I never saw the movie - I prefer to get my science info from scientists, not politicians. But yes, I do think global warming is real. One good source on the issue is RealClimate.org. Here's a quote from their review of the movie.
"For the most part, I think Gore gets the science right, just as he did in Earth in the Balance. The small errors don't detract from Gore's main point, which is that we in the United States have the technological and institutional ability to have a significant impact on the future trajectory of climate change. This is not entirely a scientific issue -- indeed, Gore repeatedly makes the point that it is a moral issue -- but Gore draws heavily on Pacala and Socolow's recent work to show that the technology is there."