UPDATED: “An Inconvenient Sequel: Truth to Power” kicked off the 2017 Sundance Film Festival Thursday night, bringing a strongly positive response from an audience of 1,200 at the Eccles Center Theater.

Though Al Gore announced in “An Inconvenient Sequel” that he is a recovered politician, the audience at the Sundance Film Festival reacted to the follow-up to 2006’s “Inconvenient Truth” like they wish he would get back in the game.

Many stood at the end of the film to applaud Gore, who compared the cause of slowing climate change to other great moral causes of the modern era — like women’s suffrage and civil rights.

Robert Redford introduced the festival’s kickoff film saying that Gore was a “good friend.” “There was a moment in politics when the Supreme Court was not very kind to Al,” Redford said, referring to the court’s halt of a recount in Florida, which left George W. Bush with the presidency. “That drove him away from politics and it drove him toward film and that is to our benefit. Now he could work both sides of the street, and he has done it very, very well.”

Reminiscent of the original, “An Inconvenient Sequel” depicted dire consequences of a warming earth — from flooding in Miami and the Philippines, to the worst drought on record in Syria, bringing human suffering there that predated the ongoing civil war, to air pollution so bad in some parts of China that life expectancy has declined by six years.

The now 68-year-old Gore acknowledges that he “would be lying” if he didn’t admit slow progress on slowing greenhouses gases sometimes causes him despair. “In order to fix the climate crisis we have to fix the democracy crisis,” he declares.

After receiving his standing ovation following the premiere, Gore told the crowd that despite repeated setbacks there is reason to have hope for progress on climate change.

“This movie gives me an extra burst of hope because I think …it really effectively tells the story of how much hope is our there for transforming our energy system to become much more efficient,” Gore told the crowd, almost all of who remained in their seats after the screening concluded. Gore added: “We are going to win this.”

He pointed to a scene from late in the film when a Republican mayor of a Texas city tells why his town is going to 100% renewable energy. “That is an example of what is happening all over the world and in many parts of the U.S.,” Gore said. He described despair as “just another form of denial.”

The film also depicts another hopeful bit of progress — an agreement by India to try to move more of its power generation plants to renewable energy sources. The “Inconvenient” sequel shows Gore working tirelessly to get the developing nation the low-interest loans and new technology it needs to try to make that commitment.

The other possibility, he said, “is to expand the limits of what is politically possible.”

The film also gives one ready example: a small town mayor in Texas — a conservative and a Republican — who says he is moving his community toward 100% sustainable fuels, not because he is some latter-day environmentalist, but because he believes it will produce the lowest-cost electricity for his residents.

In apparent reference to the election of Donald Trump, who he does not name, Gore says that the climate stabilization movement has had many setbacks “and now we have another one,” adding: “There has never been a more important time to speak truth to power.”

Brought to the stage after the screening, Gore declined to attack Trump. The former vice president protested that the incoming president “appointed someone to head the EPA that I don’t think should have been appointed to head the EPA,” but he added: “This story has many chapters yet to be written.”

He concluded by suggesting that no one individual, including the incoming president, could stop reforms. “It’s too big now. We are shifting,” he said. “We are going to win this.”

In a bit of departure from tradition, the documentary was the headlining event on the opening night of the festival, rather than a narrative film. The sequel comes 11 years after Gore’s revelatory “An Inconvenient Truth” helped focus the world’s attention on climate change and the need for rapid reforms.

Like the original, the film is back by Jeff Skoll’s Participant Media. It was directed by Bonni Cohen and Jon Shenk and produced by Richard Berge and Diane Weyerman, the head of Participant’s documentary film unit. Gore thanked the Participant team and the directors for pushing him to update the story and cited Participant founder Jeff Skoll, in particular, as a long-time stalwart for environmental reforms.

Extra attention has been focused on “An Inconvenient Sequel” given the premiere’s timing on the eve of Donald Trump’s swearing in as president. The incoming occupant of the Oval Office tweeted in 2014 that climate change was “a hoax,” but in November told the New York Times “there is some connectivity” between human activity and climate change.

Gore, the former vice president under Bill Clinton, made a much publicized visit with president-elect Trump on Dec. 5 and said he has kept in touch with the Republican since then. Before Thursday’s premiere he had said in interviews he was hopeful that Trump would look on the climate crisis with fresh eyes, and not be bound by his previous statements.

He closed Thursday night’s premiere urging the audience to keep its spirits up. “For any of those who have any doubts,” Gore said, “just remember that the will to act is itself a renewable resource.”