The Becker-Posner blog has recently been discussing environmental policy and it should be noted that they are espousing some beliefs that are becoming more and more prominent in the conservative world. More specifically, both Posner and Becker argue that there is enough evidence that global warming is proceeding that governments need to take preemptive measures. They diverge in their opinion as to what these measures should be (Posner specifically endorsing the Kyoto Protocol).
I think this is a common change of heart that has not been recognized either by the Bush Administration or conservatives more generally. Essentially the thought process seems to be one that argues that the risks of global catastrophes tied to global warming are too severe to ignore, despite the fact that the probablity of their occurrence is difficult to gauge.
Now maybe the debate can shift to where I believe it should've been for quite awhile...how Kyoto and other international environmental treaties can be made more effective and efficient.