well.. it's a little off topic, but Im a scientist and know a little about climate change, and I can assure you this topic, although incredibly loaded politically and economically, is definitely not "settled".

We seem to be about 1/2 way through a 500 year warming cycle driven by solar activity, over which we have no control. It was much warmer than today in Roman times and in the middle ages (during which there was a dearth of SUV's). It was much colder in the dark ages and in the "little ice age" of the 1600-1700's. CO2 (which, contrary to Obama statement, is neither "Carbon" nor a "pollutant") has risen about 20% since the dawn of the petrochemical age. There have been documented periods in history when it has been much higher and climate has been colder, as well as periods when it has been much lower and climate has been warmer. CO2 is a minor atmospheric constituent (~350 parts/million) emitted by all living animals (as well as by burning hydrocarbons and by volcanism) and consumed by plants. It is a much less powerful greenhouse gas than, for instance, water vapor (clouds). One of the side effects of higher CO2 is more verdant crop yields. Historically, mankind has tended to prosper in the warmer periods and suffered in the colder periods.

The models that predict disaster have been consistently poor at future extrapolations. In the 50's we blamed extreme weather on atomic bomb testing. In the 70's the predictions were for an impending ice age, with images of NY under a mile of ice. More recently, the "hockey stick" in temperature proposed by the IPCC (UN panel on climate control) has benn widely discredited. We should be very reluctant to risk large amounts of national treasure on such predictions.