## Stealing the Steel Greenhouse: Cause and Effect in Earth’s Energy Flow

Posted: April 2, 2012 by tallbloke in Astrophysics, atmosphere, climate, Energy, Gravity, Ocean dynamics

The main plank of the standard theory of the flow of energy in Earth’s climate system is the notion that energy leaving the surface is partly recycled by radiatively active gases, GHG’s, in the atmosphere as ‘downwelling long-wave radiation’, DLR, which warms the surface of the planet relative to the temperature it would have without an atmosphere.

The basic idea is that the surface temperature has to rise in order to be radiating at such a temperature that the radiatively active ‘greenhouse gases’  at cold, high altitude in the atmosphere are able to emit the same amount of energy back out into space as arrives from the Sun, which in the end, along with other radiatively active object in the air such dust particles and cloud droplets, they must. The basic scheme is nicely typified in this diagram by Willis Eschenbach, in his 2009 article on WUWT, entitled ‘The Steel Greenhouse’. (though Willis uses the idea of an internally heated planet with a steel shell to simplify the concept) The diagram shows the difference between a planet with no ‘shell’ (top), and a planet with a radiatively active shell (bottom).

Willis says:

“In order to maintain its thermal equilibrium, the whole system must still radiate 235 W/m2 out to space. To do this, the steel shell must warm until it is radiating at 235 watts per square metre. Of course, since a shell has an inside and an outside, it will also radiate 235 watts inward to the planet. The planet is now being heated by 235 W/m2 of energy from the interior, and 235 W/m2 from the shell. This will warm the planetary surface until it reaches a temperature of 470 watts per square metre. In vacuum conditions as described, this would be a perfect greenhouse, with no losses of any kind. Figure 1 shows how it works.”

In his article. Willis then develops the idea that his model is analogous to the real Earth and its atmosphere.

But there are problems.

Firstly, the real situation is that the ‘shell’, the portion of the atmosphere doing most of the radiating, is colder than the surface. This is a simple observational truth. Cooler things don’t warm warmer things, as the second law of thermodynamics tells us, though they can slow the rate of cooling of the warmer thing.

Secondly, radiation from the atmosphere only penetrates around 0.07um into the ocean surface. Much less than the thickness of a human hair. This will mean that since a relatively high amount of energy is being absorbed in a layer only a small number of molecules deep, the principle effect will be to promote evaporation, which cools the ocean rather than warming it. This leads me to believe that DLR doesn’t warm the ocean, or even slow its rate  of cooling. It’s a big problem for the standard theory if so, because the ocean covers around 3/4 of the planet. For DLR to lift the Earth’s surface temperature to what it is, from the temperature it would be without an atmosphere or ocean (you can’t lose one and keep the other), by warming the ground and air is not possible, and contrary to observation. The near surface air and the ground are on average cooler than the ocean surface by 3C globally. Hitherto, theorists have got around this problem by denying it exists, or just ignoring it. In a discussion on this issue, Willis tried to get around it by saying that wind ruffling the water surface will mix the DLR heated water down into the ocean. The problem with that idea is that wind promotes evaporation too, and the effect is exponentially amplified as wind increases.

So if downwelling radiation from ‘greenhouse gases’ can’t be doing the job of keeping Earth’s surface much warmer than it would be without an atmosphere or ocean, what else could?

Energy from the sun in the form of short-wave radiation has no trouble penetrating deep into the upper 100m of the ocean, a three dimensional matrix, transferring heat into the water. But because water re-radiates long-wave radiation, which can’t travel more than a few nanometres before being re-absorbed, the only way for energy to escape is from the surface, a two dimensional plane. The the near surface air, into which the ocean has  to lose energy, principally by evaporation, is only a few degrees cooler on average which makes the job tougher. The only way the ocean can get rid of enough energy fast enough to approach equilibrium, is to keep gathering solar energy until it is at a temperature which enables it to do that effectively. The ocean ‘traps heat’. But the rate of evaporation is set by the surface pressure, which limits the energy releasing ability of the ocean.

By this analysis, the ‘greenhouse effect’ is primarily taking place in the ocean, not in the air. Rather than Earthly energy having a tough time getting past the greenhouse gatekeeping gasbags, it is long-wave converted solar energy that is having a tough time escaping from the oceans, due to the pressure they are under.

I’ve stolen the steel greenhouse and tossed it in the ocean. Sorry Willis.

If this is correct, then the atmospheric mass is the key quantity, not the amount of GHG’s by volume within that mass. This is because atmospheric mass determines the surface pressure brought about by the force of gravity acting on it, and thus the rate of oceanic evaporation.  We can further see that if that is the case, the higher value for radiation measured near the surface compared to the value at high altitude is more a consequence of its emission from higher density, warmer near surface air, rather than the cause of that higher temperature. The cold, radiatively active gases and particles fulfill the role of cooling the planet by radiating energy back to space from high altitude, which maintains overall radiative balance. Could it be that cause and effect has been fundamentally confused by an overemphasis on modeling the apparently most easily calculable quantity – radiation?

Has facility has been confused with causality?

Comments
1. P. Berkin says:

Isn’t the surface area of sea much, much greater than the figure always given because the sea is not level and there is spray?

I assume that this gets taken into account but I never see it mentioned

2. Harriet Harridan says:

Nice post TB 🙂

So, to clarify, you’re saying that over land we have much more upwelling IR than downwelling IR, as shown here, but over the oceans it’s off-set by evaporation so that they are more or less the same?

Another question, you say: “The the near surface air, into which the ocean has to lose energy, principally by evaporation, is only a few degrees cooler on average which makes the job tougher. ” How are we sure it’s *principally* by evaporation? Kirchoff’s law says it should be radiating, as it has absorbed.

3. Hans says:

TB,

Simplifications are not always the best way to explain something, especially if there is no basic support in nature and in physics. IR radiation is not dominating energy transfer in the troposhere.
That is the major reason why there exists a troposphere with declining temperature up to the tropopause.

The positive feature in your model is that it clearly shows that the bulk of IR emission to space occure from an altitude above the surface of earth.

The total energy contained in a windless atmosphere mass (disregarding phase shift energy between water vapour and water) consists of a) potential energy b) internal energy and c) PV energy.

This energy content has to exist in any real atmosphere or there will be no gas in the atmosphere.
Such an atmosphere left alone insolated from any energy transfer in or out has to arrange its energy content in a specific way and that is to reach maximum entropy according to the second law of thermodynamics. This cannot happen in a real atmosphere but it can come close as it does in the Venusian atmosphere..

When that has happened the energy content in any kg of atmosphere is approximally equal and the temperature laps rate will be -g/Cp. It is that simple.

In a real atmosphere convective energy transfer is critical both horizontally and vertically and just for that single reason (there are several more) your two IR fluxes down and up in the troposphere is nothing more than a model construct and cannot be found in nature. The earth´s atmosphere is trying to reach an energy equilibrium (energy per mass unit) but is has not reached further than -6.5 K/km instead of -9.8 K/km (see US 1976 standard atmosphere).

4. Stephen Wilde says:

“This is because atmospheric mass determines the surface pressure brought about by the force of gravity acting on it, and thus the rate of oceanic evaporation.”

It doesn’t determine the RATE of evaporation. That is down to a multitude of other factors.

What surface pressure does is determine the ENERGY COST of a given amount of evaporation.

Changes in surface pressure alter the relationship between the amount of energy required to provoke evaporation and the amount of energy taken up in the process of evaporation by way of latent heat of vapourisation. At 1 bar the ratio is about 1 to 5. At higher or lower pressures that ratio changes.

Otherwise this article is excellent in merging the significance of two distinct issues namely the inability of downward radiation to alter the background rate of energy loss from ocean to air and the ability of surface pressure to set that background rate of energy loss.

That background rate of energy transfer from ocean to air then determines atmospheric temperatures and the basic air circulation in which the permanent climate zones are embedded.

Any other influences (principally solar and oceanic) just alter the air circulation. Human sourced GHGs also alter air circulation but too little to measure.

5. Stephen Wilde says:

” the higher value for radiation measured near the surface compared to the value at high altitude is more a consequence of its emission from higher density, warmer near surface air, rather than the cause of that higher temperature”

Yes and that warmer near surface air is present due to pressure effects both on the water surface controlling the rate of energy transfer from the oceans AND from the ATE combined. But the ocean effect for Earth is by far the greater.

Which is why I pointed out before that any downwelling radiation at the surface comes from air molecules just above or at the surface and NOT from higher up in the atmosphere.

We have two different greenhouse materials (air and water) both responding differently to surface pressure with an interface between them where the primacy of the evaporative process is revealed by the cooler surface skin on top of a warmer ocean bulk below and that cooler skin only exists because evaporation pulls energy out of the water faster than it can be conducted up from below.

How much faster is directly related to surface air pressure and NOT atmospheric composition.

6. tallbloke says:

Harriet Harridan says:
April 2, 2012 at 2:57 pm

Nice post TB 🙂

So, to clarify, you’re saying that over land we have much more upwelling IR than downwelling IR, as shown here, but over the oceans it’s off-set by evaporation so that they are more or less the same?

Another question, you say: “The the near surface air, into which the ocean has to lose energy, principally by evaporation, is only a few degrees cooler on average which makes the job tougher. ” How are we sure it’s *principally* by evaporation? Kirchoff’s law says it should be radiating, as it has absorbed.

Thanks harriet. The whole concept of upwelling and downwelling creates confusion. Radiation is emitted by matter in all directions, and doesn’t get far before it is absorbed. If we are right, then atmospheric radiation is just buzzing around doing its buzzy thing, and not having much effect apart from cooling Earth when it eventually buzzes off to space because it was caused by the emission of energy which came from the Sun originally, which warms the air. Warm air emits more, so the warm air near the surface emits at ~390W/m^2 and the cold air up at high altitude loses ~240W/m^2 to space at the edge of the flux. This is a function of temperature, not a source of ‘extra energy’. We know that the net flux cools the ocean by ~65W/m^2, and that’s good enough for me.

7. tallbloke says:

Hans and Stephen, thank you both for your expert input. It’s great to have people with real meteorological qualifications and depth of knowledge around here. In the article, I have tried to keep things as simple as possible so that people without in depth specialist knowledge and strong maths skills can start to understand our new theory of climate.

The corrections and additional detail you are providing will help me improve the next iteration.

8. mkelly says:

Good Job. I was writing a post about this issue. There are several other things wrong with the example:

1. Had he written a simple heat transfer equation he would have seen that the increase temperature of the globe was impossible because when T1=T2 heat transfer stops. (note to people I did not say radiation stops I said heat transfer stops) So at the -19 C he says the globe is at is all it can be.
2. The shell has no energy it only has what the globe provided to it. So there is no “shell energy” to send back and heat the globe to a higher temperature.
3. A thing cannot heat itself.
4. If the first 235 heated the shell to 235 the 470 must heat the shell to 470. Since the 470 is equatable to heat per his post the shell now must per heat transfer go up to 470.

You beat me to it as I was working on a post about this very thing. Thanks.

9. wayne says:

“Simplifications are not always the best way to explain something, especially if there is no basic support in nature and in physics.”

I agree with Hans there. Usually it just adds confusion, but, sometimes they can be great puzzles!

The first point I see is the outside area of the shell is greater than the surface which immediately then means the temperature of the outside of the shell will be below the 235 W/m2 equivalent radiative brightness. Ignoring the emissivity that put’s it somewhere south of 253 K at he outside surface of the shell.

If the ‘internal heat’ is because the planet is 253 K throughout. the air between will organize to somewhere below 253K meaning by the Stefan-Boltzmann relation the surface’s output would be much lower, and the shell’s temperature would be even lower than that due to the greater area.

But if the 235 W/m2 is from 5000 K central heat, nearly unlimited, at the core of the planet then the surface is just going to get hotter and hotter until the outer surface is then at just below 235 W/m2, once again because of the increased area of the shell. The surface would be much hotter for the surface would always be outputting 235 W/m2. The air at the surface would be high enough that, by S-B, the flow was still maintained at 235 W/m2.

If the internal heat is being generated by nuclear fusion diffuse within the planet, well, how hot is a nuclear relation in W/m2? That might be hard to calculate by S-B seems would no longer apply in this case for heat differentials do not stop that heat by split atoms the way thermal energy by temperature difference.

Well, enough for now, got to break for a while.

Interesting topic, tallbloke.

10. tallbloke says:

mkelly: There is much MUCH more that could be said about the article. But I refrained, because … well, because. 😎

So go ahead and write it, if it comes from someone who doesn’t have ‘previous’ with Willis, so much the better.

11. Hans says:

Stephen Wilde says: April 2, 2012 at 4:29 pm

“This is because atmospheric mass determines the surface pressure brought about by the force of gravity acting on it, and thus the rate of oceanic evaporation.”

“It doesn’t determine the RATE of evaporation. That is down to a multitude of other factors.
Any other influences (principally solar and oceanic) just alter the air circulation. Human sourced GHGs also alter air circulation but too little to measure.”

Stephen,

Agree with you and your comment is of outmost importance IMO. The energy flux (RATE) leaving the ocean surface is proportional to the wind speed^2 and the temperature difference between the ocean and the air. The highest value I have heard of is 270 W/m^2 (over the Japanese See). Less often the wind is warming the ocean since warm air over land has a tendency to ascend. Enormous quantities of energy is moved from the southern hemisphere to the northern one by currents and especially to Northern Atlantic. This is a major reason why Stockholm 59N has a relatively mild climate compared to Siberia. West winds are frequent and picks up energy from the Gulf Stream.

Long term mass replacement (winds) are partially caused by extraterrestrial factors (tides and more) including Mobile Polar Highs (Marcel Leroux).

12. tallbloke says:

Wayne, you need to read the original article, where Willis forestalls some of your criticisms. The whole thing is in vacuum, the shell is only a few miles bigger in diameter than Earth etc. They key issue I’m trying to get at is the relative power of a slowing of the rate of cooling of the ocean by radiative gases in the atmosphere, compared to the ‘greenhouse effect’ of sunlight going deep into the ocean and the converted energy having a tough time getting out again.

I wish I could concieve of a simple experiment to demonstrate the relative power of those effects.

At one time I thought it’d be enough to point out that the top seven feet of ocean has as much heat capacity as the entire atmosphere above it. But I’ve been pointing that out for years, and the lukewarm dogmatists still don’t (or won’t) get it.

13. tallbloke says:

Hans, wind is very important as you say. We’ll have a full thread on that soon, when the people I’ve sent copies of your thesis to have had time to read and digest the information.

14. tallbloke says:

Harriet: I didn’t answer your second question

Another question, you say: “The the near surface air, into which the ocean has to lose energy, principally by evaporation, is only a few degrees cooler on average which makes the job tougher. ” How are we sure it’s *principally* by evaporation? Kirchoff’s law says it should be radiating, as it has absorbed.

Kirchoff’s law of radiation states that:

A body at temperature T radiates electromagnetic energy. A perfect black body in thermodynamic equilibrium absorbs all light that strikes it, and radiates energy according to a unique law of radiative emissive power for temperature T, universal for all perfect black bodies.

“For a body of any arbitrary material, emitting and absorbing thermal electromagnetic radiation in thermodynamic equilibrium, the ratio of its emissive power to its dimensionless coefficient of absorption is equal to a universal function only of radiative wavelength and temperature, the perfect black-body emissive power.”

The ocean absorbs solar shortwave at one set of wavelengths, and emits radiation at longer wavelengths. It also conducts and evaporates and convects. Kirchoff’s law doesn’t apply to that complex situation. However if the ocean is in thermodynamic equilibrium, the sum total of the energies involved in all those complex processes will balance the energy being absorbed from the Sun, notwithstanding the effect of the biological processes which may take energy in and out of the system as defined, and the effect of the interaction of atmospheric radiation with its surface, which I contend is minimal. Also thought to be minimal, is the energy input from thermal vents, undersea volcanoes, and general flux of heat from inside the Earth – so far as we know…

15. Stephen Wilde says:

Hans said:

“The earth´s atmosphere is trying to reach an energy equilibrium (energy per mass unit) but it has not reached further than -6.5 K/km instead of -9.8 K/km (see US 1976 standard atmosphere).”

I agree that that is right so far as it goes but in theory a planet that fails to complete the equilibriation process should either boil the atmosphere off into space or allow it to congeal on the surface.

Instead, I think one needs to look at the entire vertical column from the surface to the point in space where energy in equals energy out. That point has to be completely outside the atmosphere.

Wherever a planet retains a gaseous atmosphere it must be the case that on average through all the layers of the atmosphere the actual lapse rate must average out to match the lapse rate set by the gravitational field of the planet.

I aver that the slope of the lapse rate is set by the intensity of the gravitational field and the height of the atmosphere is set by total solar irradiation and all else is simply noise introduced by the presence of an atmosphere interfering with the energy flow rates in and out.

As on Earth, Venus and presumably every other planet, that will result in widely differing lapse rates through different layers.

Many thanks to TB for moderating this site in such a way that such ideas can be constructively pursued without external derailment.

16. Stephen Wilde says:

“if the ocean is in thermodynamic equilibrium, the sum total of the energies involved in all those complex processes will balance the energy being absorbed from the Sun”

Yes.

And the background air circulation resulting in the positions of the permanent climate zones is a reflection of the oceans in thermodynamic equilibrium.

Alter anything other than surface pressure (from gravity plus atmospheric mass) or TSI at the top of the atmosphere and all one gets is a change in air circulation and a change in the size intensity and positions of the permanent climate zones for little or no change in system equilibrium temperature.

17. Stephen Wilde says:

“Hans and Stephen, thank you both for your expert input. It’s great to have people with real meteorological qualifications and depth of knowledge around here.”

Whoah there.

No meteorological qualifications on my part apart from a lifetime of study and observations. If that results in a depth of knowledge that is useful and constructive then that is good enough for me. 🙂

18. tallbloke says:

Which leads to two key conclusions:

1) A well mixed trace gas like co2 isn’t going to alter anything in any consequential way if its concentration rises .

2)Beyond the cyclicities of the Moon, Solar variation (plus secondary effects on GCR’s, ozone etc) is the climate driver, since eventually, no matter what oscillations they get up to, the oceans have to follow what the Sun gives them in terms of energy.

19. Stephen Wilde says:

“the oceans have to follow what the Sun gives them in terms of energy.”

Yes, and that brings us full circle to the cloudiness issue because that dictates what the Sun gives the oceans bearing in mind that TSI variations are small on timescales meaningful to humanity.

So, is it GCRs as per Svensmark or ozone induced changes in the length of the jetstream cloud bands (associated with meridionality/zonality) as per me or a combination of the two ?

I think the GCR link is simply a spurious correlation with no causative effect, but I would think that wouldn’t I ?

20. tallbloke says:

Stephen:

I think scientific investigation is taking place around upper atmosphere chemistry, but hasn’t been directed particularly towards the problem we are identifying. However, we ought to make an effort to investigate the literature, because a lot of good work has been done which doesn’t get the limelight because it doesn’t support the mainstream narrative.

21. Stephen Wilde says:

Rog,

The upper atmosphere stuff is getting lots of attention now and so far is tending to support my top down scenario as in these recent papers here:

http://www.nature.com/nature/journal/v467/n7316/full/nature09426.html

“our findings raise the possibility that the effects of solar variability on temperature throughout the atmosphere may be contrary to current expectations”

http://www.atmos-chem-phys-discuss.net/12/7039/2012/acpd-12-7039-2012-print.pdf

“SORCE SSI produces a response that is larger in the lower stratosphere but out of phase with
respect to total solar irradiance above 45 km”

However in this thread of yours we are also considering the bottom up oceanic aspect.

I have seen nothing anywhere regarding the implications of the well known fact that the energy cost of the evaporation process varies with pressure. No one else seems to have realsed that that simple observation influences the rate at which the oceans can dispose of energy content for a given amount of evaporation.

Are you aware of any literature, anywhere that raises that issue ?

In my opinion the ocean / air pressure relationship sets the basic equilibrium temperature for a given amount of energy getting into the oceans but it is that top down solar effect on cloudiness that introduces an amplification of solar energy variations into the oceans which is out of proportion to top of atmosphere changes in TSI.

Anyway, whatever happens the system response is negative in that the air circulation changes to cancel out anything that seeks to move the temperature away from equilibrium set by pressure and insolation.

The human CO2 effect is negligible in comparison to those solar effects on cloudiness and the effects of internal ocean cycling on the rates of oceanic energy release to the air.

I guess that human CO2 might shift the air circulation latitudinally barely a mile compared to 1000 miles from MWP to LIA and LIA to date.

22. tallbloke says:

“Are you aware of any literature, anywhere that raises that issue ?”

No, but to be truthful, I haven’t had time to look.

I guess it’s not a biggy for oceanologists, since the ocean is by definition at sea level. maybe someone has studied alpine lakes? Titicaca is well studied and high. I need to get a Spanish speaker to do some hunting for us on that line of investigation.

Part of the problem is that all such studies are dependent on local weather conditions (ambient temperature, wind and cloud cover), so comparisons are difficult. I’m still trying to think of a useful observational comparison, or experiment.

Maybe I’ll play with orbits for an hour. Much simpler. 🙂

23. David Springer says:

Am I banned or what?

[Reply] You are now. Yes. 🙂

Anonymous wrote…
FYI on Tallbloke’s Talkshop I tried telling the Tallbloke that you knew what you were talking about re thermodyanmics. It appears he banned me. None of my comments are showing up.

FYI I banned you because you wouldn’t respond to my request to deal with your ad hom comment. Your thermodynamics knowledge is woeful, as your specious Venus internal flux argument demonstrates.

24. wayne says:

TB, noticed you comment on mine. You right, I didn’t go back and read Willis’s original again before diving in. 😉 That was quite a while ago. Now that I have some time tomorrow I’ll read it deeper to refresh exactly what Willis was up to at that time.

25. Richard111 says:

Time! How much time is needed to absorb so much energy and how much time is needed to lose that energy by a multitude of different paths? Even if the whole ocean is being ignored the total heat capacity of the top 700 metres is some 250 times more than the total heat capacity of all the atmosphere above. And every 24 hours a pulse of energy from the sun is fed into the ocean and the land. Most of that incoming energy is transparent to the atmosphere. The atmosphere ‘sees’ mostly low intensity long wave radiation from the surface continuously over that 24 hours and is much stirred by the different rates of energy release from the surface which facilitates energy transport to the upper troposphere where it is lost by radiation alone to space.

So far I have read no convincing explanation that a 100ppm increase in CO2 gas in the atmosphere over 200 years has caused any change in the way energy is released through the biosphere.

Time. Nobody seems to talk about time. Everything is instantaneous! The world does’nt work that way. In some four and a half billion years the sun is reported to have become 30% hotter yet the geological record does not show a 30% increase in global surface temperature. The apparent present increase of atmospheric CO2 is a minor event when viewed over the geological record. There are some very effective mechanisms maintaining the global temperature over the last 500 million years or so that have evolved with the life process itself. Life evolved with carbon dioxide and ‘knows’ how to handle it.

26. tallbloke says:

Thanks Richard, you have raised a key issue. I have written articles published here which make that very point about the biosphere. Much vilified by the sceptical community for his later work, James Lovelock had this one nailed long ago in his first book ‘Gaia – A new look at life on Earth’.

It’s a ‘must read’ for anyone hoping to understand the macro-scale forces which shape the chemistry of the atmosphere. The discovery that plankton blooms release chemicals which seed clouds to give themselves an umbrella shielding them from UV is a ‘heads-up’ example. That’s just one tiny mechanism in a mind-bogglingly complex chain of being which maintains our atmosphere in a highly neg-entropic state.

That atmosphere, charged as it is with the reactive capacity to neutralise all kinds of intrusions and insertions of unequilibriated input is incredibly resilient. Four billion years of the evolution not just of individual species, but a complex network of mutually beneficial and balancing biological inputs and outputs has resulted in a biosphere which Lovelock rightly characterised as a supra-organism capable of looking after itself.

But this realisation led to the mistaken interpretation by some that human activity is an external problem for the well being of the biosphere. It’s the result of a homocentricity which separates us from the rest of the biosphere and elevates our own importance as a species by bemoaning and mischaracterising our puny effect. While it’s true we have squeezed out a lot of our predators, there’s still no shortage of ‘pests’ we have to co-exist with. And the supra metabolism rolls on, operated as it is by a mass of micro-organisms which collectively outweigh us by many orders of magnitude.

In 1918-20 the Spanish flu wiped out OVER 5% OF THE WORLD POPULATION IN THE SPACE OF TWO YEARS. The ‘black death’ took out half the population of Europe in seven years. Those microbes sure know how to take care of business. I doubt any ‘wonder drugs’ will prevent a recurrence at some point.

It’s right to be concerned about the loss of the higher species which enrichen the world we experience, but we need to maintain perspective and not extrapolate our effect on Bengal tigers to our effect on planetary scale bio-systems which maintain the atmosphere and oceans.

27. Has anyone considered what the salinity of the sea water does to the energy input it takes to cause evaporation? How much thermal energy does it take to overcome the hygroscopic attraction of the salt content in the surface layer to the (attempting to escape) water molecules?

Does this provide an offset to the maximum relative humidity level at night due to some re-absorption of water vapor molecules above what volume would be set by the purely condensational action at the dew point, as the air cools to below the dew point at night?

How much is this offset compared to the about 3 degree cooler air just above the sea surface? Most of it, all of it? Does this need to be figured into the surface film heat loss/balances, with regard to changes in salinity %? Difference between fresh water, sea water, and in land more concentrated Salton seas?

If so then would this differential affect the temperatures needed the next day to activate the normal increases in humidity to trigger the afternoon rain storm natural thermostat mechanisms Willis and others have proposed? Just trying to close all loopholes in the energy budget/regulation mechanism we are proposing as a group in the TB talk shop hypothesis.

28. Joe's Lalonde says:

TB,

Due to scientists enclosing themselves into their individual areas of expertise, they fail in changing of parameters department. The “what if” is not in consideration.
Our study on atomics is based on observed parameters to a certain pressure. Add massive pressure or take away all pressure and the area of atomic energy fails.
This is why you do NOT see any atomic weapons ready for anything coming in from space and they changed technology to lasers and such.
So, theories of sun or our planets core with atomic energy is incorrect.
Now if you had a piece of our super compressed core and released it instantly to this pressure, you will have a spectacular show of quick expansion.

But these were created by mechanical means which motion has generated.

29. tallbloke says:

Richard, here you go:
http://www.waderllc.com/Finley/Evap_Paper.pdf

Joe, you’ll be interested too.

30. Joe's Lalonde says:

TB,

This is what really “pisses me off”!
Doing a pan study on only one point on this planet and CONCLUDING that it will be exactly the same at ALL points on this planet at the SAME time at this single point of time generating a calculation.
Laboratory studies of opportunistic means and NOT actually looking for any failures or outside the box parameters.

31. TB, Joe these papers look at evaporation (terrestial) in different parts of the world
Roderick, M, Hobbins, M & Farquhar, G 2009, ‘Pan Evaporation Trends and the Terrestrial Water Balance. I. Principles and Observations’, Geography Compass, vol. 3, no. 2, pp. 746-760.

Roderick, M, Hobbins, M & Farquhar, G 2009, ‘Pan Evaporation Trends and the Terrestrial Water Balance. II. Energy Balance and Interpretation’, Geography Compass, vol. 3, no. 2, pp. 761-780.

I had a link to the first paper but it no ;longer works. Roderick is at ANU (Australian National University) and i think the AGW believers did not like his research.
This is from a page of Graham Farquhars web page at ANU.
Physics of pan evaporation

Observations from around the world have shown that on average, pan evaporation, a measure of the evaporatiove demand of the atmopshere has decline over the last 50 years.

We want to know why and from that, deduce the implications for plant water use and for water availability.

As part of that research we constrcuted the fully instrumented pan at Canberra airport. With that pan we are examining the hour-by-hour energy balance of this unique, fully-instrumented evaporation pan.

Email contact(s): Michael Roderick

Supervisor(s) profiles: Michael Roderick

ANU Researchers: Michael Roderick, Graham Farquhar

32. tallbloke says:

Thanks CF. As a cautionary note on a salt related issue, WUWT has a great article up on paleothermometry using d18O reconstructions
http://wattsupwiththat.com/2012/04/03/proxy-science-and-proxy-pseudo-science/

Informative primer on salt in the hydrological cycle
http://www.palomar.edu/oceanography/salty_ocean.htm

33. Sparks says:

I must have missed that post by Willis, I’m getting the impression from this post (and some others of late) that in order to defend the Greenhouse theory, the excuses are beginning to take on all manner of wild assumptions.
And the joke is, that the Greenhouse theory as it stood before the additional BS, it was irrelevant to begin with IMHO.

There has been no evidence for a runaway Greenhouse Effect i.e. CAGW, AGW, Man Made, Climate Change, Global weirding (is weirding even a word?) etc…

34. Sparks says:

OT, There are snow Blizzards in Northern Ireland at the moment.

35. tallbloke says:

Snowing here in Yorkshire too, just started.

36. Richard111 says:

tb, I have Lovelock’s book GAIA, A new look at life on Earth. I second your recommendation that this is a ‘must read’. The book epened for me at Chapter 6, The Sea, and I was trapped. Now have to read the whole book again. 🙂

Temp. here in Milford Haven is 3C. Solid overcast and light drizzle. This is April ! ! !

37. tempestnut says:

Hi TB My first post here. I’m just an interested member of the public but trained as an engineer and fascinated in all things scientific. I have always had trouble with greenhouse gas warming as it has never been able to explain past climates or represent changes with any precision, or any observational proof. I have actively followed all matters climate since 2005 but recently have been more concerned with economic matters. Anyway I came across this article the other day
http://pubs.acs.org/subscribe/archive/ci/30/i12/html/12learn.html

about atmospheric pressure and how it must have been 3.5 to 5 bar 65 million years ago. Why, because flying dinosaurs needs the extra pressure to carry their weight. It also goes on about recycling CO2 and about how much has been sequester into the earths crust. I thought it may add just a bit to your developng theory/model.

Given that our life is based on carbon an alarming amount is no longer available. Another article I found but have lost for the moment tried to work our how long CO2 will last and at what point it would get too low to support plant life as we know it. It was thousands of years rather than millions, ignoring evolutionary changes of course.

For me there has been very little joined up thinking in the whole climate debate. I agree with all you have said in the 9:40 post above, and would love someone to revisit the whole evolutionary life cycle linking together how life reacted to atmospheric changes, the slow changes in the sun and even how the suns journey through the solar system could have effected climate and life. I believe much evidence exists that we have evolved to need a certain amount of radiation, at levels higher than we currently normally recieve. This would be essential reading for all children so they do not grow up to make the same mistakes some of our generation have made.

I have 4 children, none of whom have been conned by the green religion, and all of whom have enquiring minds, despite the education system trying to knock it out of them. We need to rekindle the fascination with life again by making it interesting, rather than todays constant diet of what we are
doing wrong.

Keep up the good work.

Peter

38. tallbloke says:

TN: Thanks for that, and welcome. Did you see this article:
https://tallbloke.wordpress.com/2012/01/26/greenhouse-gases-cool-planets-volcanos-warm-them/
A couple of cool pterosaur skeleton pics and some discussion about pressure as well as GHG’s and their role.

Sounds like you brought your kids up well, engineers make good enablers I say. 😉

Stick around and pitch your own ideas into the mix, the more the merrier.

39. Wayne Job says:

High Tempestnut and thank you tall bloke for welcoming a genuine bloke.
Today I would like to posit one of the main thermostats that control the earths temperature.
In this blog much has been spoken about the ocean and its uptake of heat from the sun, the distance from the sun and the planets curvature it can be taken the the earth is a flat surface ball as regards to the suns input.

However the output from the ocean is some what different in that the ocean and the atmosphere are in a constant state of flux. Transfer of heat from the ocean is at a molecular level or an atomic level with pure gases as in O2, N2 etc, this changes the game.

Mathematics down to a fractal level gives the ocean surface area with its ups an downs and ripples an almost infinite area in contact with the atmosphere, a lot different to what the sun is looking at. Thus the transfer of heat to the atmosphere is a direct result of the surface area of the ocean and the prevailing wind.

This is self regulating as too much heat from the sun causes storms and wind thus making waves and other blemishes in the ocean surface, making the area bigger and not just in a fractal sense.

This takes heat from the oceans that causes the winds, our poor earth is fighting the good fight to keep our temperature within bounds, it is the outside influences and a few on the inside like volcanoes that make the job of stability a constant task. I have failed to see any CO2 influence on the climate but my trees and vegetable garden are behaving extremely well.

40. tjfolkerts says:

At the risk of being called “pendantic”, I take issue with your first objection:
“Cooler things don’t warm warmer things, as the second law of thermodynamics tells us”

I have never seen the 2nd Law defined in quite that way in any technical discussion. The 2nd law more specifically tells us “the entropy of the universe tends to a maximum.” If you have a textbook with your wording, I would love to have a reference.

If you really want to show that something is violating the 2nd law, you need to calculate the change in entropy of the universe and show it is decreasing. (You could also isolate some specific subset of the universe and show that its entropy is decreasing.) If you don’t want to do the calculations (or reference some source that has), then you really don’t know if there is a violation.

An alternate statement of the 2nd Law is closer to what you said — that “no process is possible whose sole result is the transfer of heat from a body of lower temperature to a body of higher temperature.” So now if you want to claim a violation, you need to define specifically what two objects you mean, what “process” you are discussing, and then show that there is indeed heating of the warmer body by the cooler body. I suspect you will find that rather challenging, (mostly because I suspect in the end you will find there is no violation).

41. tallbloke says:

Hi Tim,

At the risk of being called “pendantic”

No, this time you get called an evasive sophist. 😉

There are as you say various formulations of the Second Law. More correctly we should couch it in terms of energy rather than ‘heat’, since that is what scientists and engineers have been doing since Maxwell’s time more or less.

However, the simple maxim I used holds up pretty well to empirical reality. Can you offer a counter-example, which doesn’t include any extraneous additional ensemble such as some kind of heat pump?

I think it is for proponents of the theory of back radiation heating the surface to show that it can, rather than for those who doubt to prove that it can’t. This is because proving a negative isn’t a logical way to proceed. So, what is your evidence?

Using the Phil Jones approach of “it must be co2, what else could it be” isn’t going to work here.

I hope this response isn’t the only one you intend to make to my comment on the Postma thread:
https://tallbloke.wordpress.com/2012/04/04/joseph-postma/#comment-22266
because there are other points raised in that apart from the radiative issue I’d welcome your thoughts on.

Cheers

42. tjfolkerts says:

Tallbloke asks “Can you offer a counter-example”

First of all, since the 2nd Law of thermodynamics is suppose to be universal, the way to disprove it is to offer a single counter example that DOESN’T work, not a single example that does. Ideally you or the original author can provide the calculations to show a violation. In classical thermodynamics, the change in entropy is simply dS = DQ/T, so the math is not tough. Rather than discussing, do the math.

But I can easily counter the specific example that is a supposed statement of the 2nd Law. Put a sphere with an emissivity = 1 and a surface area of 1 m^2 deep in space far from any star with a 240 W heater inside. The surface temperature will be 255 K.

Now add a thin, concentric, emissivity =1, T=0K, evacuated shell a small distance above the surface. The surface of that shell must warm until it reaches 255 K so that it can radiate 240 W. (To be overly precise, the temperature will be 255K – dT because the surface area will be 1 m^2 + dA.) Both the inner and outer surfaces of the shell radiate 240 W. The original sphere is now receiving 240 W from the heater and 240 W from the shell, or 480 W total.

[Snip]

[Reply] Hi Tim. Sorry to stop you there, but we don’t need to repost the whole of Willis’ steel greenhouse theory to make an analysis at this point. I’ve saved your original comment in full, so if you want it emailing let me know.

Now, if the shell heats up to the 240 W the sphere is putting out, it is going to radiate 120 up and 120 down, not 240 up and 240 down as you claim. i.e. it doesn’t magically radiate 480 W from a 240 W input. That breaks the Law of the conservation of energy. So it’s only going to radiate half of what it received back towards the surface and the other half out into space.

So it’ll send 120 back down and this should raise the inner sphere’s temperature so it radiates a higher number of Watts towards the shell. After a nuumber of iterations we get:

360 up 180 back
420 up 210 back
450 up 225 back
465 up 232.5 back
472.5 up 236.25 back

And so eventually we approach the 480 up 240 back and 240 to space scenario. Slowing down the rate of cooling of the inner sphere means a higher equilibrium temperature. That is fine and dandy and I have no problem with it.

But here’s the rub: In the real world, there’s a big hole in the outer shell through which the inner sphere is able to radiate directly to space (atmospheric window). Add to this the fact that the space between the spheres is filled with a highly convective medium (air and water vapour) which reduces the amount the outer shell manages to land back to the inner sphere’s surface by a large percentage. Add to this the difficulty the longer wavelength re-radiated by the cool atmosphere that doesn’t penetrate 3/4 of the inner sphere’s surface by more than 7um concentrating it’s power into a layer only a few molecules deep and so causing evaporation and we find the heating effect of ‘back radiation’ becomes negligible.

So when we run the calc again we find that the equilibrium temperature of the Earth’s surface is not going to be much higher than the 240 it started with if we’re going to rely on radiation to do the job of lifting its temperature.

43. tjfolkerts says:

1) “but we don’t need to repost the whole of Willis’ steel greenhouse theory “
YOU asked for a counter-example. I gave it. It seems pretty odd for you to now say you (and your readers) didn’t REALLY want to see the counter example that showed — with actual math — that back-radiation does NOT contradict the 2nd Law.

2) “And so eventually we approach the 480 up 240 back and 240 to space scenario.”
Naturally I mean this as a limiting process as equilibrium was approached. I thought that was understood, but maybe I need to spell things of more carefully and slowly. (But then you seem to clip things that are more complete and mathematical).

3) “In the real world, there’s a big hole … the space between the spheres is filled with a highly convective medium … “
Ya can’t keep moving the goal posts! You wanted a simple example of a “cooler object warming a warmer object”. I gave it to you.

Of COURSE the real world is more complex. Some of the complexities will work against the simple calculations I gave (like the atmosphere not being a perfect black body, or convection). Some will enhance the temperatures (like the fact there is not just a single layer blocking the outgoing IR).

But just because other things are happening does not change any of the results for radiation itself. If convection lowers the surface temperature from 303 to 288, that just lowers the amount entropy is increasing — but entropy is still increasing.

4) “So when we run the calc again we find that the equilibrium temperature of the Earth’s surface is not going to be much higher than the 240 it started with if we’re going to rely on radiation to do the job of lifting its temperature.”
Who is “we”? Where is that calculation? How much above I would be much more impressed with numbers and equations, not abstract claims and hand-waving.
And you can’t say “if we’re going to rely on radiation to do the job” but then specifically include all the OTHER things besides radiation that are ALSO “doing their jobs”.

This statement of yours is the crux: “Slowing down the rate of cooling of the inner sphere means a higher equilibrium temperature. That is fine and dandy and I have no problem with it.”

Just to be clear … are you agreeing that “back-radiation” is NOT a violation of the 2nd Law? That “back-radiation” could (at least in principle) raise the surface temperature from 255 K to 288 K (or higher)? That photons from the cooler atmosphere do indeed help raise the surface temperature?
(It is a “yes or no” question.)

44. Stephen Wilde says:

tjfolkerts said:

“That photons from the cooler atmosphere do indeed help raise the surface temperature?”

Well I would say not.

You have already accepted the relevance of gravity and pressure in reating a lapse rate and accepted that the models do not fully deal with it.

The ATE of N & Z (and the warmer surface beneath the long established standard atmosphere) relies on higher density at the surface reacting more strongly with incoming solar radiation than the less dense air above to produce a lapse rate.

So if there are more photons swishing about in the air from more GHGs higher up then the air will simply expand and the density at the surface will fall.

So the surface must become cooler than it otherwise would have been even whilst the air gets warmer.

The net effect on equilibrium temperature is zero because it is just a redistribution of energy between air at the surface and air higher up.

Because the warmth is then higher up it escapes to space faster which offsets the alleged slowing down effect from downward radiation for, again. a zero net effect.

The actual lapse rate changes between surface and effective radiating height so that a higher effective radiating height fails to be accompanied by the warmer surface assumed by AGW proponents.

That leaves pressure and gravity as the sole determinants of surface temperature.

You can have changes in air circulation affecting the climate zones in theory (a pitifully small effect) but you cannot have a higher equilibrium temperature without increasing atmospheric mass or more solar input at the top of the atmosphere.

45. tallbloke says:

Tim says:
Just to be clear … are you agreeing that “back-radiation” is NOT a violation of the 2nd Law? That “back-radiation” could (at least in principle) raise the surface temperature from 255 K to 288 K (or higher)? That photons from the cooler atmosphere do indeed help raise the surface temperature?
(It is a “yes or no” question.)

It’s three questions and they are not ‘yes or no’ questions, but I’ll do my best to be brief.

We need to be careful that we are both on the same page about what back radiation in the real atmosphere is and is not. In a vacuum, there is nothing to prevent a photon from the shell getting all the way to the inner sphere, so it travels all the way in one go.

In the real atmosphere, a photon emitted at altitude is likely to be reabsorbed or the energy is likely to be thermalised through collision of the molecule carrying it within a very small distance. So just as surface exiting photon suffers a delay in its journey to space due to the presence of GHG’s, so a photon trying to get back to the surface suffers the same delay, plus more, during which time, other photons from the surface are escaping via the ‘atmospheric window’. The downward moving photon has even more hurdles to overcome than the upward photon, because every time it gets absorbed or thermalised, it find that the carrier molecule or the ones near it which have been thermalised due to collision start turbulently convecting upwards carrying the photon higher again.

Those photons which do get back to the surface have a 7/10 chance of hitting the ocean where they will be absorbed within 7 nanometres of the surface. They will contribute to evaporation, which cools the ocean surface. Any h20 molecule that is thermalised but not evaporated will be more buoyant due to its higher temperature and so is not going to contribute to the bulk ocean heat content.

The net result is a ~65W/m^2 cooling of the surface by radiation.

I don’t think ‘back radiation’ from the atmosphere is the reason the surface is at 288K. We have a better explanation for that. One that doesn’t involve the equivalent of trying to heat a swimming pool with a hairdryer.

Now you asked for more figures and less handwaving. I rarely bother getting my calculator hot for climate science discussions because the data are so poor it just leads to a false sense of knowledge. However, if you can provide me with pointers to solid data for global convection and conduction from sea to air, windspeeds affecting the rate of evaporation, and the actual surface area of the wind ruffled ocen surface, and explain how gas at -18C at 4000m of altitude can be radiating downwards at 340W/m^2, I’ll give it a go. 😉

46. tjfolkerts says:

“In a vacuum, there is nothing to prevent a photon from the shell getting all the way to the inner sphere, so it travels all the way in one go.”

It appears we are agreeing on the fundamentals
–> There is nothing in the 2nd Law to prevent photons from the cool atmosphere being absorbed by the warmer ground, thereby adding energy to (ie “warming”) the ground.

The DEGREE of warming is certainly up for debate, but not the principle.

“Those photons which do get back to the surface have a 7/10 chance of hitting the ocean where they will be absorbed within 7 nanometres of the surface. They will contribute to evaporation, which cools the ocean surface. “
I would say this differently. The evaporation is enhanced in an attempt to carry away the EXTRA energy. If 10 extra W/m^2 of photons starting hitting some section of water, it is NOT going to get cooler than it was before because evaporation increased. It will get WARMER, which LEADS TO some extra evaporation. Perhaps the water would warm up enough so that at equilibrium, it would radiate 2 extra W/m^2 and evaporate 8 extra W/m^2. But there is NO WAY that it will evaporate 12 extra W/m^2 and cool off to radiate 2 less W/m^2 than it had before.

Everything else being equal (wind, humidity, waves …), more evaporation must mean higher temperate.

(BTW, I think you meant 7 micrometers, not nanomenters. http://www.lsbu.ac.uk/water/images/watopt.gif)

“Any h20 molecule that is thermalised but not evaporated will be more buoyant due to its higher temperature and so is not going to contribute to the bulk ocean heat content.”

The fact that there is a sharp thermal gradient at the every top skin layer of the ocean means there must be considerable heat conduction through that layer: Q = – k dT/dx. (dT is small, but dx is also small, and the net result appears to be significant). Anything that warms the top-most layer would reduce that conduction from the water below. So a few thermalized H2O molecules in that skin layer reduce dT and could indeed limit the loss of heat from the bulk of the ocean (ie help keep the ocean warm).

47. tjfolkerts says:

“I don’t think ‘back radiation’ from the atmosphere is the reason the surface is at 288K. We have a better explanation for that. One that doesn’t involve the equivalent of trying to heat a swimming pool with a hairdryer.”

Personally, I like the “TOA radiation/lapse rate” framing of surface warming. There are so many OTHER things that happen between the TOA snd surface that it is tough to talk about just “back-radiation” as THE cause.

But in any framing, GHGs are critical. They prevent some “warm photons” (ie photons from a ~ 255 K BB distribution) from the surface from leaving, replacing them with “cool photons”(ie photons from a ~ 220 K BB distribution) generated in the upper atmosphere. To compensate, the surface must warm up (to ~ 288 K). It is simple energy balance, and doesn’t require detailed understanding of the conduction/convection/evaporation occurring in between.

48. tallbloke says:

tjfolkerts says:
April 7, 2012 at 5:13 pm

“In a vacuum, there is nothing to prevent a photon from the shell getting all the way to the inner sphere, so it travels all the way in one go.”

It appears we are agreeing on the fundamentals
–> There is nothing in the 2nd Law to prevent photons from the cool atmosphere being absorbed by the warmer ground, thereby adding energy to (ie “warming”) the ground.

There’s a difference between ‘getting there’ and ‘being absorbed’ as well you know. And a big difference between photons travelling through a vacuum and a photon emitted high up in the cool atmosphere and running the gauntlet of interaction necessary to reach the ground. I’ve never had a problem witth the ‘fundamentals’ of physics. I do have a problem with greenhouse theorists playing fast and loose with the differences between idealised situations used to define ideal physical laws and the real physical situation in Earth’s atmosphere. So cut the crap and get real.

The evaporation is enhanced in an attempt to carry away the EXTRA energy.

What EXTRA energy? The energy was emitted from the ocean in the first place, thereby cooling it.
There is no EXTRA energy Tim. If there was, you could build one of these:

If 10 extra W/m^2 of photons starting hitting some section of water, it is NOT going to get cooler than it was before because evaporation increased. It will get WARMER, which LEADS TO some extra evaporation. Perhaps the water would warm up enough so that at equilibrium, it would radiate 2 extra W/m^2 and evaporate 8 extra W/m^2. But there is NO WAY that it will evaporate 12 extra W/m^2 and cool off to radiate 2 less W/m^2 than it had before.

In fact, you re wrong about this, because the latent heat of vapourisation is such that for every molecule evaporated, the energy required lowers the temperature of four surrounding molecules. I’ll ask Stephen for the reference. But at least you’ve reduced the warming effect by 80% so far so all is good.

Everything else being equal (wind, humidity, waves …), more evaporation must mean higher temperature.

No. because a lot of evaporated water is whisked up the centre of storm systems, as Willis Eschenbach explained in his thermostat hypothesis, to cloud top which radiate directly to space, at altitudes above most of the CO2. This is a COOLING effect.

The fact that there is a sharp thermal gradient at the every top skin layer of the ocean means there must be considerable heat conduction through that layer: Q = – k dT/dx. (dT is small, but dx is also small, and the net result appears to be significant). Anything that warms the top-most layer would reduce that conduction from the water below. So a few thermalized H2O molecules in that skin layer reduce dT and could indeed limit the loss of heat from the bulk of the ocean (ie help keep the ocean warm).

The top layer of the ocean isn’t warmed by back radiation as explained above, so this idea fails.

Empirical data is hard to come by so I suggest we agree to disagree and move on.

49. tallbloke says:

tjfolkerts says:
April 7, 2012 at 5:23 pm

“I don’t think ‘back radiation’ from the atmosphere is the reason the surface is at 288K. We have a better explanation for that. One that doesn’t involve the equivalent of trying to heat a swimming pool with a hairdryer.”

Personally, I like the “TOA radiation/lapse rate” framing of surface warming. There are so many OTHER things that happen between the TOA snd surface that it is tough to talk about just “back-radiation” as THE cause.

So you are saying there are other factors besides back radiation which lift the average surface temperature above 255K. Excellent, this is more good progress.

But I have to point out that without direct warming from back radiation, you are left with a theoretical energy balance which doesn’t have a physical mechanism. Hanging the theory off a sky hook attached to a mythical ”effective height of emission” which doesn’t exist as a real measurable. Time to attach a parachute Tim, gravity beckons.

50. tjfolkerts says:

>Excellent, this is more good progress.
Funny — i was thinking it was good that YOU were making progress 😉

>In fact, you re wrong about this, because the latent heat of vapourisation
>is such that for every molecule evaporated, the energy required lowers
>the temperature of four surrounding molecules.
Conservation of energy still applies. Suppose we set up some situation of heat, humidity, incoming IR, etc for a tank of water. We measure the evaporation rate and the water temperature.
Suppose we increase the incoming energy (in the form of more IR) to the water. The evaporation rate will certainly go up in response. Are you seriously saying the overall water temperature would go down?

>>The evaporation is enhanced in an attempt to carry away the EXTRA energy.

>What EXTRA energy? The energy was emitted from the ocean in the first place,
>thereby cooling it.There is no EXTRA energy Tim.

I meant the extra energy from the extra photons from the atmosphere (like in the scenario reiterated above).

And while we are at it, the whole idea of where thermal energy came from “in the first place” is basically irrelevant. Energy does not come with labels documenting its history. Energy simply exists (in multiple, changing forms). If a liter of water has 100 units of thermal energy, you can’t say “these 37 units came from the sun, and these 12 units came from the air, and these 14 came from the water an hour ago, but returned … “

51. tjfolkerts says:

“So you are saying there are other factors besides back radiation which lift the average surface temperature above 255K. ”

No, not per se. The other factors modify the energy flow within the atmosphere. But in a world with no GHG, then convection or evaporation or a thick atmosphere in and of themselves would not warm or cool the temperature of the surface from the effective BB temperature.

52. tallbloke says:

I don’t fall for that one. See my request for the mathematical proof you spoke of on the Postma thread regarding BB limit of 255K.
https://tallbloke.wordpress.com/2012/04/04/joseph-postma/#comment-22435

Thanks

53. tallbloke says:

>Excellent, this is more good progress.
Funny — i was thinking it was good that YOU were making progress 😉

Conservation of energy still applies. Suppose we set up some situation of heat, humidity, incoming IR, etc for a tank of water. We measure the evaporation rate and the water temperature.
Suppose we increase the incoming energy (in the form of more IR) to the water. The evaporation rate will certainly go up in response. Are you seriously saying the overall water temperature would go down?

Of course conservation of energy still applies, but in this case the energy isn’t any longer anywhere near the tank, it has headed upwards to the top of the troposphere.

the whole idea of where thermal energy came from “in the first place” is basically irrelevant. Energy does not come with labels documenting its history. Energy simply exists (in multiple, changing forms). If a liter of water has 100 units of thermal energy, you can’t say “these 37 units came from the sun, and these 12 units came from the air, and these 14 came from the water an hour ago, but returned … “

Well I’m sorry but since the whole argument rests on back radiation slowing the rate of cooling, time does come into this. It’s a dynamic system, and instantaneous snapshots which fail to properly account for the fact that the back radiation coming back down to haunt the surface recently left (and thereby cooled) it gets a big fat fail, because you end up with one of these:

54. Stephen Wilde says:

tjfolkerts said:

“The evaporation rate will certainly go up in response. Are you seriously saying the overall water temperature would go down?”

No, but it won’t rise either because evaporation is a net cooling process.

1 unit of energy coming in causes 1 molecule to evaporate which draws 5 units of energy from the surrounding environment for a net cooling result. The latent heat of evaporation is well established at 5 times more than the energy required to provoke it at 1 bar atmospheric pressure.

The energy required is drawn from where it is most readily available which (if water and air were at the same temperature) would be from the rest of the downward IR.

So if you have 20 units of downward IR with 4 units each provoking 1 molecule more in evaporation then all 20 units get used up for no change in surface temperature and no change in the rate of energy flow from water to air.

25 units of downward IR gives 5 molecules evaporated, again for a zero net effect on the surface and so on.

The process is self limiting because when all the downward IR is used up the rate of evaporation stops increasing.

You might however be able to register additional warmth in the region of evaporative interaction but that will not spread outside the region of interaction and will dissipate if the rate of interaction declines.

The only effect would be a change in air circulation speed and a faster water cycle overall but far too small to measure compared to natural solar and ocean induced variability.

Many times I have asked AGW proponents to demonstrate that there is surplus energy left over after the increase in the rate of evaporation. They have not done so. Can you ?

55. Stephen Wilde says:

tjfolkerts said:

“But in a world with no GHG, then convection or evaporation or a thick atmosphere in and of themselves would not warm or cool the temperature of the surface from the effective BB temperature.”

Of course they would via conduction from the heated surface and consequent convective energy transfer to the night side.

The lapse rate, Ideal Gas Law and standard atmosphere do not distinguish between GHGs and non GHGs do they ?

56. tallbloke says:

Heh, Stephen, don’t fall for the old ‘atmosphere with no GHG’s’ argument. They are necessary to cool the planet by radiating to space, and raise emission from the surface to a colder place.

Many thanks for the detail on the evaporation energy cost.

Tim: The atmosphere does have radiatively active gases in it. Let’s stick to talking about the real world.

57. Stephen Wilde says:

TB

I don’t think I ‘fell’ for it. More to the point I think I have ‘dealt’ with it.

If there were no GHGs the surface would do the radiating instead and the air circulation would have to replace the energy lost on the night side by carrying it round from day side to night side for radiating it out from the night side surface.

There would be very vigorous upward convection on the day side as the atmosphere conductively absorbed energy from the surface and convected upwards.

That energy would not then be radiated out by the surface on the day side so an excess of energy develops in the system for a warming effect.

That upward convection on the day side has to be matched by downward convection on the night side and on the nightside the downward flow warms adiabatically thus delivering all that excess energy from the day side back to the surface on the night side by air to surface conduction so that the night side surface can radiate out to space just as much energy as necessary to offset the surplus gained on the day side.

If one then adds GHGs you get a lower energy surplus on the day side because GHGs radiate some of it out. The winds and convection do not need to be so strong but,just as before, downward convection on the night side deals with any surplus that remains after GHGs have done their outward radiating.

Adiabatic heating from compressing descending air on the night side is a very effective way of returning energy to the rapidly radiating surface.

That adiabatic compression on the night side has been missing from all the descriptions I have seen elsewhere.

The ‘no GHG’ canard fails.

58. Lars P. says:

I find this explanation much more rational for the explanation of the temperature of the earth. I think there are 2 other points supporting this:

Through the ice sheets the oceans stop radiating energy when on the “dark side” – south and north pole – when they are longer time not heated by the sun, or receiving not enough energy, this is why the flat world scenario for the energy budget is wrong – there is always about 22 million km2 actually not radiating – and it is self regulating. Ice being one of the best insulators.

The oceans also explain the early sun’s paradox, as the early earth had much more water coverage:
http://sciencenordic.com/earth-has-lost-quarter-its-water

The oceans warming take the big chunk of the 33°C warming and they are not even accounted for, with greenhouse gases being responsible only for a smaller part of it.

59. tjfolkerts says:

The “free energy oven” is obviously incorrect. But it also has a grain of truth. If you put a hot chicken in outer space, it will cool quickly by IR radiation. But if you put it inside a perfectly reflecting container, then it would never cool (becasue there is no conduction, convection or radiation escaping)! All the IR photons that leave the chicken will bounce back and get re-absorbed. (Of course, it would also never warm from where it started.)

If anyone thinks that “IPCC science” would approve of this strawman arguement for “re-radiating more energy”, then they know nothing of how radiation works.

Sorry, Tallbloke, you simply advertise your lack of scientific understanding if you equate this oven (and its obvious violation of Conservation of Energy) with the standard “Radiative Greenhouse Effect” as applied to climatology.

60. tjfolkerts says:

Tim says:
>> “But in a world with no GHG, then convection or evaporation or a thick atmosphere
>>in and of themselves would not warm or cool the temperature of the surface
>>from the effective BB temperature.”

Stephen replies:
> Of course they would via conduction from the heated surface and
>consequent convective energy transfer to the night side.

I don’t think you understand the concept of “effective BB temperature”. If 240 W/m^2 of sunlight get absorbed on average, then the earh will on average radiate 240 W/m^2. To radiate 240 W/m^2 from a surface of constant temperature, a blackbody would have to be 255 K. Ie the effective BB temperature is 255 K. Period. End of story.

If the surfce is the only place radiating, then the surface will have an effective BB temperature of 255 K. Some places could be a little warmer; some could be much cooler. Conduction from the sunny side to the night side will reduce the temperature swings, but will not change the radiation balance of 240 W/m^2 in & 240 W/m^2 out.

Tallbloke adds “Tim: The atmosphere does have radiatively active gases in it. Let’s stick to talking about the real world.”
There is a long history of “gedanken experiments” in science to try to focus on key points. So while keeping an eye on the real world is important, there is nothing wrong with trying to understand simple concepts to use as buildingblocks on our way to more complete understanding.

61. tallbloke says:

Tim F says:
Tallbloke, you simply advertise your lack of scientific understanding if you equate this oven (and its obvious violation of Conservation of Energy) with the standard “Radiative Greenhouse Effect” as applied to climatology.

Tim, the point which you haven’t responded to is that some of the ‘back radiation’ is returning to the surface after it already left the surface (thereby cooling it) and some of the ‘back radiation’ is actually ‘forward radiation’ from energy asorbed directly in the atmosphere from the Sun which has never been absorbed by the surface before. Do you accept that we need to differentiate between these two components to get any kind of a handle on the budget?

There is a long history of “gedanken experiments” in science to try to focus on key points. So while keeping an eye on the real world is important, there is nothing wrong with trying to understand simple concepts to use as buildingblocks on our way to more complete understanding.

There are “buildingblocks” and there is bullsh1t&bollocks. The ‘no greenhouse gases’ argument is the latter, because as you pointed out to Stephen, since radiation is the only means by which energy leaves the Earth’s system, the ‘effective height of emission’ would be at ground level without them. All this proves is that GHG’s are necessary to cool the planet. It does not tell us anything about the ability of ‘back radiation’ to heat it.

62. mkelly says:

Mr. Folkerts says: “Sorry, Tallbloke, you simply advertise your lack of scientific understanding if you equate this oven (and its obvious violation of Conservation of Energy) with the standard “Radiative Greenhouse Effect” as applied to climatology.”

And you Mr. Folkerts demonstrate you lack the ability to show how any of this can happen using the standard radiative heat transfer equations.

If you think Willis’ example is valid please write it out in proper heat transfer equations.

63. Stephen Wilde says:

“If the surface is the only place radiating, then the surface will have an effective BB temperature of 255 K”

Did I say otherwise ?

However the surface should be taken as the top of the atmosphere as observed from a point completely outside the atmosphere.

64. tjfolkerts says:

Tallbloke says: “Tim, the point which you haven’t responded to is that some of the ‘back radiation’ is returning to the surface after it already left the surface (thereby cooling it) and some of the ‘back radiation’ is actually ‘forward radiation’ from energy asorbed directly in the atmosphere from the Sun which has never been absorbed by the surface before. Do you accept that we need to differentiate between these two components to get any kind of a handle on the budget?”

No, I don’t think we need to differentiate the two components. Energy does not carry tags saying where it came from or how long it had been there.

I could (in principle) go out and measure the the temperature at millions of places around the globe at one instant in time (and other parameters like humidity, windspeed, …). From the temperature of some cubic meter of air (along with info about the chemical composition) I could calculate how much IR radiation will leave that parcel of air in the next second. I don’t need any information about what it was that warmed the air in the first place.

From the temperatures around around that parcel of air, I could calculate how much energy is being received. I don’t need to know whether the water in the ocean got its energy from upwelling currents or sunlight or underwater volcanoes.

The point is that I don’t need to know anything about the history to calculate the current IR radiation. The current temperature is sufficient. I don’t need to know the temperature a second earlier. I don’t need to know if the energy came from the sun or the moon or an electric heater.

Another way to say that is that once something has thermal energy, the enegy is ONLY that object’s. It is not “the energy that formerly was in the ground and before that in the ocean and before that in sun.” And object at 300 K will radiate the same wherever that energy might “originally” have come from.

PS. In my understanding, “backradiation” is a synonym for “downward radiation”. So energy absorbed from the sun by the atmosphere and then radiated downward is STILL “backradiation”. You are, of course, welcome to define the terms however you want. How do you define “backradiation”?

65. tallbloke says:

How do you define “backradiation”?

Why, as radiation which is coming back of course. 🙂

Seriously though, I think you lose a lot of information regarding the dynamics of the system by considering a static instant from which you then determine an energy budget.This goes back to Postma and his day/night differences too.

If you consider only a single ‘instant’ you are losing too much information about the very different energy budget regimes on the two sides of the planet. While it’s true the ocean temperature away from shore doesn’t change much overnight, the vertical temperature profile and convection in the troposphere does, and this makes a big difference to properly computed totals against the smeared out averages demanded by the ‘single instant’ approach. On top of that there is the issue of averaging temperatures and convection processes across latitudes, when the energy involved in raising or lowering temperature a few degrees at the equator or the poles is vastly different.

Tremberth’s energy budget is a crock because of these deficiencies. What I do know is that while various models attempt to do the job properly, and after suitable ‘tuning’ get more or less realistic anomalies, the absolute temperatures they come up with for the global average surface temperature vary by as much as 5K from each other.

A supposed 1.7W/m^2 signal from CO2 is lost in that sort of variance.

66. tjfolkerts says:

“If you consider only a single ‘instant’ you are losing too much information about the very different energy budget regimes on the two sides of the planet. “

No, I was talking about a single instant, not a single spot. I quite agree that day and night matters. But I was positing exactly such a possibility by getting simultaneous data from many locations.

And if you think the “origin” of the energy is important, then tell us a practical way to determine how much of the thermal energy in a given cubic meter of air came from the sun directly vs the ground’s IR vs convection. Heck, it would be a good start if you could even calculate the total thermal energy (regardless of its source).

“A supposed 1.7W/m^2 signal from CO2 is lost in that sort of variance.”
Don’t be too quick. Determining DIFFERENCES is often MUCH easier than determining the actual values. For instance I might have only a very rough idea how deep a lake is (perhaps to within 10 m), but I can still easily measure changes in depth to within a cm.

It is quite true that one model might differ by a few degrees from another model in terms of global predicted temperature. But if they both predict a similar increase from 1.7 W/m^2 od CO2 IR, then that small increase can be significant.

Its like the difference between a simple t-test and a paired t-test.

67. tallbloke says:

Tim, Ok, it seems you are implicitly agreeing that the Trenberth style energy budget is useless, so that’s progress too.

It’s true that you can measure a change in the surface level of a lake without knowing the depth, very easily. However, more germane to this discussion is how impossible it is to measure a change in the ‘effective height of emission’ to space. This is what the back radiation argument ultimately relies on, because as you point out, we can’t accurately measure the energy flow in the troposphere or be sure about the flows crossing the air ocean interface. On top of that, the error term on measurement of Top of Atmosphere energy balance is around three times larger than the claimed co2 signal. On top of that there is no firm global data for changes in optical depth of the atmosphere to infer a change in the ‘effective height of emission either.

We’ve been here before when discussing this together onn WUWT, so I don’t need to labour the point further.

68. tchannon says:

Just as I hoped it was going to get interesting and time to say something.

Lets drop in a snippet http://www.noao.edu/staff/gillespie/projects/cloud-detector.html

69. tjfolkerts says:

No, the Trenberth-style diagrams are NOTuseless. They are very useful to get a general idea of the mechanisms involved, and it presenting estimates of the magnitudes. They are a great starting point for discussion of climate and possible warming, and for teaching beginners the basics.

If the discussion is going to get deeper that an introductory level, then people need to read the Trenberth paper to get the details of what was said. They need to read the papers about what is indeed known about TOA radiation to space (and you will have to forgive me if I don’t automatically believe your unreferenced claims about what is and is not known).

” … how impossible it is to measure a change in the ‘effective height of emission’ to space. “
More precisely, we want to know the “effective temperature” of the emitted radiaton at each wavelength. To get global surface warming, you would need global cooling at the TOA where CO2 is emitting IR to space. So the measurement that is needed is the effective temperature of the TOA CO2. Presumably cooler CO2 would be higher, but strictly speaking, no measurement of the actual height is needed — just a measurement of the temperature & IR energy.

70. RKS says:

This ‘backradiation’ nonsense is fun to play with as a mental exercise but, in order to take account of the emissivity and atmospheric density of CO2, if an area of the surface of the Earth is to be the heated radiating plate, the ‘backradiating’ CO2 must be represented by a hemisphere [ to allow for scattering ] with a surface area of approximately 0.0004 of the radiating surface area.

Lets get real, as my nurse once said, “what’s all the fuss over such a little thing?”

71. tjfolkerts says:

I shouldn’t even bother but …

“We can postulate that there will be natural maximum frequencies with which the electrons can vibrate between energy states.”

First of all, the energy states involved for thermal IR are vibrations and rotations of the MOLECULES as a whole, not electron energy states.

So if a molecule is vibrating with a particular energy in a particular state, what does it mean to “vibrate between energy states”? Do you mean that for a moment it is vibrating in one state, but a moment later it is vibrating in a different state with a different energy? But to oscillate between energy states, it would need to repeatedly gain energy and then lose energy.

“So radiation with a matching frequency can resonate with molecules in the target.”
Matching WHAT frequency? The frequency of the higher energy vibrational state? The lower energy vibrational state? The frequency that that molecule might be changing back and forth between energy states (which has not been defined).

“that energy will be just the right amount to excite an electron to a particular higher state, but not enough to go the extra distance required for any the radiated energy to be converted to thermal energy.”
What does this even mean? How much specific energy could a CO2 molecule absorb? How much extra energy would be needed to create some thermal energy? Can you calculate the “exta distance” you mention? How many meters is it?

And the excited vibrations ARE thermal energy. Giving the molecule extra vibrational energy is conceptually the same as giving a molecule extra speed. One of the degrees has extra energy. This energy is rapidly shared amoung molecules by collions until it is “thermalized”

“As this resonating process is taking place”
Again, what process? The molecule mysteriously changing from one vibrational state to another?

“a photon in the incident radiation excites an electron to a higher state, let’s say at the crest of the wave, and then immediately lets it relax back to its original state at the trough.”
Incident IR radiation excites MOLECULES to new vibrational states. But the photon is destroyed in the process. So there is no photon to “let it relax back”. The molecule can, of course, relax back to its original state by emitting a new photon in a random direction. But as stated before, this natural process typically takes ~ 1 second, which is definitely not “immediately”.

I could go on, but frankly none of it makes much sense! You are welcome to keep “postulating” impossible things, but don’t expect anyone who has actually studied and learned these topics to agree with you.

[Reply] Tim, you meant to post this to Doug Cotton’s thread. Please repost it there so I can remove it from here. Thanks – TB

72. tallbloke says:

Tim C: Excellent, an empirical result. I’ll post it.

Tim F: Trenberth’s energy budget diagram has wasted too much of everyone’s time. It should come with a health warning wherever it is printed, like Al Gore’s movie has to when shown in a UK school.

The 5W/m^2 error range on TOA balance appears in one of Trenberth’s own papers. He then goes on to tell us that it doesn’t matter because his theory can fill in the gaps. Lol. 🙂

we want to know the “effective temperature” of the emitted radiaton at each wavelength. To get global surface warming, you would need global cooling at the TOA where CO2 is emitting IR to space. So the measurement that is needed is the effective temperature of the TOA CO2. Presumably cooler CO2 would be higher, but strictly speaking, no measurement of the actual height is needed — just a measurement of the temperature & IR energy.

Good luck with that. Let us know when you have a proposal for how it can be done. 😉

73. Stephen Wilde says:

If 240 Wm2 is coming in at TOA we need less than 240 Wm2 going out for a period of time if the system is to rise to a higher equilibrium temperature.

If we are adding more CO2 to the system constantly then there should be a persistent outgoing of less than the incoming.

Is there ?