AGW (thank you Andrew for the acronym), practically and politically, is little more than a replacement for the Cold War. Something huge and intractable to keep us all beholden to the crop of wondrous politicians we are so fortunate to have.
Of course, if there is a problem, then that problem is surely man-made. For, only by accepting this premise can we (humankind) hope to be able to deal with it, and in spite of the ludicrous profiteering schemes (emissions trading etc.) there is some worthwhile work going on, and much yet to do.
http://www.guardian.co.uk/environment/2012/aug/21/alternatives-food-based-biofuels