"I think they're swine," the renowned filmmaker told an audience member Sunday on the final day of the American Renewable Energy Day summit in Aspen.
Just before saying that, Cameron received a standing ovation for a short documentary he screened about a coalition of people he joined who are opposed to a massive hydropower project in Brazil that would displace a large tribal community there.
It was during a series of talks Sunday about the strong effect the right-wing punditry — Cameron named the regulars: Glenn Beck, Sean Hannity and Rush Limbaugh, who are known for their sharp attacks on environmentalists — has on Americans.
"Effing demigods," as green communications strategist Richard Greene called them.
"A lot of really good American people are being lied to," added Peter Byck, the director of an upcoming climate change documentary called "Carbon Nation."
Byck stressed that Americans' hearts are in the right places, but that skeptics of climate change have such a vast infrastructure in getting what he called their false message out, many don't know whom to believe.
Greene, Cameron and a host of other climate-change activists said there needs to be a broad educational campaign, one aimed at convincing voters and politicians that not being able to prove that fossil fuel-produced carbon is changing the temperature of Earth is not a license for inaction.
They also criticized the media for giving half of its attention to a very small — less than 1 percent, they said — portion of scientists who say global warming is not caused by humans.
With campaigns like the production of his blockbuster hit "Avatar," Cameron said people are starting to realize the gravity of the problem.
"I think we did move the needle a little bit," he said.
But that effort alone is not enough to fix it, panelists said.
Harvey Wasserman, a senior adviser to Greenpeace and author of the book "Solartopia!", told audience members that if the government would stop its military operations in Afghanistan, it would be able to refocus those dollars on finding substantive solutions to climate change.
"We have to stop this god damn war in Afghanistan," Wasserman said.