SAN FRANCISCO — Having climate change skeptic Donald Trump in the Oval Office won’t stop the U.S. from mounting an effective fight against rising global temperatures, former Vice President Al Gore argued at an event here on Monday.

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Walters: Newsom’s battle against climate change vs. reality Trump has yanked the U.S. from the Paris climate agreement and quickly dismantled environmental regulations. But America will continue to reduce its carbon dioxide emissions “regardless of what President Trump says or does or tweets,” Gore said during a talk sponsored by the Commonwealth Club.

He struck an optimistic tone, telling attendees they should take hope from both the swiftly dropping costs of renewable energy technologies like wind and solar power as well as local and state leaders who were picking up the mantle of addressing climate change.

Gore shouted out Gov. Jerry Brown, who he said won an “amazing legislative victory last week” when the state Legislature passed Brown’s plan extending California’s signature cap-and-trade system.

Monday’s event marked the release this week of Gore’s second movie, “An Inconvenient Sequel,” following up on the 2006 documentary “An Inconvenient Truth.” The film follows Gore around the world as he lobbies presidents and prime ministers at climate summits and hugs people who’ve had their homes washed away by flooding and hurricanes.

The movie originally intended to show the world coming together to meet a shared challenge. But that narrative was derailed by Trump’s election and his decision in June to withdraw from the Paris accord, in which nearly every country committed to emissions reduction targets intended to keep the planet from warming more than 1.5 degrees Celsius over preindustrial levels.

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Gore — who helped negotiate the anti-emission Kyoto Protocol in 1997 only to see President George W. Bush pull out of it — tried to convince Trump to stay in the Paris agreement during personal conversations at Trump Tower and the White House, he said. Trump has voiced doubts that man-made activity is responsible for rising global temperatures and called the notion a Chinese hoax.

“I really did think there was a chance he would come to his senses,” Gore said, “but I was wrong about that.”

But he said he was heartened that other countries around the world didn’t use Trump jumping ship as an excuse to get out of their own commitments — “almost as if they were saying, ‘well, we’ll show you, Donald Trump.’”

Even as an adoring San Francisco crowd cheered him and gave him a standing ovation, Gore argued that the climate movement should do more to reach out to conservatives and Republicans, citing the story of a small Texas town converting to renewable energy to save money.

Many Republicans in Congress are in the “climate closet,” he said — they believe in human-created climate change and want to do something to fight it but are “scared to death” that they’ll face a well-funded primary challenge if they say so publicly.

That’s slowly changing, he argued: “I think the dam may break soon.”

While most of his talk focused on climate change and his new movie, Gore also obliquely addressed the ongoing Trump-Russia scandal. In response to a question about collusion, he said that “the next few months are going to be a real challenge for our country and we best gird ourselves for it.” (As a U.S. senator and representative from Tennessee, Gore actually focused much more on national security issues than on environmentalism.)

“I’m heartened by the slowly increasing number of Republicans who have said things that lead me to believe they are going to be prepared,” he added, seeming to refer to a possible impeachment against Trump. “I think there is now a chance that they will step up to the plate if history and destiny call them out.”