  With all this talk of Roland Emmerich's movie floating around, I thought I'd point out a more interesting science fictional resource on the matter of global warming. David Brin's novel urlLink Earth portrays a world in the not-too-distant-future where a great deal has changed. The novel has its own weird excesses toward the end, but seems to do better at getting the science of global warmning (and in tracking its effect on global society) right. There is a lot here, though, including the aftermath of a war against Switzerland to create a transparent society (that is, a society with no privacy, which Brin discusses in a social sciences context in urlLink The Transparent Society ), and a small black hole that slipped into the center of the Earth, which gives this novel its own disaster movie flare.
It's representative of some of the best hard science fiction around, melding hard science with a nuanced view of social relationships and how they might disintegrate in the face of impending doom. Of course, the politics of Brin's book are too complicated, and too real, for Gore and Emmerich to deal with.
They'll take the easy way out. I also saw, in the bookstore today, a new novel my Kim Stanley Robinson (whose urlLink Mars books grapple with the equally thorny issue of Martian terraformation) called urlLink Forty Signs of Rain which seeks to cover the political terrain of the issue as it unfolds. Robinson is good with both politics and science, so I think it's a good bet. 
