Don't call it a comeback—former Vice President Al Gore has been honing his presentation on global warming for years. Now, director Davis Guggenheim has brought Gore's well-researched, sometimes humorous slideshow to a wider audience and, some might say, to life in An Inconvenient Truth.

Those who know Gore only for his eight years as vice president and his 2002 appearance on Saturday Night Live may not realize he's been doing political stuff like battling the forces of global warming for most of his adult life. In this documentary, he put his onscreen talents to work driving his message home: Climate change is here. We did it. It's not part of the natural cycle—it's off the charts.

Recently, President George W. Bush quipped that he had no plans to see An Inconvenient Truth. Guggenheim, in an interview shortly after his return from the Cannes Film Festival, told WW he wasn't surprised. "Do I expect Bush to watch the film, no, but I know that if he did it would change his mind," said the director. "Anyone with an open mind will learn something."

In the wake of the film, Gore's cachet has seemingly done a 180, leading pundits like Arianna Huffington to write, "In Washington, the talk was all about 2006. In Cannes, the talk is all about 2008."

But Guggenheim says those who are engaged in political second-guessing about a second run for the White House for Gore are missing the point of the film. "His focus is solidly and completely on the issue of global warming and waking people up. That is his campaign," says Guggenheim.

While An Inconvenient Truth might not be the most romantic date movie or a pick-me-up for depressive viewers, Gore's message is far from apocalyptic. He wants us to know that now is the time for us to get off our butts and start tackling the greatest crisis in the planet's history. (And that he should be president.) PG.

An Inconvenient Truth

opens Friday, June 9.