Pundits have hypothesized that Al Gore is feeling out a third presidential run with this new global-warming documentary, and it's true that the attendant rush of publicity wouldn't be such a bad way to launch a campaign. An Inconvenient Truth allows Gore to fire up his liberal base on unimpeachable grounds (namely, the federal government's reprehensible attitude toward science and research) without alienating the currently disgruntled middle. He can bask in his supposedly newfound charisma (the movie puts his wonkish personality in a complimentary light). And he can field softball interview questions from film critics like me.

But first: How's the movie? An Inconvenient Truth is workmanlike and clumsy at times—but it's also hugely invigorating. Tracking Gore's global-warming lecture as he schleps his Apple laptop across the country and to China, it's a collection of scientific facts and correlations made urgent through human drama and low-tech slide-show magic. It should be required viewing for every American citizen. And if it kicks up a storm of speculation regarding Al Gore's political prospects in 2008? So much the better.

Gore is in a unique position right now—part elder statesman, part rueful political hero, part public intellectual. And as an undeclared candidate (forgive the oxymoron), he has the latitude to philosophize on any issue he cares to take up. In our interview, he talked freely about market management by OPEC and the oil industry ("Just when the country gets to the point where we're willing to go whole hog on alternative energy, they manage to bring the price back down again"); the politically sensitive issue of which agricultural products ought to be used to manufacture cellulosic ethanol ("Corn may play a role in this, but it's not the way to go"); and—I swear I didn't prompt this—the demonic scourge of TV ("Full-motion video and vivid color produce a quasi-hypnotic state that partly accounts for the fact that Americans on average this past year watched television four hours and 39 minutes a day").

We also talked about the movie's highly personal tangents. An Inconvenient Truth didn't need to look very hard to find its human drama: We all know what happened to Gore in 2000. But in a (perhaps ironic) bid to temper that disaster's partisan tang, director Davis Guggenheim wanders far afield to such campaign-ready topics as the candidate's—I mean, subject's—childhood summers in Tennessee and his sister's death by lung cancer. According to Gore, "[Guggenheim's] interview technique was different from any that I've ever experienced, partly because it just took so long—hours and hours and hours for each one of those interviews, and he only used a little bit of each one—but I began to suspect that his basic technique was to get me completely exhausted so that I didn't care what I was saying." The personal anecdotes are ultimately justified, but it's hard not to notice their political coin.

But that is no reason to avoid this film. What's especially effective about a global-warming slide show—as opposed to, for example, Elizabeth Kolbert's elegantly anecdotal book Field Notes for a Catastrophe—is that it serializes and thereby dramatizes statistics, following up a graph of carbon dioxide concentrations over time with the eerie visual echo of average global temperatures. The evidence itself powerfully conveys the argument without requiring rhetoric (for fun, if you like rhetoric, check out the ludicrous opposition ads from the Competitive Enterprise Institute). There's also opportunity for a high-impact sight gag: As Gore is presenting the CO2 line graph, he delays the current and projected concentrations of CO2 until a mechanical lift hoists him to the final, frightening coordinates—higher and higher he soars until he's hovering, comically and uncomfortably, near the ceiling.

I want Gore to run in 2008. I think he owes us the substantive conversations—about greenhouse-gas emissions, but also domestic surveillance and torture—that his entrance into the race would bring. Whenever he gets asked whether he might run again, he says something stock and noncommittal about plans and intentions. At the end of our interview, I asked whether he would run in 2008, and he said, sharply, "No." He paused, and then softened: "I do not have any plans or intentions to be a candidate again."

Click here for the entire interview.