Help! -- climate change

Some of the readers of this blog know much more about climate change than I do. Could someone please comment on this web page of Eric Baum's, in which he claims the evidence for human causation is weak and that state of the art climate models are shoddy? (Excerpts below.) Baum is a brilliant guy -- former theoretical physicist and AI researcher. I've recommended his book on AI here before.

Greenhouse Gas global warming (as opposed to other sources) should be measured in the tropical troposphere, because the models say that is the signature of greenhouse gas warming: the tropical troposphere should warm at roughly twice the surface rate. To verify this, see for example Figure 9.1, p675, Vol 1 IPCC Report. http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter9.pdf (The whole report can be found at http://www.ipcc.ch/ipccreports/ar4-wg1.htm .)
This was always an embarrassment for global warmists, because the troposphere has never warmed much, but in the last few years its cooled. The tropical troposphere has now not warmed at all. See http://www.climateaudit.org/?p=3048 for the graph of temperature according to three satellite series since 1978.

The Radiosonde (weather balloon) data series is an independent measurement of the tropical troposphere temperature. It goes back to 1958 and is presumably extremely reliable, because all they are doing is sending thermometers up in balloons. You can see the time series at: http://www.climateaudit.org/wp-content/uploads/2008/06/hadat42.gif The graph is flat, and the most recent data point is the coldest.

...This shows that the IPCC's GCM's (Global Circulation Models) are wrong. Not that it can be too surprising that the GCM's are worthless since p 596 of the IPCC 4th report cautiously admitted they didn't know whether their GCM's had more data points or free parameters! Yet the GCM's are absolutely central to any argument for expecting warming by more than a few tenths of a degree by 2100, and to the amazingly porous argument the IPCC report gives to demonstrate man caused the alleged observed warming.

...The IPCC 4th report says "attribution of anthropogenic climate change is understood to mean demonstration that a detected change... is not consistent with alternative, physically plausible explanations."[p668] But the report contains several alternative possibilities that are said to be "not understood" or whose magnitude is said to be "largely unknown". For example, two are mentioned just in the last paragraph of 1.4.3. (p108): unknown large feedbacks from changes in solar irradiance, and the effects of galactic cosmic rays. Actually, as I point out in the above few paragraphs, cosmic rays seem to explain climate fluctuations extremely well. The IPCC devotes considerable space to the strawman that solar activity could directly affect the earth's temperature, but ignores the actual indirect means by which solar variation seems to affect temperature. Global Warmists routinely attack the strawman of direct solar effect any time the subject is raised.

Also, Mars, Jupiter, Triton, Neptune, and Pluto have recently been observed warming, suggesting some cause external to the earth, but none of them are mentioned anywhere in the 987 pages of the 4th Report. Another physically plausible explanation for recent warming (if indeed warming has actually occurred) as remarked by Lindzen would be thermal transfer from the deep oceans. The oceans and atmosphere are turbulent fluids prone to exchange heat in unpredictable ways over a wide range of time scales simply because chaotic systems do that kind of thing, which the computer models of the IPCC are completely inadequate to simulate.

Its also worth noting that intuitive physics (and pencil and paper calculation) says that greenhouse gas warming scales logarithmically. The theoretical reason for the effect is that CO2 molecules (for example) absorb and reflect certain wavelengths. But they only do it in certain wavelengths. Once you've got some molecules of CO2 in the air, the effect of each next molecule is less than the one before, because those wavelengths are already getting scattered, and mostly heat is already only getting out in other wavelengths. So even if you believed everything else, one's expectation would be that we've already seen the substantial majority of all the warming we will ever see, if we quintuple the CO2 from here. To believe otherwise, you have to rely in detail on the GCM's prediction of positive feedbacks, that they are not competent to calculate, to predict warming in the future that is several times greater than anything we've seen before.