A burrow project?
UPDATE: Part I on the second law of thermodynamics and its criminal misuse is now available above
Gerlich and T have managed to get their paper published in the International Journal of Modern Physics B, Vol. 23, No. 3 (30 January 2009), 275-364. For those of you who don't have access, pretty much the same thing can be found in arXiv. Eli was dreading wading through 90 pages, when it occurred to him that the fisking had already been done and something else was needed. As a young Physicist Rabett, the bunny had often read papers with two pages of authors, examples are not hard to find, and it is daunting just to look at the As in that one
T. Aaltonen,24 J. Adelman,14 T. Akimoto,56 M. G. Albrow,18 B. Álvarez González,12 S. Amerio,44b,44a D. Amidei,35 A. Anastassov,39 A. Annovi,20 J. Antos,15 G. Apollinari,18 A. Apresyan,49 T. Arisawa,58 A. Artikov,16 W. Ashmanskas,18 A. Attal,4 A. Aurisano,54 F. Azfar,43 P. Azzurri,47d,47aIt struck Eli that we need a group paper, from Rabett Labs, published, or at the least inserted into arXiv. One of about 15-20 pages, with supplementary materials as necessary. Not a fisking but a demolition, a scientific one. To start Eli wrote a bit over the top abstract
Gerlich and Tscheuschner have published a polemic, full of error, irrelevancy, fulmination and accusation, in the International Journal of Modern Physics B. Long known from its arXiv versions, and well refuted, it is difficult to understand how their paper could appear, 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 manuscript concentrates on the physical basis of their argument. Supplementary material deals with G&T in detail. The first forty or so pages of G&T are devoted to showing that the greenhouse effect has nothing in common with how a glass greenhouse works, a commonplace dealt with in every introductory atmospheric science course. A simple paragraph would have sufficed. Concisely, greenhouses work by restricting the outward flow of energy by convection, the greenhouse effect limits the flow of energy to space by radiation. In both cases, the system heats in order to restore the balance between the inward and outward flow of energy. etc for a bitLest you think this is really over the top G&Ts abstract is
The atmospheric greenhouse effect, an idea that many authors trace back to the traditional works of Fourier (1824), Tyndall (1861), and Arrhenius (1896), and which is still supported in global climatology, essentially describes a fictitious mechanism, in which a planetary atmosphere acts as a heat pump driven by an environment that is radiatively interacting with but radiatively equilibrated to the atmospheric system. According to the second law of thermodynamics, such a planetary machine can never exist. Nevertheless, in almost all texts of global climatology and in a widespread secondary literature, it is taken for granted that such a mechanism is real and stands on a firm scientific foundation. In this paper, the popular conjecture is analyzed and the underlying physical principles are clarified. By showing that (a) there are no common physical laws between the warming phenomenon in glass houses and the fictitious atmospheric greenhouse effects, (b) there are no calculations to determine an average surface temperature of a planet, (c) the frequently mentioned difference of 33◦ is a meaningless number calculated wrongly, (d) the formulas of cavity radiation are used inappropriately, (e) the assumption of a radiative balance is unphysical, (f) thermal conductivity and friction must not be set to zero, the atmospheric greenhouse conjecture is falsified.Well, G&T is a good laugh. To get you started, here are G&Ts conclusions and our targets
(1) There are no common physical laws between the warming phenomenon in glass houses and the fictitious atmospheric greenhouse effect, which explains the relevant physical phenomena. The terms “greenhouse effect” and “greenhouse gases” are deliberate misnomers.and some previous research:
(2) There are no calculations to determinate an average surface temperature of a planet
(a) with or without an atmosphere,
(b) with or without rotation,
(c) with or without infrared light absorbing gases. The frequently mentioned difference of 33◦C for the fictitious greenhouse effect of the atmosphere is therefore a meaningless number.
(3) Any radiation balance for the average radiant flux is completely irrelevant for the determination of the ground level air temperatures and thus for the average value as well.
(4) Average temperature values cannot be identified with the fourth root of average values of the absolute temperature’s fourth power.
(5) Radiation and heat flows do not determine the temperature distributions and their average values.
(6) Re-emission is not reflection and can, in no way, heat up the ground-level air against the actual heat flow without mechanical work.
(7) The temperature rises in the climate model computations are made plausible by a perpetuum mobile of the second kind. This is possible by setting the thermal conductivity in the atmospheric models to zero, an unphysical assumption. It would be no longer a perpetuum mobile of the second kind, if the “average” fictitious radiation balance, which has no physical justification anyway, was given up.
(8) After Schack (1972), water vapor is responsible for most of the absorption of the infrared radiation in the Earth’s atmosphere. The wavelength of the part of radiation, which is absorbed by carbon dioxide is only a small part of the full infrared spectrum and does not change considerably by raising its partial pressure.
(9) Infrared absorption does not imply “backwarming.” Rather, it may lead to a drop of the temperature of the illuminated surface.
(10) In radiation transport models with the assumption of local thermal equilibrium, it is assumed that the absorbed radiation is transformed into the thermal movement of all gas molecules. There is no increased selective re-emission of infrared radiation at the low temperatures of the Earth’s atmosphere.
(11) In climate models, planetary or astrophysical mechanisms are not accounted for properly. The time dependency of the gravity acceleration by the Moon and the Sun (high tide and low tide) and the local geographic situation, which is important for the local climate, cannot be taken into account.
(12) Detection and attribution studies, predictions from computer models in chaotic systems, and the concept of scenario analysis lie outside the framework of exact sciences, in particular, theoretical physics.
(13) The choice of an appropriate discretization method and the definition of appropriate dynamical constraints (flux control) having become a part of computer modeling is nothing but another form of data curve fitting. The mathematical physicist v. Neumann once said to his young collaborators: “If you allow me four free parameters I can build a mathematical model that describes exactly everything that an elephant can do. If you allow me a fifth free parameter, the model I build will forecast that the elephant will fly.” (cf. Ref. 185.)
(14) Higher derivative operators (e.g., the Laplacian) can never be represented on grids with wide meshes. Therefore, a description of heat conduction in global computer models is impossible. The heat conduction equation is not and cannot properly be represented on grids with wide meshes.
(15) Computer models of higher dimensional chaotic systems, best described by nonlinear partial differential equations (i.e., Navier–Stokes equations), fundamentally differ from calculations where perturbation theory is applicable andsuccessive improvements of the predictions — by raising the computing power — are possible. At best, these computer models may be regarded as a heuristic game.
(16) Climatology misinterprets unpredictability of chaos known as butterfly phenomenon as another threat to the health of the Earth.
Jochen Ebel has posted the most complete refutation, line by line, in German
Arthur Smith has destroyed G&Ts argument about average temperature in arXiv
Much stuff in Rabett Run, here and here and here and here and here
Atmoz (sorely missed)
UK Weather World
Real Climate, where gavin said
It’s garbage. A ragbag of irrelevant physics strung together incoherently. For instance, apparently energy balance diagrams are wrong because they don’t look like Feynman diagrams and GCMs are wrong because they don’t solve Maxwell’s equations. Not even the most hardened contrarians are pushing this one…. - gavinHe missed on that last one.
Eli wants arguments with references, experimental data and theoretical calculations.
You too can be a published author.
Posts
69 comments:
Well, to his credit, Steve McIntyre wouldn't host discussion of it. I wondered cynically whether, if you have a ms around long enough, there is eventually going to be an editor somewhere who finds a sudden desperate need to fill a 90-page gap for an issue.
Thanks Nick, I was not aware of that.
From International Journal of Modern Physics B home page:
"To ensure top quality, review articles are by invitation only and all research papers undergo stringent refereeing."
http://www.worldscinet.com/ijmpb/mkt/aims_scope.shtml
That makes it seem like G&T wasn't peer-reviewed at all.
What's the story with Atmoz, being sorely missed?
I've missed his blog, too ...
I hope his being missing is voluntary but fear the worst.
"That makes it seem like G&T wasn't peer-reviewed at all."
My understanding is that this is true.
My attempt at fisking here:
http://taavi.livejournal.com/102444.html#cutid1
James
Well, perhaps letters/e-mails to some or all of these editors of IJMPB (especially the "in-Chiefs", listed below) should be sent asking how such nonsense could be allowed in their journal.
IJMPB Editors-in-Chief:
W Schommers
Forschungszentrum Karlsruhe
Institute for Scientific Computing
D-76021 Karlsruhe, Germany
Telephone: +49-7247-82-2432
Email: wolfram.schommers@iwr.fzk.de
Wang Yu Peng
Institute of Physics
Chinese Academy of Sciences
P O Box 603
Beijing 100190
People's Republic of China
Email: yupeng@aphy.iphy.ac.cn
Fa Yueh Wu
Matthews Distinguished Professor of Physics
Northeastern University
Boston, Massachusetts 02115
USA
Email: fywu@neu.edu
Cymraeg llygoden
This gets publishing and my neo-feminist deconstruction of The Smurfs ("Blue Balls: Animated Phallocracy and the Rise of Diminutive Sexualization in Pre-Viagra America") gets multiple rejections?!? Unfair!
The fact that it is 90 pages says it all.
Surely, a physical theory that is as "wrong" as G&T say the atmospheric greenhouse theory is would not require anything close to 90 pages to "demolish".
It's as if they are unsure themselves, so they are grasping for something that might stick.
They seem to have thrown in everything, including the kitchen sink.
"Eli wants arguments with references, experimental data and theoretical calculations."
Forgive me but that's a little like saying you want calculations and data to refute some crackpot claim that relativity is wrong or that plate techtonics is wrong.
No matter how many crackpot claims you refute, someone will always come along with another crackpot claim.
After all, the crackpot pot is cracked and filled to overflowing.
Re Anon 5:25
Ah, but it's a (presumably invited) review paper. 90 pp. can be small beer. I've waded through review papers in Coord Chem Rev on the order of 200 pp.
Of course, the latter invariably had more of relevance to relate, even to those to whom coordination chemistry was of little academic interest.
Cymraeg llygoden
Boris, have you thought about submitting to the International Journal of Inactivism as Eli recalls from his teenbunny days it would seem to fit your paper on "Blue Balls"?
(OK, cut it out, this is a family blog)
This discussion on Open Mind is relevant -- look especially for my comments and those of Ray Ladbury:
http://tamino.wordpress.com/2009/03/07/open-thread-11/
In addition, I address the saturation argument and the 2LOT argument quantitatively here:
http://www.geocities.com/bpl1960/Saturation.html
http://www.geocities.com/bpl1960/JJandJ.html
-BPL
True, but although the crackpot is full, Eli needs to pad his CV
Speaking of cracked pots.
Where's Lubos been since Harvard gave him the boot?
Sorry, let me rephrase that "Where's Lubos been since Harvard asked him to give himself the boot?"
(No one ever "quits" Harvard of their own volition. Especially not physics )
Tell me if this is wrong. I may be applying 2LOT incorrectly.
1-square-meter area plates A and B radiate to one another from 10 meters apart. Both have insulated backs and sides. Both have absorptivity = emissivity = 1 on the facing sides. A is at 200 K, B is at 300 K. A radiates 90.7 watts, B radiates 459.3 watts.
A picks up 4.6 watts from B, and B picks up 0.9 watts from A. We can assume their stable temperatures are provided by an outside source of say, induced electrical resistance, amounting to 86.1 watts for A and 458.4 watts for B.
In the absence of the radiation from A, the hotter B would be at a temperature of 299.85 K, 0.15 K cooler than it actually is, so radiation from the cooler A is warming B by 0.15 K.
In the interacting system, entropy per second for A is 0.0045 Joules per Kelvin, and entropy per second for B is 0.0153 J/K. Defining increasing entropy as flowing from B to A, net entropy is 0.0108 J/K positive and there is no violation of the second law of thermodynamics.
Can I define entropy with a direction as I did? What's the proper way to calculate the overall entropy of this system?
Maybe Rabett Labs or someone else could do a real "pot" experiment.
Equipment:
Electric constant power heater.
Two thermocouples or thermometers. A blanket, maybe black foil or something like that.
You should do this in a vacuum to be closer to the Earth situation, but it's harder that way.
Also it would be nice to be able to keep the vacuum flask's surface at a constant temperature.
First keep the heater on until it reaches a steady temperature state. Say, this is temperature T_X1.
Now, put the blanket around the heater. Measure the new steady temperature, both of the heater and the blanket. Call these T_X2 and T_Y.
Now, according to G&T interpretation of the second law (I haven't read the latest, but if it's still the same as it was much earlier), if T_Y is smaller than T_X2, no energy flow at all* can occur from the blanket to the heater.
Be it convection, conduction or radiation. Hence the blanket should not be able to affect the amount of energy at the heater, and T_X1 and T_X2 should be similar.
Now, this is the hypothesis and the test can be done.
*: be especially careful here, as they are not talking about net energy flow, but any energy flow.
Yes, we all know that G&T have proved that space blankets do not work.
What about all those times I have used them on winter back-country camping trips to "keep warm"?
Placebo effect.
While you're at it, bunnies, Dr. Brian G. Valentine, PhD, PE (chem. eng.) of the Heartland Snake Oil Medicine Show is in bad need of a harecut over at the WaPo.
The serious point in all this is not so much to debunk this particular paper, much as that will be fun for those inclined, as to improve science.
Journals (& newsletters) have reputations of various sorts, ranging from {Science, Nature, etc} to Energy&Environment, Quadrant, etc.
Journals that care about their reputations and ought to know better, need to think about the sort of things they publish, and how. Sometimes they may need others to help them understand that they goofed. Then it's up to them to take action (or not, which tells one something).
Hence, the first action indeed (as Cym... suggests) might be polite comments to the editors, or finding somebody who knows them.
Once upon a time, it probably made sense for organizations to publish low-overhead, non-peer-reviewed papers in newsletters, with responses as letters or further papers. That's what there was.
It makes absolutely *no* sense in the Web era for serious organizations to take the effort to:
a) Publish long technical-looking articles far outside the editors' expertise.
b) Without any serious peer review or even relevant editorial board review.
c) On journal-style cycles.
If organizations want to support low-overhead style interactions, (and they are important) the mechanism above is anachronistic.
I'd much rather have a subsidiary moderated blog site, into which editors could easily stick such articles if they chose, and accumulate comments right there as immediate feedback.
Of course, publications that waste 90 pages on junk, and don't learn from it, will irretrievably damage their reputations or will go away. Hence, I hope someone with connections to these folks gives them useful advice.
Of course, the people waving the G&T article that denies the concept of global average temps are the same ones arguing that global average temps haven't risen in the last decade. Irony, is not dead.
why are we so mean?
Why don't we give scientists like G&T the respect their positions merit?
Well, start with "deliberate misnomer."
Okay, you FRAUDS, you CRACKPOTS. Do you know, even, how long that deliberate misnomer has been around?
Hint: If it was a deliberate misnomer as an AGW ploy, then we already plot so far ahead you'll never beat us anyway. We make generational plans.
Also, do G&T imagine we, ourselves, haven't explained to people till we're blue in the face that it's not only not a greenhouse, but not as simple as this layer of CO2 somewhere up there in the sky that lets light through and traps heat?
furthermore, if you could create a structure that had ... i dunno, a force field or something with itself not trapping infrared, that trapped gases and they absorbed energy and then reradiated it in a spherical fashion so half of it was roughly going back down into the non-misnomered THING and it kept the plants warm, wouldn't someone say, someone not in the climate science world at all, that it had a greenhouse EFFECT?
There's an old russian saying, whether you whack the pole with the owl or the owl with the pole, the owl is still dead.
BPL,
There's an analysis of a similar entropy problem on this thread.
CC, Valentine appears to be ramping up to a full Gish Gallop, e.g.:
"Patterns of evidence: The asymmetric heating of the Earth that occurred over the period 1985-1998 say was the result of a number of influences I believe. Arctic ice loss could certainly be attributed to slower North Atlantic currents arising from the MOC; extended heating of slower Arctic Ocean currents occurring in summer; the MOC influenced by the extraordinary El Nino event of 1987 et seq. 1995. Subsea volcanism off the coast of Greenland may or may not have been a factor; another factor was almost certainly a notation of the Earth’s rotation about the polar axis, arising from the crustal movement precipitating in the earthquake in the South Indian Ocean in 2005; the nutation identified by the resolution of a Northern component of rotation angles measured with a rotating Earth over the stated time period (B Valentine, paper subm to Geophys Res Lett)"
Yikes. To borrow Al Gore's phrase, every bit of that is wrong, but refuting it in a debate format couldn't be done quickly enough even with all the facts at one's fingertips.
Challenged, BV expanded on that last point:
"The earthquake that led to the terrible Tsunami in the Indian Ocean was a collosal event; an event of that magnitude must have been preceded by crustal shifts that resulted in the immense stresses released by the earthquake, and as I stated I have resolved a slight nutation that has a resultant North, meaning the northern hemisphere was slighly biased toward the Sun during a period of some years"
I was interested enough to look this up. A quick google finds that some NASA scientists beat him to it, the difference being that they don't think it means much. Amusingly the effect isn't the impressive-sounding nutation at all (as a matter of definition, so no amount of calculation saves him from this boo-boo), but rather just plain polar motion. Note that the observed nutation (a lunar effect) is much larger than the polar motion from the earthquake, so a question he would have to answer is why there is no apparent cycle in temperature from the former.
Yeah, the guy's a regular Galileo.
G&T: "Re-emission is not reflection and can, in no way, heat up the ground-level air against the actual heat flow without mechanical work."
G&T have obviously never read Richard Feynman's little book QED or they would know that "reflection" does involve (brief) absorption and "re-emission".
sorry to burst their bubble, but "reflection' of light ain't just billiard balls (photons) bouncing off a hard surface (molecules or atoms).
Point out to the editors that they need to retract the paper.
As a physicist, I have been trying to come up with a simple explanation as to why their heat pump / 2nd Law of thermodynamics argument is wrong.
I think the simplest statement that I can come up with is this: G&T assume that because the earth's surface is warmer with an IR-absorbing atmosphere than without it that this means that there is a net flow of heat from the atmosphere to the surface in violation of the 2nd law. However, this assumption about the NET flow is clearly wrong: In the comparison case of no IR-absorbing atmosphere, all of the heat that the earth's surface radiates by the Stefan-Boltzmann Law is lost to space. So, it is not necessary (and in fact is not the case) that the NET flow of heat be from the atmosphere to the earth in order to cause a greenhouse effect. Rather, such an effect occurs even if the heat flow from the atmosphere to the earth is only a small fraction of the heat that the earth radiates to the atmosphere.
One can actually come up with problems simple enough to be given to a first-year physics class studying radiative heat transfer for which you can solve for the temperatures and heat flows of the bodies involved exactly and demonstrate this.
Joel
FWIW Eli has it on reasonable authority (bet the house on it) that G&T was refereed.
Which raises other issues.
Eli --- Oh. My. God.
By the way, here is the e-mail that I just fired off to all 3 chief editors:
Dear Editors:
As a physicist, I am shocked and embarrassed that the International Journal of Modern Physics B has published the paper by Gerlich and Tscheuschner entitled "FALSIFICATION OF THE ATMOSPHERIC CO2 GREENHOUSE EFFECTS WITHIN THE FRAME OF PHYSICS". This paper of nothing but pseudoscientific nonsense and when it appeared on the arXiv preprint archive, it was rightfully torn to pieces by many serious scientists across the internet.
Some of this paper's major claims were shown to be false by Arthur Smith (http://arxiv.org/abs/0802.4324). Its claim that the greenhouse effect posits what is essentially a heat pump and violates the 2nd law of thermodynamics is just silly and can be demonstrated to be false with an exactly-solvable radiative transfer problem easy enough to be given to first-year physics students! (The basic point is that with the greenhouse effect the net heat flows in the system are still from the warmer surface to the cooler atmosphere. The reason this leads to the earth's surface being warmer than in the absence of an IR-absorbing atmosphere is simply that the comparison case is a situation where NONE of the heat radiated by the earth according to the Stefan-Boltzmann equation finds its way back to the earth's surface. Hence, it is NOT necessary...and in fact is not the case...that the net heat flow be from the atmosphere to the earth in order to cause a greenhouse effect.)
On the other hand, its argument that the greenhouse effect is somewhat of a misnomer because greenhouses operate by a different mechanism is correct but very belabored especially since it is so well-known that it appears in many popular explanations of the greenhouse effect (see, e.g., the section "Real Greenhouses" here: http://en.wikipedia.org/wiki/Greenhouse_effect). The Gerlich and Tscheuschner article could perhaps best be summarized by the statement, "What is correct is not original and what is original is not correct."
I understand that no peer-review process is perfect and that incorrect papers will get published. However, it puzzles me that a paper that is such a collection of gibberish and nonsense would actually make it through your editorial process. Could you please provide an explanation of how your editorial process has broken down so completely that a paper such as this was accepted as a review article in your journal and how you plan to rectify this and prevent such a future occurrence?
Nick's pointer to pliny's comment is the place to start, but yes, G&T ARE claiming that it is not the net heat flow that counts but the fact that ANY heat flows from the colder to the hotter body.
As Eli pointed out elsewhere, this reduces to the following stupidity. Take pliny's discs, one at T1 and the other at T2. If you place them by themselves in space each will emit thermal radiation in all directions from the front and back (anyone want to play??). If you place them opposite each other G&T are claiming that somehow radiation from the colder one is majically turned off.
Intelligent thermal radiation or nonsense. Eli reports, the bunnies decide.
In one sense dealing with their fantasies is amusing, in another boring and in a third distressing.
Let me get this straight -- I've spent a long stretch out of the lab and in courtrooms and legislatures and classrooms: These guys say greenhouses don't work.
Isn't that it?
Damn. Don't tell the roses or the tomatoes. They won't grow if they know.
on the second law question - I think the source of their problem is fundamentally one of confusion about system state and boundaries.
That is, for a fixed system of surface, atmosphere, sun, space, etc., the increases in entropy as energy flows through the system are simple and clear, and the net flows are always from hotter to colder objects, as they must be.
But when we talk about greenhouse gases "warming" the surface, we are talking about the effects of *changing the system*. In this new (steady-state) system the stratosphere is colder and the surface warmer; the change is to a constituent of the atmosphere but the phrasing "warm the surface" simply does not mean that net heat is flowing from the middle atmosphere to the surface in this case. The net heat flow is still from the hot sun through the system to the cold of space, the problem is that this is a *different system* than the previous one with less GHG's.
But of course this isn't about physics, we're delving into the mental state of G&T to try to understand why they could think the second law applies in the way the claim here. So I could be completely wrong about whether this explains their erroneous argument or not - the validity of that explanation of course has nothing to do with the complete invalidity of that argument.
Nick,
Thanks for the link.
Okay, so the proper way to continue my example is:
A body gains entropy when it receives energy. It loses entropy when it emits energy. For a body at a given temperature, entropy is:
S = Q / T
where S is entropy (in Joules per Kelvin in the SI), Q the amount of heat involved (J), and T the absolute temperature (K). So considering the total input and output of each body, there is no net energy change, and thus no net entropy change, and the second law is not violated.
Considering the radiation alone:
A receives 4.6 / 200 or 0.023 J/K in one second, and loses 90.7 / 200 or 0.4535 J/K.
B gains 0.9 / 300 or 0.003 J/K and loses 459.3 / 300 or 1.531 J/K.
A loses a net 0.4305 J/K and B loses a net 1.528 J/K. Total loss: 3.059 J/K. Entropy has decreased and the second law is violated.
What did I do wrong here? Do I have the signs backward?
Sorry, that should have been 1.9615, of course. I added up the wrong two numbers at the end.
Still violates 2LOT.
Aaarrgh! 1.9585!
0.4305 + 1.531 = 1.9585.
Oh, man, I can't do elementary arithmetic -- what hope do I have of ever understanding thermodynamics? I abase myself.
I get 0.4305 + 1.531 = 1.9615.
How did you get 1.9585?
Berbalang
Arthur,
I agree with you completely. Indeed, their notion that because the greenhouse effect warms the surface means there must be a net heat flow from the atmosphere to the surface seems to be exactly their error (or perhaps their purposeful deception?). And, like you say, the reason why this assumption is wrong is because they are confused on the issue of "warming" relative to what. A warming relative to a system without such an IR-absorbing atmosphere can occur even when the net heat flow is from the surface to the atmosphere.
BPL,
I think where you're going wrong is that much of the emission from both plates is unaccounted for (entropy-wise). That would be picked up by some other surface, where it would show up as entropy gain. Or it would go into space. Radiation that goes out of the system does show up as entropy loss - this is discussed in Eli's next post.
You request "arguments with references, experimental data and theoretical calculations". Here is an specific argument, which I have also published on http://www.physicsforums.com/showpost.php?p=2127073&postcount=7 writing as "sylas".
From the arxiv preprint, top of page 65, we read:
According to the consensus among global climatologists one takes the -18C computed from the T^4 average and compares it to the fictitious Earth's average temperature of +15C. The difference of 33C is attributed to the natural greenhouse effect. As seen in Equation (83) a correct averaging yields a temperature of -129C. Evidently, something must be fundamentally wrong here.
What the authors describe as the "correct" calculation is bizarre. It comes from section 3.7.4.
First, they consider the energy per unit area for each part of the globe coming from the Sun. This is done correctly. Hence the portion of the Earth which is directly facing the Sun is given a full solar constant. Higher latitudes have this scaled by the cosine. The back of the globe (night) has no radiation at all.
They compute the solar constant as σ.5780^4/215^2, which comes to 1369 W/m^2; about correct. They use a factor of 0.7 for ε (table 12 on page 64) which corresponds to the effect of albedo. Hence the incoming solar radiation is treated as 958.4 W/m^2 for a plane surface facing the Sun; a reasonable figure.
They then contrast two ways to proceed. One way is to integrate the incoming energy of the surface of the globe, and then calculate a temperature which can be given to the whole globe that would radiate out that same amount of energy again. Another way to proceed is to take each point on the globe individually as having the temperature to radiate away what it receives from the Sun at that point; and then average this over the whole globe. They call this second method the "correct" method. Their so-called correct method gives a temperature of 0K absolute to the night of the planet, and a temperature of about 360K, or 87C, to the point on the globe facing the Sun.
The authors' so-called "correct" calculation is indeed calculating an average temperature, obtained by integrating an imputed temperature over the whole globe. This integration over the surface gives a value of about 144K, or -129C for the average temperature imputed to the simple model of a globe.
The feature of this imputed temperature is that it is just what is required to radiate (as a blackbody) the radiation coming from the Sun at every point. Now this is of course not a physical model of the Earth. Points on a planet do not instantaneously achieve thermodynamic equilibrium with the Sun's incoming radiation; even the Moon, with no atmosphere and very little heat transport across the surface, does not instantly reach absolute zero on the night side! The calculation provided by the authors can be sensibly understood as a lower bound on average temperatures; assuming radiative balance with the Sun. With any sharing of heat energy around the globe, while maintaining energy balance with the Sun, will give a higher average temperature. (You can show this with Holder's inequality, also used by the authors on page 65).
Now the other extreme model is to calculate a temperature such that if every point on the globe has that same temperature, then the globe remains in energy balance. This is the calculation that the authors disparage as "incorrect". Here, you calculate the average amount of energy radiated per unit area, and find the temperature this corresponds to. This is also called the "effective" temperature. It is equal to 1.25*2^0.5 (1.768) times the authors' "physical" temperature. (Compare equations 81 and 83). This works out to about 255K, or -18C. You can see the numbers -129C and -18C compared in table 12.
The proper implication of these numbers is that if you integrate temperatures over the surface of a globe which is radiating away the same energy it receives from the Sun, you'll get a value more than -129C and less than -18C.
Of course, if you integrate over the Earth's surface in reality, you get a number that is substantially more than -18C! It really doesn't matter whether you integrate temperature, or the fourth power of temperature. Whichever is chosen, you'll get an average of more than -18. That is… the Earth's surface is radiating more than what is required to balance solar radiation. But this IS the effect called "atmospheric greenhouse"!
Physically, this is because we have an atmosphere, which is heated from the surface. The atmosphere is (by thermodynamics) cooler than the surface, and the radiation that escapes into space is mostly from this cooler atmosphere. This is (by the first law) in long-term balance with solar radiation. The atmosphere radiates in all directions, of course. It radiates out into space, and also down to the surface; and this means the surface gets more energy. There's the solar energy (most of which passes through the atmosphere just fine) plus also the energy radiated from the atmosphere. The surface is in balance with this total… which is more than what you'd have without an atmosphere. This is what is called the atmospheric greenhouse… a poor choice of terms given that the physics is quite distinct from a glass greenhouse; but it is certainly physically real.
At the end of section 3.7.6, page 66, the authors make two claims. The speaks of a physically incorrect assumption of radiative balance. That's ludicrous. By the first law, there is necessarily a long term balance between the energy arriving from the Sun and being radiated from the planet. It is a physically correct implication that the Earth radiates an amount of energy into space that is equivalent to that of a blackbody uniformly at -18C.
The second claim speaks of effective radiating temperature being higher than measured averages. That is correct, and the authors are the ones who do not take this into account. The measured averages over the surface of the Earth are much more than -18C. Therefore the surface is radiating more than what you would get from a globe at -18C! Therefore the energy being radiated from the Earth's surface is MORE than the energy you get from the Sun. That IS the greenhouse effect, right there.
This text could no doubt be tightened up. You are welcome to use it, and to edit particularly for more brevity. If you want to credit me, you can list me as "Chris Ho-Stuart", my real name.
Duae (Chris) - your analysis is a more verbal version of what I did in the arXiv paper Eli referenced. It's a good point that the two temperatures are the upper and lower bounds of the non-greenhouse planet, which I don't think I explicitly stated.
But the whole G&T paper is replete with logical incoherence of this sort; I also thought this was the most scientifically addressable claim in the paper, but it doesn't make much more sense than most of their other arguments.
Thanks, Arthur. I must confess, I did not read right through your arXiv paper. But I did note people mentioning the equations, and so I went to look carefully at that part of the Gerlich et al paper. It's no surprise then that we've ended up doing the same thing!
Sorry for the redundancy. I'll make a note in the physicsforum that you've got a more thorough mathematical analysis of this point available!
Your paper will be the better basis for explaining this point. But if some of the more "verbal" stuff is at all useful (and it might be for a wider readership, especially if cleaned up) you are still welcome to use -- or not use -- as you consider best!
Arthur and Duae, could you work together to produce a statement combining your stuff. I would aim at something accessible to an educated layman in the first part and then perhaps something more technical with links to Arthur's paper in arXiv.
I think we pretty much have G&Ts 3.7 and 3.9 handled. We could ask Spencer Weart for something on 3.8, the historical summary, and I am working on demolishing their table top "experiments" 3.5. I'll also do a figure for Joel's argument.
I hope this is okay; but I'll use this thread to supply a suggested statement this is meant to be an understandable "verbal" account. But I have included some data from the Moon, which I found interesting to work through.
On page 65 of their paper, Gerlich and Tscheuschner contrast two methods of calculating a temperature for a hypothetical planet, which they call T_eff and T_phys.
The basis for both numbers is a consideration of solar energy reaching the globe of the planet. This is described in section 3.7.4. They use a value of σ.5780^4/215^2 W/m^2 for the solar constant at Earth's orbit, which is the blackbody energy for the Sun's surface, scaled for the distance to the Earth. This works out to 1369 W/m^2.
1. Temperatures for a globe exposed to solar radiation.
Gerlich and Tscheuschner consider the amount of energy reaching each point of the Earth's sphere. This is zero on the night side, and on the day side it is scaled by a cosine to account for the angle at which light reaches different regions. The energy is also scaled by 0.7, to account for the amount of energy is reflected away rather than absorbed. (The Earth has an albedo of about 0.3.)
T_eff is the temperature you must to give to every point on the globe in order to radiate all this energy away again as a blackbody.
The method Gerlich and Tscheuschner prefer is to assume every point on the globe is in equilibrium with the local solar radiation at that point. This corresponds to a planet with no rotation, and with no heat transport over the surface, and uniform albedo. They then take an average of the temperature for this hypothetical and unphysical planet; ironically calling it the physical average temperature.
These two values correspond to the two extremes of having uniform temperatures over the globe, and having temperatures at each point depending only on the instantaneous solar input.
Comparing equations 81 and 83, it can be seen that T_eff = 1.25*sqrt(2)*T_phys = ((1-α)S/4/σ)^0.25, where S is the solar constant (1369) and α is the albedo (0.3). Plugging in the numbers, we get T_phys = 144K (-129C) and T_eff = 255K (-18C). These values are shown by Gerlich and Tscheuschner in their table 12.
In practice, of course, the distribution of temperature over a planet will be between these two extremes. If the conventional average temperature is taken by integrating real temperatures over the globe, the value T_mean should be between T_phys and T_eff.
From the first law, the energy emitted has to be the same, no matter how temperatures are distributed. It follows that the fourth power of temperature, integrated over the globe, should be an invariant, since this is proportional to energy. This is why T_eff is a more useful quantity in practice than T_phys. In any case, we should have T_phys < T_mean < T_eff. The more uniformly distributed temperatures are over the globe, the higher the value of T_mean.
2. The effect of an atmosphere
These values can only be associated with the surface if there is no atmosphere, and no greenhouse effect, so that the surface radiation is equal to the planet's radiation. If there is an atmosphere that absorbs surface radiation, then this atmosphere will be heated from the surface, and will be cooler than the surface. Most of the radiation escaping to space will be emitted from the atmosphere, and this is what must match solar input. The surface must be warmer than the atmosphere, by the second law, because the surface is heating the atmosphere.
That is, T_mean corresponds to somewhere in the upper atmosphere where most of the energy escapes into space, and the average surface temperature T_surf must be something warmer than this.
In practice, when you integrate temperatures over the surface of the Earth, you get about 15C. This is indeed much greater than the -18C of T_eff, and this is called the greenhouse effect; the difference between surface temperatures below the atmosphere, and the effective temperature for radiation escaping into space.
Gerlich and Tscheuschner show how to integrate temperatures over the globe's surface, and they correctly note that the value obtained by such integration should be less than T_eff to balance the solar input. They completely fail to note that if you actually DO integrate over the surface, you get a value substantially greater than T_eff. The reason for this difference is the greenhouse effect.
This is a bit like having a blanket on a cold night. You end up warmer than you would be without a blanket, but not because the blanket is a source of energy to heat you up. In fact, you are the source of energy heating the blanket, and this means you have to be warmer than the blanket.
Gerlich and Tscheuschner make this elementary mistake in their section 3.9, when they describe the greenhouse as a violation of the second law. In fact, the second law is what requires the surface of a planet to have a higher temperature when there is an atmosphere that is being heated from the surface.
3. The example of the Moon
The Moon is a good example to contrast with the Earth. It rotates much more slowly, and therefore has a temperature distribution that approaches what is used by Gerlich and Tscheuschner to derive their "T_phys". Each point on the Moon's surface is tolerably close to radiative balance with the solar input at that point.
The Moon has an albedo of about 0.12. It therefore absorbs more of the incoming solar energy than Earth. Using the solar constant of 1369 W/m^2, the absorbed radiation for the surface facing the Sun is about 1205 W/m^2. Hence T_eff for the Moon is (1205/4/σ)^0.25 = 270K, or -3C. This is the temperature that would radiate back the solar energy, if evenly distributed over the moon. But directly facing the Sun, the temperature will be more like (1205/σ)^0.25 = 382K, or 109C. Albedo is not uniform. In any particularly dark patches, the temperature could even get up to (1369/σ)^0.25 = 394K, or 121C. On the night side, however, temperatures will fall close to zero. Bear in mind that as temperatures fall, so too does the rate of emission of energy. Hence it takes a long time to fall all the way to zero. Say rather that temperatures should fall far enough for the emission of energy to be small.
Now consider data on the Moon from http://www.solarviews.com/eng/moon.htm
Average day temperature is 107C. Maximum day temperature is 123C. These are close to theoretical expectation, to within a couple of percent.
The mean night temperature is -153C. This about 120K, and radiates a bit less than 12 W/m[sup]2[/sup]. That's less than 1/100 of the solar constant, so the temperature has indeed fallen close to zero, using radiated energy as the basis for comparison.
There's no average temperature given, but the mid point of mean day and mean night temperatures is in the ballpark. This is -23C. And, just as should be expected, it is somewhere between T_phys (-120C) and T_eff (-3C). But it is closer to T_eff, because it is the cool side of the moon that is most different, in absolute temperature, from the unphysical extreme that is the basis of Gerlich and Tscheuschner's T_phys.
On Earth, fortunately, we have an atmosphere that has to be heated from the surface. By basic thermodynamics, the Earth's average surface temperature is therefore substantially warmer than our airless moon. where surface radiation escapes directly to space.
Well, for a better example, let's use Trenberth et al. 2008's Earth energy budget. They have 350 watts per square meter going from Earth to atmosphere, and 333 going from atmosphere to Earth. The Earth's surface temperature is 288 K. The average temperature of the atmosphere in their model isn't given, but assuming a typical figure of 250 K, we have:
Atm: Gains 359 / 250 = 1.4 J/K/m^2 in one second, loses 333 / 250 = 1.332.
Surf: Gains 333 / 288 = 1.156, loses 350 / 288 = 1.215.
Net for atm: Gain of 0.068.
Net for surf: Loss of 0.059.
Total: Gain of 0.009. No entropy violation. Atmospheric greenhouse effect is physical. G&T lose. Science wins. Everybody can go home.
1st calculation should read 350 / 250, not 359 / 250. Sorry about that.
I had an idea for a thought experiment:
Two large black electrically heated plates are held quite close to each other.
G&T physics are ON.
Case 1:
Plate 1 is kept with a thermostat at 1001 K and plate 2 at 1000 K. So energy does flow from plate 1 to plate 2 but not from plate 2 to plate 1. Plate 2 does not radiate at all towards plate 1, since colder objects can't transfer energy to hotter objects.
It does radiate to the rear though. This is a mystery how plate 2 knows to radiate in one direction but not the other. The almost identical plate 1 radiates happily in both directions.
Actually, either plate 2 must radiate with practically double intensity to the rear to maintain a stable energy level (this should be very easily observable), or the heater must be turned way down in power (to half the power from plate 1) so that a stable temperature (energy level) is held. Again easily observable.
This large asymmerty stemming from a 0.1 percent difference in temperature seems astonishing.
Case 2:
Plate 2 is warmed two degrees, now plate 1 is at 1001 K and plate 2 at 1002 K. At some point all energy flow between the plates reverses suddenly and completely, when plate 2 gets warmer than plate 1.
This is a mystery as well. It seems that perhaps if the radiation a plate is receiving is more than it would be radiating, it can't radiate outwards at all anymore?
Case 3:
Both plates are warmed to really close to 1001 Kelvins and the heaters are turned off. The flow direction oscillates wildly between them, since the warm is always warming the colder one, gets colder and the situation is reversed. Perhaps if the shifting is rapid enough (only limited by the speed of light delay between the plates), it would seem they are cooling both at the same rate and the radiation in between is traveling in both directions when averaged over a short time.
:)
Hmm, I had a thought error.
In Case 1,
Plate 1 receives heater power P and radiates with two surfaces, both power 0.5 P.
Plate 2 receives either
1) 0.5 P from plate 1, P from the heater, and thus must radiate backwards with at power 1.5 P to maintain steady temperature.
or
2) receives 0.5 P from plate 1, and radiates 0.5 P backwards, and the heater must be turned off to maintain a steady temperature.
Don't know which one the complete G&T physics postulates as what happens because of the 1 K difference in temperature of the plates.
Further thought experiments:
Three plates named A, B and C and placed sequentially from left to right. All happens in a vacuum bottle and which sits in an ice bath so no significant radiation or reflection is contributed by the outside.
G&T physics are ON.
Plate A has an electric heater of power P. It radiates 0.5 P both ways. Plate B gets the 0.5 P from A. If we assume it's colder, it can't radiate any energy back (G&T 2nd law), so it radiates it all forwards. So 0.5 P forward, on to plate C. Which is in similar situation, and radiates 0.5 P forwards.
Hence the system should stabilize in a situation where plates B and C radiate with equal amounts (only to one side) and B is warmer than C. This is only possible if C is infinitely close to B:s temp. You can add a number of plates, say, ten, and you should see no temperature drop.
-
G&T physics are OFF.
Let's assume radiation does not care about the destination, so all plates radiate symmetrically in both directions.
In a steady state,
Plate A gets and also radiates an energy flow of
P_A=P_heater+0.5*P_B
plate B:
P_B=0.5*P_A+0.5*P_C
plate C:
P_C=0.5*P_B
We combine the last two to
P_B=0.5*P_A+0.25*P_B
P_B=0.67*P_A
and thus
P_A=P_heater+0.5*0.67*P_A
P_A=1.5*P_heater
and we can solve
P_B=P_heater
P_C=0.5*P_heater
Then we can solve the temperature relations:
If P=k*T^4
then
T=(P/k)^(1/4)
T_1/T_2 = (P_1/P_2)^(1/4)
and thus
T_B/T_A = (1/1.5)^(1/4) = 0.90
T_C/T_A = (0.5/1.5)^(1/4) = 0.76
So, if plate A is at 400 K, plate B should be at 360 K and plate C at 300 K.
Did I make a mistake? Someone should check this work. :)
From the draft paper, Eli:
"(1) At the surface: S(1-α)/4 + σT14 = σTsur4
(2) At Layer 1: σT24 + σTsur4 = 2 σT14
(3) At Layer 2: σT14 = 2 σT24
Starting with the observed solar flux at the top of the atmosphere, 1364 W/m2, we can solve for
T2 = 255 K
T1 = 303 K
Tsur = 335 K
Tsur in this simple model is too high because of the assumption that only radiation governs the atmospheric thermal equilibrium. In reality, the latent and sensible heat fluxes, remove substantial amounts of energy from the surface. In the global, annual mean these terms equate to roughly 100 W/m2 of energy removal from the surface and put in the atmosphere (Trenberth et al., 2009). Taking this into account, the Tsur would be close to the observed 288 K"
Eli, your calculated surface temperature is no too high for the reasons you state.
It is too high because you have assumed 2 atmospheric layers.
If n is the number of layers into which you divide the atmosphere, the ratio of Tsurface to T1 (the top) is the fourth root of (n+1). It is easy to prove, and is set as a problem in Grant Petty’s book on Atmospheric Radiation, Page 144.
Try it for T surface:
One layer – Fourth root of 2 = 1.19. Tsurf = 1.19 x 255 = 303K
Two Layers - Fourth root of 3 =1.315 T surf = 1.315 x 255 = 335K
Three Layers - Fourth root of 4 = 1.415 Tsurf = 1.415 x 255 = 360K
Four Layers - Fourth root of 5 = 1.495 Tsurf = 1.495 x 255 = 381K and so on.
Do we really believe that the surface temperature on the planet depends on the number of layers into which we (arbitrarily) divide the atmosphere?
Something must be wrong here, as G and T say.
The “something wrong” is the fundamental greenhouse assumption that upward radiation is absorbed and re-emitted, half up and half down.
G and T labour their description of Woods’ greenhouse experiment precisely because he was trying to detect this back-radiation. It was not there. If he had increased the number of layers of glass and rock-salt in his greehouses, he could have looked for the much larger radiative temperature increases, above.
I confidently assert that they would not have been detected.
Before you submit this paper, Eli, would it be a good idea to eliminate some of the interminable thermodynamic confusion over heat, energy, entropy, and radiation?
The best way to do this is to follow G and T (and Clausius) and analyse the factors involved from the stand-point of a steam engine. As an ex reactor physicist, (the clown with the pencil) this is easy for me to do.
Start with the heat source, super-heated steam, upstream of the engine turbine. Does this contain energy? Certainly. Entropy? Substantial. Heat? Not necessarily, not if its surroundings are at the same temperature.
Heat is a process – the transfer of energy to the surroundings Heat in the form of energy can be transferred if there is a lower temperature heat sink available – a cooling tower, for instance. On the way it can perform work and/or warm the heat sink.
What about the sink? The transfer of energy from the source will warm the sink, and its entropy gain is much greater than the entropy loss from the source, because it’s temperature is lower.
Does the sink contain energy? Certainly, enough to warm a small town. Does it contain heat? Only if there is a sink available at a lower temperature. That is why you can see the waste heat disappearing up the cooling towers into the atmosphere.
Can this sink energy be used in any way to warm the source, by radiation or in any other way? Of course not. The idea is preposterous, but if it were possible one of my colleagues would have tried it before now.
Apply the same logic to AGW. The sun warms the earth, which is analogous to the steam heat source. The earth transfers heat energy to a sink, the atmosphere, which warms. In principle, useful work could be obtained from this heat.
Can the warmer atmosphere transfer heat back to the earth? If it could, useful work could be extracted on the way back, and we would have achieved perpetual motion, just as G and T say.
Since this is the usual argument put by AGW proponents, it is perfectly fair for G and T to demolish it.
However, we can also address a further question. In the steam case, would more heat transfer if the sink were at a lower temperature, and less if the temperature were higher? Of course this is true, as Lord Kelvin was the first to recognise.
So, it makes some sense to suggest that a warmer atmosphere will slow down the heat transfer from the surface until the sun restores the temperature differential. In other words, as G and T say, the greenhouse gas effect is a kind of super-insulation, the experimental evidence for which, they claim, is non-existent. If they are wrong, a straightforward experiment would demonstrate the fact without endless debate.
Personally, I think it likely that the lapse rate would adjust and, since the temperature of the final sink, space, would not be affected, the surface temperature would not change.
Nevertheless, it is arguable that a warmer atmosphere will warm the surface indirectly, but the argument that it will warm it directly is, as G and T say, absurd.
Fred as you know within thermodynamics you can only calculate changes of internal energy, not absolute internal energy, although you can calculate total entropy. A body's internal energy can change when work is done on it or it does work on the surroundings or heat flows into or out of the body.
I think we have been pretty clear to maintain those distinctions
“A body's internal energy can change when work is done on it or it does work on the surroundings or heat flows into or out of the body.
I think we have been pretty clear to maintain those distinctions”
Sadly, Eli, I can’t agree that you have done anything to clarify the distinctions between heat, work, and energy. Quite the opposite. The most basic thermodynamic example makes the distinction clear. Suppose a falling weight drives a paddle in a well insulated container containing air at room temperature. The weight converts potential energy into work. The paddle converts work into energy, which raises the temperature of the air.
The first law of thermodynamics, the conservation of energy, would allow the additional energy in the gas to turn the paddle in the opposite direction, and raise the weight. The second law states that this is impossible because the entropy of the gas would have to fall, spontaneously.
You refer continually to “net heat flow” when you mean “net energy flow”. The difference is fundamental because heat can do work and raise temperature. Energy can do these things only if it flows from a higher to lower temperature, which is the definition of heat.
Colloquially, we all use heat both as a noun and a verb. Rigourously, heat is a process.
Thus you say :
“There seems to be confusion about whether the Clausius statement applies to net heat flow or simply any flows of heat.
If the Clausius statement referred to any flow of heat when the two disks were placed opposite each other B would have to stop radiating towards A because if it did not, heat would be transferred between a body at lower temperature to a body at higher temperature. This is obviously absurd.”
It is your idea of net heat flow which is absurd. Energy will be transferred as heat from your warmer plate A to your colder plate B, in one direction only. Plate A will cool. Plate B will warm. That’s it. Plate B can radiate energy towards A. It cannot warm A.
Of course, plate B can slow the cooling of plate A in the same way that a warmer atmosphere can slow the cooling of the surface. This is an insulation effect, as G and T point out.
The most interesting part of your paper (I am tempted to say the only interesting part, but I won’t) is Figure 9. This is the “higher is colder” argument which G and T do not address, and it is the only plausible explanation for AGW which I have come across. Real Climate get this right. As Gavin Schmidt said “there would be no greenhouse effect without the lapse rate”.
The lapse rate, of course, has nothing to do with radiation. It is a function of gravity and adiabatic expansion via the gas laws. G and T’s housewife could see the effect of adiabatic expansion by using a pressurised CO2 cylinder to produce soda water.
Viva Gerlich and Tscheuschner!
WHOOP! WHOOP! WHOOP!
They have liberated the human race from an obvious FRAUD!!!!
"Brian G Valentine said...
They have liberated the human race from an obvious FRAUD!!!!"
Even better is watching the religious nuts crying about the global warming god being disproved... Nothing can better define irony then the ppl in this thread and countless others demanding "peer-review" or how its "FALSIFICATION".... this coming from a group that's given us the "hockey stick" and hundreds of other "studies" and "research" that even a 3rd grader could review and see their are problems with them.(worse of all from an ethics standpoint)
I do find it funny how false and misleading information is perfectly ok when its to support "the goal" but dare challenge "the goal" and its a rope and tree for you.
O well good times had by all...
The hockey stick is a good example of how skeptics like kurt have lost the puck and are still trying to figure out where it went, while failing to notice that the game is still being played and they are now losing eight to nil.
The "hockey stick" has become a popular catch phrase for the basic conclusion, now backed up by many different studies and lines of evidence, that late twentieth century stands out for a sharp rise in global temperatures, beyond anything seen in recent centuries.
Critics tend to focus on one study only -- now more than 10 years old -- by Michael Mann and colleagues in 1998. This was, as far as I know, the first study to take the multiple proxy records available, and construct a single temperature record with quantified error bounds. This study found with high confidence that recent decades are anomalously warm and show an anomalously rapid rate of increasing temperature, by comparison with the last 600 hundred years.
Subsequent work has continued to build upon this basic conclusion, confirming the primary result, and refining and extending the methods and the estimates.
This original paper was not perfect. Its defects, such as they are, have been inflated out of all recognition, and the most vociferous critics in fact made much worse errors of their own in their proposed alternatives. There was, however, room for improvement, and indeed there HAS been improvement. The primary conclusions of the original work continue to hold under more rigorous analysis, and those conclusions have been extended. Real science focuses on the ongoing work that continues to refine and develop what has gone before.
The original work has long since been mainly of historical interest as breaking the ground for this kind of quantified reconstruction. The claims of any "ethical" issues are total moonshine -- a contemptible fantasy. There was NEVER any concern with ethics. The only issues have been highly technical questions of mathematical uncertainty estimation, which have been picked up and addressed as work progresses. The primary conclusions of the original work have not been altered by the improvements in statistical method; they are stronger than ever with the additional data and analysis that has been subsequently applied.
For a more up to data example of these reconstructions, with much more data and with analysis that takes into account methodological concerns, see Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia by Mann et. al. in PNAS vol 105, no. 36, pp 13252-13257 (Sept 2008); or The Spatial Extent of 20th-Century Warmth in the Context of the Past 1200 Years, by Osborn et. al. in Science Vol. 311. no. 5762, pp. 841 - 844, (Feb 2006). That's just two of the more significant papers in a body of large body of ongoing work.
Kurt's remark about 3rd graders is particularly ridiculous. The defects in the original paper, such as they were, are extremely technical and subtle; and certainly not of a nature to simply invalidate the whole project! Most importantly, those defects no longer apply as work has continued; and the major conclusions have the original work continue to hold up under more rigorous analysis and additional data. (See, for example Robustness of the Mann, Bradley, Hughes reconstruction of Northern Hemisphere surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence, by Wahl and Ammann, in Climate Change Vol 85, No 1-2 (Nov 2007) pp 33-69.
The irony is palpable. Since Kurt dares to make insinuations about "ethics" on the basis of nothing at all that I can see, it is just as well to be blunt in reply. Kurt is either a third grader himself, or a bald faced liar; or perhaps he's just an idiot.
To Duae Quartunciae
Lol I love it... I suppose next I'm a plant from the evil oil companies to... you conspiracy nut jobs are all the same. Have your fun but the tide is turning.... you see we only need to delay the global warming nutters and the truth will be proven(yet again) that you have no idea what your talking about... but you've lost momentum... in your effort to "educate" ppl to many ppl turned around and took notice of your scam and have decided that they will fight back.... just a matter of time....
No; I still think third grader or idiot fits the bill best. If oil companies were ever looking for a "plant", I think they'd want someone with a capacity for giving some kind of actual argument. Any idiot can make assertions.
I've been very harsh on you, but I think you earned it when you tried to accuse the scientists working on this of ethical lapses.
What the scientific literature shows is stock standard work of science, with exclusively technical concerns and criticisms being raised, and getting addressed in further work on the subject. The NAS report on research related to the so-called "hockey-stick" confirmed the main conclusions of the original papers, expressed reservations about some of the technical detail and said nothing whatsoever about ethical problems.
Subsequent work has explicitly taken up some of the NAS recommendations for where more work is needed... such as Mann et al (2008) I cited previously. Insinuations of ethical concerns are (ironically) merely a lie, having not the slightest connection to reality. Whether it's your own lie, or -- more likely -- something you've witlessly passed on from other nutbars, I don't know.
The record here shows that I'm the only one of the two of us who has actually given any substance or references. What polls I've seen indicate a trend the reverse of what you would like; by and large people on the fence who approach this with any integrity do tend to recognize where the wind blows in the scientific work on this. See, for example, this recent survey by Time magazine: Poll: Americans See a Climate Problem.
Harsh on me? lol thats funny I suppose next you'll apologize for eating the glue huh?
I know lets play a game... I do so love games.
But first lets find out how much of a conspiracy buff/global warming nutter you are...
Are you one of end of the world nutters who believes global warming will do something along the following
Cause a CAT 4,000 hurricane,
Cause massive flooding and the sinking of most of the world,
The massive spread of deserts across the world, It will be so hot that we won't even be able to grow wheat inside the lower 48... etc, etc, etc.
Or do you believe their will be a mild climate shift which will have little practical effect other then washing out some port cities and causing nothing more then a handful of minor issues that pretty much can be fixed by installing an A/C.
Next do you even believe in global warming...? Is their no more debate left its 100% correct that global warming is happening? Are you 100% sure?
The 100% certainty strawman is a contrast to how science actually works. Science is, in principle, always open to new discoveries that may upset everything we think we know.
In the meantime we provisionally go with what has been well established by conventional empirical science and tested physical principles. I'm never 100% sure of anything, but for the time being there are some basics that are so far pretty damn solid.
What solid is the basic phenomenon of anthropogenic global warming.
The planet is heating up. The total mean increase in surface temperatures over the last century is around 0.75C (+/- 0.2), mostly in the latter half of the century. The heating rate has increased in recent decades to about 0.15 to 0.2 C per decade. The greenhouse effect, and the effects of thermal absorption for increasing temperatures, is elementary physics, calculated using well founded principles as a forcing. The forcing is large; and commensurate with what is indicated by the measured global temperature increase. There are other less well known forcings and so the total has significant uncertainty. But the atmospheric greenhouse effect stands out easily as the largest single forcing at present. That's why scientists conventionally speak of "anthropogenic global warming". It's a good summary of the state of scientific knowledge on how climate is currently changing.
The net effects of rising global temperatures are much less certain. Impacts on hurricane frequency and intensity, for example, are not well known at all. Personally, I suspect the biggest impact will come from shifting conditions for agriculture and primary production. For example, here in Australia it is likely that there will be less rainfall. That's a major economic problem looming... not as a definite prediction, but a clear risk that it would be foolhardy to ignore.
Human society adapts to prevailing conditions. When conditions change, the tendency is for a mismatch between infrastructure and conditions, and that is expensive and disruptive. Beyond that, I can't predict. It's not my own main interest, or expertise.
My own main interest is simply the basic physics. Much of the public dispute on climate is not actually about the consequences of increasing temperatures, but confusion on fundamental physics of how climate changes at all. Things like the greenhouse effect, the nature of radiative forcing from greenhouse gases, the details of other forcings, or the overall sensitivity to forcing, as degrees per W/m^2.
The biggest impediment to a rational consideration and risks and costs, at present, is widespread head in the sand denial of the basic underlying science. That's where I will continue to focus as an individual. It's what matches my own interests and where I have the best potential to help.
This paper is a full frontal attack on the science that has been presented and relied on by the IPCC crowd for the past several years. I am not aware of ever seeing such an unforgiving denunciation of anyone’s science.
So, Two Farthings, you want to use the principles of basic Physics to explain Global Warming. You are not satisfied by a natural recovery from (and a natural descent into) the Little Ice Age, so, like Eli, you invoke the absorption of thermal radiation by additional CO2, and the conservation of energy principle.
The simplest explanation has been around for a century or more, and depends on the Stefan-Bolzmann equation. Thermal radiation from the surface of the planet (or the interior of a greenhouse) is proportional to the fourth root of its absolute temperature.
If the surface is surrounded by a material capable of absorbing and re-radiating all the radiation emitted, and the incoming radiative energy is W, the radiation emitted must increase to 2W, to compensate for the back radiation of W.
So, the ratio of the surface temperatures with and without an absorbing cover is the fourth root of 2W/W, which is the fourth root of 2, which is 1.19.
The absorbing blanket, whether glass or air, will raise the surface temperature by 19%, which is not much more than the 33degrees K claimed for the back radiation effect. We can easily produce an exact result by allowing a small proportion of the radiation to escape without absorption.
To a Physicist, that result is absurd. The back radiation from the colder absorbing blanket cannot heat the warmer surface in this way. RWWoods, who measured the effect in a terrestrial greenhouse, duly demonstrated that the absorption of the surroundings made no difference to the interior temperature.
Eli, in his paper assumes two absorbing layers (equivalent to two layers of glass) which increase the radiative ratio to 3, and the temperature ratio to the fourth root of 3, or 1.315. The surface temperature increase becomes a substantial 31.5 per cent, about 80 degrees K.
Every Climate Scientist should be compelled to construct or quote an experiment demonstrating this temperature increase (Woods use glass and rock salt) before building their models or constructing their theories.
Not quite, fred. What I actually want is for popular discussion to be informed by a minimal comprehension of basic physics.
It is symptomatic of the dreadful problems with scientific literacy in this whole debate, that you have just walked through a nice simple toy example (isothermal opaque slab atmosphere) and obtain the physically correct result using the Stefan-Boltzmann relation.
Then you follow with this:
"To a Physicist, that result is absurd. The back radiation from the colder absorbing blanket cannot heat the warmer surface in this way."
It's hard to know how to deal with this level of ignorance. You've just gone through some physics showing that adding an absorbing blanket will mean a warmer surface than otherwise... and then you turn right around and say a physicist would find it absurd!??
Note that Woods was NOT studying atmospheric radiation effects. He was showing the effects in a glasshouse, which is physically different. A glasshouse works mainly by preventing convection, rather than by the thermal absorption in the glass.
Try again. You proposed a "blanket" which absorbs all the surface radiation and then emits thermal radiation W to space and W back to the surface. It's a useful toy example, which is sometimes used at the start of a book of atmospheric physics as an exercise, and you actually calculated this effect correctly with the Stefan-Boltzmann relation.
In our example, W for Earth is about 240 W/m^2. Without the blanket, the surface will radiate W, and be at a temperature of about 255K.
With the blanket, the surface will radiate 2W, and be at a temperature of about 303K (19% more), an additional 48 degrees. The blanket will be at 255K.
Note that the blanket is heated from the surface! It is NOT a case of a net flow of energy from the blanket to the surface. There's 2W from the surface up into the cooler blanket, and only W coming back down again. That's the second law of thermodynamics for you. The net energy flow is from the hot surface to the cooler blanket. It's just ignorant to look at the W of backradiation while ignoring the 2W coming upwards. The second law means that the energy into the cooler blanket (2W) must be greater than the energy from the cooler blanket to the surface (W). That's it. Blankets are still consistent with the second law of thermodynamics. This is really elementary thermodynamics here!
The surface is warmer when the blanket is in place, not because the blanket is a source of energy, but because the blanket absorbs the energy from the surface, which means the surface has a higher temperature to supply the net flow of energy 2W required to get W out into space through the blanket.
I am happy to try again, Two Farthings.
Woods knew how greenhouses work. That is why he built two, one of glass (absorptive) and the other of rock-salt (non-absorptive). The convective effects (suppression of) were the same for both. He was looking for the additional heating from back radiation, using exactly the same theory as I described (you can find it on page 18 of Houghton’s Global Warming Book).
He did not find it (the additional warming of about 19%, some 50 degrees C – difficult to miss) because it was not there.
We are discussing here Eli’s rebuttal of the G and T paper, and he uses a two-layer model of the atmosphere. His surface temperature is 335 degrees C.
Use three layers, and you will get 381 degrees C.
Now the number of layers is arbitrary, ie assumed, and my argument is a reductio ad absurdum for the first two-thirds of Eli’s paper.
I have never succeeded in explaining the implications of the second law, though not for the want of trying. The point is that energy, viewed in isolation, is not necessarily a source of either work or heat. It depends on the relative temperature of the surroundings (next time you pass a power station, have a look at the cooling towers).
To produce either work or warming, energy must pass from a higher to a lower temperature. The back radiation, W, does the opposite. If sinks could warm sources we would have perpetual motion.
There's no question about how greenhouses work. They work mainly by restricting convection heat loss, which is different from how the atmospheric greenhouse effect works. They are, therefore, completely irrelevant here. Noone is proposing that a glasshouse works like the atmosphere, or that the atmosphere works like a glass greenhouse. The whole thing about a glass greenhouse is a distraction.
You still are getting the whole idea of backradiation wrong.
The backradiation is LESS than the radiation up from the surface. There is no conflict with the second law in having W coming down from the cooler atmosphere while 2W is going up from the hotter surface.
Neither is there the slightest conflict in the second law in having a surface without an atmosphere being colder than one with an atmosphere. The atmosphere is certainly cooler than the surface, but it one heck of a lot warmer than the cold of space, and so WITH the atmosphere the surface is much warmer than it would be if the surface radiated direct into the cold of space without impediment.
I'm glad you are still trying, but you are still making a trivial mistake. With all due respect, you don't understand the second law yet. You will never be in a position to "explain" it until you actually get it correct yourself. You may know the formulae, but you can't say you actually understand it until you can apply it to real situation. And in fact, you haven't even tried that. You've simply made vague claims of a supposed conflict, but with reference to energy flows that are all completely consistent with the second law. The second law says that heat always flows from a hot object to a cooler one. That's precisely what is happening with the surface is radiating 2W up and the atmosphere is only radiating W down.
This isn't "Eli" doing something weird. The explanations used here are simple examples of elementary thermodynamics similar to what is used in undergraduate textbooks for ANY course in thermodynamics of the atmosphere.
http://www.americanscientist.org/Libraries/images/200912111339237675-2009-12-14entropyseminar.jpg?st=11
There was a time, a century ago, Two Farthings, when it was believed that radiation played a significant part in the heating of terrestrial greenhouses. The mechanism was held to be exactly what you and I have described for the single-slab model of AGW – 2W radiated from the surface, and W radiated back from the glass, which absorbed infra-red radiation.
In a non-absorbent greenhouse surface radiation would be transmitted directly to the atmosphere, that radiation would be W, and the temperature would be lower than in the radiative case by a factor equal to the fourth root of 2.
This theory was exactly analogous to the AGW theory with a single slab model, and it was nonsense. To prove that it was nonsense, R W Woods constructed two greenhouses, one absorbent/radiative (glass) and one non-absorbent/non-radiative (rock-salt). The convective effects in both were identical, so any difference in internal temperatures would have had to be due to a back-radiative effect from the glass. In the event there was no difference in temperature, so there was no back radiative warming from the glass. The second law was firmly in control of the energetic photons.
In January 1976 SDSilverstein set up a heat transfer model of the two Woods greenhouses to show why the glass did not warm the interior. His argument is based on heat transfer equations, as follows:
The difference between the two green-houses is that the glass is warmer than the rock-salt because it absorbs the radiation which the rock salt transmits. The warmer glass loses heat to the atmosphere faster than the rock salt. This compensates for the direct heat transmission through the rock salt, so the overall heat transfer is much the same. The temperature and heat transmission data is in the paper. There is no term for heat transfer from the glass to the interior (your W, Two Farthings) because this would be from a lower to a higher temperature. The back radiation is the negative term in the uni-directional heat transfer equation.
In other words, the glass is warmer than the rock salt and the atmosphere, but cooler than the interior. It cannot (and does not) warm the interior directly, and any tendency to act as a radiative blanket (slowing radiative cooling) is compensated by the faster convective heat loss to the atmosphere. The overall heat transfer from the greenhouses is much the same.
Now apply this argument to the AGW theory. Additional CO2 absorption will warm the atmosphere (as Eli describes very convincingly at RC) and this will slow the radiative transfer of heat from the surface. However, it will simultaneously increase vertical convection (warmer air rises faster) and radiation to space from the warmer upper air. The net effect on surface temperatures will be negligible.
It is the lapse rate, two farthings, which is responsible for the temperature difference between the surface and the tropopause, and this has nothing to do with radiation, as Woods concluded.
The answer to what RW Wood measured can be found here. The answer is not the greenhouse effect but that the cylinder radiates at the same rate either from the top of the tube through the IR stopping glass, or the bottom when covered with a salt window.
Rabett Run, answers all.
They do not radiate at the same rate, Eli, because their temperatures and the relevant differentials are not the same.
In the detailed example I posted to your link, the interior surface is at 21 degrees C, the air outside at 0degrees C, and the glass interior and exterior are 4.9 and 4.3 degrees C respectively.
The glass, radiating to the air, loses 24 watts per square meter, while the interior to the glass radiation is 75 watts per square meter.
Relative to the rock salt container, there is a greenhouse radiative blanket effect, compensated by increased convection from the warmer glass
Well, to his credit, Steve McIntyre wouldn't host discussion of it.
In the comments on that page, he writes
Again I do not want “skeptic” articles cited on this topic. I know that literature. I do not want to discuss Gerlich on this site. I am not interested in expositions why the effect is impossible – it isn’t. Can people simply STOP posting “skeptic” references on this. This site is devoted to auditing and verification of articles being relied on by IPCC for policy purposes. The skeptic literature is not relied on, so I’m not interested in hosting discussions of it. Period.
The answer, of course, is no, his followers can't stop, because they are ignorant intellectually dishonest ideologues. And McIntyre himself, if he really had integrity, wouldn't just ask them to stop, he would tell them in no uncertain terms that they are ignorant and wrong.
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