'Correcting' Trenberth et al.

(See the note below before taking this post seriously – Anthony)

Guest essay by Steven Wilde

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Here we see the classic energy budget analysis supporting the hypothesis that the surface of the Earth is warmer than the S-B equation would predict due to 324 Wm2 of ‘Back Radiation’ from the atmosphere to the surface.

It is proposed that it is Back Radiation that lifts the surface temperature from 255K, as predicted by S-B, to the 288K actually observed because the 324 Back Radiation exceeds the surface radiation to the air of 222 Wm2 ( 390 Wm2 less 168 Wm2) by 102 Wm2. It is suggested that there is a net radiative flow from atmosphere to surface of 102 Wm2.

I now discuss an alternative possibility.

The portions I wish to focus on are:

i) 390 Wm2 Surface Radiation to atmosphere

ii) 78 Wm2 Evapo-transpiration surface to atmosphere

iii) 24 Thermals surface to atmosphere

iv) 324 Back Radiation atmosphere to surface

The budget needs to be amended as follows:

The 78 Wm2 needs to be corrected to zero because the moist adiabatic lapse rate during ascent is less than the dry lapse rate on adiabatic descent which ensures that after the first convective cycle there is as much energy back at the surface as before Evapo-transpiration began.

The 24 Wm2 for thermals needs to be corrected to zero because dry air that rises in thermals then warms back up to the original temperature on descent.

Therefore neither ii) nor iii) should be included in the radiative budget at all. They involve purely non radiative means of energy transfer and have no place in the radiative budget since, being net zero, they do not cool the surface. AGW theory and the Trenberth diagram incorrectly include them as a net surface cooling influence.

Furthermore, they cannot reduce Earth’s surface temperature below 255K because both conduction and convection are slower methods of energy transmission than radiation. To reduce the surface temperature below 255K they would have to work faster than radiation which is obviously not so.

They can only raise a surface temperature above the S-B expectation and for Earth that is 33K.

Once the first convective overturning cycle has been completed neither Thermals nor Evapo-transpiration can have any additional warming effect at the surface provided mass, gravity and insolation remain constant.

As regards iv) the correct figure for the radiative flux from atmosphere to surface should be 222 Wm2 because items ii) and iii) should not have been included.

That also leaves the surface to atmosphere radiative flux at 222 Wm2 which taken with the 168 Wm2 absorbed directly by the surface comes to the 390 Wm2 required for radiation from the surface.

The rest of the energy budget diagram appears to be correct.

So, how to decide whether my interpretation is accurate?

I think it is generally accepted that the lapse rate slope marks the points in the atmosphere where there is energy balance within molecules that are at the correct height for their temperature.

Since the lapse rate slope intersects with the surface it follows that DWIR equals UWIR for a zero net radiative balance if a molecule at the surface is at the correct temperature for its height. If it is not at the correct surface temperature it will simply move towards the correct height by virtue of density variations in the horizontal plane (convection).

Thus, 222 UWIR at the surface should equal 222 DWIR at the surface AND 222 plus 168 should add up to 390 and, of course, it does.

AGW theory erroneously assumes that Thermals and Evapo-transpiration have a net cooling effect on the surface and so they have to uplift the radiative exchange at the surface from 222 Wm2 to 324 Wm2 and additionally they assume that the extra 102 Wm2 is attributable to a net radiative flux towards the surface from the atmosphere.

The truth is that there is no net flow of radiation in any direction at the surface once the air at the surface is at its correct temperature for its height, which is 288K and not 255K. The lapse rate intersecting at the surface tells us that there can be no net radiative flux at the surface when surface temperature is at 288K.

A rise in surface temperature above the S-B prediction is inevitable for an atmosphere capable of conducting and convection because those two processes introduce a delay in the transmission of radiative energy through the system. Conduction and convection are a function of mass held within a gravity field.

Energy being used to hold up the weight of an atmosphere via conduction and convection is no longer available for radiation to space since energy cannot be in two places at once.

The greenhouse effect is therefore a product of atmospheric mass rather than radiative characteristics of constituent molecules as is clearly seen when the Trenberth diagram is corrected and the lapse rate considered.

Since one can never have more than 390 Wm2 at the surface without increasing conduction and convection via changes in mass, gravity or insolation a change in the quantity of GHGs cannot make any difference. All they can do is redistribute energy within the atmosphere.

There is a climate effect from the air circulation changes but, due to the tiny proportion of Earth’s atmospheric mass comprised of GHGs, too small to measure compared to natural variability.

What Happens When Radiative Gases Increase Or Decrease?

Applying the above correction to the Trenberth figures we can now see that 222 Wm2 radiation from the surface to the atmosphere is simply balanced by 222 Wm2 radiation from the atmosphere to the surface. That is the energy being constantly expended by the surface via conduction and convection to keep the weight of the atmosphere off the surface. We must ignore it for the purpose of energy transmission to space since the same energy cannot be in two places at once.

We then have 168 Wm2 left over at the surface which represents energy absorbed by the surface after 30 Wm2 has been reflected from the surface , 77 Wm2 has been reflected by the atmosphere and 67 Wm2 has been absorbed by the atmosphere before it reaches the surface.

That 168 Wm2 is then transferred to the atmosphere by conduction and convection leaving a total of 235 Wm2 in the atmosphere (168 plus 67).

It is that 235 Wm2 that must escape to space if radiative balance is to be maintained.

Now, remember that the lapse rate slope represents the positions in the atmosphere where molecules are at their correct temperature for their height.

At any given moment convection arranges that half the mass of the atmosphere is too warm for its height and half the mass is too cold for its height.

The reason for that is that the convective process runs out of energy to lift the atmosphere any higher against gravity when the two halves equalise.

It must follow that at any given time half of the GHGs must be too warm for their height and the other half too cold for their height.

That results in density differentials that cause the warm molecules to rise and the cold molecules to fall.

If a GHG molecule is too warm for its height then DWIR back to the surface dominates but the molecule rises away from the surface and cools until DWIR again equals UWIR.

If a GHG molecule is too cold for its height then UWIR to space dominates but the molecule then falls until DWIR again equals UWIR.

The net effect is that any potential for GHGs to warm or cool the surface is negated by the height changes relative to the slope of the adiabatic lapse rate.

Let’s now look at how that outgoing 235 Wm2 is dealt with if radiative gas concentrations change.

It is recognised that radiative gases tend to reduce the size of the Atmospheric Window (40 Wm2) so we will assume a reduction from 40 Wm2 to 35 Wm2 by way of example.

If that happens then DWIR for molecules that are too warm for their height will increase but the subsequent rise in height will cause the molecule to rise above its correct position along the lapse rate slope with UWIR to space increasing at the expense of DWIR back to the surface and rising will only stop when DWIR again equals UWIR.

Since UWIR to space increases to compensate for the shrinking of the atmospheric window (from 40 Wm2 to 35 Wm2) the figure for radiative emission from the atmosphere will increase from 165 to 170 which keeps the system in balance with 235 Wm2 still outgoing.

If the atmosphere had no radiative capability at all then radiative emission from the atmosphere would be zero but the Atmospheric Window would release 235 Wm2 from the surface.

If the atmosphere were 100% radiative then the Atmospheric Window from the surface would be zero and the atmosphere would radiate the entire 235 Wm2.

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

Note: I’m glad to see a number of people pointing out how flawed the argument is. Every once in awhile we need to take a look at the ‘Slayer’ mentality of thinking about radiative balance, just to keep sharp on the topic. At first I thought this should go straight into the hopper, and then I thought it might make some good target practice, so I published it without any caveat.

Readers did not disappoint.

Now you can watch the fun as they react over at PSI.  – Anthony

P.S. Readers might also enjoy my experiment on debunking the PSI light bulb experiment, and note the reactions in comments, entirely opposite to this one. New WUWT-TV segment: Slaying the ‘slayers’ with Watts

Update: Let me add that the author assuredly should have included a link to the underlying document, Earth’s Global Energy Budget by Kiehl and Trenberth …

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Dave Worley

Convection carries water vapor above the densest layer of Greenhouse gases, where it is more likely to radiate into space. Hadley cells circulate a large percentage of the entire atmosphere in an up and down cycle.

Edim

This is not correct. Evaporation and convection are the main surface cooling fluxes. Most of the energy radiated to space by the atmosphere, got there by non-radiative means.

Nylo

Convection does have a cooling effect in the lower levels of the atmosphere which needs to be accounted for. Convection causes a mass of hot air near the surface to be replaced by a mass of cold air. This increases the loss of heat of the surface due to conduction to the air immediately on top. If the air didn’t move, loss due to this conduction would be lower (conduction losses depend on diference of temperature). It is true that, while descending later, the air gains as much energy as it lost while ascending. However, between the two moments, the air has lost additional energy due to radiation that took place while it was in the upper layers of the atmosphere. So the air returns colder than it left. What convection does is increase the temperature of the upper layers of the atmosphere with heat coming from lower layers. This both reduces the temperature of the lower layers and increases the outward radiation of the upper levels which means that it is a way to radiate the same but with a lower temperature in the lower levels. Which means it does cool the lower levels.

johnmarshall

There is so much wrong with Trenberth’s idea but let us start with his flat earth idea with 24/7 sunshine. Hardly realistic. He spreads solar energy over the whole planet’s surface but reality spreads it over half the ROTATING planet.
Evapouration is far too low. Every cloud formed includes latent heat so every cloud is evidence of heat being LOST from the surface as well as increasing albedo on formation.
Reality has 960W/m2 on the subsun point decreasing to 0 at the poles. The average is 480W/m2 which relates to a temperature of 33C not the -49C from Trenberth’s 167W/m2.
If you want a realistic model see Postma’s paper ”A Discussion on the Absence of a Measurable Greenhouse Effect. His model is realistic and simple to understand

JPS

Sorry but this post is nearly completely incorrect and extremely confused.

“Therefore neither ii) nor iii) should be included in the radiative budget at all.”
Who said it’s a radiative budget? The article you have taken it from (if it’s T&F2008) is titled “Earth’s Global Energy Budget”. Above the diagram, in big red letters there it says: Global Energy Flows Wm-2.
But the 78 W/m2 latent heat flow is hard to argue with. It is simply calculated from precipitation. The water that condensed left that amount of heat behind in the atmosphere.
The thermals flux is a nett upward flux. It is heat transport.
“I think it is generally accepted that the lapse rate slope marks the points in the atmosphere where there is energy balance within molecules that are at the correct height for their temperature.”
Reference?

hunter

Interesting conjecture. Do you have the calculations and the physics to support it?

Box of Rocks

This post is a start.
Thanks for starting a conversation on the diagram.
I have a sens that the original idea from Trenberth is incorrect, I at this point in time can’t put my finger on it.
The whole idea of 324 watts/m^2 of back radiation needs a good look. Just because it exist does not mean it does any work to warm the atmosphere.

trenberth’s, wilde’s, posma’s….which of the theoretical models contrasts better with empirical data or measurements…or is it we have not yet enough data to assess them, as prof. Freeman Dysson explained …

MikeB

Here we see the classic energy budget analysis supporting the hypothesis that the surface of the Earth is warmer than the S-B equation would predict.

This diagram is not intended to support any hypothesis whatsoever. It is a simple attempt to allocate numbers to various heat transport mechanisms. It is no more than that.

Neither ii) nor iii) should be included in the radiative budget at all?

The diagram doesn’t purport to be a radiative budget…it’s an energy budget….back to the drawing board for you
The S-B expectation for Earth is 33K? What does that mean?
Convection doesn’t cool the surface? Isn’t that obviously wong?
Evaporation doesn’t cool the surface either?
And finally, the surface of the Earth is not warmer than the S-B equation would predict. The amount of radiation from the surface precisely accords with the temperature of that surface as determined by S-B. It can do no other. You need to clarify that what you mean is when ‘seen from space’ the Earth system appears to be at 255K (and we know that the surface is much warmer).
Sorry, couldn’t read the rest.

Chris @NJSnowFan

If a normal everday person looked at this they would be lost.
I even find it confusing.

> the surface of the Earth is warmer than the S-B equation would predict due to 324 Wm2 of ‘Back Radiation’ from the atmosphere to the surface.
I’d be more inclined to say it “retards surface cooling” rather than imply it warms the surface. You really don’t want to wake up the Slayers….
Though it’s probably too late.

Martin A

If you work out what happens, starting with a cold planet and allowing its temperature to rise until there is equilibrium between incoming energy (primarily in the visible wavelengths) and outgoing energy (in the long infra red), you find that all the warming is done by the incoming sunlight. Back radiation is there, but all the warming was caused by the incoming light. So no need to cause confusion by talking about back radiation warming things

RobertInAz

Agree with the prior comments – the analysis needs a lot of work. It appears to me the 24 + 78 are “absorbed” by the atmosphere to be returned as part of the 324 back radiation or last as part of the 165 emitted. So, looking at the atmosphere we have
67+24+78 + 350 – 165 – 324 – 30 = 0.

The 78 Wm2 needs to be corrected to zero because the moist adiabatic lapse rate during ascent is less than the dry lapse rate on adiabatic descent which ensures that after the first convective cycle there is as much energy back at the surface as before Evapo-transpiration began.

Like other commenters have noted, IR radiation is more efficient at altitude than lower thanks to the bypassing a lot of the greenhouse effect. I don’t have a good sense for the difference between the radiation that escapes from the warm ground vs. the cold gas higher up. Also, in wet adiabatic conditions there are clouds and IR radiation from the ground is reflected and reradiated from the cloud base.
Thanks to latent heat release, wet adiabatic convection, think thunderstorms, gets a lot of IR radiating material higher in the atmosphere so it radiates better than dry convection. Also, rainfall cools the surface as it undergoes no adiabatic compression on the way down.

Crashex

As a long time reader and fan of WUWT, I just want to note that this has to rank as one of the worst posts ever. It is wrong on so many levels. This is the type of post that will be ridiculed by many for its lack of understanding of fundamental science in an effort to discredit everything else this site has ever posted.
To claim that evapotranspiration cooling should be omitted from an assessment of the heat transfer budget at the surface because it operates at a lower rate than radiation is ridiculous.
REPLY: I don’t disagree, but see my note below about the real reason I published this. +1 for your comment – Anthony

DirkH

“If a GHG molecule is too warm for its height then DWIR back to the surface dominates but the molecule rises away from the surface and cools until DWIR again equals UWIR.
If a GHG molecule is too cold for its height then UWIR to space dominates but the molecule then falls until DWIR again equals UWIR.”
Why? Let’s say mean free path length for an IR photon at 15 micrometer, in the CO2 absorption / re emission band is 25 m at 1 atmosphere. Meaning it gets emitted and re absorbed and re emitted multiple times on its way until it reaches either surface or open space (or a water droplet in the atmosphere, which acts as a blackbody). Each re-emission happening in a random direction.
In all cases this should result in the atmosphere being an opaque fog on this frequency , “shining” roughly the same amounts of IR on this frequency back to Earth and the other half to outer space.
I am assuming Local thermodynamic equilibrium, allowing for the application of Kirchhoff’s Law. As a GHG molecule travels in a parcel of air with the same temperature (to find its correct height), this should hold most of the time.
The climate modelers seem to think that GHG molecules swallow IR photons, not re-emitting them, leading them to call them “heat-trapping gases” and modelling a tropospheric hotspot that has not been observed in reality. At least I think that’s one of their mistakes.

NotAGolfer

They’re making it more complicated than it needs to be. The Beer-Lambert equation is used to determine the amount of heat absorbed by various levels of CO2 at various lengths. You need to integrate across the changing pressure profile and gas-mixtures as they change with altitude, which makes it complicated, but it is still much more straight forward than trying to determine what the actual temperature of the earth is, was and should be. Those are a fool’s game.
The Beer-Lambert can be used to accurately predict the expected change in temperature with any change in concentration, whereas the Steffan-Boltzman requires estimating emissivity and such. Using SB is like trying to determine the amount of solids suspended in a tank of water by using 2 different pressure transducers at top and bottom of the tank, then hoping they are calibrated, then subtracting… When you could just insert one end of one transducer into the bottom of the tank and the other end of the same transducer into the top to read the difference directly. Well, actually, using the Steffan-Boltzmann is much more complicating than this example shows.

Doubting Rich

“The 24 Wm2 for thermals needs to be corrected to zero because dry air that rises in thermals then warms back up to the original temperature on descent.”
I am afraid you are not correct here. This does have a net transfer of energy, as in thermal circulation the air warms to be warmer than the surrounding air then rises. The cooling in rising is adiabatic, so there is no energy transfer, as is the warming during sinking. So the warm air rising is taking energy it has absorbed from the ground. Once aloft it moves towards the cooler air column (which has lower pressure at altitude) and cool, thus sinking again.

Doubting Rich

How can the back radiation to the Earth from the atmosphere be approximately double the outward radiation from the atmosphere? Surely radiation is not directional, and while the atmospheric density and temperature fall with altitude so the lowest levels will radiate most, the upper levels allow much of that through and add their own, and the lower levels also absorb some of the downwelling radiation from higher parts of the atmosphere. Overall these should roughly balance out.
What am I missing here?

Doubting Rich

Just realised that al I needed for the last comment was “what DirkH says”.

Leonard Weinstein

This post shows the author does not understand the actual processes of the so called atmospheric greenhouse effect. While Trenberth may be wrong in some of his levels, his basic model is correct. The back radiation does not HEAT the surface, it is effectively a net radiation resistance, reducing the net surface radiation up to well below black body level. The numbers to consider are the 390 up minus 324 back radiation for a net radiation up of only 66 w/m2. The difference of absorbed radiation of 168 minus this 66 net radiation up gives an excess of 102 w/m2. This 102 is then carried up by the conduction, convection and evapo-transporation processes. Increasing back radiation by adding more greenhouse gases would result in the NET radiation up from the surface decreasing, and other processes increasing to keep the balance. this also would further increase the altitude of outgoing radiation and increase the surface temperature. It is the raising of the average altitude of radiation to space (by radiating up from the clouds and greenhouse gases) that results in the net average surface temperature increase. The lapse rate is a critical part of this process, since the average temperature is lower at the higher altitude where radiation to space occurs.

Roy Spencer

Sigh. 🙁

tty

“The 78 Wm2 needs to be corrected to zero because the moist adiabatic lapse rate during ascent is less than the dry lapse rate on adiabatic descent which ensures that after the first convective cycle there is as much energy back at the surface as before Evapo-transpiration began.”
This is nonsensical. The reason the dry adiabatic lapse rate is steeper is because dry air has a smaller heat capacity than dry air, so it will heat more for a given amount of energy. The 78 W/m is simply due to water condensing and precipitating, and leaving the heat of evaphoation behind.
“The 24 Wm2 for thermals needs to be corrected to zero because dry air that rises in thermals then warms back up to the original temperature on descent.”
If that was true it couldn’t get back down. It can do that only because it has lost energy at altitude.

Truthseeker

I know, let’s start by not having a flat Earth and have a spherical one, then we can add … I know, I know … a day/night cycle with planetary rotation … yes and then we could have … maybe just maybe … a Sun that actually provides 1370 W/m2 of energy to the top of atmosphere on the day side of the planet. Let’s try that and see how we go.
This is a cartoon, not a diagram and Trenberth’s most important piece of equipment seems to have been crayons. It does not matter what you do to it, you are still not going to end up anywhere useful.
Try this for a realistic diagram:
http://tinypic.com/usermedia.php?uo=fNkd6hpTbcMU7xs0vRLosYh4l5k2TGxc#.U0PyR156PRo

Trying to calculate the greenhouse effect of atmospheric CO2 with any simple global model of energy balance is not likely to give you an accurate answer. Since radiation is “fast as light and speed of light”, you should be able to do your calculations from daily swings in temperature and dew point (with clear sky) at any point on earth. Since days are a year long at the poles, and water vapor is the least, the relative effect of CO2 should be most observable at these locations.

RobertInAz

What I would love to see is the error bars around each of the energy budget terms. After all, apparently 3.3 W/M2 is going to bring civilization as we know it to an end. /sarc

Steve Case

First off, Steven Wilde uses an old version of Trenberth’s iconic heat budget.
Trenbeth’s “Global Energy Budget” was updated March 2009 to show an imbalance of 0.9w/M²
I wonder how that came about, might have gone something like this:
Once upon a time on a bright sunny morning a few years back, Dr. James Hansen was looking at Kevin Trenberth’s iconic “World Energy Budget”
http://www.grida.no/climate/ipcc_tar/wg1/images/fig1-2.gif
when he choked on his morning coffee because he realized that the darn thing balanced. That’s right, energy in equaled energy out. You see, he’s been saying for some time now that heat energy is slowly building up in Earth’s climate system and that’s not going to happen if the energy budget is balanced.
So he did some fast calculations, snatched up his cell phone and punched in Trenberth’s number.
“Hi Kev, Hansen here, how’s it goin’ with you? Got a minute?”
“Sure Doc, what’s up?”
“Glad you asked. I’ve been looking at your energy budget and it balances, can you fix that?”
“What do you mean fix it, it’s supposed to balance?”
“Kev, listen carefully now, if it balances, heat will never build up in the system do you see where I’m going?”
“Uh I’m not sure, can you tell me a little more?”
“Come on Kev don’t you get it? I need heat to build up in the system. My papers say that heat is in the pipeline, there’s a slow feedback, there’s an imbalance between radiation in and radiation out. Your Energy Budget diagram says it balances. Do you understand now?”
“Gotcha Doc, I’ll get right on it” [starts to hang up the phone]
“WAIT! I need an imbalance of point nine Watts per square meter [0.9 Wm²] for everything to work out right.”
“Uh Doc, what if it doesn’t come out to that?”
“Jeez Kev! Just stick it in there. Run up some of the numbers for back-radiation so it looks like an update, glitz up the graphics a little and come up with some gobbledygook of why you re-did the chart you know how to do that sort of thing don’t you?”
“Sure do Doc, consider it done” [click]
And so:
http://journals.ametsoc.org/doi/pdf/10.1175/2008BAMS2634.1
And here’s the new chart:
http://www.nar.ucar.edu/2008/ESSL/catalog/cgd/images/trenberth9.jpg
I’ve run the numbers, and 0.9 Wm² will warm the ocean 600 meters deep about 1/2°C in a little over 40 years. Truly amazing stuff. The noon-day sun puts out nearly 1370 wm² and these guys are claiming they’ve added up all the chaotic movements of heat over the entire planet and have determined an imbalance of 0.9 Wm². That’s an accuracy to five places. No plus or minus error bars or anything.
What it means is, all of the components
Reflected by clouds
Reflected by aerosols
Reflected by atmospheric gases
Reflected by surface
Absorbed by the surface
Absorbed by the atmosphere
Thermals
Evaporation
Transpiration
Latent heat
Emitted by clouds
Emitted by atmosphere
Atmospheric Window
AND
Back radiation
need to have an accuracy to those five places or better for the 0.9 Wm² to be true.
Perhaps Hansen didn’t ring up Trenberth and bully him into changing his chart but, Trenberth did change it to show an imbalance and I bet he did so because he realized that if it balanced like his 1997 version, heat wouldn’t build up.
And we all are supposed to sit still for this sort of thing.
**************************************
Ok, I just needed an excuse to post that (-:

You can assume away about anything you like and maintain a “net” radiation budget, but the actual errors in the Trenberth and others Earth Energy Budgets are a bit more subtle. One that is often overlooked is the Atmospheric Window of 40 Wm-2. That is closer to 20 Wm-2 and depends on what “surface” you are using. There is a big difference between a sea level “surface” and a 2 meter “surface”. Stephens et al. did a good job of showing what a more realistic Earth Energy Budget should look like.
What is interesting about the “window” error is that it is primarily due to mixed phase clouds. That is both energy and mass that has an impact on the which ever “surface” budget you choose. Water vapor that converts to ice then gets stored at the poles or high altitudes produces a budget deficit and if the energy of fusion is released closer to the poles than source of evaporation is more easily transferred to space. Mass transfer in the stratosphere (water vapor and ozone) accounts for roughly 8 Wm-2 of the Stephens et al. estimated +/- 17 Wm-2 of “surface” uncertainty.

Slartibartfast

I’d be happier if “Back radiation” or “Backradiation” were erased from the GW lexicon. It’s just radiation. There isn’t anything special about it that merits a new name.
Except it’s been “used”, maybe. But radiation doesn’t care who had it next to last.
REPLY: That’s a good idea, really the only thing that is happening is retarding the escape of energy to space – Anthony

mathman

Ah, energy. Where does it come from? The Sun. Where does it go? in all directions.
What happens to the Earth? It is rather like what happens when you put your hand out in the sunlight. Your hand gets warm and the space behind your hand (the shadow) gets cold. Does your blood boil? No. All kinds of stuff happens, your hand gets a little warmer, and the energy absorbed gets released in various ways.
Thus the Sun shines on the Earth, the Earth gets a little warmer, and that heat is then radiated away (in all directions). The problem is that the system has to balance: over time the energy in equals the energy out (remember: energy cannot be created or destroyed). Earth gets a little warmer–more energy released. Earth gets a little colder–less energy released. All kinds of negative feedback here. Guess what? The single most important factor is the slight variability of Solar Flux (all wavelengths). Proof: the Maunder minimum.
Were there any positive feedback, the Greenland ice cores would show much larger swings. But they don’t.
Sorry, AGW fanatics. This has been going on for a LONG time. And the flux predates humanity by some billions of years. We didn’t do it, we are not doing it, we can’t do it.
I doubt that we are even minor actors in the drama.
You can’t escape the laws of thermodynamics. You just can’t. Entropy always wins. Better go look again at the energy budgets for Mercury, Venus, the Moon, and Mars. Everything out there balances. So do we.

John West

”It is proposed that it is Back Radiation that lifts the surface temperature from 255K, as predicted by S-B, to the 288K actually observed because the 324 Back Radiation exceeds the surface radiation to the air of 222 Wm2 ( 390 Wm2 less 168 Wm2) by 102 Wm2. It is suggested that there is a net radiative flow from atmosphere to surface of 102 Wm2.”
The 168 you’re subtracting from the 390 is not from the atmosphere. The NET energy transfer is from the surface to the atmosphere (350 – 324 = 26 W/m^2).
Here is a “corrected” (showing net flows) version:
http://theinconvenientskeptic.com/wp-content/uploads/2010/11/FT08-Blocked1.png
Here is an overview of calculations involving the effect of clouds and humidity on the GHE:
http://www.asterism.org/tutorials/tut37%20Radiative%20Cooling.pdf

John Eggert

I have to agree with Dr. Spencer. Very sad to see this here.

Ian

Anthony,
Seriously? You missed April 1st by a week!
I see that Dr. Spencer restrained himself.

Jim

Its nonsensical. Even with my understanding of movement and momentum, I am supposed to see no involvement of Brownian movement. I understand the radiation input, powering the system, and the radiation of molar body, by to lay a flat assumption that the molecule goes up? Illogical. Simplistic, yes. Reality no.

Steve Case says:
April 8, 2014 at 6:09 am
> Ok, I just needed an excuse to post that (-:
A fine rant. Feel better now?

MikeUK

Just to throw something else into the melting pot, infrared photons can do different things:
A: IR-photon + CO2 –> IR-photon + CO2
B: IR-photon + CO2 + (N2 or O2) –> CO2 + (N2 or O2)
Type A interaction could be said to provide back-radiation (some of the IR-photons return to Earth).
Type B interactions provide a direct heating effect on the atmosphere, no back-radiation.
We’ve probably already had most of the heating from Type A. It is Type B that is still growing, from the “wings” of the CO2 absorption bands, mostly due to pressure-broadening, but how big is this new heating? My gut feeling says not very big at all, but quite tricky to calculate …

Mike M

“Therefore neither ii) nor iii) should be included in the radiative budget at all. They involve purely non radiative means of energy transfer and have no place in the radiative budget since, being net zero, they do not cool the surface. ”
Yes latent heat (ii) should be included because even though it is not initially radiative, the latent heat is transported from the ground, separate from the adiabatic cooling of the water vapor, to then radiate from a higher altitude than from the ground upon condensation. It’s as though heat was pumped up from sea level to heat a 10k’-30K’ mountain top.

Note that rising air cannot lose energy with altitude other than by radiation to space.
Instead, KE at the surface is converted to PE off the surface and PE does not register as heat. The air loses heat but not energy as it rises adiabatically and gains heat but not energy as it falls adiabatically.
The adiabatic component of convection returns heat to the surface on descent by converting PE back to KE. That heat is not radiated back to the surface so including it as an addition to the underlying back radiation of 222 to make that back radiation 324 is wrong.
The non adiabatic (diabatic) portion is then dealt with in overall atmospheric emission of 165 from the atmosphere and 30 from clouds.
The accuracy of the individual components doesn’t matter for current purposes. The Trenberth diagram successfully shows how the system achieves overall balance by juggling the components.
The point I am making is that his treatment of some of the components is incorrect and if one takes proper account of the return of energy to the surface on adiabatic descent then the back radiation figure need be no higher than the figure for radiation from the surface.
If both figures are equal then there can be no surface warming from back radiation. All the action goes on off the surface.
For a balanced system the amount of energy stored and the rate at which energy is shed depend on mass, gravity and insolation but the method of shedding is shared between surface and atmosphere in variable proportions depending on the radiative characteristics of the atmosphere.
If the atmosphere had no radiative capability at all then radiative emission from the atmosphere would be zero but the Atmospheric Window would release 235 Wm2 from the surface.
If the atmosphere were 100% radiative then the Atmospheric Window from the surface would be zero and the atmosphere would radiate the entire 235 Wm2.
The difference between the two scenarios would be in the rate of convective overturning. Fast for a non radiative atmosphere and slow or near zero for a 100% radiative atmosphere.
One cannot prevent convection in a non radiative atmosphere due to uneven surface heating and the decline in temperature with height caused by the conversion of KE to PE with height.

Ron Clutz

Leonard Weinstein says:
April 8, 2014 at 5:55 am
What you say makes sense. But extensive analysis of radiosonde data shows little effect from CO2 upon the temperature profile in the atmosphere up to mid Stratosphere.
“The fits for the barometric temperature profiles did not require any consideration of the composition of atmospheric trace gases, such as carbon dioxide, oxone or methane. This contradicts the predictions of current atmospheric models, which assume the temperature profiles are strongly influenced by greenhouse gas concentrations.”
http://oprj.net/articles/atmospheric-science/19

Ashby

Eliminating convection from the energy budget??? I think some correction to Trenberth’s energy budget may be in order, but I don’t think this post is helpful.

Chris: “If a normal everday person looked at this they would be lost. I even find it confusing.”
This is true about most physics, which is why Newton is still highly regarded.

David Reeve

Kudos to Anthony for running this……. but sigh. Maybe we can have the interpretive dance next?

MikeB

DirkH says:
April 8, 2014 at 5:46 am
The mean free path length for an IR photon at 15 micron is much shorter than 25m. At sea level you could expect 95% of such radiation to be absorbed within 1 metre. As you say, the atmosphere is a thick fog at this wavelength.
When the CO2 molecule absorbs the photon it is elevated to an ‘excited’ state. Left to its own devices it would re-emit this photon within a few milliseconds and revert to its ‘ground’ state. But, at low altitudes, it is rarely left to its own devices. The chances are that it will collide with another air molecule before it can emit a photon. When it does so, it transfers energy to the colliding molecule (and can no longer emit a photon). This has the effect of warming the surrounding air which is mostly nitrogen and oxygen. These gases cannot absorb radiation directly but they are nevertheless warmed by collision with the excited CO2 which has. In this way the CO2 could be called ‘heat trapping’, but I don’t like that term myself.
What’s more, the process is reversible. CO2 molecules can acquire energy from collisions and become ‘excited’. They can then emit radiation at 15 micron. The proportion of CO2 molecules in the excited state at any one time is roughly constant, depending on the local temperature (the equipartition principle). This fact allows us to determine the temperature of the air at various altitudes according to how much radiation we detect at 15 microns.

ferdberple

if GHG is radiating 324 inwards, it must be radiating 324+ outwards. Yet, total radiation to space from the atmosphere is only 235. Trenberth’s diagram cannot be right.
GHG theoretically warms the surface at the expense of cooling the atmosphere. The lapse rate gravitationally limits the temperature difference between the two. Since we are already at the gravitational limit for lapse rate, further increases in GHG will simply increase the rate of convection, cooling the surface in an amount equal to any increase in back radiation.

“Eliminating convection from the energy budget??? I think some correction to Trenberth’s energy budget may be in order, but I don’t think this post is helpful.”
Adiabatic convection hasn’t been eliminated. It is simply a zero net effect at the surface after the end of the first convective cycle.
It is still accounted for within all the other numbers which is why the numbers still balance on my interpretation.

ferd berple has it right.

Leonard Weinstein

Ron C. says:
April 8, 2014 at 6:45 am
The lapse rate (on average) depends only on the specific heat of the atmosphere, the gravity, and the added effect of water condensation (the wet lapse rate). Changing composition results in a VERY small change in specific heat for actual CO2 and water vapor changes, so the lapse rate (a gradient) does not change for these effects noticeably. It is the absolute level of temperature, not gradient, that is the issue, and it is about 33 C warmer every where due to water vapor, CO2, and clouds, among other effects (such as aerosols). The question, whether feedback has limited rather than enhanced the effect of any CO2 increase, is the major issue between skeptics and supporters of the strong effect. It appears that weak positive feedback, or even negative feedback, along with larger natural variation dominated the measured variation, contradicting the CAGW position. All the radiosonde data does is support a weak water vapor feedback (and water vapor content also affects clouds, resulting in negative feedback), which is not in disagreement with anything I stated.

HankHenry

288K is not the surface temperature. It is the surface AIR temperature. There’s a substantial difference and it matters in these global scale budgetary considerations.

Arfur Bryant

Oh Dear.
For your delectation, please listen to this. In particular the second half. While you listen, have a think about Trenberth’s “…324 W/m^2 absorbed by the surface.”

Trenberth’s cartoon (any version) is a joke – without the funny bit.
Have a nice day.