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|Published comment, and reply, on Gerlich and Tscheuschner 2009|
|Topic Started: May 8 2010, 03:45 AM (4,903 Views)|
|sylas||May 8 2010, 03:45 AM Post #1|
Early in 2009, an unusual paper appeared in the International Journal of Modern Physics (B), claiming to falsify the atmospheric greenhouse effect using physics. Amongst other things, it claimed that a violation of the second law of thermodynamics was required in conventional descriptions of the atmospheric greenhouse effect.
The paper had little impact in the world of science, although there has been a lot of discussion at various blogs.
In response to this, a number of people, led by Joshua Halpern of Howard University, have submitted a rebuttal. The rebuttal, and a reply from the authors of the original paper, Gerhard Gerlich and Ralf Tscheuschner, has now appeared in the April 20, 2010 issue of the journal. The papers are, unfortunately, behind a paywall.
I also am one of the co-authors of the rebuttal, under my own name of Chris Ho-Stuart, so I am deeply involved in this.
I expect there will be a lot of of discussion on this in various places around the net, and I hope this board will be a particularly convenient place for it to occur. I plan to keep a very strong eye on the tone of discussion and will keep a strict requirement on courtesy to persons, while allowing robust criticism of ideas, including my own. I don't know how much moderation will be required, but since I am so involved, please feel free to complain without feat of reprisal if you feel I do anything inappropriate in the moderation capacity.
The references are:
PS. Added in edit. I have added a link for finding the rebuttal paper.
Edited by sylas, May 9 2010, 05:00 AM.
|sylas||May 9 2010, 03:01 AM Post #2|
Since these papers are behind a paywall, I am going to give a series of comments with extracts. One curious feature of all of them... the original paper, the rebuttal comment and the reply to the rebuttal, is that they are all unusually long. Too long, IMO!
The original paper is 90 pages long; the rebuttal is 23 pages long, and the reply is 27 pages long.
The original is available via arxiv, linked in the first post.
The rebuttal is organized into the following sections:
The rebuttal conclusion reads:
The reply is organized into the following sections.
The conclusion of the reply reads as follows:
All in all, this episode is quite extraordinary. I have never before seen anything like this sort of exchange taking place in mainstream physics journal. Bad papers do get published from time to time, but this really stands out. Whether you think it is our rebuttal or the reply that is completely out to lunch.
Feel free to request comment on particular aspects of this exchange. Please bear in mind the aims to keep things scrupulously courteous and substantive. There will certainly be implications that some people here are making dreadful errors, and that is fine; but let us keep the focus on the substance and the errors themselves, not the persons.
Welcome to the forum, visitors! We are getting a few people looking in on this thread. Check our board guidelines for an idea of what we are trying to do here, and then sign up if you would like to participate.
Edited by sylas, May 9 2010, 05:38 AM.
|jshore||May 9 2010, 03:57 AM Post #3|
||Well, one thing that I found very disappointing with G&T's reply is that they repeat assertions such as "The correct question is, whether the colder body that radiates less intensively than the warmer body warms up the warmer one. The answer is: It does not." However, they do not actually engage in any substantive discussion whatsoever regarding any of the simple models of the greenhouse effect (or just of radiative transfer in general) where one can show that indeed the presence of the colder body results in the warmer body being warmer than it would be if the colder body were not there to essentially return some of the heat radiated by the warmer body.|
|sylas||May 9 2010, 04:57 AM Post #4|
|At the Rabbet Run Labs of Eli Rabbet you can find a whole pile of drafts of the rebuttal paper, up to almost the same as what appears in the journal; differences being minor typos if any. So you can even see how the rebuttal altered over time.|
|sylas||May 9 2010, 09:20 PM Post #5|
Hey Joel; thanks for joining in! (And for those who didn't guess; Joel is one of the co-authors of the rebuttal.)
I can't say I was "disappointed". The reply is more or less what I expected. What I find more "disappointing" is that any of this got into the journal at all; and that is more a reflection on the procedures at the journal than anything else. There will always be odd ideas floating around; the editorial process at a science journal should keep the quality much higher.
Yes, the reply merely repeats many of the same fundamental errors as were in the original paper. The original paper is the worst paper I have ever seen get into a legitimate journal. It has had no impact in the world of science, and the only reason it was worth publishing a rebuttal was basically for the sake of all the discussions that went on in the public sphere.
Given the interest this topic is attracting, here is a brief broader context. Perhaps many of the visitors looking over this thread will appreciate the background, as I see it.
(1) Gestation of a curious paper
About three years ago, in 2007, a paper appeared on axiv claiming to falsify the atmospheric greenhouse effect. It is the same as is linked in the first post of this thread, by Gerhard Gerlich and Ralf Tscheuschner.
It must be understood that this is not your traditional objection to anthropogenic global warming or climate change. The matter of changing climates is not addressed; the paper rather purports to undercut the whole idea of an atmospheric greenhouse effect at all. This is a surprising conclusion, to say the least. Pretty much any basic textbook on Earth's global climate will include some account of the greenhouse effect, and how certain gases absorb infrared thermal radiation, which leads to a higher surface temperature than would otherwise be the case.
The paper attracted a certain amount of attention; but not a great deal. It was too obviously silly to have any traction with most of the working scientists who are skeptical of the conventional views of anthropogenic impacts on climate. There was a rebuttal produced, by Arthur Smith, and a reply to that, but it all occurred outside the conventional peer reviewed literature, while being pretty much ignored by more prominent players in the climate debates; scientists like Richard Lindzen or John Christy or Roy Spencer or David Douglass and so on.
(2) Triumph and publication
Then, in 2009, it appeared in a legitimate physics journal; the International Journal of Modern Physics (B). This was a remarkable turn of events, and a number of people (myself included) emailed the editors at the time to point out that something had gone badly wrong with their usual editorial processes. The response I had from the editors was to suggest that if the paper was really as bad as I thought, then I should submit a rebuttal.
Initially, I did not think this was appropriate; and this is not my usual field in any case. My own professional academic background is in mathematics and computer science. (I have a brief biography in my forum blog: Who is sylas?) The paper was -- and is -- the worst paper I have ever seen in a legitimate science journal; and it seemed to me that it had no chance of making any impact on the work of scientists; only on the reputation of the journal. If the journal did not care to look again at their processes, so be it. It was never going to be a scientific debate. So I ignored it.
As expected, scientifically the paper went over like a lead balloon. It has no citations in the usual citation databases... until now, of course! Despite the enormous significance of its conclusions, had they any validity, it excited no response or debate in the normal professional scientific channels whatsoever. From anyone.
(3) Gestation of a rebuttal
But then at the blog Rabbet Run, blogger Eli Rabbet started putting together a rebuttal, and made a good case for why this was worth doing. There was (in my opinion) something very strange about the editorial process of the journal. The publication had excited a fair bit of gleeful attention at quite a few blogs that tend to be critical of the notions of anthropogenic warming. It was being treated as a done deal that having a peer reviewed paper falsifying the atmospheric greenhouse effect was sufficient to overturn the whole field of atmospheric physics.
Scientifically it was a complete non-issue, but in the public sphere it was another matter; and it was worth having a rebuttal because of the potential distractions that could be caused by a superficially technical falsification of some basic physics underlying our understanding of climate. Eli called for people to join in, and I came on board.
This rebuttal paper and the way it was produced has been something quite unprecedented. Many people commented on the various drafts that Eli made available, and the end result is something in which all concerned -- not only those who ended up as authors -- may legitimately take pride.
(4) Publication and reply
The formal review process with the journal was not without its own hiccups; but that is now done with, and the rebuttal has appeared. At the same time, as is usual, the authors of the original article were invited to make a reply, which also had to be reviewed.
Here again I say frankly -- it is incredible to me that the reply was considered acceptable. The journal is not actually obliged to publish the author's reply if it fails to have an acceptable standard, and the standard of the reply to our rebuttal is, as with the original paper, beyond dreadful. But there you go. With a stiff double whiskey it is actually quite amusing. This is, of course, my own opinion of the scientific merits of their reply. Evidently there's some reviewer out there who does not agree with me.
I am content. The rebuttal and reply are now both formally published and they pass together now into the scientific literature where they are now available for the judgment of the whole scientific community.
I do not mind that there's a reviewer or two out there who considered the reply to be worth publishing, or that Dr Gerlich and Dr Tscheuschner consider our rebuttal to be worthless. I have that view of their reply, and so it would be unfair of me to take offense.
It is the response -- if any -- of the wider community which I consider more relevant, and as before I expect nothing whatsoever to come of this in the development of atmospheric physics.
(5) What would you like now?
We are getting a lot of visitors to this thread; and I encourage anyone to ask a question or make an observation. It's intended to be a discussion forum rather than a platform for me to comment. The forum guidelines require courtesy for all members, but you can be as robust as you like in criticism of ideas -- mine especially.
I will take particular care that no-one is abused or personally denigrated if they wish to present an alternative view of this little episode.
Note too that this forum is intended to become a useful educational resource on a whole range of matters. I hope future discussions and topics will spring up on all kinds of other aspects of climate science.
|jshore||May 10 2010, 12:20 AM Post #6|
Yeah...The whole role of the journal in all of this seems pretty mysterious to me. Of course, how the G&T paper got in there in the first place is bizarre, but it is even more bizarre that they allowed this reply...a reply that makes fun of the fact that two of the authors of the comment are in chemistry and not physics departments and which says that one of the comment authors (in a previous unpublished rebuttal) "essentially has plagiarized our inequality" because he noted (properly crediting them) that a widely-known inequality that G&T had cited in their work could actually be used to derive interesting results rather than just used to spout nonsense. It just seems so completely unprofessional and over-the-top. But, maybe the journal editors have decided at this point that they will just let G&T discredit themselves. (Or maybe they haven't even read it themselves but just let the referee make the call?)
I do really find myself wondering about the motives of the various people involved (e.g., whether G&T really believe the nonsense that they write or whether they just think of themselves as defense lawyers who are doing their best to defend a client who they know is really guilty but who they still feel duty-bound to defend). But, then I guess that this is my own hangup of wondering about self-awareness. I used to wonder whether dogs have enough self-awareness to know that they are dogs (and actually had quite animated arguments about this). And, then, once I went into industry, that shifted to wondering about the self-awareness of upper management. But, I guess some things simply can't be known without doing a mind-meld to get into someone else's head.
|sylas||May 10 2010, 03:52 AM Post #7|
Time for some nitty gritty.... This is one really minor and trivial point of the published exchange. But I happened to notice it after hearing indirectly what Grant Petty thought of the reply to the rebuttal.
My excuse for bringing up such a trivial issue is that it is comparatively straightforward, and well suited to the objective of this board becoming a useful education resource. The rebuttal and reply themselves are not really all that significant of themselves; but if interested onlookers can learn a bit of the relevant physics, then we have really achieved something worthwhile and of value to our readers.
In our original rebuttal, we cited the following basic textbook within our discussion of backradiation (section 3.4 of the rebuttal).
At the link above you can also read much of the first edition as freely available pdf files; which some folks may find a handy technical resource. Figure 7 of our rebuttal is from Petty's book; it appears as follows:
[indentblock]Fig. 7. IR spectrum at the North Pole, looking down (a) at the surface from 20 km and up (b) from the surface. Note the emission from water vapor below 800 cm−1, from CO2 between 800 and 950 cm−1, and from ozone at ~ 1100 cm−1. The sharp lines throughout are from water vapor. From Petty.[/indentblock]
This is, by the way, a beautiful illustration of the atmospheric greenhouse effect at work. When you look down from space (a), what is "seen" is the thermal radiation from Earth that gets out into space. Some of that radiation comes from the surface. This is the parts of the spectrum that follow a line of something like 275K: just above freezing. (I guess this must have been in summer at the North Pole.) The smooth dotted lines in the diagram labeled with temperatures are the curves for a simple blackbody radiating at that temperature.
Some of that radiation comes from high in the atmosphere, where it is much colder than the surface. This is the parts of the spectrum that follow a line of something like 225K; a temperature roughly what you could expect in the tropopause, where the Earth's stratosphere begins. The bites taken out of the spectrum are in those bands where greenhouse gases absorb radiation from the surface, and so the radiation that eventually escapes to space is actually emitted high in the atmosphere.
When you look up from the surface (b), what is "seen" is thermal radiation from the atmosphere. This is called atmospheric backradiation. One of the basic thermodynamic properties of matter is that any substance will absorb radiation most effectively in precisely those frequencies where it can emit radiation. (This is called Kirchoff's thermal radiation law.)
The radiation coming back down to the surface from the atmosphere is coming in those same frequencies where it is being absorbed. In some frequencies, thermal radiation is blocked very efficiently, and the "optical depth" of the atmosphere is very small. At such "saturated" frequencies, the backradiation shows the temperature of the warm air right near the surface. But in the "infrared window" of the atmosphere, the atmosphere is transparent. In these frequencies, no radiation is absorbed, no radiation is emitted, and here is where IR telescopes and microwave sounding satellites can look out to space, and down to the surface, respectively.
In the intermediate frequencies, called the "wings" of the main saturated region, the optical depth of the atmosphere is something intermediate, and backradiation corresponds to cooler temperatures at some altitude.
Invariably, and as expected from the second law of thermodynamics, the net flow of energy is from the warmer surface up into the cooler atmosphere. The net flow is, of course, the difference between what goes up, and what comes down; and both upwards and downwards radiation fluxes can be observed and measured and are completely consistent with the second law. One of the most egregious errors of the original paper -- continued in the reply to our rebuttal -- is to suggest that conventional descriptions of the greenhouse effect involve a violation of the second law of thermodynamics. This is, of course, utter nonsense.
The consequence of this capacity of our atmosphere to absorb and emit thermal radiation is that the surface is warmer than would be if the atmosphere was completely transparent to thermal radiation; if we had a dry atmosphere of Oxygen and Nitrogen only, for example. In that case, the atmosphere would be transparent to radiation all across the infrared bands, and the surface would radiate directly in to space; shedding radiation much more efficiently. In this case, the surface temperatures would be expected to be sufficient to give enough radiation to balance the solar input, with no backradiation involved; and Earth's temperature would be roughly 33 degrees cooler. The greenhouse effect is not a bad thing! It keeps the planet habitable. The global warming phenomenon is simply a consequence of making the effect a little bit too effective... but that is complete different story. This paper is simply about whether there is an atmospheric greenhouse effect at all, and does not deal with the how it might be perturbed.
The reply to our rebuttal takes up the matter
In the acknowledgements of Gerlich and Tscheuschner's reply include this:
However, within the body of the reply, the only mention of Petty's book is this gem. (The quoted paragraph and diagram, by the way, makes up the entire content of section 4.2.7.)
It is strange that the reply does not actually deal with the rebuttal itself, but goes into a rebuttal of a different diagram in this elementary level textbook. The reply does a lot of that, repeating intemperate and invalid attacks on all kinds of other people rather than simply dealing with our rebuttal.
It is downright surreal that they do not understand the word "normalized", especially when it is explained in the book. To normalize the curves is to scale them so that they have the same area. A normalized curve doesn't have units. There's no error in the diagram. Quoting the same textbook:
This is just one little taste of the rebuttal and reply, which I think is worth explaining as it is so useful for seeing how the atmospheric greenhouse effect works.
Edited by sylas, May 10 2010, 12:14 PM.
|Cthulhu||May 10 2010, 10:04 PM Post #8|
I think what you guys have done is great source of educational material on the matter of the greenhouse effect and it's worth it just for that even if it doesn't convince G&T of their error.
Regarding questions about the mindset of G&T I think I can shed some light, at least in respect of one of their arguments.
I once had a long argument online with someone making the claim that the greenhouse effect violates the 2nd law because it proposes heat flows from a colder body to a warmer one. It went back and forth, forth and back for well over a month if I recall correctly. Sometimes dozens of responses an hour.
I tried just about every argument under the Sun to convince this individual that the greenhouse effect didn't violate the 2nd law, but I never found the ellusive argument to end the stalemate. Not entirely my fault as what I encounted from this individual was a great deal of word play and switching of definitions to evade my points. Most of my time was spent trying to word my responses in a way that couldn't be deliberately dodged with a word trick.
You could easily interpret that as meaning the individual was just arguing it for the sake of argument. The problem with that explaination is that this was a side corner of the internet and the individual was just an everyday person who was spending a lot of time arguing with me. There was no clear motive for them to be arguing for the sake of it. Even trolls would have got bored by then. I eventually decided they probably weren't being decietful, they really believed what they claimed about the greenhouse effect violating the 2nd law and that overrode anything I could possibly say.
In G&T's original paper they quoted Rahmstorf:
G&T replied with:
I don't believe for a second that they couldn't understand Rahmstorf's point. Everything they write there is clear obfuscation and word play. Exactly the kind of "heat" vs "energy" word dodging I experience in discussions with the earlier mentioned individual. Even if they had a genuine problem with the words, they could have easily changed Rahmstorf's post to "net heat flow" instead and addressed his point without such nitpicking. Instead they sidestep his counterargument with a dictionary appeal.
I think the reason G&T didn't engage in substantive discussion regarding your points is that they can't, and don't want to admit they can't. They aren't being disingenuous in the sense that they know your points prove them wrong. They still think they are right. They understand what you are saying, but can't coin a response. They believe the 2nd law is being violated due to what I will call Thermodynamic Literalism and they consider that to trump anything you can say, so they just repeat that claim.
When they say "The correct question is", that's just a short way of saying, "that's all irrelevant - a cold body warming a hot body violates the 2nd law that's all that matters"
Their minds are so closed because they are not willing to consider their literal interpretation of the 2nd law might be wrong. In their mind the atmosphere is cold, the surface is warm, the 2nd law forbids the atmosphere warming the surface. End of story.
This is what I concluded about the individual I debated with. They can understand the arguments and can see that it would indeed imply warming of the surface, they have no counteragument, but they probably just put that down to something they haven't yet thought of. They have no proper response, but not willing to show that, they respond with evasion. They probably justify that because they think they are right and don't want to "mislead" you by implying your argument is solid.
Edited by Cthulhu, May 10 2010, 10:07 PM.
|Hank Roberts||May 11 2010, 10:45 PM Post #9|
I'm trying to figure out why they assert--as recently as last month--that Venus's atmosphere is opaque to visible light, saying that means Venus couldn't have a greenhouse effect:
They can look at the spectra and pictures!: http://www.mentallandscape.com/C_CatalogVenus.htm
The sky of Venus, seen from three different landers, is always a nice carrot-orange color!
There's another good thread which is relevant here; Explaining Venus; Making the role of greenhouse effect clear. That thread would be a great place for members to start working out how to write a good description of what goes on in Venus!
The arxiv paper linked above is On The Barometric Formulas And Their Derivation From Hydrodynamics and Thermodynamics, by Gerhard Gerlich and Ralf D. Tscheuschner (March 2010). This paper has not been otherwise published or peer reviewed that I can see, and is quite distinct from the 2009 paper that is the focus of the rebuttal and reply discussed in this thread.
However, it IS referenced in the reply, and in particular section 5 of the reply is basically a summary of this paper! I have updated this third paragraph of my advisory to acknowledge this. Thanks for the addition, Hank![/moderate]
Edited by sylas, May 12 2010, 10:02 AM.
|sylas||May 13 2010, 03:03 AM Post #10|
I am in the process of putting together my next major contribution looking at this reply. I have decided to follow up from Hank's reference above.
It turns out that large slabs of the arxiv paper on Barometric Formulas are lifted entire and placed into their reply to our rebuttal -- even though neither the original paper GT2009 nor our comment makes any reference to this. It appears that the reply has been used as a vehicle to publish a series of new arguments taken from this later manuscript -- though not better ones -- under the guise of a reply. The reply does cite the arxiv paper, as reference number 44.
Does anyone know of a convenient software package or accessible tool could be used to do a comparison of two pdf documents, showing how identical or at least exceptionally similar paragraphs are arranged or repacked within the documents? Basically, sections 5 and 6 of the reply seem to be mostly section 3 and the appendix of the Barometric Formulas paper, though the paragraph order is altered and some paragraphs added/omitted.
Edited by sylas, May 13 2010, 10:48 PM.
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