Some physics offerings for the profferings of persons of interest to the psychology community
There are also a number of climate "skeptics" who have a physics background. I'll talk a bit more about Freeman Dyson and Will Happer later in this note. Among blogger and blog-comment "skeptics" there are several who prominently tout their physics background - Lubos Motl for instance - asserting that their physics expertise in some way makes their commentary on the subject more relevant. Of course I have used much the same stance myself - arrogance isn't confined to those who are wrong... Most recently Nathan Myhrvold, with a triple dose of arrogance in his physics PhD, his information technology background and his long tenure at Microsoft has come out as a climate skeptic - or at least a skeptic on the merits of solar energy. Though perhaps he was misquoted, as others have been.
But the first example I want to look at in detail, because the violations of the standards of science are so egregious, is the case of two German physicists and some of their colleagues who have come to their defense. In July 2007, Gerhard Gerlich and Ralf D. Tscheuschner posted this article (a version of which has, even more remarkably, actually appeared in a scientific journal) that claims to "falsify" the "atmospheric CO2 greenhouse effects" - i.e. the entire premise of a greenhouse effect in the first place.
This isn't merely old-guard reactionism, in this case. Gerlich and Tscheuschner are claiming that the greenhouse effect discovered by some of the founders of thermodynamics itself over 100 years ago (Fourier and Tyndall) violates those same laws of thermodynamics. That is a stunningly bold and arrogant assertion. If they were actually right, it would be of monumental importance. Surely, to avoid embarrassing themselves, they must have been very careful to understand their subject before diving in? But the arrogance of physicists, in some cases at least, knows no bounds.
There are dozens of ways to show that the greenhouse effect indeed involves no violation of the second law of thermodynamics, that net heat flows in the system are always from the hot sun to the surface of the Earth and up through the atmosphere; the colder atmosphere does not "heat" the surface in the second-law violating sense that Gerlich and Tscheuschner assert. Figuring out why they think it does anyway is a problem of psychology, not physics.
But they also assert (essentially 4 of the six claims in their original abstract) that the whole framework describing the natural greenhouse effect is fundamentally wrong. That framework uses balance of energy flux (the first law of thermodynamics) and a variety of averages over Earth's surface to show the natural greenhouse effect has warmed our planet's surface by at least 33 degrees Celsius, above what it would be without infrared-trapping gases in the atmosphere. In February 2008 I posted a response using the most straightforward-possible mathematical reasoning in a Proof of the Atmospheric Greenhouse Effect. This was of course no new scientific result - Fourier and Tyndall had it right in the 19th century. Nevertheless my posting received several interesting responses. First from some very prominent global warming "skeptics" who thanked me for my clear refutation of the nonsense of Gerlich and Tscheuschner, an article that they found personally embarrassing to be in any way associated with. But second, I was vehemently attacked on a variety of grounds, including apparently my ignorance of basic mathematics, by one Gerhard Kramm, who seems to have allied himself with Gerlich and Tscheuschner and comes to their defense at every opportunity. Arrogance amplified - interestingly half of Kramm's arguments also logically contradict Gerlich and Tscheushcner's paper, but it doesn't seem to embarrass any of them.
To briefly summarize the Gerlich and Tscheuschner argument on the 33 K issue and my refutation (and to pause in wonder that such logic could have been approved by the editor of a scientific journal) first let's make note of the essential, agreed-upon observations of the system:
(1) Earth's surface absorbs a certain pretty steady amount of total incoming energy from the Sun (some is reflected by the atmosphere or surface, so leave that part out)
(2) Earth's surface radiates essentially as a black body everywhere, which by the Stefan-Boltzmann law means the rate of radiated energy flow varies as the fourth power of the local surface temperature
(3) If Earth had no atmosphere, (1) and (2) would be the only heat transfers touching Earth's surface, so they have to balance in the long run. Using the standard equations you find an effective radiating temperature for the Earth of 255 K (-18 degrees C).
(4) There is a mathematical relationship between first-power averages and fourth-power averages that ensures that the average temperature must always be less than the effective radiating temperature (3).
(5) But the real Earth does have an atmosphere, and it also has an observed average temperature that is much warmer than 255 K - satellite and surface measurements agree on close to 288 K (+15 degrees C), for a difference of 33 K.
So the question is, what explains the difference between these two numbers, the 255 K effective radiating temperature of (3), and the observed 288 K average temperature of (5)?
The standard answer, as explained in my "proof" paper, is that the atmosphere's blocking of infrared radiation presents a barrier to the flow from Earth's surface, so to get the same energy flow rate out to space to balance incoming sunlight, the surface needs to warm up. The greenhouse effect. The conflict between observations (5) and (3) given the mathematical relationship (4) is proof that the atmosphere is having this real effect on our planet.
In Gerlich and Tscheuschner's paper, while acknowledging (and using) each of the above assertions, they also throw confusion on every one of them at the same time, and it is hard to follow the logic. In section 3.7.4 of their paper they present calculations for a planet in instantaneous balance with local incoming radiation, so that on the dark side of the planet (where no radiation comes in) the temperature is absolute zero, and corresponding temperatures on the warm side are inordinately hot. Computing the average temperature for their model planet, they find it a very cold 140 K (-133 C). This clearly satisfies the inequality in question (4 above) - in fact the two averages are expected to become all the more unequal the greater the divergence in individual measured temperatures that go into the averages.
To illustrate this, rather than going through the Gerlich and Tscheuschner case in full, look at a slightly simpler model with our planet uniformly at 0 K on one half, and 304 K on the other. Then the average temperature of the planet is (0 + 304)/2 = 152 K, not much warmer than the 140 K they found. The effective radiating temperature is ((0 + 304^4)/2)^(1/4) = 256 K, a full 104 degrees warmer. So it's easy to find a model of a planet where the average temperature is much lower than the effective radiating temperature, satisfying the inequality (4).
But this says nothing about how to get a planet with a higher average temperature than the effective radiating temperature. If the fourth power average is kept fixed, as it must be on a planet with no atmosphere, then the highest possible average surface temperature is when the temperature is completely uniform, all at the same temperature (255 K in Earth's case). Without an atmosphere there is no way to maintain a higher average.
All this Gerlich and Tscheuschner appear to agree with. Their eq. 89 is the same as my assertion (4) above. But they conclude from their mathematical model that the greenhouse effect increase in temperature is not 33 K, but a much larger number (their calculation shows that the "difference temperature that defines the natural greenhouse effect [can] explode"). And therefore "something must be fundamentally wrong here". And go on to make essentially hand-waving arguments about the invalidity of energy balance and how local temperatures are so variable you can't really average them. How they believe that any such measurement errors could mean Earth's actual average temperature is well below freezing, with a mostly liquid water surface, is still beyond me.
They have found no logical contradiction, only a contradiction to their (poor) intuitions. Let 'G' stand for the assertion that Earth's average temperature without an atmosphere would be less than or equal to 255 K (combining (3) and (4) above). If some model could be found that showed 'G' to be false, showing a temperature distribution on the surface that gave a higher average than the effective radiating temperature, then we might have an explanation of Earth's observed average temperature of 288 K that didn't involve the greenhouse effect. That would be a stunning achievement, deserving of their paper's title. But in fact every one of their examples shows 'G' to be true, and they even essentially prove it to be true. They assert it in their eq. 89. There is no logical disproof of 'G' anywhere in Gerlich and Tscheuschner's paper. And therefore no logical counter to the simple truth that the presence of Earth's infrared-absorbing atmosphere does indeed raise our planet's surface temperature by at least 33 degrees C from what it would be otherwise.
Any ordinary person would surely be embarrassed by such illogic, once the error was pointed out. Understanding how they got there and still apparently claim they are right to this day (after well over a year of people pointing out how they're wrong) is definitely a matter for psychology, and not physics.
arthur.shumwaysmith.com |
