http://en.wikipedia.org/wiki/Global_Warming http://en.wikipedia.org/wiki/Global_warming_controversy There is a strong consensus (not full) among scientists that the recent rise in temperature is human caused.
And as far as treaties such as the Kyoto Protocol; the US did not ratify this for two reasons: it would hurt the US economy, and other top polluters (China and India) were exempted from the requirements.
Regardless of our scientists' ability to predict weather patterns 100+ years out (I know they have a hard time predicting tomorrow's weather), I think that it would be prudent to make reasonable efforts to lower pollution rates worldwide.
