As I prepare to review An Inconvenient Truth, directed by Davis Guggenheim, my news feeds inform me that America's "fair and balanced" news source is already launching a frontal attack on the movie. "If people buy into [Al Gore’s] global warming hysteria, will it put him in the White House and our economy on the skids?" Fox News host David Asman asked of his guests this weekend. Note the clever framing of the question: the hysteria is a given, and all we're supposed to be interested in are the consequences, most likely dire. Other commentators are even less circuitous in their slander.

And Fox News is not alone. Pundits all over the blogosphere are wondering aloud if the movie marks the beginning of a possible Gore run for the Presidency in 2008--and what about his tuxedoed appearance at Cannes!? With all the noise, one begins to suspect that their true purpose is diversion: if we focus on Al Gore's personality or spend time speculating on his Presidential aspirations, perhaps we won't take notice of the film's carefully elaborated argument. Maybe we'll even forget about global warming.

"Hysteria" is just about the last word that comes to mind in describing An Inconvenient Truth--the film's approach is rational to a fault. With a little help from Simpsons creator Matt Groening and state-of-the-art flat screen monitors, An Inconvenient Truth lays out Gore's case: we are now seeing the beginning of a climate crisis that threatens life on Earth as we know it. The on-screen evidence is difficult to dismiss--charts and graphs reveal frightening trends, and the film loses no time showing us the destruction of Hurricane Katrina along with a series of comparative photographs from disappearing glaciers around the world, footage of collapsing ice shelves, data on the record numbers of storms, floods, and other kinds of extreme weather, animations of the effects of rising sea levels, new diseases, photos of dying polar bears and disappearing coral reefs. "A nature hike through the Book of Revelations," Gore calls it.

Gore, who estimates that he has given his global warming presentation about a thousand times all over the world, builds his argument with measured, road-tested ease. He is no scientist, but he manages to convincingly portray himself as an expert on the topic. Short segments offer brief biographical sketches that dramatize Gore's personal dedication--here he is onboard a nuclear submarine surfacing in the Antarctic, here he is reminiscing about the 2000 election and his sister's death from lung cancer. These digressions always tie back into the film's argument rather than functioning purely as puff pieces.

Gore insists that global warming is not a political issue at all--it is "a moral issue." With evenhanded precision, he also demolishes the usual skeptic's talking points. There is no "controversy" surrounding global warming; among scientists, there is one hundred percent agreement on the threat. With a few more well-selected graphs, he shows that the choice between economical and ecological well-being is also a false dilemma. American car makers, for instance, are currently losing money because U.S. gas mileage standards are so lenient that their product can't be exported to many countries.

Still, the question remains--why would anybody in their right mind want to spend their hard-earned money on what admittedly sounds like a bummer of a slide show? Because knowledge is empowering, and An Inconvenient Truth is not a depressing film. Gore's forecast is serious, but he knows better than to leave us in despair. There is room for hope. He insists that the solutions to the problem are within reach; we are only lacking the political will to do anything about what he calls a "moral imperative." Indeed: anybody who takes a long-term interest in the state of the planet--say, more than next hurricane season--would do well to see An Inconvenient Truth. It would be a welcome surprise if this well-crafted and well-argued film actually started a national debate about the very real threat of global warming.