 and the very-important (near-inscrutable) emissivity factor..??

Alex the skeptic
July 23, 2010 1:03 pm

Herman and Pielke end their dissertation with the following pragraph:
“For those that might still question this conclusion, consider taking away the atmosphere from the Earth, but change nothing else, i.e., keep the solar albedo the same (the lack of clouds would of course change this), and calculate the equilibrium temperature of the Earth’s surface. If you’ve done your arithmetic correctly, you should have come up with something like 255 K. But with the atmosphere, it is about 288 K, 33 degrees warmer. This is the greenhouse effect of the atmosphere.”
______________________________________________
Now, apart from the fact that without CO2, life as we know it would be non existent on this planet, can Ben Herman and Roger A. Pielke Sr. please tell us what the temperature would be like if we remove only the CO2 component from the atmospheric mix and keep all else unchanged? How much less the temperature of our planet would be? Wouldn’t this hypothetical removal of all CO2 be the reverse of doubling CO2, or would the logarithmic ‘diminishing returns’ characteristic come into play? If the latter is true (logarithmic diminishing return), then why the GE increase due to increase in CO2? Is it tru that the effect of increased CO2 is practically capped at 50ppm?
I m waiting with baited breath.

Rob
July 23, 2010 1:05 pm

‘If you’ve done your arithmetic correctly, you should have come up with something like 255 K.’
All the above sounds great and convincing, a fundamental question should be how did you come up with the value of 255 K for the earth without an atmosphere ? Is this fundamental equation correct – how do we know, shouldn’t this be the first point that is debated and resolved ?
I doubt anyone realistically doubts the IR absorbing effect – but there must get a point when at some point all IR leaving the surface at the absorbing wavelengths of CO2 is absorbed – at what concentration of CO2 does this happen, and are we at that point already ? If not, when ?

Phil.
July 23, 2010 1:06 pm

P Wilson says:
July 23, 2010 at 11:43 am
One notices at the beach that when the sand and paving is hot, water waves are still cool. That means no amount of greenhouse effect can cause either thermal expansion of water, or water vapour “feedback”. Certainly, since c02 intercepts heat at 15 microns, then re=emits it in less than a billionth of a second, to oxygen and nitrogen, when its saturation window closes. This wavelength on the spectroscopic band is already in the subzero region. In other words, the energy absorbed by c02 is dependent on freezing regions, such as Antarctica. Normal IR radiation leaving the earth is around 10 microns, 0r 7-14, incidentaly at the bandwidths where water vapour intervenes which co-incides with an average 288k (15C), and which is invisible to c02. That leaves very little energy for c02 to delay – around 3-4% of subzero energy. It is so miniscule that the effect cannot, and has not been measured. In tropical deserts where temps are 45C plus, radiation leaves at 8.5 microns, which puts it even further out of the c02 micron band.
So c02 absorbtion is a rare event in the atmosphere. Its also forgotten that most heat leaves by convection and evaporation, and not from re-radiation.

Sorry but this is complete nonsense. Here’s a set of spectra showing the relative absorption of various GHGs.
The first panel shows the total effect and progressively each gas is removed.
http://i302.photobucket.com/albums/nn107/Sprintstar400/Atmos.gif

Phil.
July 23, 2010 1:11 pm

Juraj V. says:
July 23, 2010 at 12:53 pm
OK gentlemen. Whats wrong with this scheme?
http://i480.photobucket.com/albums/rr165/magellansc24/hansen_oven.jpg

You forgot the sun, it should look like this.
http://en.wikipedia.org/wiki/File:GSO.JPG

Peter
July 23, 2010 1:15 pm

Juraj V:

OK gentlemen. Whats wrong with this scheme?

I think you know the answer to that already, but, for the benefit of those who might not:
This is not about heat flow (which would violate the 2nd law of thermodynamics) but rather nett energy flux A warmer body can absorb radiation from a cooler body because, being warmer, it must still be emitting more energy than it’s receiving from the cooler body. In other words, the nett energy flux is still away from the warmer body and towards the cooler body – it’s just that the nett energy flux from the warmer body is less than it would be in the absence of the cooler body. This does not warm the body, but rather slows down the rate of its cooling (if it’s cooling) or increases the rate of its warming (if it’s warming)

July 23, 2010 1:17 pm

“Bill DiPuccio says:
July 23, 2010 at 11:58 am
…On a clear calm night, temperatures drop rapidly at the surface boundary layer as IR heat radiates into space. On a calm cloudy night, the temperatures drop more slowly because that IR heat is re-radiated downward by water droplets in the clouds.”
Another explanation is, that clouds partially block the natural convection of warm air upwards, thus slowing down the night time cooling.
Here is a real measurement of solar, and upwelling+downwelling IR radiation, made probably by pyrgeometer.
Clear sky: the downwelling IR does not react on fact, that the surface warms and emits more IR upwards during the day.
http://www.srrb.noaa.gov/cgi-bin/surf_check?ptype=gif&site=desr&date=17-jun-2008&p1=dpsp&p5=dpir&p6=upir
My take is, that downwelling IR is a sign, that the atmosphere above has certain temperature and radiates accordingly.
Cloudy sky:
http://www.srrb.noaa.gov/cgi-bin/surf_check?ptype=gif&site=desr&date=17-sep-2008&p1=dpsp&p5=dpir&p6=upir
When solar radiation is limited by cloud, upwelling IR goes down (as the surface cools in shade) and now the downwelling IR increases at this very time. Hard to say whether the night was cloudy as well, but the downwelling IR radiation is fairly constant, like during the clear night above.

Phil.
July 23, 2010 1:22 pm

Dave Dardinger says:
July 23, 2010 at 11:49 am
Robert,
the atmosphere would still affect the temperature of the planet through conduction and convection, to the point that the same radiative balance would exist at the top of the atmosphere, the surface being at a higher temperature than without an atmosphere, due to the physics of the lapse rate.
I think you’re incorrectly assuming that this atmosphere which is transparent to all radiation could still emit radiation. This is a contradiction. If it can emit LWIR then it must also absorb LWIR. Which brings up something I’ve asked about a few times without getting an answer. I assume that if molecules like O2 and N2 were to interact in a collision, there’s a small possibility they could emit IR (or absorb it). The reason that O2 and N2 don’t normally absorb or emit IR is that they’re symmetric molecules and thus can’t interact with an electromagnetic field. But while they’re in the process of collision, there will be some asymmetry set up which could lead to emission. The question is just how likely this is? My guess is that it’d be quite rare since the interaction time would be much quicker than the average time it takes for a quantum of IR to be emitted from a GHG (for instance). But the math to do the calculation is likely to be quite hairy and beyond my abilities. But surely there’s someone here who’s a wizz at QM who could solve the problem?

Such temporary dimers do exist and to do a very accurate accounting you should account for them, observed in Titan’s atmosphere if I recall correctly.

RuhRoh
July 23, 2010 1:23 pm

So,
Why do not Dewar (‘Thermos’) bottles contain CO2 for the excellent properties of impeding radiative heat transfer?
I’ve just filed a provisional patent on this as we speak.
I’ll remember all of you small people when I am rich beyond measure…
RR

Phil.
July 23, 2010 1:27 pm

Alex the skeptic says:
July 23, 2010 at 1:03 pm
Herman and Pielke end their dissertation with the following pragraph:
“For those that might still question this conclusion, consider taking away the atmosphere from the Earth, but change nothing else, i.e., keep the solar albedo the same (the lack of clouds would of course change this), and calculate the equilibrium temperature of the Earth’s surface. If you’ve done your arithmetic correctly, you should have come up with something like 255 K. But with the atmosphere, it is about 288 K, 33 degrees warmer. This is the greenhouse effect of the atmosphere.”
______________________________________________
Now, apart from the fact that without CO2, life as we know it would be non existent on this planet, can Ben Herman and Roger A. Pielke Sr. please tell us what the temperature would be like if we remove only the CO2 component from the atmospheric mix and keep all else unchanged? How much less the temperature of our planet would be? Wouldn’t this hypothetical removal of all CO2 be the reverse of doubling CO2, or would the logarithmic ‘diminishing returns’ characteristic come into play? If the latter is true (logarithmic diminishing return), then why the GE increase due to increase in CO2? Is it tru that the effect of increased CO2 is practically capped at 50ppm?
I m waiting with baited breath.

Assuming that the frozen oceans give the same albedo as clouds, about 260K, basically were talking about a ‘snowball’ earth. The albedo effect could lead to it being even colder than that.

Nylo
July 23, 2010 1:28 pm

George E. Smith wrote:
“Since the rate of loss of energy goes as T^4; so it is non-linear with temperature, the colder parts of the ball, are not doing their fair share of cooling, and the hotter parts are being overworked, and if we average the Temperature all over the ball surface that average will ALWAYS be hgher than the original case of an isothermal ball at 278 K all over”.
I followed your argumentation quite well until this point, but here I think you got it backwards. The average temperature will always be colder, the bigger the temperature differences in the surface, for the same total emissions. It is because of the emisivity depending on T^4. The emission gain that you get by increasing 1K the temperature is quite bigger than the emissions you lose by decreasing the temperature 1K. So in equilibrium, for the same total emissions, the bigger the temperature differences between different parts of your blackbody, the lower the average temperature will be.
Take it to the absurd. A black body with one half at 0K and another half at 100K emits the same energy as an isotermal blackbody at 84K, yet its average temperature is only 50K, considerably colder.

the fritz
July 23, 2010 1:32 pm

R Gates says
This is the worst response I’ve seen to this thread.
——————
I thank you for your comment; we can do a little more calculations; the average temperature of the atmosphere is -17°C approximately what is given by applying the Stefan law; the thermal capacity of the stratosphere is approximately 1/5 of that of the troposphere; that means that if the troposphere warms by about .7°C due to GHG effect, the stratosphere has to cool by about 3.5°C, approximately what is observed by satellites

EthicallyCivil
July 23, 2010 1:32 pm

w.r.t. to feedback, the increase of convection surely can be quantified within orders of magnitude vs. radiation. From my “Spacecraft Design” course the huge pain in heat rejection in space is the lack of convective mechanisms (even within cooling systems themselves). This leads to (plural) orders of magnitude large cooling system in space.
This would seem to indicate that pretty clearly any increase in surface temperature will alter the convective heat flow at a far higher rate than the introduced radiative forcing.
What’s the back of the envelope numbers for these?

Steve in SC
July 23, 2010 1:33 pm

Several commentators have expressed it more eloquently than I would have so I will not retread that ground. I would, however, say that the things that you dismiss and assume away have more effect than the CO2 and its radiation. Note that radiation is not the only mode of heat transfer. Radiation only becomes important when you are dealing with heat energy leaving the earth-atmosphere system. Remember, you are dealing with trace amounts of the substance. I would recommend some detailed study on the subject of heat and mass transfer. You might find it enlightening.

Dave Wendt
July 23, 2010 1:36 pm

Many years ago Sapir and Whorf posited a theory, a much oversimplified statement of which would be, that language dominates thought. It never got a lot of traction in the linguistics community, though occasional efforts are still made to support versions of it. The way the climate debate has developed and proceeded suggests that maybe their work should be given more consideration.
The rather simple error of selecting a seriously flawed analogy, the greenhouse, has lead to decades of people talking past each other on this topic, mostly it would seem, because they are trying to rectify their arguments to an analogy that has no common definition and fundamentally misstates what is actually occurring. The plants inside a greenhouse enjoy a “climate” that is different from the external ambient atmosphere in which it stands. The planet with its atmosphere enjoys a climate which is different from what it would if it had no atmosphere. Other than that, none of the other efforts to extend the analogy are without serious logical flaws.
The human mind likes, perhaps even requires, analogies to attempt to process the flood of information about its external environment that it must deal with continuously. The problem this creates in discussing the planet’s climate is that for something as multifariously complex as our little blue marble the only thing that is properly analogous is the entire thing itself. As a result we end up in forums like this mostly questioning each others intelligence based on arguments that are often apples and oranges,and occasionally it seems, kumquats and water buffalo.
There is certainly a broad range of apparent intelligence among the visitors here, but as far as I can see, when it comes to the climate of the planet, what we all share along with all of humanity is incredible ignorance. From my view the only ones in this debate that can rightfully be described as “deniers” are those that will not accept that basic fact. For every press release, statement, presentation, paper, study, presentation, or off the cuff remark put forth on this topic in the last several decades there is only one response that would be almost universally applicable and that is “WE DON’T KNOW THAT”.

Nylo
July 23, 2010 1:45 pm

Forget about GHG and atmospheric processes. The mere presence of our oceans, with their large heat storage capacity, cause the earth temperature differences between night and day to be much smaller than they would be without the oceans. The mere fact of keeping temperatures stable, increases the average temperature of the planet for the same total IR emissions. And yet, I never see it mentioned when people talk about what the planet temperature should be with or without GHGs. I really wonder even if anyone has tried to calculate it. If our planet were to suffer the same temperature swings between night and day that, say, Mars suffers, its average temperature would be much colder. It is oceans that save us from that, not GHGs.

John Whitman
July 23, 2010 1:50 pm

Ben Herman and Roger A. Pielke Sr.,
Great post, thanks.
In your post shouldn’t the equation be as follows:
4 x pi x Re2 x sigma x T4 = pi x Re2 x Fso
You show the equation:
4 x pi x sigma T4= pi x Re2 x Fso
Where T4 is T to the fourth power and Re2 is Re to the fourth power.
I am wondering you left out an “Re squared” in the first half of your equation?
John

John Whitman
July 23, 2010 1:54 pm

Ben Herman and Roger A. Pielke Sr.,
CORRECTION : Re2 means Re squared, not “Re2 means Re to the fourth power”. I corrected in the post below. Sorry about that.
—————————
In your post shouldn’t the equation be as follows:
4 x pi x Re2 x sigma x T4 = pi x Re2 x Fso
You show the equation:
4 x pi x sigma T4= pi x Re2 x Fso
Where T4 is T to the fourth power and Re2 is Re squared.
I am wondering you left out an “Re squared” in the first half of your equation?
John

Dave Springer
July 23, 2010 1:57 pm

It’s not quite as simple as described in the OP.
Consider the atmosphere like insulation in your attic. It works two ways. It keeps the house warmer in the winter but it also keeps it cooler in the summer. Now consider day and night like winter and summer. The GHG insulation keeps the earth warmer at night but it also keeps it cooler during the day.
There’s an explanation why the effects don’t cancel out. To understand that one has to consider the spectrum of sunlight and the absorption bands of the GHGs.
The GHGs are largely transparent to the visible part of the spectrum. So during the day the GHGs are keeping the earth cooler that it would be otherwise as they acting as insulation against the incoming infrared radiation. But they are passing the visible spectrum straight through (discounting clouds) where some portion is absorbed by the ground and some is reflected right back out into space.
At night the visible spectrum absorbed by the ground is emitted but it is emitted as infrared radiation. Now, because the GHGs are insulators in the infrared, they are keeping surface warmer.
The GHG effect wouldn’t raise the surface temperature if the ground weren’t absorbing visible light during the day and reemitting it at night as infrared.
It’s important that be understood.
The actual mechanism of insulation is that photons in the GHG absorption bands are absorbed from a directional source (from the sun during the day and from the ground during the night) and quickly reemitted in a random direction. The net effect is that the transport of heat via infrared radiation is slowed down across the GHG insulation because, since the direction of reemission is random, some of the photons go right back in the direction they came from. One might also think of it like running through a mile of forest vs. running a mile across an open field. It takes longer to go through the forest because you have to zig zag through the trees effectively increasing the distance travelled getting from point A to point B.

Jim G
July 23, 2010 2:05 pm

stephen richards says:
July 23, 2010 at 12:15 pm
R. Gates says:
“Another of your cracked replies courtesy of the Gavin Schidt school of answers.”
“Gravity does not generate energy. Energy cannot be made or destroyed einstein.
Sure, gravity is a force which creates the conditions for the creation of stars and the nuclear energy in those stars is started by the force of gravity compressing the gases.”
As several of us discussed in a previous post, gravity is not even really a force but a condition, curvature, of space-time which occurs in the presence of mass causing everthing in its reach to move in a straight line though curved space. The source of energy represented by radioactive material in otherwise empty space would not be due to present gravity though it was originally created by gravity, previously, in the formation a large enough star to forge its properties when it exploded at the end of its life. I believe iron is the heaviest material that can be created in a “living” star that has not gone super nova. Fun stuff.

July 23, 2010 2:08 pm

Nylo says:
July 23, 2010 at 9:01 am (Edit)
tallbloke, the GHE will by itself (i.e. without feedbacks) cause warming. However as it happens, other collateral effects may cause the warming to be increased, decreased or perhaps even reverted into cooling. Roger is only talking about the GHE, alone, without considering feedbacks.

I stand corrected – as you were Dr Pielke. I thought we’d got past that stage a few decades ago, even if we haven’t got much further since. 😉

Scott Basinger
July 23, 2010 2:09 pm

ScienceofDoom has a great article series which is quite detailed on the subject, the first of which is called “CO2 – An Insignificant Trace Gas? Part One”
This is a great website which deals only with the science. The administrator is a true scientist and excellent teacher. In the storm of political discussion, this is a great science website to get the basics.
[url]http://scienceofdoom.com/2009/11/28/co2-an-insignificant-trace-gas-part-one/[/url]

Theo Goodwin
July 23, 2010 2:09 pm

Would someone please explain the different mechanisms of CO2 and water vapor? We know that CO2 captures and radiation and releases it randomly, so somewhat less than half of all captured radiation is sent toward Earth. What about water vapor? Does it capture radiation and than radiate it? What is the mechanism of warming?

Ryan
July 23, 2010 2:09 pm

I’m going to put this another way for you. Lets say we were talking about visible light energy rather than infra-red energy (they are, in any case, only distinct in terms of our physical perception of them rather than physical properties in any case) . What AGW proponents are saying is that we have, in CO2, a translucent panel above our heads (i.e. it absorbs light). According to AGW proponents, if we put more and more translucent panels above our heads the area beneath the translucent panels will get brighter and brighter.
Something sounds wrong with that idea doesn’t it?
What’s more, what happened to the idea that when a gas receives heat energy it causes the gas to do work which in turn results in its expansion. According to AGW theory this would happen with O2 but not with CO2 because CO2 is busily doing something else with all that heat.

Dr A Burns
July 23, 2010 2:12 pm

Well expressed although a discussion of the lapse rate should have been included. The misunderstanding arises from many who suggest that the cooler atmosphere radiates to a warmer earth, ignoring the greater radiation from the warm earth to the cooler atmosphere.

Theo Goodwin
July 23, 2010 2:13 pm

Would someone please address the assumption that CO2 is distributed randomly throughout the atmosphere? If the assumption is correct then CO2 is the only thing in the atmosphere that is randomly distributed. Oxygen, for a handy example, is not randomly distributed. Yet this assumption underlies all so-called science by the warmist crowd. To me, the fact that this assumption is used just show that climate science has not advanced to the stage of experiment.

Andrew W
July 23, 2010 2:20 pm

Thank you Ben Herman and Roger A. Pielke Sr for the tidy post, it’s resulted in the funniest thread I’ve read in ages, that kill-joy from Brenchley tried to derail it all but to no avail.
The thread is a testament to humans being rationalising rather than rational creatures.

Frank K.
July 23, 2010 2:22 pm

RuhRoh says:
July 23, 2010 at 1:23 pm
So,
Why do not Dewar (‘Thermos’) bottles contain CO2 for the excellent properties of impeding radiative heat transfer?
I’ve just filed a provisional patent on this as we speak.
I’ll remember all of you small people when I am rich beyond measure…
RR

Just call it “CarboJug – a carbon-capture device which keeps your coffee warm!” Pre-loaded with CO2 generated from coal-fired power plants!
Put a bunch of “endorsed by the WWF, Greenpeace, and NASA/GISS” stickers on the box, get Al Gore to do the infomercials (“improve your Chakra with CarboJug”), and voila – a blockbuster product that will make you millions!

PolyisTCOandbanned
July 23, 2010 2:28 pm

[snip- your name says it all ~mod]

Scott Basinger
July 23, 2010 2:31 pm

From scienceofdoom.com:
“The Stefan-Bloltmann Law states:
j = εσ(T^4)
Where
j = total energy radiated per unit area per unit time
ε = emissivity, ranging from 0 to 1, where 1 is a perfect black body
σ = the Stefan Boltzmann constant, 5.67 x 10-8
σ = temperature in K
The effective temperature of the sun is 5780K, it is pretty close to a blackbody, and its radius, r = 696 x 10^6m
The area of the surface of a sphere = 4πr^2
So Total Energy, E = 5.67-8 x 57804 x π x (696 x 10^6)2 = 3.85 x 10^26 W – That’s a lot of Watts!
How much hits the earth?
Radius of the earth, re = 6.37 x 10^6 m (6,370 km)
Distance from sun to earth, ao = 1.5×10^11 m (150 million km)
Imagine a giant sphere with a radius the distance from the sun to the earth, and the earth as one tiny circle pasted onto it – that’s the proportion of the Sun’s energy that hits the earth.
The giant sphere has an area of 4πa^2 = 4π x (1.5×10^11)^2
The earth’s “circle” pasted on this giant sphere has an area = πre2 (not the whole area of the earth’s surface which would be 4πre2, just the effective 2D disc that the sun’s energy hits).
So the proportion incident on the earth’s surface = (πr^2)/ (4πa^2)
= (6.37×10^6)^2 / (4 x (1.5×10^11)^2) = 4.5 x 10^-10 -or around 1/2 billionth of the total energy
The total energy hitting the earth’s “disc” = 1.73 x 10^17 Watts
And per unit area (area = πre2) = 1,360 W/m2
First major result!
Applying the same maths to the earth – the earth’s surface also emits radiation according to the same law. This is where is starts to get tricky, but let’s consider the simple case.
Energy received from the sun = Energy emitted by the earth (if the temperature of the earth’s surface stays the same).
So we have to solve the total energy radiated out from the earth, where Te is the surface temperature of the earth:
Energy flux x total area of the earth = 1.73 x 10^17
5.67 x 10^-8 x Te^4 x (4πr^2) = 1.73 x 10^17
The result, Te = 278K = 5°C ?
Actually, not quite right. The problem is, and can easily be demonstrated by satellites measuring the energy reflected back – not all of the energy gets absorbed by the earth’s surface. Some gets reflected by clouds, the atmosphere, and some by the earths surface. On average about 30% gets reflected.
Redoing the same equation with only 70% of the energy incoming:
Adjusted Te = 254K = -19°C ?
Wow, it doesn’t feel that cold, what went wrong? Nothing went wrong, and you’re right, across the globe the “average temperature” is higher – about +16°C.
The explanation is in the (inappropriately labelled) “greenhouse gases”, which include water vapor, CO2 and methane (CH4). These gases absorb energy from wavelengths in the earth’s range, and hardly any in the sun’s range.
So the sun’s energy just passes through like they don’t exist, but when the earth emits its radiation, these gases absorb energy and then re-emit, so that the earth’s energy doesn’t just fly off into space but instead it’s absorbed and re-transmitted, some of it back down to earth.
The “greenhouse gases” heat the earth’s surface up approximately 35°C higher than it would be otherwise.”

The same website dismisses other silly myths as well. Lord Monckton’s post elegantly summarizes this.
My concern with the field in general is the magnitude of feedback / response in the natural system, continued careless use of statistical methods, missing error bars, the relative impact of CO2 vs land use, and obvious hockey team cronyism in publication including the publication of a blacklist which undermines and cheapens the entire field of study.

July 23, 2010 2:35 pm

One of the staple arguments for a general greenhouse effect on earth is the assertion that this planet would be an overall 30-35K cooler were it not for greenhouse gases. This is based on a theoretical calculation based on the Stefan-Boltzmann law of black body radiation. Now the earth is not a black body, but the theoreticians claim they have made the necessary adjustments for this in their calculations. Of course no one can test this by removing supposed greenhouse gases from our atmosphere.
However the moon has no atmosphere. The later Apollo missions left an array of temperature sensors on the moon and recently NASA released an analysis of the results. Amazingly this shows that the moon also has an elevation of temperature (~40K) above that calculated by the theory. Does the moon then have a greenhouse‘ effect? Clearly not – it has no atmosphere. So it looks as if the calculated starting point is wrong and neither the earth nor the moon are kept warmer by any ‘greenhouse effect’.
http://climaterealists.com/attachments/database/RadiativeNonEquilbrium_BHermalyn_Final.pdf
Absorbed radiant heat incident on the surface of both is conducted downwards and is released like heat is released from any storage heater, at night.

Joss
July 23, 2010 2:37 pm

@R.Pielke, Ben Herman, Lord Monckton,
“the cooling is slowed down.”
That’s plausible. But if it is that simple, why not laying down the equations and publish a much needed paper ?
How does this translate in terms of heat capacity, heat conductivity, thermal diffusivity, heat transfer and so on ?
What precisely means ” the cooling is slowed down” ?
Greenhouse effect is physics. Physics requires specific and precise statements, equations and numbers.
In the present state, this is just one more climatologist’s assertion.

Enneagram
July 23, 2010 2:39 pm

Misconception is a failed conception, a natural or an induced abortion. Is your theory the equivalent of the “Day After pill”? 🙂

kwik
July 23, 2010 2:40 pm

Phil. says:
July 23, 2010 at 12:42 pm
“Suppose you have an isolated black ball which you heat so that it eventually equilibrates at a certain temperature, introduce another ball nearby at a lower temperature, the hotter one will get hotter (as will the cooler).”
Are you sure about this, Phil? That the hottest will be hotter? I allways believed that this is exactly what was impossible, according to the 2’nd law….because if it got hotter…then heat has gone from colder to hotter….. or is this Trenberts hidden heat?

July 23, 2010 2:42 pm

Monckton: how much warming a given increase in CO2 concentration will be expected to cause (around a third of what the IPCC projects
.
Climate Sensitivity Reconsidered
http://www.aps.org/units/fps/newsletters/200807/monckton.cfm
.
Real Climate: Once more unto the bray
http://www.realclimate.org/index.php/archives/2008/07/once-more-unto-the-bray/
.
The APS and global warming: What were they thinking?
http://duoquartuncia.blogspot.com/2008/07/aps-and-global-warming-what-were-they.html

Enneagram
July 23, 2010 2:42 pm

BTW:
Why forests are so fresh:
Examples of Endothermic and Exothermic Processes
Photosynthesis is an example of an endothermic chemical reaction. In this process, plants use the energy from the sun to convert carbon dioxide and water into glucose and oxygen. This reaction requires 15MJ of energy (sunlight) for every kilogram of glucose that is produced:
sunlight + 6CO2(g) + H2O(l) = C6H12O6(aq) + 6O2(g)

July 23, 2010 2:47 pm

Dr. Ferenc Miskolczi says in his paper (Miskolczi, Ferenc M. 2007. “Greenhouse Effect in Semi-Transparent Planetary Atmospheres.” Időjárás 111, 1-40) that water vapor and CO2 are in permanent equilibrium, and that for the past 61 years there has been no global warming, whatsoever, as a result of CO2 increases. For the last 3 years, as far as I know, no one has been able to prove him wrong.

Roger Clague
July 23, 2010 2:49 pm

Talking of greenhouse gases ( GHG ) assumes that it is the chemistry of the gases that matters. O2 is OK, CO2 is a GHG, and therefore bad.
The temperature of the earth’s atmosphere depends on the kinetic, translational energy of all the gas molecules in it, mainly oxygen and nitrogen.
1. THE “GREENHOUSE EFFECT”
AS A FUNCTION OF ATMOSPHERIC MASS
http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/FunctionOfMass.pdf
planet pressure Atmosphere effect Atmosphere gas
mars low low CO2
earth medium medium O2and N2
venus high high CO2
The surface temperature of planet atmospheres depends on the pressure not the type of gas.
There is similar effect on Jupiter and other planets made of hydrogen and helium
The atmosphere is physics not chemistry

July 23, 2010 2:50 pm

Scott Basinger says:
July 23, 2010 at 2:31 pm (Edit)
The “greenhouse gases” heat the earth’s surface up approximately 35°C higher than it would be otherwise.”

No they don’t. They slow the rate of cooling.
Please don’t try to say that ‘this is the same thing’.

Theo Goodwin
July 23, 2010 2:54 pm

Ryan writes:
“What AGW proponents are saying is that we have, in CO2, a translucent panel above our heads (i.e. it absorbs light). According to AGW proponents, if we put more and more translucent panels above our heads the area beneath the translucent panels will get brighter and brighter.”
Let me put that a bit differently. From the posts we have seen today, especially including Pielke, Sr’s article, CO2 in the atmosphere can be treated as a magnifyer of the Sun’s energy, in appropriate bandwidths, of course. From that, it follows that the effects of CO2 would necessarily parallel changes in the sun’s energy output.
Aside from the point above, would someone who knows the math undertake the exercise of treating CO2 as a magnifyer of the sun’s output? I think it would be greatly illuminating.

Theo Goodwin
July 23, 2010 3:00 pm

Joss writes:
“That’s plausible. But if it is that simple, why not laying down the equations and publish a much needed paper?”
This is what is so frustrating about attempting to discuss matters with climate scientists, both warmists and deniers. No one introduces actual hypotheses about phenomena in the environment that can be shown to be true or false at some future time. All discussions are about unchallenged principles or the sort of thing that happens in the laboratory. Does no one have a genuine hypothesis about behavior of the atmosphere under the influence of CO2?

Jimbo
July 23, 2010 3:11 pm

Steven Mosher says:
July 23, 2010 at 10:50 am
GHGs will not cool the planet. There no science to suggest they will. C02 will warm the planet, up to limit. That limit has not been reached and the questions are:
1. how fast will we reach that limit
2. will it be damaging
3. Can and should we do anything about it.

You forgot point 4 i.e. will increased co2 lead to a runaway warming of the planet? That is the most important question for me and so far all I get are caveats. (Point 2 kind of hited at it though)

Leonard Weinstein
July 23, 2010 3:14 pm

The basic points made by Ben Herman and Roger A. Pielke Sr. are quite valid as far as they go. Also the comments by Monckton of Brenchley put the whole issue in correct perspective. The Earth is a particularly complex case with oceans, clouds, water vapor and the main gases of the atmosphere. However it should be remembered that water vapor and clouds constitute the main part of the greenhouse effect on Earth.
Mars, mainly consisting of CO2 at a much lower pressure is a totally different case. The first point to make about Mars is that the adiabatic lapse rate (=g/Cp) is less than 1/2 that of Earth due to lower gravity dominating the slightly lower Cp. In addition, lack of water vapor and clouds decrease the absorption of long wave radiation compared to Earth. It has also been observed on Earth and Venus that there is a minimum pressure where lapse rate assumptions break down (about 1/10 bar), and the lapse rate becomes smaller than at the higher pressures. This may be due to the solar wind and other external forcing being more significant. The result is that a lower lapse rate would be expected for Mars, and is in fact seen.
Venus is different from both Earth and Mars. There is a mostly CO2 atmosphere that is both very massive and high, and a solid cloud layer very near the location of outgoing radiation. It is likely that the cloud layer both absorbs most of the incoming solar radiation that is not reflected, and emits most of the long wave outgoing radiation. Only a very small fraction of the sunlight reaches and is absorbed at the surface. The atmosphere is also extremely dense (about 91 bar). The absorption by the CO2 near the surface is so high that back radiation to the surface is also very large and net radiation heat transfer is very small. The net result is that the hot surface and hot lower layer of the Venus atmosphere are mainly maintained by the flowing atmosphere (convection and turbulent mixing), not solar heating of the surface or radiation heat transfer. The flow that maintains the high temperature is that portion of the atmosphere that absorbs most of the sunlight, and is adiabatically compressed as it is convected down and mixed through the atmosphere. The lapse rate, which is in this case the adiabatic lapse rate, is the result of the increased temperature from conversion of gravitational potential energy to kinetic energy as the gas goes down. It is almost exactly the value expected from g/Cp for CO2 at the high temperatures. One could say it is the combination of high pressure, tall atmosphere, and greenhouse gases that result in the very high ground temperature on Venus.
Getting back to Earth, as the greenhouse gas concentration increases over the present level, due mainly to CO2, the only way the temperature would increase (assuming water vapor feedback is not a large factor, and it does not seem to be) would be for the altitude of the effective outgoing radiation to increase (the lapse rate would not increase). Since the high altitude pressure drops very rapidly with increasing altitude, the increase is limited to a few degrees. However, that is assuming the water vapor does not become a significant fraction of the total mass of the atmosphere. The possible water vapor fraction is limited for any reasonable temperature, so this should not be an issue.
A final parting point. The wet lapse rate is smaller than the dry lapse rate. The greater the water vapor content, the smaller this wet lapse rate becomes. As the water vapor content became more significant, the lapse rate would actually DROP. The result would be a cooling at lower levels even with a modest raising of the level of radiation out. The problem is very complicated, and there is no realistic chance of greenhouse runaway or heating more that a few degrees.

wayne
July 23, 2010 3:18 pm

From what I remember any atom or molecule when it’s electron have a change in velocity (acceleration/deceleration) will always radiate no matter what type of particle it is of where the change in velocity came from (collisions, vibrations, etc.). Is this when two O2 and/or N2 also radiate when they collide? I think it in the microwave so weaker photons but there are many magnitudes more of those molecules within the atmosphere than CO2 which should compensate. WUWT? Never have seen it mentioned.
Boy, did Ben Herman and Roger A. Pielke Sr. ever leave gapping holes in their explanation !! Just read the comments above. Where are all of the inconvenient and lacking-complete-understanding factors which should have at least been mentioned? Come on climatologist, you can do better than that. Give us some real info, don’t worry, you won’t go over most heads here.

NickB.
July 23, 2010 3:28 pm

I’ve always wondered if the equation that comes up with 33 degrees of greenhouse effect took into account that space really isn’t absolute zero – if I recall correctly it’s 3 or so K. Not that it really matters, just curious if anyone knew

RockyRoad
July 23, 2010 3:33 pm

Maybe instead of “greenhouse” gasses we could call them “blanket” gasses, for that is what they do.

Rob
July 23, 2010 3:34 pm

‘From what I remember any atom or molecule when it’s electron have a change in velocity (acceleration/deceleration) will always radiate no matter what type of particle it is of where the change in velocity came from (collisions, vibrations, etc.). Is this when two O2 and/or N2 also radiate when they collide? I think it in the microwave so weaker photons but there are many magnitudes more of those molecules within the atmosphere than CO2 which should compensate. WUWT? Never have seen it mentioned.
Boy, did Ben Herman and Roger A. Pielke Sr. ever leave gapping holes in their explanation !! Just read the comments above. Where are all of the inconvenient and lacking-complete-understanding factors which should have at least been mentioned? Come on climatologist, you can do better than that. Give us some real info, don’t worry, you won’t go over most heads here.’
Too true wayne, too true.
It is almost like a propaganda post.
we want real answers to the unaswered questions, not to be patronised in a – don’t be a denier – kind of way.
We know it warms
HOW MUCH ???????

1DandyTroll
July 23, 2010 3:42 pm

Maybe I’m missing something, but of course I do miss a lot, but why does everyone use the sun as a constant when its output is highly variable on a day to day basis, month to month, year to year, cycle to cycle? Is it like gravitational pull and push which is used as a constant, in junior high lol, for being conveniently abstract rather than accuracy and detailed?
And using CO2 as some form of a starting point in the whole so called green house effect is moot since nobody frakking knows which gas molecule exhibit the main secondary forcing or what ever. What does CO2 mean if water vapor is first, or heh argon? What would happen to the temperature, in reality, if we could switch co2 for argon, or oxygen, or nitrogen? After all if we remove the “overhead” of co2 something will take its place, especially if you believe that the atmosphere only can consist of 100% of stuff at 1 bar and 1 bar at sea level is an absolute constant.
If the earth’s atmosphere really worked like a green house effect you’d be able to remove the sun and exchange it for an artificial non-heating light source, what with it gets its supposed heating from the ground up rather then from the sun. lol try convincing people of a real green house effect when it is 40 below. The so called green house effect is naught but a self made statistical phenomenon.

Marc77
July 23, 2010 3:55 pm

If the black body radiation is the primary way by which energy is emitted and we know it is proportional to the FOURTH power of temperature. It seems clear the energy budget must depend on the distribution of heat on the planet. So any change in the movement of air or seawater can change the radiation budget. So some of the recent warming could have been caused by a transfer of heat from the tropics to the arctic.

John Whitman
July 23, 2010 3:59 pm

Steven Mosher says:
July 23, 2010 at 10:50 am
PTCO.
It’s more than sad that people continue to fight against the basic physics. Physics that working engineers understand and use on a daily basis. The problem is this: The warmists have been very successful in lumping those of us who understand how GHGs work to warm the lower portion of the atmosphere, with those who deny this fundamental physics. They lump those who deny the science of GHGs with those who question the accuracy and completeness of our understanding of sensitivity.
GHGs will not cool the planet. There no science to suggest they will. C02 will warm the planet, up to limit. That limit has not been reached and the questions are:
1. how fast will we reach that limit
2. will it be damaging
3. Can and should we do anything about it.

————————-
Steve,
Hi, I loved your book : )
Overall, your comment rings true to me with two exceptions:
Exception #1 – in your leading paragraph you show a significant concern about the negative things the “warmists” (your word not mine) might think about some of the GHG effect (or lack of effect) comments by individuals on this active and long thread. In an open society like this wonderful venue Anthony has created, people will do naturally what the commenters are doing on this thread. Limiting comments here because of concern about what the “warmists” think will tend to make for a much more limited participation and there would eventually be less learning going on about very important things. The key is learning.
Exception #2 – you also say “C02 will warm the planet, up to limit”. Ben Herman and Roger A. Pielke Sr give us an introductory tutorial on “the greenhouse effect”, but it is simplistic by their own intention to illustrate fundamental points to try to teach people who they think are missing the physics fundamentals about “the greenhouse effect”. They are to be commended for that and I admire them for that. In their simplistic example they show “GHGs, all other things being constant, will warm the planet”. But when adding in all the very high level complexity of our earth’s systems (which cannot be any farther from constant), however, there is no automatic assurance that about the statement that “C02 will warm the planet, up to limit”. It may try to, but does it when combined with everything else? I think so, but think also that we have hardly started the climate science homework to be convincing about it.
Bless Anthony and the WUWT team.
John

kwik
July 23, 2010 4:10 pm

Roger Clague says:
July 23, 2010 at 2:49 pm
http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/FunctionOfMass.pdf
Roger, I read that paper. Difficult to debunk, I would say.

George E. Smith
July 23, 2010 4:12 pm

“”” NickB. says:
July 23, 2010 at 3:28 pm
I’ve always wondered if the equation that comes up with 33 degrees of greenhouse effect took into account that space really isn’t absolute zero – if I recall correctly it’s 3 or so K. Not that it really matters, just curious if anyone knew. “””
Has no effect. Remember that objects are limited to radiating sigma.T^4 W/m^2 max (thermally); so just how much radiation do you think you are going to receive from a 3 Kelvin Black Body radiator ?
It is weak enough that it takes a major radio telescope antenna to even detect it in the noise. But a good question.

Reed Coray
July 23, 2010 4:13 pm

George E Smith’s response (10:58) to Jeff’ comment is, I believe, an example of what I perceive as the need when discussing energy flow and temperature to carefully define terms. I ask the readers of this post: (a) are the following two statements equivalent; and (b) if not, which statement, if either, is the commonly accepted definition of “cooling”.
(1) An object is “cooling” if the net energy flow is away from the object.
(2) An object is “cooling” if its temperature is decreasing.

George E. Smith
July 23, 2010 4:17 pm

“”” kwik says:
July 23, 2010 at 4:10 pm
Roger Clague says:
July 23, 2010 at 2:49 pm
http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/FunctionOfMass.pdf
Roger, I read that paper. Difficult to debunk, I would say. “””
You may be right on that debunk being difficult; I would say it is just about pure bunk.

July 23, 2010 4:23 pm

Steven Mosher says:
July 23, 2010 at 10:50 am
PTCO.
It’s more than sad that people continue to fight against the basic physics. Physics that working engineers understand and use on a daily basis. The problem is this: The warmists have been very successful in lumping those of us who understand how GHGs work to warm the lower portion of the atmosphere, with those who deny this fundamental physics.

I’m sorry to see the warmists have successfully brainwashed Mosher into believing co2 warms the planet.
The Sun warms the planet. Co2 does not and cannot warm the planet. As Pielke senior correctly points out, GHG’s (mostly water vapour) can slow down the rate of cooling of the planet. Slowing down the rate of cooling is not the same thing as being able to warm something up.
Can my blanket warm my bed up before I get in it Mosh?

John Whitman
July 23, 2010 4:25 pm

Reed Coray says:
July 23, 2010 at 4:13 pm
George E Smith’s response (10:58) to Jeff’ comment is, I believe, an example of what I perceive as the need when discussing energy flow and temperature to carefully define terms. I ask the readers of this post: (a) are the following two statements equivalent; and (b) if not, which statement, if either, is the commonly accepted definition of “cooling”.
(1) An object is “cooling” if the net energy flow is away from the object.
(2) An object is “cooling” if its temperature is decreasing.

—————-
Reed Coray ,
My wife tells me it is better to grab the tail of the dragon (lung in chinese), than to look in its mouth.
John

John Whitman
July 23, 2010 4:35 pm

tallbloke says:
July 23, 2010 at 4:23 pm
The Sun warms the planet. Co2 does not and cannot warm the planet. As Pielke senior correctly points out, GHG’s (mostly water vapour) can slow down the rate of cooling of the planet. Slowing down the rate of cooling is not the same thing as being able to warm something up.
Can my blanket warm my bed up before I get in it Mosh?

——————–
tallbloke,
Ahhh heck, I wish I could have said that blanket thing. : )
John

Anders Boman
July 23, 2010 4:39 pm

Pardon an ignorant question.
I assume that a perfect thermal insulator covering the whole earth high up in the atmosphere would result in the world freezing as no radiative transfer of solar energy would reach the earth’s surface.
Then, the reason for the glass of greenhouses to have an effect is because it minimises conductive and convective heat losses.
In what way does CO2 reduce such conductive and convective losses to produce a greenhouse effect?

JAE
July 23, 2010 4:42 pm

It is very easy to prove that backradiation has no effect on temperatures. The direct solar energy at noon on a clear summer day in an arid area is about 1000 wm-2. That’s enough to raise the temperature of a black surface to about 91 C (196 F). And that is about what happens on an asphalt roadway. If backradiation had any effect, the surface would be much hotter.

DirkH
July 23, 2010 4:44 pm

RockyRoad says:
July 23, 2010 at 3:33 pm
“Maybe instead of “greenhouse” gasses we could call them “blanket” gasses, for that is what they do.”
Why not call them “heat transporting gasses”. For they absorb and re-emit LWIR.

Leonard Weinstein
July 23, 2010 4:46 pm

Tallbloke,
I am sure Mosher is saying that greenhouse gases warm the lower atmosphere and surface compared to no greenhouse gases and do it by trapping some of the solar energy (similar to a blanket trapping heat). I don’t think he is implying the energy comes from the gas. I fear that poking at details such as this make us seem nitpicking and not interested in coming to agreement.

DirkH
July 23, 2010 4:48 pm

George E. Smith says:
July 23, 2010 at 4:17 pm
“[…]You may be right on that debunk being difficult; I would say it is just about pure bunk.[…]”
Maybe this one is easier to digest; it is also about the lapse rate (the part by William Gilbert):
http://docs.google.com/viewer?a=v&q=cache:A81VTnHUPkEJ:www.tech-know.eu/NISubmission/pdf/Politics_and_the_Greenhouse_Effect.pdf+adiabatic+lapse+rate+greenhouse+effect&hl=en&pid=bl&srcid=ADGEESiwZvv2w8O-I2jVLvl_jNAyMMK0oFFvnwWm3qZAom59wDIjAF9Q5k-_voIQCmn1hoWtEBgjtFGGZ22LU9giDVTnMmCmdQ7GIUpCrHNeNm6G4nKLg14djiR6c7SgRbj7b3uck3hb&sig=AHIEtbTG1haSI1yNANL1FwkTLacvcOBU0w

wayne
July 23, 2010 4:50 pm

Rob says:
July 23, 2010 at 3:34 pm
Too true wayne, too true.
It is almost like a propaganda post.
we want real answers to the unaswered questions, not to be patronised in a – don’t be a denier – kind of way.
We know it warms
HOW MUCH ???????
~~~~~
Exactly. That’s the big question. Though of all the question marks still in my head but most are asked by others above in one form or another. Also one great question above was how much of the 33C is from water vapor? Never have got a handle on that factor. If water vapor performs basically parallel to Co2 plus it’s additional capabilities, and doubling is close to the same at 3.7C per doubling, then the difference from a 95% humidity day and a dry desert should be huge. Right? See, put water vapor in every statement where you read CO2 and it doesn’t seem to jive by physics.
Of take Co2 and half it (-3.7C) and half it (-3.7) and… yes it is logarithmic but you very quickly place a huge drop in temperature on Co2 but all of the water vapor is still there. That definitely doesn’t jive.

Anders Boman
July 23, 2010 4:55 pm

Please bear with me with another novice question:
Since the atmosphere has a smoothing effect on the earth’s temperature, compared with if we did not have an atmosphere at all;
1) Of all the gases in the atmosphere, does CO2 contribute more of this effect than the other gases?
2) If CO2 contributes on average less of this effect than the other gases combined, then if CO2 concentrations increase as a proportion of all gases – how can this increase the greenhouse effect in total?

July 23, 2010 4:55 pm

Leonard Weinstein says:
July 23, 2010 at 4:46 pm (Edit)
Tallbloke,
I am sure Mosher is saying that greenhouse gases warm the lower atmosphere and surface compared to no greenhouse gases and do it by trapping some of the solar energy (similar to a blanket trapping heat). I don’t think he is implying the energy comes from the gas. I fear that poking at details such as this make us seem nitpicking and not interested in coming to agreement.

Mosher and the warmists say co2 warms the atmosphere. Pielke and I say it slows the rate of cooling of the atmosphere. You say “it doesn’t matter”.
IT FUNDAMENTALLY MATTERS.

July 23, 2010 4:57 pm

Am I right to think about G&T that:
A possible way for atmospheric “greenhouse gases” to warm a planet could be by temporarily delaying some escape of heat?
Infrared absorbing gases in the atmosphere could slow the cooling of the Earth?

old construction worker
July 23, 2010 5:07 pm

Being just an old construction worker. All I know is that no one is trying to sell me a home climate control system based on CO2.
We stopped using “dead air space” as an insulator between inside and outside wall a long time ago. I think everyone knows why.

George E. Smith
July 23, 2010 5:08 pm

“”” Nylo says:
July 23, 2010 at 1:28 pm
George E. Smith wrote:
“Since the rate of loss of energy goes as T^4; so it is non-linear with temperature, the colder parts of the ball, are not doing their fair share of cooling, and the hotter parts are being overworked, and if we average the Temperature all over the ball surface that average will ALWAYS be hgher than the original case of an isothermal ball at 278 K all over”.
I followed your argumentation quite well until this point, but here I think you got it backwards. The average temperature will always be colder, the bigger the temperature differences in the surface, for the same total emissions. It is because of the emisivity depending on T^4. The emission gain that you get by increasing 1K the temperature is quite bigger than the emissions you lose by decreasing the temperature 1K. So in equilibrium, for the same total emissions, the bigger the temperature differences between different parts of your blackbody, the lower the average temperature will be.
Take it to the absurd. A black body with one half at 0K and another half at 100K emits the same energy as an isotermal blackbody at 84K, yet its average temperature is only 50K, considerably colder. “””
Well Nylo; I think that you have caught me in a fox pass; fancy that; must be the third time this century that I have goofed.
yes I solved the wrong problem !!
So suppose the Temperature at some location goes through a sinusoidal cycle between T0 + a at the maximum and t0 – a at the minimum; but the average temeprature over the cycle is T0.
So I can calculate the energy radiated at a Temperature of T0.
Let’s say our Temperature follows T = T0 +a sin (2pi.t/tau) where tau is the period of the Temperature cycle (could be a spatial period).
So actually the instantaneous emittance is sigma.(T0 + a.sin (2pi.t/tau))^4
and that equals sigma.(T0^4 + 4T0^3.asin(2pit/tau) +6T0^2.a^2sin^2(2pit/tau) + 4a^3 T0.Sin^3(2pit/tau) + a^4 sin^4(2pit/tau)).
It is left to the reader to show that the sin and sin^3 terms integrate to zero when we integrate the above over a complete cycle; and only the first, third, and fifth terms integrate to a non zero value over a complete cycle and they are ALL positive; so the result is ALWAYS higher that sigma.T0^4.
And I already knew that ; so that is clearly the wrong problem.
The simplest way to see that delaying the cooling process results in a higher temperature, is that during the delay time between energy coming in, and an equivalent energy exiting, the sun is still pouring in energy at a constant rate; so an increment of energy is added to the earth system that grows linearly with the propagation delay of the cooling process, and that must result in the Temperature going up.
Good to have you watching my back there Nylo; I almost slipped that one by.

John Whitman
July 23, 2010 5:12 pm

The most lovely word in the english language might be “fundamentally”.
John

DirkH
July 23, 2010 5:18 pm

Anders Boman says:
July 23, 2010 at 4:55 pm
“[….]1) Of all the gases in the atmosphere, does CO2 contribute more of this effect than the other gases?”
Absorption bands of CO2 and H2O:
http://wattsupwiththat.files.wordpress.com/2008/06/atmospheric_spectral_absorption.png
Notice that H2O vastly outperforms CO2.
“2) If CO2 contributes on average less of this effect than the other gases combined, then if CO2 concentrations increase as a proportion of all gases – how can this increase the greenhouse effect in total?”
Not very much, is the answer. Even the warmists know this; that’s why they phantasize about a small warming caused by CO2 which makes H20 evaporate, which will with its wide absorption band lead to a feedback which will make the Earth melt and the Oceans boil and we will all be down on our knees and pray for bloody mercy or somesuch.
Which is of course comple lunacy as hot places on the Earth, say in the tropics during noon, are not known for melting down due to a sudden outbreak of water vapor feedback. But sanity does not enter the skulls of the AGW boneheads.

July 23, 2010 5:20 pm

A premise of Herman and Pielke’s description of “the greenhouse theory” is that in the infrared band and outside the window of transparency the magnitude of the downwelling radiative flux increases with concentrations of greenhouse gases while the magnitude of the upwelling flux stays stationary. Would the two authors care to comment on Miskolski’s finding that the two fluxes are equal?

George E. Smith
July 23, 2010 5:26 pm

“”” Phil. says:
July 23, 2010 at 12:58 pm
stephen richards says:
July 23, 2010 at 12:03 pm
I’ve got problems with all of this.
What follows is a question and not a statement;
CO² 0.04% “””
Note to Phil.
I think you made a typo in your response Phil. You said that the spoantaneous decay time of the CO2 excited state was much shorter than the collision time in the lower atmosphere.
I’m sure you meant to say much longer; so that collisional thermalisation is far more likely than re-emission from the CO2 excited State. I’m having the same sort of problem today.

DirkH
July 23, 2010 5:27 pm

Andres Valencia says:
July 23, 2010 at 4:57 pm
“Am I right to think about G&T that:
A possible way for atmospheric “greenhouse gases” to warm a planet could be by temporarily delaying some escape of heat?
Infrared absorbing gases in the atmosphere could slow the cooling of the Earth?”
Yes i think so. G&T don’t talk much about any “slowing down”; as physicists, they just compute some balance or equilibrium and are done with it; they don’t care much for some temporary upswings or downswings. See my comment above at
July 23, 2010 at 9:40 am

sky
July 23, 2010 5:27 pm

I’m very surprised that any meteorologist of stature would offer a radiation-only explanation of the “greenhouse effect,” dismissing all other modes of thermal energy transfer as “too complicated to discuss here and not completely understood anyway,” but nevertheless maintaining that “adding more CO2 warms the atmosphere.” In effect, they conflate a) thermodynamics (flow of thermal energy) with IR radiative transfer, b) forcing with release of stored energy, and c) energy content with thermal capacitance. And then there’s the usual reference to phantom “feedbacks” in a passive feed-through system that is entirely dependent upon insolation for its energy supply.
Somehow it has not occurred to them, that LATENT heat transfer is the principal mode of cooling the surface over oceans. And is the PRESENCE of an atmosphere, rather than trace chemical concentration, that is the key to the “greenhouse effect,” because that’s what makes backradiation possible. That radiation comes largely NOT from CO2, or even water vapor, but from the far-more massive constituents of the atmosphere radiating collisionally transferred energy in the seldom-shown regions of the thermal spectrum.

JimF
July 23, 2010 5:28 pm

Hmmm? So the science isn’t settled, after all?

Bill Hunter
July 23, 2010 5:51 pm

Are clouds part of the greenhouse effect?

July 23, 2010 6:02 pm

tallbloke: In running through the above comments, only a dozen or so even think to mention the oceans. Kind of odd, don’t ya think? But a few noted that the temperature of the earth would be much cooler if not for the oceans.
The oceans, of course, have their own “greenhouse effect”; that is, downward shortwave radiation can warm the oceans as deep as 100 meters but the oceans can only release heat at the surface. So all in all, most of the arguments miss the obvious.

Bill Illis
July 23, 2010 6:05 pm

I want the theory and this whole discussion to move to the level where all of this happens – at the quantum level. It operates with photons and molecules and the speed of light (300,000 km/sec) and the EM spectrum (from infrared to ultraviolet) and the molecular collision rate (6.9 billion per second).
There is too much Macro and note enough Micro.

July 23, 2010 6:08 pm

from Ben and Roger’s guest-post:
“we use quotation marks around the words “greenhouse theory” to indicate that while this terminology has been generally adopted to explain the predicted warming with the addition of absorbing gases into the atmosphere, the actual process is quite a bit different from how a greenhouse heats.”
This is a very important point, and I don’t mind reiterating it in my own words. Real greenhouses keep the flowers, fruits, and veggies inside of them warm by goofing up convection cells. Atmospheric IR-absorbing gases, like gas-phase H2O, and to a much lesser extent CO2, cause warming by an entirely different mechanism.
It’s a mistake for skeptics to jump on the buzzword, “greenhouse”. It’s not a conversation-stopper. On the other hand, AGW buffs are mistaken in their belief that recent increases in atmospheric levels of CO2 are causes for concern. The experience of the last 30 years demonstrates beyond all reasonable doubt, that the actual warming effect of moderately increased atmospheric concentrations of CO2–together with all of the intertwined positive and negative feedback mechanisms–is *immeasurably* small. CO2 is *not* the 800-pound gorilla of climate change.
In principle, the AGW buffs may be *qualitatively* correct about the warming effects stemming from IR-absorbing gases. However on a *quantitative* level, it’s a different story.
We should courageously face the facts about those with whom we strongly disagree. They are simply not smart enough to be wrong about everything. And knee-jerk reactions to each and every AGW expression is counterproductive; it makes all of Skepticdom look foolish.
In order to minimize confusion, I propose that the atmospheric-warming mechanism of interest to us be rechristened as the Larry Effect. One of these days, I really should catalog and number all of the Larry Effects. 🙂

Anders Boman
July 23, 2010 6:13 pm

DirkH says:
July 23, 2010 at 5:18 pm
“Not very much, is the answer. Even the warmists know this; that’s why they phantasize about a small warming caused by CO2 which makes H20 evaporate, which will with its wide absorption band lead to a feedback which will make the Earth melt and the Oceans boil and we will all be down on our knees and pray for bloody mercy or somesuch.”
Thanks for the answers, much appreciated.
Is it really correct that the AGW alarmists think that CO2 will indirectly cause an increase in water vapour which will create an even greater greenhouse effect? That does not make much sense.
I just find that cloudy days are cooler than clear days. So there must be a large difference in the greenhouse effect of water vapour depending on whether atmospheric H2O is in gaseous form or in aerosol form as clouds? Surely more water vapour in the atmosphere would result in increased cloud formation also?
It just seems likely that the earth is a stable system with biodiversity having survived this long. If the system was inherently unstable (that is, having dangerous positive feedback loops), then it seems statistically unlikely for a world as old as ours to have thrived so much.
I read somewhere that the earth has already experienced periods with significantly higher CO2 concentrations in the atmosphere in the past. What was the climate and biodiversity like during those periods?

jorgekafkazar
July 23, 2010 6:13 pm

NickB. says: “I’ve always wondered if the equation that comes up with 33 degrees of greenhouse effect took into account that space really isn’t absolute zero – if I recall correctly it’s 3 or so K. Not that it really matters, just curious if anyone knew”
Yeah, I heard (a few decades ago) that it was an average of 4°K. (Or 4 K, if you wish, and don’t mind people thinking you mean 4,000). I’m not so sure, given the recent order-of-magnitude changes in the thermosphere, that it’s a constant. But as you suggest, it doesn’t matter much for most purposes, since there’s not a lot of difference between, say:
q = AFσ(298^4) and q = AFσ(298^4 – 4^4)
Note that the thermosphere’s temperature can be range from 200°K (at lower altitudes) to as high as 2800°K during the day (high altitudes). The thermosphere is extremely tenuous, so it’s not considered to have a measurable effect on the Earth’s heat balance. This may be in error.

Rick Bradford
July 23, 2010 6:15 pm

I was amazed when I read the succession of recent papers saying that the ‘greenhouse effect’ violated established laws of physics, as I understood this to be the bedrock of global warming theory.
I am even more amazed after reading this thread; after 30 years and tens of billions of dollars in ‘climate research’, we still don’t have agreement on even this basic point?
What have the scientists been doing all these years?

jae
July 23, 2010 6:20 pm

Andres Valencia says:
July 23, 2010 at 4:57 pm
“Am I right to think about G&T that:
A possible way for atmospheric “greenhouse gases” to warm a planet could be by temporarily delaying some escape of heat?
Infrared absorbing gases in the atmosphere could slow the cooling of the Earth?”
Almost exactly. The gases (including the IR absorbing ones) have a thermal capacity and they are poor conductors. That’s why they slow the cooling. The radiation freaks are ignoring this part of the equation!

jae
July 23, 2010 6:28 pm
jae
July 23, 2010 6:45 pm

BTW, Herman and Pielke Sr. don’t have any qualifications that exceed G&T or some of the others I linked to. So the Jury is still out, I think. We have a hypothesis not a theory; no empirical evidence; DEFINITELY not proven!

899
July 23, 2010 6:47 pm

Guest post By Ben Herman and Roger A. Pielke Sr.
With regards to the violation of the second law, what actually happens when absorbing gases are added to the atmosphere is that the cooling is slowed down. Equilibrium with the incoming absorbed sunlight is maintained by the emission of infrared radiation to space. When absorbing gases are added to the atmosphere, more of emitted radiation from the ground is absorbed by the atmosphere. This results in increased downward radiation toward the surface, so that the rate of escape of IR radiation to space is decreased, i.e., the rate of infrared cooling is decreased. This results in warming of the lower atmosphere and thus the second law is not violated. Thus, the warming is a result of decreased cooling rates.
The more you people write, the more you reveal yourselves to be the pseudoscientists you are. Who’s paying you to push that line of crap? Whomever it is must be paying you well! Are you hierodules in the temple of CACC or CAGW?
[1] The natural state of all matter is: REST. Ergo, gasses DO NOT ABSORB –AND RETAIN– ANYTHING.
Hell, it doesn’t ABSORB anything!
Certainly CO2 molecules may be excited to a higher energy level, but as soon as the energy source either diminishes or ceases, the resonance decreases/ceases.
You two make it sound as if the gas acts as a battery of some sort which absorbs —and saves— energy, only to release it at an inconvenient time.
Hell, you even make it sound as if the CO2 “amplifies” the Sunlight!!!
CO2 —just as with other atmospheric gases— acts as an insulator. And while it is true that it resonates with energy of a certain spectra, that in NO WAY implies that it will behave differently otherwise.
Any energy received by CO2 molecules, is released by that molecule consonant with the energy received, and the ability of the atmosphere to accept the energy released.
The Sun is a PRIMARY radiator, and the Earth a secondary radiator. That being the case, when ‘Sun don’t shine,’ then the Earth is THE ONLY source of radiated energy, and NOT the gas.
[2] Now then, since the gas acts merely as a ‘transmission’ medium for a certain spectra, then it may well be said that it DOES NOT retain energy of that spectra, but instead helps to disperse it MORE RAPIDLY than if it were it not in existence — FOR THAT SPECTRA.
Ergo, with MORE CO2 in the atmosphere, the amount of energy reradiated by the Earth is actually facilitated by the CO2 which actually leads to better cooling.
This reciprocity then is beneficial: Even when the Sun radiates at a stronger level, the radiation from the Earth sends even more energy back into space by dint of the fact that the energy from the Sun coupled with the re-radiated energy from the Earth, EXCEEDS the energy received from the Sun, contributing to the space-bound energy.
AND, with no Sunlight —hours of darkness— the CO2 thence facilitates the release of energy into space.
[3] NOW AGAIN: why with all that CO2 locked in the matrices of the polar and glacial ice, isn’t said ice turning to water every time the Sunlight hits the ice?
And WHY aren’t the seas —with all of that entrained CO2— roiling whenever the Sunlight hits them?
And WHY aren’t the lot of us roasting like pigs on a spit whenever the Sunlight hits us, if only that the atmosphere is virtually flooded with that dreadful CO2 gas?

cba
July 23, 2010 6:49 pm

anna v
I putter with the toy Earth a bit in 1-d with some fairly sophisticated in my spare time. I use a combination of stefan’s law and a full bore hitran IR database radiative power transfer application along with a model atmosphere from 1976. It doesn’t deal with particulates but it seems to do a good job on spectral analysis when compared with actual high resolution spectrums.
It provides some interesting things IMHO when combined with some concepts from Keihl and Trenberth 97.
In essence we get an averaged surface T and emission of 288.2K and 391w/m^2. We have an averaged incoming solar of 341w/m^2 with about 0.305 of that reflected away due to albedo, leaving 239w/m^2 solar power being absorbed by Earth’s surface & atmosphere. Simple energy balance demands that there must be an averaged value of 239w/m^2 emitted. Simply put, there must be an average of 391-239 = ~150 w/m^2 of outgoing power which must be absorbed without being reemitted. Note that about 107 w/m^2 is all that ghgs absorb so the balance due to clouds must be the difference, about 43 w/m^2.
In answer to your question about n2 and o2, I’ve modeled no co2 and no2 h2o and that removes about 99 of the 107 w/m^2, leaving about 8 w/m^2 absorption due to all other small ghg contributors.
One can establish a sensitivity – although not quite the same as (mis)defined by the ipcc by taking the 33deg C rise and dividing by the 150 w/m^2 ‘forcing’ power. That gives us 0.22 deg C rise per W/m^2 power absorption increase and is the actual Earth’s sensitivity factor.
Note that a straight radiative ‘sensitivity’ can be done by taking the emission of 239 divided by 391 – the emission from the surface to get the fractional estimate of power leaving the surface and escaping. That’s about 0.61 so divide that into 1 W/m^2 gives a needed increase of 1.6w/m^2 emitted from the surface in order for 1 w/m^2 to escape and at 288.2k, that corresponds to a T increase of around 0.29 deg C rise per W/m^2 absorption increase. This suggests that a net negative feedback is present as the needed change is less than a straight radiative change.
A doubling of co2 comes out with a 3.7 W/m^2 increase in absorption at the tropopause (11km and over the spectrum range of 0 to 75 um). This gives a (n ipcc) sensitivity of 3.7 x 0.22 = ~0.8 deg C rise per co2 doubling. If one resorts to look at absolute humidity and goes with the climatology assumption that relative humidity stays constant with the change in averaged T, one can assume a 2 deg C rise and come up with only a 13% increase in averaged h2o vapor. That is much less than an h2o doubling so it amounts to around 5.1 w/m^2 when combined with the co2 doubling. This gives a sensitivity for co2 doubling of 5.1 x 0.22 = 1.1 deg C rise- which means that unless there are additional significant effects causing another 0.9 deg rise, that we’ve actually overestimated the additional h2o consequence.
At present we are now below the claimed sensitivity measurement ranges, but only slightly and only if there are no other effects. We are also a long way from the potentially serious high sensitivities claimed by the warmistas. Note that the nice long list of these claimed papers gets quite short when each is held to any scrutiny as each has a rather wide error range and lots of potential problems with methodology or assumptions.
Another factor is the nature of the albedo. With 70% ocean and liquid water, the surface averaged albedo is about 0.08. With 62% cloud cover, that puts the cloud albedo at around 0.22 and clouds themselves with an albedo of around 0.37, significantly less than the sulfur based clouds of Venus. The clouds provide a most interest averaged situation. They’re blocking most of the surface radiation and are emitting essentially a full blackbody spectrum since we’re dealing with droplets of h2o water or ice. I’ve not looked into the emission characteristics of water droplets but they’re not going to be molecular spectrums like that emitted from a gas and I think they’re going to be full bore (or close to it) bb continuum curves (at the characteristic T of the droplets). That means there’s broad band emissions above the altitudes where much of the ghgs reside.

Reed Coray
July 23, 2010 6:51 pm

George E. Smith says:
July 23, 2010 at 5:08 pm
The simplest way to see that delaying the cooling process results in a higher temperature, is that during the delay time between energy coming in, and an equivalent energy exiting, the sun is still pouring in energy at a constant rate; so an increment of energy is added to the earth system that grows linearly with the propagation delay of the cooling process, and that must result in the Temperature going up.

If you have a well-mixed mixture of distilled water and ice, the temperature of the mixture will be 0 degrees Centigrade. As you add heat to the mixture, the temperature will stay at 0 degrees Centigrade until the ice has melted. If you add enough heat the ice will melt and the temperature of the water will rise. But during the interval the ice is melting, the added heat does NOT raise the temperature. So I don’t believe that the claim “an increment of energy” must result in “the Temperature going up” is correct.

suricat
July 23, 2010 7:03 pm

Ben Herman and Roger A. Pielke Sr.
I find your post confusing. Surely you can present a post more logical and explanatory than your current offering? I’ve given up reading the responses here after reading about 30% of them.
IMHO I believe you would do better service by concentrating your effort into describing the effect that pressure invokes on the speed and type of energy transfer between molecules in a mixed gas. This would lead to a discussion on internal molecular energy (twisting, stretching and bending of bonds, their resonant frequencies and the time-scale that may, or may not, lead to a photon emission).
If you took this approach, it would be easier to explain that GHE (greenhouse effect) is dependant on the time permitted for a given ‘radiatively active’ molecule to either, receive internal energy by irradiation absorption from the EM field and emit a photon to the EM field (re-radiation), or receive internal energy by irradiation absorption from the EM field and passes this energy on to another molecule by ‘collisional transfer of energy’ (thermalisation of EM radiation). At least WRT to OLR (outgoing long-wave radiation), for example, is it ‘outgoing’, or ‘not’!
IOW! If a molecule’s internal energy reduces and it produced a photon it’s not within the ‘greenhouse’, but if a molecule’s internal energy reduces without the manifestation of a photon the energy has added to the general gas kinetic and is within the ‘greenhouse’.
This ‘microscopic’ view may seem to give more ‘focus’ to the definition of GHE, but it also adds complexity. However, I believe that the readership here is up to this and those who aren’t will be helped by those who are.
That received, I think you’ll realise that GHE is dependant on the gas selected and the local atmospheric pressure. Why not post on this?
Best regards, Ray Dart.

Dr. Dave
July 23, 2010 7:03 pm

This is slightly O/T but I can’t help myself. I had this afternoon off, I was home alone in peaceful quiet and thoroughly enjoying this comment thread. There’s some mighty meaty stuff here! Great reading! I was thoroughly engrossed.
Then my doorbell sounds and my dogs start barking like idiots. I go to my door in disgust and tell my “man killer” Golden Retrievers to sit down and shut up (and quit wagging your tails…that’s embarrassing). I find a kid of about 19, standing all of about 5’8″ with greasy hair with a Sierra Club badge on a lanyard holding a clipboard. He had holes in his earlobes expanded by what looked like huge metal Cheerios. He explained that he was from the Sierra Club and he was here because of the oil spill in the Gulf. Of course I asked if that was the case why he was here in Santa Fe and not down on the Gulf Coast. He said, “Well sir, we’re here looking to recruit new members”. I couldn’t help myself. I’m 6’2″ and I’m already standing on a stoop a good 5″ above him. I leaned in and slightly over him and in my deepest, most menacing voice I said, “I would rather DIE than join the Sierra Club.
His smile vanished and he beat a hasty retreat to the street as fast as he could go without breaking into a run. Childish, perhaps…but hey…you find your fun where you make it!

Andrew W
July 23, 2010 7:07 pm

Tallbloke:
“Mosher and the warmists say co2 warms the atmosphere. Pielke and I say it slows the rate of cooling of the atmosphere. You say “it doesn’t matter”.”
I’m pretty sure there’s no disagreement between Pielke and “warmist” scientists on the basics of how the GH effect works, so I guess that claim of yours is just a strawman.
I think you’re being a bit unfair on Mosher, the analogy I’d use is if you’ve got and electric blanket but then put more blankets over the top, do the additional blankets work to help increase how warm the bed is? no one would be claiming that the extra insulation (blankets or CO2) is a heat source, but a warmer bed (or Earth surface) is the result.

Theo Goodwin
July 23, 2010 7:22 pm

Tallbloke responds to Basinger as follows:
Scott Basinger says:
July 23, 2010 at 2:31 pm (Edit)
The “greenhouse gases” heat the earth’s surface up approximately 35°C higher than it would be otherwise.”
No they don’t. They slow the rate of cooling. Please don’t try to say that ‘this is the same thing’.
So, Tallbloke, is it wrong to say that CO2 molecules capture radiation from Earth’s surface and then emit radiation randomly so that near half what they admit goes to Earth’s surface? If this description is correct then how can it be that the emitted radiation does not heat the Earth’s surface?

Dave Springer
July 23, 2010 7:39 pm

Theo Goodwin says:
July 23, 2010 at 2:09 pm
Would someone please explain the different mechanisms of CO2 and water vapor? We know that CO2 captures and radiation and releases it randomly, so somewhat less than half of all captured radiation is sent toward Earth. What about water vapor? Does it capture radiation and than radiate it? What is the mechanism of warming?

This chart is illustrative.
http://en.wikipedia.org/wiki/File:Solar_Spectrum.png
Note how much more power in the infrared spectrum is absorbed by H2O compared to CO2.
Water vapor accounts for some 95% of GHG warming. The mechanism is the same. There are interesting differences however.
Water vapor can vary a lot from region to region and in the same region it can vary a lot and do it quickly. CO2 doesn’t vary nearly as quickly or as much.
Water vapor also also forms clouds and ice. CO2 doesn’t. Cloud formation causes cooling in at least two different ways. CO2 of course doesn’t form clouds. When water vapor condenses into a cloud it releases a lot of latent heat of vaporization. That heat was picked up at the surface where the water evaporated. The water cycle works like a heat pump with the cold side on the ground and the warm side in the clouds. And then of course a cloud is has a much higher albedo so it bounces a lot of the visible spectrum back out into space before it reaches the surface. Ice of course also has high albedo.
Albedo is a big flaw in global circulation models (GCM). The earth’s average albedo is difficult to measure even today and various different attempts to measure it are not in satisfactory agreement. We do know it varies however and but the GCMs model albedo as a constant. Moreover, the value assigned to the constant in different models (the guesstimates) differ greatly. It’s bascially a fudge factor that the model maker gets to adjust but so long as it’s a constant in the model where it’s a significant variable in reality it mucks up the model in one way or another no matter what constant value they assign. Neat huh? Hide the albedo.
These aspects of cloud formation are very poorly modeled in the so-called Global Circulation Models and they have huge potential for variable effect.

July 23, 2010 7:47 pm

Your rebuttal of the two misconceptions is spot on, as far as I can see.
However, your conclusion doesn’t follow, except in the trivial sense that more GHCs imply more warming covers warming of any amount, including infinitesimal amounts.
You are also correct that the Earth’s temperature in excess of 255K is due to GHCs. However, if “more warming” at the current temperature and concentration of GHCs means a significant amount if warming, then you have not made that case and I believe the evidence is completely against it.
Steve Goddard’s adiabatic lapse rate argument makes much more sense. Personal observations that anyone can do, such as watching an eagle rise on a thermal, should be enough to convince you that convection completely dominates heat dissipation from the Earth’s surface and does so on a scale far too small to be accounted in the expensive supercomputer climate models. If this is so, and it certainly seems as if there is overwhelming evidence that it is, then all fear of greenhouse disasters is entirely misplaced.

jae
July 23, 2010 7:56 pm

Why oh why does nobody address simple heat storage effects? The Earth is NOT a simple blackbody that emits exactly what it absorbs. It absorbs and stores heat. The SB equations don’t accomodate this fact, so they cannot be used to predict the temperature of the planet without GHGs. This very obvious fact is not being addressed by those who think they are “in the know.”

Ninderthana
July 23, 2010 7:58 pm

Most serious sceptics recognise that the greenhouse effect is a physical reality, however they also recognise that totally unrealistic and unphysical to consider this effect in total isolation.
Basic physical principles tell us that any increase in the downward IR radiation in the atmosphere (e.g. caused by increasing levels of CO2) must originate in the levels of the atmosphere where the absorportions by that particular green-house gas are not saturated. This corresponds to the upper troposphere for CO2 (and water vapor).
In its simplest terms, it means that it requires increasing levels of either CO2 and/or water vapour in the upper (tropical) troposphere, in order for their to a significant warming of the atmosphere due to green-house gases.
The truth is that increases in CO2 levels in the atmosphere result in greater amounts of IR radiation being reflected back upon the Earth’s ocean surfaces. This additional energy leads to a greater level of evaporation from the Earth’s tropical oceans.
This additional evapouration at the oceans surfaces leads to an additional deposition of energy in the mid level (tropical) troposphere through the dual processes of the latent heat of evaporation (at the ocean surface) and condensation (in the tropical thunderclouds). This deposition of energy warms all levels of the (tropical) troposphere, with the level of warming with altitude being set by the relative contributions of the dry and wet adiabatic lapse rates.
Many people seem to missing the crucial point that the increase in convective overturning in the (tropical) troposphere (caused by increasing evaporation
from the oceans surface and condensation as rainclouds) results in the pumping of massive amounts of de-humdified air into the upper (tropical) troposphere.
This lowers the specific humidity (mass of water vapour per 1 kg of air) in the upper reaches of the tropical tropsphere.
It doesn’t take a genious to see that the resultant decrease in water vapor ( a dominant green-house gas) in the same level of the atmosphere where increasing amounts of
of CO2 is having its greatest impact on warming the atmosphere produces a MASSIVE NATURAL NEGATIVE FEEDBACK MECHANISM, that effectively nulifies CO2 ability to warm the atmosphere.
This simple physical model is backed up by direct radiosone observations which show that:
a) the overall (i.e global) IR optical depth of the atmosphere has not changed in the
last 61 years
b) that the IR optical depth of the atmosphere appears to be controlled by the column
density of water vapour (NOT CO2).
c) the specific humidity of the upper troposphere has been systematically dropping
over the last 30 – 40 years.
When will people start waking up to these simple realities?

Dave Springer
July 23, 2010 8:02 pm

Theo Goodwin says:
July 23, 2010 at 7:22 pm
So, Tallbloke, is it wrong to say that CO2 molecules capture radiation from Earth’s surface and then emit radiation randomly so that near half what they admit goes to Earth’s surface? If this description is correct then how can it be that the emitted radiation does not heat the Earth’s surface?

Say you have one of those insulated coffee cups. When you put hot coffee in it do you say the cup heats the water? Of course not. The keeps it warm long.
CO2 does the same thing as the cup.

Dave Springer
July 23, 2010 8:03 pm

Oops – meant to say “the cup keeps the coffee warm longer”

astonerii
July 23, 2010 8:09 pm

It is interesting to see this as proof of the “obvious”:
“If you’ve done your arithmetic correctly, you should have come up with something like 255 K. But with the atmosphere, it is about 288 K, 33 degrees warmer. This is the greenhouse effect of the atmosphere.”
My understanding is that the atmosphere has density, this density causes compression, compression causes an increase in temperature. How much of the 33 degrees warmer is the compression? For an idea, just 30,000 feet up in the air the temperature outside the cockpit of an aircraft is frequently -30f to -50f. If the surface air temperature is 70f this is a difference of 100 to 120 f. Sorry, but I am not going to be duped into the greenhouse effect, the amount of radiation escaping from the surface of the earth at the wavelengths for which it can be absorbed by the “greenhouse gasses” are fully 100% saturated by 10 feet elevation, moving that 10 feet of elevation down to 5 feet or even 2 feet is not going to significantly increase the temperature of the atmosphere, which is more than 100,000 feet deep.

jae
July 23, 2010 8:12 pm

“CO2 does the same thing as the cup.”
And if you put a vacuum between the coffee and the cup, it stays warmer much longer. So just what is your point?

July 23, 2010 8:35 pm

The core issue here apparently is: more CO2 slows down the IR escape to space. Then, TIME is the variable I see absent from the equations regarding irradiation, either downwell radiation or to outer space.
Photons travel at the speed of light, so a photon irradiationg from the surface will be about 300.000 km from Earth’s surface in the first second. And it is not coming back.
How much time it takes for a molecule to reirradiate a photon after receiving it? How much does it take to go down a Fermi level and radiate a new photon? Picoseconds, Nanoseconds, femtoseconds? Has anyone measured that? And how?
Can there be calculated the number of molecules a photon will impact before going out to space? The atmosphere is not a solid block of gas molecules, so quadrillions of photons will be escaping to outer space without hitting any molecule. On the other hand, millions of photona can impact several quadrillion molecules before finally escaping without a possibility of return.
If someone could calculate that, making an overall average and adding the delay in reirradiation could give an idea of how much -(if it ever happens)- GH gases retard radiation going to outer space. And those gases non GH as oxygen and nitrogen, will absorb the photon but will only get rid of it by conduction! And the sheer difference between GHG and O2 and N2 is humongous, so the chance of giving away the energy by trasnferring the heat to a CO2 molecule is negligible. This complicates things further.
Uncertainties are too broad here. I wish someone had an answer. I hope it is not I the only one who jumps in a huge mattres of ignorance.

Phil.
July 23, 2010 8:35 pm

Mods
As pointed out by George (above) I made a typo in the following:
Phil. says:
July 23, 2010 at 12:58 pm
…….”In fact for CO2 the time it takes to emit a photon from the excited state is much shorter than the mean time between collisions in the lower atmosphere so the most likely fate of the excited state is to transfer kinetic energy to the surrounding gases via collisions. Higher up in the atmosphere collisions become less likely and therefore emission of radiation more likely.”
It should be ‘longer’ not ‘shorter’. Can you fix it since it doesn’t make sense otherwise.
REPLY: I have fixed it for you. – Anthony

July 23, 2010 8:49 pm

Thanks Anthony, Ben Herman and Roger A. Pielke Sr.; Great article!
Thanks DirkH and jae, I am using the delay concept to limit the scope of my article on the G&T paper published at “Climate Change; The cyclic nature of Earth’s climate”, at http://www.oarval.org/ClimateChange.htm
Clear Skies

Reed Coray
July 23, 2010 8:52 pm

Dr. Dave says:
July 23, 2010 at 7:03 pm
“I would rather DIE than join the Sierra Club”.

Send the Sierra club recruiter to Los Osos, CA. I’d like to confirm your feelings.

Amino Acids in Meteorites
July 23, 2010 8:56 pm

“The rest of the processes, including convection, conduction, feedbacks, etc. are too complicated to discuss here and are not completely understood anyway.”
Scratches head……
But they do know that co2 will warm the earth?????

Amino Acids in Meteorites
July 23, 2010 8:58 pm

There can be no runaway warming in earth from co2.

Amino Acids in Meteorites
July 23, 2010 9:00 pm

Increasing co2 will likely cause cooling because of negative feedback.
Reginald Newell, worked at MIT, NASA, IAMAP

Amino Acids in Meteorites
July 23, 2010 9:01 pm

Willis Eschenbach on co2 and negative feedback
Part 1

Amino Acids in Meteorites
July 23, 2010 9:01 pm

Willis Eschenbach on co2 and negative feedback
Part 2

Tsk Tsk
July 23, 2010 9:02 pm

Juraj V. says:
July 23, 2010 at 12:53 pm
OK gentlemen. Whats wrong with this scheme?
http://i480.photobucket.com/albums/rr165/magellansc24/hansen_oven.jpg
😀
I call it a thermos. Maybe that’s why I don’t get grant money. 😉

Amino Acids in Meteorites
July 23, 2010 9:02 pm

Roy Spencer on clouds and negative feedback
Part 1

Amino Acids in Meteorites
July 23, 2010 9:03 pm

Roy Spencer on clouds and negative feedback
Part 2

Barry Moore
July 23, 2010 9:11 pm

It appears that the general assumption here is that there is an unlimited amount of radiation within the region of the resonant frequencies of CO2. This is not true according to Dr. John Nicol’s paper at the current level of CO2 virtually all of the radiation at the resonant frequencies is absorbed in the first 50 meters of atmosphere the close neigbours to those frequencies are absorbed progressivly higher but all are absorbed in the lower 2000 meters thus the so called “greenhouse gas” effect of CO2 is saturated and adding CO2 only lowers the height of the absorbtion but does not change the amount of energy absorbed once the mini Stefan Boltzman curves around each resonant frequency have overlapped which occurs far below the current levels of CO2. Thus the line broadening effect of increasing CO2 concentration which is the basis for the IPCC formula has flattened out.
It should also be understood that the CO2 molecules will only reradiate energy at its specific resonant frequencies and their mean path length according to Beer’s Law is about 2 meters which explains why there is effectively no radiation at the specific resonant frequencies remaing after 50 meters. So the CO2 molecule will absorb close neigbours to its resonant frequencies higher in the atmosphere but the reradiated energy has a very short path and can not return to the earths surface.
It should also be noted that much of the energy absorbed by the CO2 molecules is transferred to the other molecules in the atmosphere by kinetic energy transfer through collision thus there is very little reradiation anyway.

Tsk Tsk
July 23, 2010 9:30 pm

kwik says:
July 23, 2010 at 2:40 pm
Phil. says:
July 23, 2010 at 12:42 pm
“‘Suppose you have an isolated black ball which you heat so that it eventually equilibrates at a certain temperature, introduce another ball nearby at a lower temperature, the hotter one will get hotter (as will the cooler).’
Are you sure about this, Phil? That the hottest will be hotter? I allways believed that this is exactly what was impossible, according to the 2′nd law….because if it got hotter…then heat has gone from colder to hotter….. or is this Trenberts hidden heat?”
The statement bugged me at first too, but then I realized it was just poorly worded. The two balls he’s using have their own internal heat sources. If they didn’t, then both would just reach the local background temperature. Take an object in the steady state at 500k radiating into a 0K background (makes it simple). Now add another object at 250k under the same conditions. Both objects would get hotter because they would radiate some of their energy to each other instead of losing it to the 0k background. Since we want the system to be in equilibrium, each ball must raise its temperature to net out the increased energy it receives from the other. The exact amount depends on the geometry of the problem.