Tuesday, March 24, 2009

The Rabett is fisky

(As part of Rabett Run's Gerlich and Tscheuschner project, Eli has started drafting parts of a response, which we will gift wrap in Bozo paper and send to some unsuspecting journal, but certainly arXiv. We have spent a lot of time being serious, but for the introduction/conclusion all may enjoy a snark break. The Editorial Board expresses its thanks for your patience =:> . Some of this comes from previous posts, some from Georg Hoffmann on Prima Klima and some from somewhere. Suggestions for changes and additions are welcome.

UPDATE: Some changes to reflect Arthur's comments 3/25 11 PM EDT


Gerlich and Tscheuschner [1] have published a polemic in the International Journal of Modern Physics B, full of error, irrelevancy, and accusation. Long known from its arXiv versions and well refuted, it is difficult to understand how their work could appear in a respected journal, however, recent history has shown that such papers are occasionally published where editors and referees are not familiar with the underlying science, or themselves are outliers with respect to the field in which the paper lies. This is often the case where expertise in one area is generalized to arrogance about another. A refutation is needed lest anyone be mislead.

This comment will clearly demonstrate major errors in simple physics that Gerlich and Tscheuschner's make, invalidating their entire paper. Supplementary material deals with Gerlich and Tscheuschner's errors in detail. The first twenty or so pages of Ref. 1 are devoted to showing that the greenhouse effect has nothing in common with how a glass greenhouse works, a commonplace taught in and useful for every introductory atmospheric science course. A simple paragraph would have sufficed. Concisely, greenhouses work by restricting the outward flow of thermal energy by convection, the greenhouse effect limits the flow of thermal energy to space by radiation.

A careful, although painful, reading of the rest of the paper shows that there are only two physically based criticisms of the greenhouse effect in Ref. 1, embedded into a mass of opinion and commonplace knowledge badly stated

Gerlich and Tscheuschner assert that Clausius' statement of the second law of thermodynamics forbids transfer of heat from a colder atmosphere to a warmer surface. Their entire 90 page argument rests on this claim. As made clear below, the second law requires consideration of all heat flows in a process, so one must simultaneously include the larger transfer of thermal energy from the surface to the atmosphere. Ref. 1 does not do this and thus errs. When done properly, there is no contradiction

The fundamental equations of radiative transfer have the Second Law of Thermodynamics built into them, via Kirchoff's Law, which can be derived directly from the Second Law. When solved numerically the solutions perforce obey the 2nd law. This applies equally well to simple models, and to the most elaborate line-by-line calculations. All show that the presence of greenhouse gases in the atmosphere results in a warmer surface than in their absence.

Next, following Arthur Smith's criticism [2] of an earlier version of Ref. 1, we consider a non-uniform distribution of temperature on the surface of a planet. It is shown that when doing this, Gerlich and Tscheuschner obtain an absurd result by using a ridiculous assumption, that each part of the planet's surface immediately cools or heats to reach an equilibrium with the locally impinging solar radiation thereby neglecting the thermal inertia of the oceans, atmosphere and ground. Were this to be the case, all parts of the Earth would cool to well below 200 K (-73 C) at night. It is shown that a uniform surface temperature model provides a lower, but useful, bound on the greenhouse effect, the commonly quoted ~33 K.

These two points alone invalidate Gerlich and Tscheuschner's entire paper, and show that the radiative greenhouse effect does significantly increases the surface temperature of the Earth. Beyond this readers with basic understanding of physics and climate cannot help but be amused by the rich bounty of irrelevancies, silly errors, lack of understanding and significant omissions that Gerlich and Tscheuschner provide. Coupled with the authors' embarrassing false pride, the manuscript would pass from hand to hand labelled as a revenge of social scientists for Alan Sokol's joke, were it not for the demonstrated capacity of this paper to mislead the naive and those hungering to be mislead. It is only this that makes a reply necessary.

Section 2 below disposes of Ref. 1's arguments about the second law of thermodynamics, principally laid out in their Section 3.9. As a part of that, in Section 3, simple models are introduced and then used to demonstrate Gerlich and Tscheuschner's aphysical picture of heat flow on a rotating planet (Section 3.7).

Much of the rest of Ref. 1 is simply argumentative and irrelevant. A humorous example is the denigration of a simple net energy flow schematic for the earth because such diagrams (pp 322)

(1) cannot represent radiation intensities, the most natural interpretation of the arrows depicted in Fig. 23, as already explained in Secs. 2.1.2 and 2.1.5;

(2) cannot represent sourceless fluxes, i.e., a divergence free vector fields in three dimensions, since a vanishing three-dimensional divergence still allows that a portion of the field goes sidewards;

(3) do not fit in the framework of Feynman diagrams, which represent mathematical expressions clearly defined in quantum field theory.159

(4) do not fit in the standard language of system theory or system engineering.
It is legitimately hard to decide which of these four points is the most ridiculous. (1) and (2) might charitably be called querulous, demanding a full vector representation of all the heat/energy flows of a schematic representation. Gerlich and Tscheuschner might be pleased to know that the angular dependence of the heat flows is captured in radiative transfer and global circulation models (GCMs are commonly known today as global climate models, but originally were called global circulation models, and are built on fluid dynamics). GCMs solve the non-linear Navier-Stokes equation for fluid flow. Fig. 1 is not meant to be a GCM, but an illustration of the vertical thermal energy flow from the sun, the surface and in the atmosphere. Importantly, each of the energy flows has been linked back to experimentally measured global averages.

(3) and (4) are risible. Why should representations of a total thermal energy flow require a Feynman diagram? Worse, how would such a Feynman diagram be constructed. (4) is the engineering equivalent. Finally the authors might reconsider their standard representations of heat engine (Fig 31 and 32 in [1] and Fig. 3 below) which uses the same sort of arrows.

Less amusing are Gerlich and Tscheuschner's libelous attacks on others. Perhaps the most notable of these, is upon Stephan Bakan and Ehrhart Raschke for using Fig. 2.
Figure 13 is an obscene picture, since it is physically misleading. The obscenity will not remain in the eye of the beholder, if the latter takes a look at the obscure scaling factors already applied by Bakan and Raschke in an undocumented way in their paper on the so-called natural greenhouse effect.102 This is scientific misconduct as is the missing citation. Bakan and Raschke borrowed this figure from Ref. 103 where the scaling factors, which are of utmost importance for the whole discussion, are left unspecified. This is scientific misconduct as well
According to Gerlich and Tscheuschner, Bakan and Raschke's scientific misconduct was to scale the incoming solar and outgoing terrestrial radiation to the same size. Referring to Fig. 1, the outgoing terrestrial radiation at the top of the atmosphere is 239 W/m2 on average which is balanced by the amount of solar energy absorbed in the atmosphere and by the surface. With much hemming and hawing Ref. 1. arrives at about the same numbers. In other words, Bakan and Raschke took note of the observed energy balance to construct their figure. Gerlich and Tscheuschner are not only misleading, they are wrong on this point, and insulting to Bakan and Raschke.

We close the introduction by discussing a simple illustrative example that the two authors, trained physicists, Gerlich and Tscheuschner completely misunderstand. They discuss experiments carried out by a physics obsessed housewife
In Sec. 3.3.5, it was indicated how simple it is to falsify the atmospheric greenhouse hypotheses, namely by observing a water pot on the stove: Without water filled in, the bottom of the pot will soon become glowing red. However, with water filled in, the bottom of the pot will be substantially colder.

In particular, such an experiment can be performed on a glass-ceramic stove. The role of the Sun is played by the electrical heating coils or by infrared halogen lamps that are used as heating elements. Glass-ceramic has a very low heat conduction coefficient, but lets infrared radiation pass very well. The dihydrogen monoxide in the pot, which not only plays the role of the “greenhouse gas” but also realizes a very dense phase of such a magic substance, absorbs the infrared extremely well. Nevertheless, there is no additional “backwarming” effect of the bottom of the pot. In the opposite, the ground becomes colder.
This, of course, neglects the latent heat carried away from the pot and thus the heating element by evaporation of the water in the pot. Since it is well known that people who are physics obsessed are often forgetful, we postulate that the housewife forgets that she has put the pot on the range, and all the water boils away. At that point, when all the water has evaporated, measurements show that the heating element rises to a higher temperature than it was before the tea pot was placed on it.

Comments?

24 comments:

Arthur Smith said...

Hi Eli,

first you write that G&T say "the greenhouse effect has nothing in common with how a glass greenhouse works", and basically agree with that, but then you say "In both cases, the system heats in order to restore the balance between the inward and outward flow of energy"

-- which means, there *is* something in common. Which is why all the references G&T cite make the comparison in the first place.

I don't think you should even grant their claim that there's nothing in common; the analogy has faults like every analogy, but they both boil down to the same effect of limiting outward heat flow, resulting in increased surface temperature. Also, as I noted on the other thread, real greenhouses wouldn't do nearly as much good without atmospheric "back-radiation" anyway, so there's more in common than just the heat flow restriction issue. Like most of their arguments, the beginning premise is just off the wall here.

Second, on the global energy flow diagrams, they are more than "an illustration of the sources and sinks of thermal energy" - I believe every number in that figure actually has precise and in principle measurable value, determined by global averaging of vertical energy flow. Of course forgetting that the important things are global averages goes along with G&T's other misconception about instantaneous local radiative equilibrium.

chriscolose said...

We need to professionalize our langauge a bit, as hard as it may be in this case. Remove,

"A careful, although painful, reading of the rest of the paper"

"Coupled with the authors' embarrassing false pride...necessary."

And other random jabs.

Duae Quartunciae said...

I've been continuing my engagement on confusions arising from this paper at physicsforums.com, with the result that I have, I think, successfully conveyed some of the problems with the paper to a few people who were initially citing it as a disproof of the greenhouse effect.

My view on the analogy with a glass greenhouse...

The main process by which a glass greenhouse works is that it prevents hot air from rising out through the roof. Sunlight comes in, and heats up the floor, which in turn heats up the air above the floor. Now normally, hot air would rise up away from the floor, and cooler air from up higher in the atmosphere would be circulated back down again. It's why we have thermals and air circulation out in the open. But in the greenhouse, the hot air is trapped near the floor.

As for the atmospheric greenhouse effect, this is not the same as a glass greenhouse. What they have in common is that they both work by inhibiting movement of heat up from the surface. But they do it by very different processes. The atmospheric greenhouse works by blocking radiant heat flow from moving up into space. The glass greenhouse works by blocking convective heat from moving up into the atmosphere.

Georg said...

Eli
reserve a last paragraph for the Bakan/Raschke remark, some funny stuff and some slaps to the editor. I think in this paragraph it is justified to speculate that the paper didnt get a worthwhile review (slight understatement) and given that they made something like "Bakan/Raschke did scientific misconduct" to a peer-reviewed statement it is also justified to speculate that actually nobody from the journal read the paper.
Georg

EliRabett said...

Damn it Chris, can't a bunny have some fun.

More seriously, Eli has been thinking of taking the argument about the second law and sending it to the journal editors fairly soon.

Chris Colose said...

On the water pot example, it might help to remind the confused that a greenhouse gas is a gas, not a liquid.

Also, GCM's make use of primitive equations, which gets rid of viscosity term I believe. Can they "solve" Navier stokes? The atmosphere is thin vertically compared to horizonatally in order to approximate the vertical momentum balance with the hydrostatic balance.

Arthur said...

The "water pot" also provides a bit of an example of how heat flow works in the other direction.

That is, when full of water, the "water pot" has an additional large heat flow mechanism consisting of the latent heat of the water vapor created as the water boils off. As soon as all the water is gone, that upwards heat flow goes away, total heat flow shrinks, and the water pot heats up.

Yet another example of this simple principle. Might not hurt to bang on that same simple theme of the relationship between total heat flow and surface temperature over and over.

Belette said...

Further, back radiation from greenhouse gases warms the windows of the greenhouse. Without the greenhouse effect, greenhouses would rapidly cool. - this is wrong. You've read Woods: http://www.wmconnolley.org.uk/sci/wood_rw.1909.html

If you're going to wazz G+T on this you'd better get it absolutely right.

More trivially, work could appear in a respected journal, however, recent history is wrong: should be "work could appear in a respected journal; however recent history" I think. Or maybe a full stop.

Chris Colose said...

Indeed...I was going to say we definitely need grammar edits throughout this piece. I haven't said anything about that but we'll have to do it eventually

Arthur said...

Belette - I assume your point is that the warming from back-radiation is not of the "glass" of the greenhouse, but of the ground? The glass typically doesn't have much radiative blocking effect, I believe.

But the surrounding atmosphere, thanks to the standard greenhouse effect, greatly limits radiative cooling of the interior of a greenhouse. Without that limit on thermal energy transport, greenhouses would cool a lot faster (as would the ground outside the greenhouse as well, of course, just like the dark side of the Moon).

I think if the focus of the response is the general theme that things cool at a rate limited by all the different processes available for heat transport, then this is an interesting point. That is, the things keeping a greenhouse warm (limiting its cooling rate), are not only the removal of convective heat loss, but also the substantial reduction in radiative heat loss caused by the greenhouse effect (back-radiation) from the atmosphere.

Hank Roberts said...

> grammar edits

Raise the flag when ready, set aside a few days for those of us who may contribute at that point.

It's a chance for us to try every way to misunderstand the text.

Best way, if time allows, is to leave a few days for the exercise of naive reading, then for the real authors to take it from the top.

Often instead of nitpicking a word at a time you'll find writing around potential problems lets you cut the length and improve the readability.

Best extant guide to clear writing:
http://www.k-1.com/Orwell/pol.htm

EliRabett said...

Eli keeps the Aspidistra flying (tastes good if you are a bunny)

I think we are about one section away from putting the whole thing together. I'll probably gather it into a MS WORD file and put that out there where everyone can pick it up. Those who are religiously against MicroSoft can use Open Office.

Eli does not TEX. There are enough printers in the family.

I want to take a shot at all the irrelevant arguments and do some pruning

Of course, other contributions are always welcome.

FancyRat said...

G'day Eli, I think the sentences "Further, back radiation from greenhouse gases warms the windows of the greenhouse. Without the greenhouse effect, greenhouses would rapidly cool" are confusing, will be criticised as misleading, and should be removed.
Otherwise I like it.
Squeek.

Chris Colose said...

//"Further, back radiation from greenhouse gases warms the windows of the greenhouse. Without the greenhouse effect, greenhouses would rapidly cool."//

After considering this and Arthur's comments, I would toss this. It's kind of ridiculous, in fact.

The whole planet would be ice-covered without a greenhouse effect. Saying that "the insides of greenhouses" would also be colder is a very strange remark. They'd be colder if the sun didn't exist as well, but that's hardly the point, and can only lead to confusion.

bluegrue said...

About the water pot experiment, have you done it the way you described it here? "When all the water has evaporated"? In your Rabett stylin entry you only described the effect of inhibiting convection above the heater by placing a glassplate close above the heating plate. In the text above you seem to be making G&T's point: They claim the bottom of the pot is colder with the water inside, you describe how the heater is colder with the water above.

Actually, I had expected the heater to be hotter with water above, if only slightly so. You have heat transfer from the heater to the pot by convection of the air, absorbed IR and to a small bit heat diffusion via the test tubes (It was good for a makeshift set-up, but a better set-up could get rid of this). With water in the pot a lot of heat goes into latent heat and the pot is kept at 100°C. So backradiation comes from a source 100° hot and rather high emissivity. Once the water is gone you have a bit of backradiation from the hotter pot at low emissivity and backradiation from the room at ambient temperature. Therefore I would expect the heater to be cooler without water above, in contrast to your "the heating element rises to a higher temperature than it was before the tea pot was placed on it".

What am I missing?

EliRabett said...

The rate of heat loss (cooling effect) by evaporation at 100 C is MUCH higher than for any of the other mechanisms you mention.

Barton Paul Levenson said...

Definitely let us know when the final draft is up! I want to see it! And I hope it gets into a journal. It would be a sad comment on the state of things indeed if G&T could get into a peer-reviewed journal but Eli couldn't.

Anonymous said...

Sir,

Your contention that “Gerlich & Tscheuschner assert that Clausius' statement of the second law of thermodynamics forbids transfer of energy from a colder atmosphere to a warmer surface.” is wrong. In fact, Gerlich & Tscheuschner (on pages 77 and 78) state clearly that the second law applies to heat transfer and not to energy. On page 78, they criticize Rahmsdorf for making the very mistake that you falsely accuse them of having made.

You make a second error when you accuse Gerlich & Tscheuschner of having developed a model that obtains “an absurd result by using a ridiculous assumption”. What they actually did was to point out that the IPCC approach leads to the ridiculous result. Gerlich & Tscheuschner later pointed out that development of a radiation balance model would require solution of differential equations of such complexity that even numerical solutions would beyond existing computer capabilities.

I do not think that you read the Gerlich & Tscheuschner article as carefully as you should have.

guthrie said...

ANonmyous- you do realise that the IPCC models work reasonably well, given the known limitations? As opposed to the G&T which has no relation to reality...

As for heat transfer and energy, could you explain the difference between them to us?

EliRabett said...

Why thank you, Eli had thought it clear to the average dolt that we were talking about thermal energy, aka heat, but for sure there were a couple of places where that had slipped. The point remains, G&T are wrong. When you consider the total process, including the flow of heat in both directions between atmosphere and surface, the process is allowed by the second law, entropy increases and the greenhouse effect exists.

FWIW, the second law is not about heat alone old chum, it is about the possibilities of interconverting heat and work, two forms of energy and of moving thermal energy aka heat, from one place to another with the production or use of energy

Anonymous said...

Gerlich & Tscheuschner later pointed out that development of a radiation balance model would require solution of differential equations of such complexity that even numerical solutions would beyond existing computer capabilities."

Not true.

Even a very simple model yields a temperature for the earth that is in the right ball park.

If what G&T said were correct, that would simply not be the case.

Relatively simple energy balance models work with the earth because energy is distributed rather quickly in the climate system. In effect, the "bumps" (which would require solving complex equations) are smoothed out to a large degree.

The proof is in the pudding and in this case, the pudding ain't bad.

Flavius Collium said...

Maybe this is a good analogy of G&T science.
http://www.fairpoint.net/~sundog_rocks/fair_display.jpg

Philip Machanick said...

Back to bluegrue: absent latent heat losses, you would be right. Putting the pot on top of the stove would slow loss of heat to the atmosphere.

All this illustrates a rather basic point that an alleged physics professor at an apparently good university fails to understand: you can’t treat selected components of a bigger system as if they constitute a closed system.

His students should demand a refund.

EliRabett said...

The EPA put it a bit differently but it comes to the same thing:
-----------------
For example, as a disproof of the greenhouse effect, the paper by Gerlich and Tscheuschner presents the example of a pot of water, noting that the bottom of the pot will be cooler if it is filled with water than if it is empty. Contrary to the assertion in the paper, the primary thermal effect of adding water to the pot is not a reduction in heat transfer, but rather an increase of thermal mass. We assert that a more appropriate example for the paper to have examined would have been the addition of a lid to a pot of water, which reduces the rate of heat loss, and leads to an increase of heating of the water compared to a case with no lid.