I think the key is that most people don't care whether or not AGW is occurring unless they can expect it to affect them. Since changing policy will negatively affect them immediately via increased taxes, decreased manufacture, etc., it's easier to just say they don't believe in AGW period. If the key counter-AGW measure on the table were funding for carbon-capture research, I think many fewer people would claim that they didn't believe in AGW.

My take on global warming is that no policy that has significant impact on the problem will be implemented until the frequency of droughts/hurricaines/floods/fires increases to obvious levels in the western world (fuck-Bengali policy is already in place, and I don't think more famines will change that). And by obvious, I mean obvious to a layman, as in 'when I was young we only had 1 hurricane per year, and now we have 10!' By this time, the only option will probably be technological.