In response to a letter written by the editor-in-chief of Scientific American, Pournelle has written one of the clearest expositions I've seen yet on why we should not begin immediately to enact the Kyoto protocol recommendations:
...assume that we put the money into reducing CO2 and it turns out the earth isn't warming; we will merely have wasted the money. But suppose it turns out that global warming is real, but it is caused by solar output. We will have spent a great deal of money, but not on ameliorating the effects of global warming: instead it will have been spent on crippling the economies that might generate the funds needed for a crash program to save lives as the Earth warms.
Tampering with the industrial sinews of the world will have real consequences. It may need to be done, but make no mistake, it will be costly. (Unless you believe that command economies are more efficient than markets; I presume that particular economic canard has been laid to rest?)