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You'd think a guy like Al Gore, who's staked his post-vice-presidential reputation on an effort to deal with the dangers of climate change, would be in a dark mood after the election of President Donald Trump.

Nope.

"There's a legitimate hope the US is likely to meet the commitments made by former President Obama in the Paris agreement -- regardless of Donald Trump," Gore said, promoting his new film, "An Inconvenient Sequel: Truth to Power" at a Commonwealth Club talk Monday in San Francisco.

Why the sunny outlook? Because states like California and businesses like Apple and Google are pushing ahead with policies to counteract climate change; economical solar and wind power means even right-wing individuals and politicians can endorse renewable energy; cheaper batteries can smooth the ups and downs of solar and wind power; and not everybody on the political right agrees with Trump-era denial of climate change.

"There are lots and lots of conservative Republicans who have asked how do we find a pathway to get off this climate denialism," Gore said. "I think the dam may break soon."

Hard sell

But Gore has a tough sales job right now, and not just because "An Inconvenient Sequel" has received lukewarm reviews.

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He's plugging a movie that was filmed over the last two years, when US politics gradually drifted toward recognition of the reality of climate change and associated problems like global warming, sea-level rise and increased storm intensity. Just as the movie production was finishing up, though, Trump was elected and the climate change denial gained new political clout.

Now the former vice president must re-argue the points of his 2006 movie, "An Inconvenient Truth," which landed Gore the Nobel Peace Prize. One part of the potential audience doesn't want to hear what he has to say, and the other part wants to hear him move on to the next phase of the discussion.

Gore is optimistic, but he certainly isn't happy about Trump's decision to withdraw the United States from the Paris climate accord, his push to reinvigorate the coal industry and its carbon dioxide emissions, or about his appointment of fossil-fuels fan Scott Pruitt to lead the Environmental Protection Agency.

He had no trouble with the San Francisco audience. They gave him a standing ovation when he appeared on stage and cheered when he took potshots at the Trump administration. "2020, Al!" one man shouted, evidently supporting another run at the presidency when Trump's first term ends.

Tech to the rescue

Green technology means those who don't like government regulations can help some efforts to deal with global climate change, Gore argues.

The mayor of Georgetown, Texas, a Trump supporter who calls his home the reddest city in the reddest county in Texas for its Republican tilt, also happens to be a certified public accountant. He ran the numbers, and the city has begun a transition to 100 percent renewable energy, Gore said. Once you're saving money, it's easy to acknowledge that it's nice to have cleaner air and less pollution, he said.

Gore likes wind power, but solar power has "the most potential," he said. "The earth receives more energy from the sun in one hour than the entire globe's consumption of energy in one year."

Lazard

The cost of wind power without government subsidies has dropped 66 percent from 2009 to 2016, according to industry management and financing firm Lazard. Solar has dropped even more -- 85 percent.

Batteries are "a complete game-change for the energy systems worldwide," Gore added. "Batteries coming down in cost gives us the ability to extend the usefulness of renewable electricity into nighttime hours for solar, and into the daytime hours for wind."

He also is happy with the response to Trump's decision to withdraw from the Paris accord, which nearly 194 nations signed in 2016 in an effort to cut emissions of greenhouse gases that warm the planet.

"I was deeply concerned other countries might have used it as an excuse to pull out," he said. Instead, "the entire rest of the world redoubled their commitment to the Paris accord, almost as if they were saying 'I'll show you, Donald Trump.'"