Having finally gotten around to seeing Al Gore's global warming film, I came away thinking it is being overpraised.
This being a film, the science had to be simplified due to time constraints. That's always true. But Gore simplifies by ignoring important points. To him, all recent warming of the Earth is human-caused. No time is spent on the important issue of how much of the measured warming can definitely be ascribed to human actions and how much is normal long-term change expected for a planet in an interglacial warm period.
The visual effects are mostly effective, even if some (like the drowning of Manhattan) illustrate "worst case" scenarios that Gore presents as likely, if not certain. Gore blames Hurricane Katrina on human-caused warming, which is hardly established fact, and, in a litany of side effects of warming, he includes the emergence of drug-resistant tuberculosis. (Huh?)
While Gore mainly points the finger at the U.S., he does a good job of making it clear the situation is global by spending some time on the contribution to greenhouse gases made by China's rapid population and economic expansion.
At one point, Gore throws out a very important statement that needs support. He says that if we "do the right thing" (changing energy technologies, ending greenhouse gas emissions) we will "create new wealth and jobs." That may be true, but it requires explanation, especially when not a word is said about the costs (hundreds of billions of dollars, on a global scale) involved in changing over from fossil to renewable energy.
As a movie, the film meanders. Detours on Gore's personal life and political experiences make the viewer suspect this is a bit of a campaign commercial as well as an environmental film. There are bits that don't make sense (the weird Simpson-ish animation near the beginning, for example) and could have been replaced with more scientific information.
Overall, Gore set out to make a point here, and he generally does it well. He's become more relaxed and engaging than he was as a candidate, although my 10-year-old (who watched with me for a school assignment) still compared him to a "really boring teacher." Still, there is too much oversimplification and overstatement involved in driving the point home. Gore leaves himself open to criticism, some of it accurate, that could have been avoided if the film spent more time on the science of the core subject and less on everything from Gore family farm to non-warming-related extinctions.
So see the film, but don't take it as the whole story of a complex subject.