Valuing Passion Over Wisdom: Hansen Awarded Highest Honour by American Meteorologists
Posted by jennifer, January 16th, 2009 - under News, Opinion.
Tags: People
THE director of NASA’s Goddard Institute of Space Studies, James Hansen, was awarded the 2009 Carl-Gustaf Rossby Medal in Phoenix yesterday. This is the highest honour bestowed by the American Meteorological Society and was awarded for Dr Hansen’s outstanding contributions to climate modelling, understanding climate change forcings and sensitivity, and for clear communication of climate science in the public arena.
Dr Hansen is passionate about global warming and quick to give advice and offer support to those who champion the idea that there is an urgent need for a global reduction in greenhouse gas emissions. He has been an advisor to Al Gore and flown to the UK to testify in support of Greenpeace activists on trial for criminal damage to a coal-fired power station.
There is, however, nothing charitable or thoughtful in Dr Hansen’s approach to controversy. He has only contempt for so-called climate change sceptics claiming they operate like tobacco scientists and he has suggested that CEOs of fossil energy companies should be tried for high crimes against humanity and nature.[1]
Dr Hansen heads a team that collates thermometer temperature data from all over the world some have described him as “the keeper of global temperature data”.
This honour will further confirm Dr Hansen’s place with opinion leaders as the most reliable source of expert advice on climate related issues. As New York Times journalist Andrew C. Revkin has commented on his DotEarth Blog: “Whatever one thinks of James E. Hansen’s mix of climate science and policy advocacy it’s hard not to take note when the country’s largest organization of weather specialists, the American Meteorological Society, gives this veteran climatologist its top honor.”
It seems we live during a period where passion is valued much more than wisdom even by scientific societies.
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1. Global Warming Twenty Years Later: Tipping Points Near, by James Hansen, Address to the National Press Club and Briefing to the House Select Committee on Energy Independence, Washington, June 23, 2008
http://www.columbia.edu/~jeh1/2008/TwentyYearsLater_20080623.pdf
Photograph of Dr James Hansen republished from Phil Aroneanu’s blog post here: http://itsgettinghotinhere.org/2008/06/24/20-years-later/
I said:
Okay, here it is:
Consider a spherical body at a constant absolute temperature T. Now surround that spherical body by a concentric spherical shell A of very slightly larger radius and then surround that by a concentric spherical shell B of very slightly larger radius than A; surrounding this all is empty space (i.e., at an absolute temperature of 0). Assume that all three bodies are perfect blackbodies. [The assumptions such as the objects being perfect blackbodies and the radii of the shells being only slightly larger than the radius of the sphere should not be necessary to show the basic effect...But they are necessary to make the problem tractable enough to be a problem one could give to first-year physics students.]
(a) Derive the steady-state temperature T_A of Shell A when Shell B is not present.
(b) Derive the steady-state temperature T_A of Shell A and T_B of Shell B when Shell B is present.
(c) What is the net radiant heat flow (W/m^2) between Shell A and Shell B?
The answers are
(a) T_A = T / 2^(1/4), which is ~0.841 T.
(b) T_A = T * (2/ 3)^(1/4), which is ~0.903 T and T_B = T / 3^(1/4), which is ~0.760 T.
(c) (1/3)*sigma*T^4 from A to B.
So, what we have is a situation where the addition of the Shell B has caused the temperature of Shell A to be higher than it would be in the absence of Shell B (~0.903 T instead of ~0.841 T), yet Shell B is at a lower temperature than Shell A. This is the sort of situation that G&T claim would violate the Second Law of Thermodynamics, i.e., that we have warmed an object (Shell A) to a warmer temperature than it would have an the absence of the “back-radiation” from a cooler object (Shell B).
Of course, as you can see, the net heat flow is from Shell A to Shell B and thus the 2nd law is not in fact violated, just as is true of the earth / atmosphere case where the net flow of heat is from the earth to the atmosphere and yet the presence of the IR-absorbing atmosphere still results in the earth being warmer.
Personally, I think that it would be pretty cool as a first-year physics student to be able to demonstrate that two PhD theoretical physicists are wrong!
Joel Shore…thanks for reply. I can’t reply at this time but I will respond in a few days. The fundamental problem I have with your mathematical analysis is that it ignores the problem of radiative heat flow between two bodies. You are describing a black body transfer which applies normally to a continuous spectrum of radiation at higher temperatures than those found in the atmophere. Also, your physical description using two concentric spheres around a sphere at constant temperature does not describe the atmophere-surface interaction for me.
I would prefer to see an analysis using known amounts of CO2 and it’s ability to absorb and retransmit IR. In the NASA article I linked to for SJT, they admit that energy budgets are not known precisely for the atmosphere. From what I have read, only a theoretical analysis of the energy exchange between surface and atmosphere have been attempted. Even your thought experiment is highly theoretical. True blackbody radiators are a theoretical concept and no one knows where the low temperature atmosphere-surface interface falls into that theory.
It’s one thing for you to give your thought experiment to first year physics student and quite another for them to go out and prove it. Then again, that’s how paradigms are cemented into the heads of undergraduates. They either swallow the bs or they fail. Later, as graduate students, they wont get far unless they are ready to accept what the profs say. Even with a doctorate, they are usually obliged to buy into the paradigm of the faculty and university they will be employed at.
Gordon Robertson says:
Thanks, Gordon. I look forward to it. In the meantime, I will try to respond briefly to the points that you bring up.
I am not sure what you mean in your first sentence. In fact, my analysis is precisely an analysis of radiative heat flow between the bodies, the bodies in question being blackbodies as this makes the problem easily tractable. Also, I am not sure what you mean by your second sentence. The radiation spectrum for a blackbody radiator can be defined for a body at any temperature. In fact, in astrophysics there is the so-called “3-deg background radiation” which is at only ~3 K above absolute zero.
Well, I am not trying to give a complete physical description of the atmospheric greenhouse effect. What I am trying to do is respond to the following argument from G&T that you summarized thusly (actually arguably better than they summarized it themselves):
Hence, to show that this argument is incorrect, it is useful to show that there is a much simpler problem, so simple that we can solve it exactly, that illustrates exactly what G&T claim cannot occur: Namely, the presence of an object Shell B (analogous to the IR-absorbing atmosphere) that “back-radiates” onto an object Shell A (analogous to the earth) causes Shell A to be at a higher temperature than it would be in the absence of Shell B. Hence, this shows that what G&T claim constitutes a violation of the 2nd Law of Thermodynamics does not in fact constitute such a violation at all.
Furthermore, this simple problem illustrates the hole in their logic: They seem to assume that if Shell B causes Shell A to be at a higher temperature than it would be in the absence of Shell B, then the net flow of heat must be from Shell B (which is colder) to Shell A (which is warmer), which would indeed be a violation of the Second Law. However, what I have shown is that the net flow is still from Shell A to Shell B. Shell A is warmer with Shell B there than without it there not because there is a NET flow of heat from Shell B to Shell A but rather because Shell B is able to radiate back to Shell A ANY of the heat that Shell A radiates whatsoever (because when Shel B is not there then, of course, it doesn’t).
I’m not going to try to explain the entire CO2 atmospheric greenhouse effect to you from first principles. I myself haven’t read back through all of the original papers…This is old settled science that even skeptical scientists like Richard Lindzen agree with (i.e., that doubling CO2 produces a radiative forcing of somewhere around 3.7 to 4.0 W/m^2). If you want to learn more about it, I suggest the link that I gave you before to the history by Spencer Weart at the American Institute of Physics which can provide you with background, history and references: http://www.aip.org/history/climate/co2.htm
And, while it may be true that ideal blackbody radiators are a theoretical concept, the fact is that many materials approach pretty close to this ideal. Furthermore, it is irrelevant for the basic point of discussion (which was whether the basic picture of an IR-absorbing atmosphere which is colder than the earth nonetheless warming the earth relative to what its temperature would be in the absence of that atmosphere constitutes a violation of the 2nd Law of Thermodynamics).
You have a pretty cynical…and, in my experience, inaccurate…view of how things work in our colleges and universities, at least in the physical sciences. Students disagree with their professors all the time…And sometimes the students even end up being correct. And, faculty often vociferously disagree with each other.
However, in this case, the problem that I have presented is simple enough that I am rather doubtful that there is a major error in it. And, of course, unlike G&T’s conclusions, it is perfectly in line with over a hundred years of understanding of the issue by thousands of scientists.
By the way, here is a website where the author, one Alistair Fraser, who is an emeritus meteorology professor gives what he feels is a simpler and more correct statement of how the greenhouse effect warms the earth: http://www.ems.psu.edu/~fraser/Bad/BadGreenhouse.html (see also the FAQ he links to at the bottom).
I think he is a bit militant in his views that his statement is the only thing you should ever say in regards to the greenhouse effect. But, strictly speaking, I suppose he is correct that statements such as “re-radiates” and “traps radiation” are sort of shorthands that can lead to confusion. At any rate, his is really a pedagogical argument more than a scientific one. (In fact, it is interesting to contrast with G&T because I think that in the examples that they give, they are really making essentially pedagogical objections to the explanation of the greenhouse effect but then they use these to essentially argue that the science is actually wrong. If they simply stuck to improving pedagogy, like this fellow, they might actually be useful rather than destructive.)
Back to original Thread: I have found Joel Shore’s contributions very constructive, but he has yet to address why the alleged increase in global mean temperature of about 0.7oC from 1900 to now, which Hansen believes is mainly due to the 40+% increase in atmospheric CO2 (i.e. [CO2]) over this period, has been bad, and why any further warming attributable to a further 50% increase in [CO2] would be worse, when set against the undeniable benefits of increasing [CO2] for world food production. Why does Hansen invariably miscalculate the airborne fraction (AF) of CO2 emissions, which has averaged only 43% since 1958 (Canadell et al PNAS 2007)*, while he and Sato claim 60%? (PNAS 2004)? Why does he never consider what becomes of the [CO2] taken up by the oceans and biosphere? Is the increase in terrestrial absorption of [CO2] from 0.5 GtC in 1958 to over 3 GtC now a BAD THING? Does Hansen truly believe that reducing [CO2] to 350 ppm or less would have no impact on the productivity of the biosphere? Do you share and support Hansen’s apocalyptic vision based as it is on wilful suppression of the truth about the benefits bestowed on humanity by the increasing CO2?
* The Canadell et al PNAS paper and their associated Global Carbon Project are a good source of data but not of growth rates; the fact of ever increasing world food production (FAO)does not support their claim of a declining capacity of the terrestrial sink.
“undeniable benefits of increasing [CO2] for world food production” – we’ve been over this how many times now
when you calculate out the hydrological cycle winners and losers , invasion of rangelands by C3 woodies, and major effects of increased frost sensitivity with higher CO2 – get back to us.
Don’t give us some piddly greenhouse trial result in ideal circumstances, or a try-on that yield increases in the field have nothing to with improved agronomy or genetics
In any case ocean sinks may be shutting down –
http://www.sciencedaily.com/releases/2009/01/090102101045.htm