I am not a climate warming skeptic. I am a skeptic about everything, especially about scientific claims made by those, like Al Gore and the Coal Alliance, who have a political agenda. For that reason, I follow the climate change debate with a skeptical eye for claims made on either side.
Among those skeptical of alarmist claims about human-caused, or anthropogenic, climate change are some of undoubted ability whose critical evaluation of the work of the mainstream school of climate science, which is closely wedded to projections of massive climate disruption due to human activity, deserves careful attention.
However, because of the politics, much skeptic clamor is as preposterous as any of the nonsense with which Al Gore has managed to pervert the course of public debate and embarrass the scientific community. In some cases, the nonsense is surely propagated with the deliberate intent to deceive, but in most cases the spread of nonsense is likely driven solely by wishful thinking, something that is with us always.
An example of the apparent will of the climate skeptic to believe is provided by the ongoing debate at Tallbloke's Talkshop and at Anthony Watt's web site concerning the "Gravito-Thermal Hypothesis" of Hans Jelbring, a debate of such intensity as to create moments of severe inter-Skeptic friction (and here).
The Jelbring hypothesis is quite obscure. So obscure in fact, that it has been claimed that no one understands it well enough to explain it. But what the hypothesis asserts is that the greenhouse effect:
...can be explained as ... a consequence of known physical laws describing the behaviour of ideal gases in a gravity field.Now this is a radical claim, published it should be noted, in a peer-reviewed scholarly journal. To understand why it is radical, one needs to be clear as to what the greenhouse effect is.
The so-called greenhouse effect has in fact little to do with greenhouses, but consists in the increase in the Earth's surface attributable to the presence of the atmosphere.
The way that the atmosphere raises the Earth's surface temperature is not immediately apparent. Ignoring internally generated heat, the Eath's surface temperature is largely determined by the amount of radiation received from the Sun. Thus the surface is usually warmer during the day than at night and warmer during the long days of summer than during the short days of winter.
The Sun does not, however, raise the Earth's temperature continuously, because the Earth emits energy to space in the form of heat (i.e., infra-red radiation), at a rate proportional to its temperature. Thus the Earth's temperature fluctuates around a stable equilibrium value, such that planet-wide incoming solar radiation matches planet-wide outgoing infra-red radiation (averaged over the course of the year). Thus any warming tendency is counteracted by an increase in surface temperature and hence an increase in outgoing radiation. Conversely, any cooling tendency is counteracted by a decrease in surface temperature and hence a decrease in outgoing radiation.
Thus, the presence of an atmosphere will make no difference to the mean, planet-wide year-round temperature at the Earth's surface, provide it is transparent to all radiation.
However, the Earth's atmosphere does affect the temporal and spatial distribution of heat at the Earth's surface by acting as a thermal buffer. For example, it cools the surface during the day, while warming it night. But here we are concerned only with mean, year-round, planet-wide surface temperature which is dictated by the radiant energy balance, and so the temperature buffering effects of the atmosphere, or for that matter of the oceans and Earth's crust, can be ignored.
Moreover, the atmosphere does raise the temperature of the Earth's surface because it is not transparent to all radiation. Although nitrogen and oxygen, the chief constituents of the atmosphere are essentially transparent to solar and infra-red radiation, the atmosphere also contains trace amounts of water vapor, carbon dioxide, methane and ozone, the so-called greenhouse gases (plus water droplets in clouds), all of which absorb radiation, particularly in the infra-red portion of the electromagnetic spectrum.
When a molecule of greenhouse gas absorbs radiation, its temperature, i.e., its kinetic energy or velocity, is raised above the ambient temperature. In time, this energy is either transmitted through collision with circumambient molecules to non-greenhouse gases such as oxygen and nitrogen that make up most of the atmosphere, or it is emitted as infra-red radiation. The radiation may be emitted in any direction, which means that some will intercept the ground and cause surface warming. This is the greenhouse effect that keeps our planet at a temperature consistent with organic life, which is to say approximately 33 K above what it would be without a greenhouse effect. The effect is evident in the difference in temperature usually experienced between clear and cloudy nights. The clouds act as radiators, beaming infra-red radiation to the ground and substantially raising the temperature.
But not so, according to Hans Jelbring.
Jelbring contends that the greenhouse effect is almost entirely the result of a gravitational effect on the atmosphere. Unfortunately, precisely what this effect is supposed to be, no one, as noted above, seems able to clearly explain. However, without overly straining one's intellect to understand the theory, one can rather more easily consider its implications and the empirical evidence that would support it.
If Jelbring is correct, it would mean that even if a planetary atmosphere were entirely transparent, which is to say free of greenhouse gases and thus incapable of either absorbing or emitting radiant energy, it would nevertheless raise the surface temperature of the planet above what it would be without an atmosphere.
What does that imply? First, that by raising the temperature of the surface, the atmosphere must raise the outgoing radiant flux at the surface, which in turn, means an increase in radiant flux to outer space, if the atmosphere is entirely transparent (i.e., free of greenhouse gases). In fact, it means that the planet would be at least slightly luminous (i.e., outgoing radiation would exceed incoming radiation). But that is not what CERES (Clouds and the Earth's Radiant Energy System) experiment satellite measurements indicate.
There are other implications that raise even more fundamental issues. For example, if as Jelbring claims, gravity is responsible for the atmospheric temperature lapse rate, this implies a refutation of the second law of thermodynamics, the rule that outlaws perpetual motion machines and free everlasting energy.
It is not inconceivable, therefore, that excitement in the climate skeptic camp about Jelbring's thermo-gravitational hypothesis stems, at least in part, from wishful thinking, not sound scientific analysis.
Consistent with this conclusion, Jelbring's paper, published in 2003, has been cited in the scientific literature only twice, and both citations are in the same journal, Energy and Environment, as the original paper.
According to SCIMAGO, an independent journal ranking agency, Energy and Environment is a low ranking journal in terms of prestige and citations of articles in the rest of the literature. For example, on the Scimago journal prestige ranking index Energy and Environment ranks fortieth out of 49 journals concerned with energy and the environment with a score of 0.03 versus a score of 0.73 for the top journal in that category and scores of 7.8 and 10.0 for Nature and Cell, respectively.
If we turn to the journal itself, we see that the Editor is Sonja Boehmer-Christiansen, who, if we look her up here, appears to be no mean scholar. She is the author of a number of frequently cited books and journal articles. However, she has not published in the fields of either climate science or physics. Moreover, according to Wikipedia, she is is an Emeritus Reader in Geography at the University of Hull in Kingston-upon-Hull England, which leads one to question her competence to determine the fate of a paper that challenges a fundamental law of physics. Wikipedia also tells us that the journal Energy and Environment, which she has edited since 1996 is aimed at, among others, "the international social science and policy communities," hardly a group liable to provide critical assessment of the thermo-gravitational hypothesis.
Wikipedia also states:
According to Fred Pearce, Boehmer-Christiansen is a sceptic about acid rain and global warming and calls the science reports produced by the Intergovernmental Panel on Climate Change "political constructs." Real Climate, a prominent blog run by climate scientists, asserted in 2011 that her journal once published a paper that claimed that the sun is made of iron; Boehmer-Christiansen responded that the claim was falseWe can say, then that Jelbring's highly questionable thesis was published in a journal of minimal scientific significance edited by a scholar of limited or non-existent credentials in the field with which Jelbring's paper deals [though we think Prof Boehmer-Christiansen, sure has the IPCC weighed up right].
The journal has an Editorial Advisory Board, but the membership does not appear strong in the physical sciences. For example, Maarten J. Arentsen holds a Master’s degree in political science specializing in scientific methodology and political modernization; David J. Ball, is Professor of Risk Management, Middlesex University, Hendon, UK; Max Beran, Independent Environmental Services Professional, Oxford, UK; etc.
None of which proves that Jelbring's hypothesis is unquestionably wrong. Perhaps the Earth really does glow in the dark, and perhaps the second law of thermodyamics will have to be repealed. But for now, mainstream science is ignoring the thing, and are probably none the worse for doing so.
Revised January 22, 2012