Hillary Clinton’s campaign is hoping to capitalize on yet another controversial proclamation from Donald Trump: That global warming is a hoax.

Trump, the Republican presidential nominee, has said he rejects the scientific consensus on climate change and opposes most U.S. efforts to reduce greenhouse gas emissions and curb fossil fuel use.

“Obama’s talking about all of this with the global warming and … a lot of it’s a hoax,” Trump said at a Dec. 30 campaign rally in South Carolina. “I mean, it’s a money-making industry, okay? It’s a hoax, a lot of it.”

Trump’s anti-climate stance is the focus of a new short film, directed by James Cameron, that will play tonight at the Democratic National Convention in Philadelphia.

“Not Reality TV” offers a gut-wrenching survey of the consequences of climate change, including deadly floods, rising seas, crop-killing droughts and raging wildfires.

But the video also highlights the deep divide between Trump’s agenda — including his avowal to “cancel” the Paris climate change agreement — and Clinton’s pledge to “tackle” the climate challenge and install millions of solar panels throughout the country.

Clinton, who last night became the first woman to head a major party ticket, vowed in a voiceover to transform the United States into “the world’s clean energy superpower.”

Trump dons a hard hat to show his support for U.S. coal miners at a West Virginia rally. Image: Getty Images

The five-and-a-half minute video is part of a broader effort by Democrats and Clinton supporters to make global warming a key issue among voters in the 2016 presidential race, Cameron told Mashable and other reporters on a Wednesday press call.

“It should be a much bigger issue than it is,” the climate activist said. “I think people of compassion, people of conscious really need to take this problem seriously.”

Cameron, who directed such blockbusters as Avatar and Titanic, also produced the Emmy Award-winning documentary TV series Years of Living Dangerously, which chronicles both climate change and clean energy progress in the United States and globally.

At the Republican National Convention in Cleveland last week, Republicans barely gave climate change a passing glance. Trump didn’t mention climate or the environment at all during his big speech, and GOP politicians who did reference the climate threat only did so when deriding Democrats.

Sen. John Barrasso (R-Wyo.), who chairs the GOP platform committee, drew laughs from other committee members when he noted that Democrats were planning to include climate change in their party platform, Talking Points Memo reported .

"There's sections about that they call 'climate justice' — climate justice!" Barrasso said at last week’s meeting.

In Philadelphia, by contrast, climate change is taking center stage.

“This election is about climate change, the great environmental crisis facing our planet,” Sen. Bernie Sanders, runner-up for the Democratic presidential nomination, said Monday on the first night of the DNC.

“Hillary Clinton understands that a president’s job is to worry about future generations, not the profits of the fossil fuel industry,” the Vermont senator said, noting that Trump “chooses to reject science.”

With Wednesday's video, Democrats also hope to appeal to undecided voters who — if not already turned off by Trump’s controversial stances on immigration, freedom of religion and national security — might be dissuaded by the candidate’s denial of climate science, Cameron said.

"A thermometer is not Republican. A thermometer is not Democrat."

To that end, the film includes the voices of Republican, military and religious leaders warning of the threats of climate change.

“We all know that human activities are changing the atmosphere in unexpected and in unprecedented ways,” former President George H.W. Bush said in an old video clip.

“I’m a Christian; I’m a conservative in many ways. And I also believe that climate change is real,” said Andrew Farley, a pastor and academic whose wife, Katharine Hayhoe, is a prominent climate scientist.

“A thermometer is not Republican. A thermometer is not Democrat,” he added.

Cameron said the video is “partially a reach across [party] lines, and partially calling bullshit on the hypocrisy of people who know this is a serious problem and refuse to do anything about it.”

The Hollywood director and his wife, Suzy Amis Cameron, made contributions to the DNC's account; that money was used to pay Mob Scene, a production company, for the film, a public relations representative told Mashable. Cameron worked with that company as a volunteer to create the film, which he made specifically for the DNC.