[anamax]

> (In particular because one can derive a correlation between atmospheric CO2 and average global temperature directly from the properties of CO2.)

Except that if you actually do the arithmetic, you find that the "heat trapping" properties of atmospheric CO2 concentrations can't produce the claimed temperature increases. That's why the AGW folks talk about the feedback effects, effects which are dependent on other things.

Note that the paleo record shows much higher levels of CO2 in the past (2-10x) with comparable to today temperatures....

[colah]

Well, we're actually in a discussion of the magnitude of its effect at this point... (Which could lead to the discussion of whether there could be multiple causes for climate change rather than _just_ rising CO2...)

Like any chaotic system, it is difficult to predict the outcome, just that temperature is likely to increase. Think about the Mandelbrot set.

In any case, this is where one needs to look at other evidence.