Washington - If past increases in the earth's temperature preceded increases in greenhouse gases by as much as 1,000 years, could Al Gore have gotten wrong the reason for global warming and its linkage with greenhouse gas emissions?

To Hollywood, that's heresy. But it's one of several provocative questions raised by a new documentary that aims to rebut Gore's global warming movie, An Inconvenient Truth. (Besides picking up two Academy Awards, including Best Documentary, Gore's movie has grossed a reported $50 million.)

The new movie--we'll call it a docubuttal--stars Steven Hayward, a scholar at the American Enterprise Institute in Washington, and takes it stylistic cues from Gore's opus by showing viewers a data-laden PowerPoint lecture woven with scenes of Hayward strolling through a forest. (Gore sat in a canoe). Two hundred people attended the film's world premiere this past Monday in San Francisco. Another screening took place yesterday in New York on the eve of the Tribeca Film Festival.

The film's launch comes as renewable and alternative fuel legislation is on the move in Congress, notes Kevin Book, energy analyst with Friedman Billings Ramsey. A bill could pass as early as next month, and the attention Gore has brought to global warming is getting at least some of the credit.

The former veep's influence reaches beyond Capitol Hill. The nonprofit Co-op America is urging U.S. mutual fund investors to pressure America's largest mutual funds to start voting in favor of climate change proxy resolutions. That would be a big change; last year, none of the 100 largest mutual funds in the U.S. voted to support climate-related shareholder resolutions, the Ceres investor group, which supports such resolutions, notes.

Who's Hayward to challenge the big G? Aside from his duties at AEI, he's also a political science professor at Georgetown and a senior fellow at the Pacific Research Institute, which provided the bulk of his film's $25,000 budget.

Savvy environmentalists may also recognize Hayward's AEI as the conservative think tank that received $1.6 million from ExxonMobil (nyse: XOM - news - people ) between 1998 and 2005 as part of a campaign by the energy giant to raise doubt about climate change. AEI grabbed attention last February when it offered scientists up to $10,000 for a policy critique of a United Nations global warming report.

Other recent rebuttal documentaries have included Farenhype 9/11 by Alan Peterson, a swipe at Michael Moore's Farenheit 9/11. Then there was Me and Mickey D, designed to counter the hit Super Size Me, and Why Wal-Mart Works And Why That Drives Some People C-R-A-Z-Y by Ron Galloway, rebutting a flick critical of Wal-Mart Stores (nyse: WMT - news - people ).

"All it takes is a little imagination and some Internet marketing," says Hayward. In his 50-minute presentation, Hayward gives his adversary his due, conceding: "The planet is warming; human beings are playing a substantial role in that warming."

Where he and Gore differ is whether the science behind global warming reveals a looming catastrophe or not.

"Gore predicts when polar ice and glaciers melt, sea levels will rise 20 feet, yet the latest UN report predicts a worst-case scenario of 23 inches," says Hayward.

Hayward spends just as much time in the movie explaining the limits of scientific estimates about global warming as he does attacking Gore's alleged exaggerations.

The movie faces several obstacles. Besides limited distribution agreements and blogger buzz, it's getting released just as summer fever heats up on college campuses, which hosted special screenings and provided a captive audience for An Inconvenient Truth.

Needless to say, Hayward doesn't see an Oscar in his future: "No, and I'm not waiting for [Hollywood producer] Harvey Weinstein to make me an offer either."