[Right Wing Professor]

Running the numbers yields a 0.6 C increase for the current 350ppm CO2 (increased from 280).

That IMO is slightly low, but not unreasonable.

The highest projected increase in CO2 (which IMO is unlikely) yeilds another 1 degree C.

You think atmospheric CO2 will top off at 470 ppm? Why?

[palmer]

No, I think 550ppm is a reasonable rough high end. The 550 (or 560 IIRC) increase from 350 yields one more degree C increase. After that the sequestration will kick in big time.

BTW, the temperature increase is not linear, but logarithmic: see http://motls.blogspot.com/2006/05/climate-sensitivity-and-editorial.html: You should realize that the carbon dioxide only absorbs the infrared radiation at certain frequencies, and it can only absorb the maximum of 100% of the radiation at these frequencies. By this comment, I want to point out that the "forcing" - the expected additive shift of the terrestrial equilibrium temperature - is not a linear function of the carbon dioxide concentration. Instead, the additional greenhouse effect becomes increasingly unimportant as the concentration increases: the expected temperature increase is something like

* 1.5 ( 1 - exp[-(concentration-280)/200 ppm] ) Celsius

[Dominic Harr]

• The Earth has been warming since the last Ice Age.

• The temp has increased faster in the past.

• There were no factories, autos, etc, then.

• Therefore, it is highly unlikely that factories, autos, etc are to blame.

By specifically leaving out this 'contextual info' that would prove them wrong, the 'Co2 is killing us' folks have really pulled a good one.