NEW YORK - This year's Tribeca Film Festival has something in common with this year's Academy Awards: Al Gore, "the world's hottest leading man," as Mayor Michael R. Bloomberg described him at the festival's kickoff Wednesday.

Gore was here not to show his Oscar-winning An Inconvenient Truth documentary, but to host the opening gala of nine short "Live Earth Films" on environmental issues. One asks children, "How long do you think the Earth will last?" and another marks a reunion of Rob Reiner's spoof heavy-metal band Spinal Tap. Reiner played a snippet of the film that reprises the cast from his 1984 mockumentary, This Is Spinal Tap.

"When I heard that you were going to reunite . . . that just did it for me," Gore said.

This time, the dim-witted band members reminisce about doing concerts for causes, particularly a "Save the Ferrets" campaign.

The Tribeca opening night was a promotion for a cause: the July 7 worldwide "Live Earth" concert to raise funds for the Alliance for Climate Protection, of which Gore, the former vice president, is chairman.

While Tribeca has, since its inception, featured films with current-events themes it has also embraced lighter fare. This year's 12-day lineup of 157 features and 88 shorts includes the premiere of Spider-Man 3, a marathon of sports films and a screening of a documentary about break dancers, Planet B-Boy, and a tribute to James Brown.

Gore praised Bloomberg's recent "gutsy" environmental proposals, which include imposing a fee - $8 for cars and $21 for trucks - on vehicles entering congested Lower Manhattan.

Also citing the initiatives of California's Republican Gov. Arnold Schwarzenegger, Gore said it showed that climate change "is not a partisan issue."

Gore did not say whether he'd give Bloomberg the autograph he requested.

"It's for my mother," the mayor said. "But if you could make it out to 'Mike ...'?"