With last summer's "An Inconvenient Truth," Al Gore managed to bump global warming to the top of the national consciousness — and sell more than $24 million of U.S. tickets. Now Leonardo DiCaprio is betting he can repeat the feat.

He hosts, narrates and partly funded "The 11th Hour," a documentary out Friday that paints a bleak picture of humanity's prospects unless environmental policy is shifted almost immediately. It's just one of an unusual number of politically motivated documentaries slated to hit theaters in coming months, from a Darfur film featuring Don Cheadle to "Taxi to the Dark Side," which uses the death of an Afghan taxi driver to examine U.S. detention policies.

But America's stomach for such sobering fare may be starting to flag. Ticket sales this year for documentaries are down about 25 percent to roughly $27 million compared with this point last year — and Michael Moore's "Sicko" accounted for all but about $3.7 million of that, according to Media by Numbers. By contrast, at this time last year, documentaries other than "An Inconvenient Truth" had racked up about $13 million.

In recent years, hits such as "Fahrenheit 9/11" and "March of the Penguins" helped spur a broad documentary renaissance, prompting independent distributors like ThinkFilm and studios' specialty divisions like Warner Independent to offer aggressive documentary slates. But other factors are now at work. Netflix, the mail-order rental firm, has opened a way for niche documentaries to find an audience and a growing number of philanthropists are funding political movies with an eye less on the bottom line than on social impact.

Festivals feature political films

The result: At least six political documentaries are headed to theaters in coming months, and more are in the pipeline. At this year's Sundance Film Festival, the number of documentary contestants with contemporary political messages rose to six from two in 2003. Next month's Toronto International Film Festival will have at least nine such films, and is expected to include a portrait of Jimmy Carter's pursuit of Middle East peace by Jonathan Demme, who directed the Oscar-winning thriller "The Silence of the Lambs."

Documentary films — on TV or in theaters — have long focused on social and political issues, from the Dust Bowl to the Vietnam War. But the new crop is different, said Sheila Nevins, president of HBO's documentary unit, which plans ones on Iraq and Darfur.

"Documentaries that look back on the sins of the past are different than documentaries about the sins of the moment," she said. "We're right in the thick of the terrors of the moment."

Many filmmakers say the charged political atmosphere is drawing them to make more political films.

"I think a lot of people are disenfranchised. They feel disconnected from the politics of the moment and powerless to affect it in any meaningful way," said Errol Morris, famed for "The Thin Blue Line," a 1988 documentary that helped overturn a murder conviction.

He's working on "Standard Operating Procedure," about the Abu Ghraib photos of prisoner abuse, a film he said isn't explicitly political but is, in essence, anti-war.

Filmmakers see need to inform

The genre's hits have made the industry more confident that there's a politically concerned audience out there, too.

"I think people are craving information," said Polly Cohen, president of Warner Independent, which is releasing "The 11th Hour." "There is a contingent of people that's not being served by the news, and this sort of fills that niche."

Enter the philanthropists. Former eBay President Jeff Skoll was an early proponent of the idea of a "double bottom line," looking at films in terms of social impact as well as profitability. His company, Participant Productions, produced "An Inconvenient Truth" and has two politically themed documentaries on tap for fall — "Darfur Now," featuring Cheadle, and "Angels in the Dust," about a South African family that gives up its middle-class life to start an orphanage for kids with AIDS.

"Since Inconvenient Truth,' more people are starting to look at media as a strategy to achieve their philanthropic goals," said Melissa Berman, chief executive officer of Rockefeller Philanthropy Advisors. John Sloss, an entertainment attorney and fixture in the independent-film world, said more people are coming to him wanting to fund films with social content than ever.

Pierre Andre Senizergues, founder of California sports-apparel company Sole Technology, had never invested in a feature film before "The 11th Hour." But the former pro skateboarder became one of its biggest investors. "My intention has never been to make any money from this," he said.

Other documentaries set for this fall, including "Taxi to the Dark Side," have also been funded by wealthy individuals with at least partly political aims. "War/Dance," about displaced Ugandan children who enter a dance competition, was produced by a New Jersey couple who contributed a quarter of its $1 million production budget to call attention to the children's plight.