The saddest, most frustrating moment in Al Gore's new climate change movie, An Inconvenient Sequel, involves the lonely former vice president walking into Trump Tower and boarding a golden elevator to meet with the then-president-elect.

That scene encapsulates both how far we've come in the climate policy arena, and how far we've fallen backwards in just the past six months. It also hints at a central theme in the film, which casts Donald Trump as just as much of a villain in the climate change story as the major fossil fuel companies that fund climate science disinformation campaigns.

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The Gore-Trump climate meeting was an utter failure, given Trump's subsequent decision to pull the U.S. out of the landmark Paris Climate Agreement. It's an experience that Gore says he's learned from.

"I was wrong in believing there was a chance that Donald Trump would come to his senses and stay in the Paris Climate Agreement, and underestimated the influence of the rogue’s gallery of climate deniers he has surrounded himself with," Gore said in an interview.

Al Gore in Greenland as seen in An Inconvenient Sequel: Truth To Power, from Paramount Pictures and Participant Media.Credit: Paramount pictures/participant media

"I would make the effort again, but, I mean, under the same circumstances, but it’s clear to me now that the chances of him changing on the issue are de minimis at best. And barring some unforeseen set of circumstances I’m not gonna waste any more time at all trying to engage President Trump on climate," he added.

Gore's new movie, which comes 10 years after the Oscar-winning An Inconvenient Truthhit theaters, is more subdued and workman-like than the first film. It accurately reflects the transformation of the climate movement into one akin to the civil rights movement: A long, hard slog that will ultimately prevail.

The film also focuses on the extreme weather events that scientists are increasingly tying to climate change.

In the film and in the interview, Gore passionately makes the case that the costs of solar and wind power are plummeting, providing a viable alternative to coal-fired power plants in the U.S. and elsewhere. Unlike in the first movie, he isn't here to scare anyone, but rather to offer hope.

In the interview, for example, he hinted that Trump may not even be president for a full term, given the scandals and chaos swirling around him.

None of us know how long Donald Trump is going to be president

A lot has changed since the first film, Gore said.

"...There have been two big changes since the first movie a decade ago. Number one: The climate-related extreme weather events are far more common and far more severe all over the world. And number two: The solutions are here now. A decade ago they were visible on the horizon, but now they’re here," he said.

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(Gore had been criticized by some for not including enough information on climate change solutions in his first film.)

"In many regions, electricity from solar and wind, for example, is cheaper from electricity from dirty fossil fuel, and before long, that will be the case in the vast majority of locations throughout the world," Gore said. "And it’s important to give that hopeful news to people even as the sense of urgency about solving the climate crisis increases."

The movie also shows Gore in a role that largely went unnoticed by the press covering the negotiations that produced the Paris Climate Agreement in 2015. He served as a behind-the-scenes fixer trying to move reluctant nations, particularly India, toward a "yes" vote on a new climate treaty.

The new movie doesn't have the same punch as the first film, which helped reinvent Gore as an eco-warrior. It lacks the revelatory quality that the first film had, given that the first film re-introduced a public figure that had largely faded from view after his bitter election loss to George W. Bush in 2000.

Chances are that you'll go into the movie already knowing who Gore is, what he's about, and what he's been up to. So, there's not much mystery about the main character of this documentary. But that doesn't mean there aren't high stakes involved here.

As Gore makes clear, the more scientists know about climate change, the more concerned they are about just how fast the climate is responding to our greenhouse gas emissions resulting from burning fossil fuels.

The film wisely casts Trump as a villain, and ends with Trump's announcement that the U.S. will pull out of the Paris Agreement.

I’m not gonna waste any more time at all trying to engage President Trump on climate

In the film, we see Gore travel to the Greenland Ice Sheet during the summer melt season, peering down as water pours deep into an open wound-like chasm on the ice, known as a moulin. Then there's Gore in India, making the point to the nation's energy minister and lead climate negotiator that the way that country has been expanding electricity access is literally obscuring the sun with pollution.

The film culminates with the Paris Climate Change negotiations in 2015 and Gore's behind-the-scenes role in brokering some of the side deals that allowed countries to come together to adopt the agreement.

Some of these scenes are rather droll, unless you have a keen interest in solar panel technology. But for climate geeks, activists, and diplomacy nerds, this film is a gold mine. The same goes for anyone vehemently opposed to Trump's pro-pollution agenda.

The crowd at a New York screening I attended was eager to lash out at Trump. When the text appeared informing the audience of Trump's Paris Agreement move, it was met with so many boo's and hisses you'd have thought Lord Voldemort had appeared on screen.

For these folks, Gore offers hope as well, strongly hinting that Trump may not last for a full four-year term.

"... None of us know how long Donald Trump is going to be president," Gore said. "I’m not predicting any kind of near-term denouement, but voices in his own party questioning his leadership have begun to get louder."

But beyond that, Gore is still hopeful that people will find ways to combat climate change in spite of the political climate, adding that, "even when things look bleak and dark, there is always room for hope."

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