söndag 15 januari 2012

Tallbloke's buzzing Talkshop

Some week ago I discovered Tallbloke's Talkshop which has feautured several posts and discussions on for example Hans Jelbring's 2003 paper "Greenhouse Effect as a function of Atmospheric Mass" and a more recent paper of Nikolov and Zeller. These authors are courageous in the sense that they propose new theories raising important questions about apparent correlations between atmospheric pressure and temperature open for anyone to discuss and critizise. Proponents of the "official" greenhouse theory seldom offer us the same curtesy, since they almost never mention any sources of the often quoted 1C "no feedback sensitivity" from a doubling of CO2 for us to check and scrutinize. Moreover, many of them shamelessly support inconsistent statements on the reason why the temperature decreases with height in the first place. Since it is the IPCC and not Hans Jelbring who dictates climate policies, sometime I would like the table turned, and we could all contribute to this happening.
Nevertheless, I would like to air some of my own thought about the Jelbring hypothesis and those similar to it.

1. As far as I can see it is incomplete as regards to the boundary conditions. It doesn't predict any specific surface temperature as a function of atmospheric mass. One could argue that for certain physical reasons the surface temperature should have a certain value, and then temperatures at other altitudes will be recovered by following the adiabat. Or, you could argue that the temperature at 10km height should have a specific value, and then the surface temperature is recovered accordingly. This is not specified.

A correction: Nikolov and Zeller do indeed provide a formula for the surface temperature, but I still think it would be desirable to justify the fitted parameters with boundary conditions.

2. As far as I can see there are no conclusive arguments from either statistical mechanics nor Navier-Stokes equations supporting the conjecture that the equilibrium configuration of the atmosphere should be adiabatic rather than isothermal. But this does of course not exclude the possibility that our thermometers measure the wrong temperature almost everywhere, or that any of the physical models referred to are invalid.

3. It does not predict the existence of a stratosphere. One reason that could be raised is that the lapse rate is reversed at a certain altitude because of the absoption of UV-light by ozone. But if this explanation is proposed then you could equally well argue that the surface maintains a higher temperature because of the absorption of sunlight at lower frequencies. 

Which leads to my last point. What would happen to the temperature in your house during winter if you were to double the thickness of your walls. It would probably increase because a thicker wall slows down the cooling. Now think about it, a thicker wall means a more massive wall, and there you have it: Greenhouse Effect as a function of Atmospheric Mass. This is of course just a conjecture that needs the same scrutiny as any other theory. But I believe that this is an approach that has until now been largely neglected.

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