Doug Z wrote >>
Among Republicans, belief in anthropogenic global warming declined from 52 percent to 42 percent between 2003 and 2008.
And among Democrats?
P.S. It's irrelevant, save to the political activists, whether it's anthropogenic or not. If a Manhattan-sized meteor were streaking towards Earth, it would not be anthropogenic, but would still require a concerted and directed response. If global warming does exist and is caused by natural geological phenomena, but those phenomena do in fact pose significant threats to human life, the effect would be the same--minus the opportunity for gratuitous finger-pointing at defenders of industrialization. What matters, assuming arguendo that the phenomenon does in fact exist, is the severity of the problem (loss of some borderline-arable farmland, or all of Indonesia underwater?), our response capabilities (can we stop 1% of it? 99%?), and the costs of doing so ($40 billion for energy efficient homes or $40 trillion for a complete abandonment of all carbon-based energy sources?).
If you dig into the IPCC's most recent report (or at least, it was at the time I did so), there is actually a not-inconsiderable degree of evidentiary support in there for the conclusion that global warming may in fact be transpiring, but that the costs of prevention far exceed the costs of adaptation, because only the most radical (by several orders of magnitude) projections actually involve the Waterworld/AI/Innocent Venus scenario.