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Because pamphlets aren’t so effective anymore, Al Gore makes movies to address important topics to large audiences. His 2006 environmental documentary “An Inconvenient Truth,” essentially a polished PowerPoint presentation, opened a lot of minds about man-made climate change and won the Oscar/Grammy/Nobel Prize trifecta.

What it didn’t do was save the world. Now the former vice president is back with the follow-up film “An Inconvenient Sequel: Truth to Power” for another try. Mother Nature keeps helping him make his case because the evidence that the world needs saving keeps on piling up. As he puts it, following climate news has become “like a nature hike through the Book of Revelation.”

The ideas are simple. Heat melts ice, which raises sea levels, which drowns coastal cities and the aquifers housing our drinking water, and 16 of the 17 hottest years on record have occurred in the 21st century primarily due to our 200-year-long fossil fuel binge. There is scant serious planning about how to handle the water oversupply on a state, national or international level.

Gore doesn’t traffic in alarmist tones but cautionary warnings and possible fixes. He lays out his case like a kindly teacher who has been teaching this particular class in monotone for a long time. Filmmakers Bonni Cohen and Jon Shenk follow him traveling far and wide. We see Gore at sites that show the dimensions of the challenges and at meetings where green campaigners consider how to pull political leaders to their side. We see him in Greenland, interviewing science researchers and observing the meltdown of rapidly collapsing glaciers and in training classes speaking to grass roots climate activists. We see him go to Paris, preparing for a global online climate conference before the Paris accord, only to have it postponed following a terrorist attack in the city. And we see him travel to a small-town Texas city hall in the reddest part of the reddest state, where the conservative mayor is committed to switching from nonrenewable to sustainable energy sources for everything and everybody.

(Spoiler: Gore flies, which strikes me not as hypocrisy but common sense. After spending most of his waking hours trying to stop business and government from wrecking the planet, he’s not just entitled to travel the world by jet, but has an obligation to do so. There’s only so much one can do via Skype.)

The moral of the film is simple: This should end. NASA’s entirely apolitical Global Climate Change website notes that 97 percent of climate scientists agree that change is real, it is happening now and it is a growing threat to society. To reject those findings is equal to ignoring an observatory’s warning that a meteor shower is on its way because you’re not into big telescopes.

There was a fair amount of mockery when the first film did some predicting a decade ago. It presented an animated graphic showing how New York City might experience flooding because of excess heat trapped by greenhouse gases, particularly carbon dioxide. Skeptics called the warning absurd, hyperbole, a hoax, guesswork. News footage in the sequel shows, six years later, the severe flooding from Hurricane Sandy. Gore delivers the reminder not in mocking tones of “just as expected, I told you so,” but sadness. Given the current anti-science bias in our nation’s capital, this reminder about climate change and our vulnerability to it could not be more relevant.

An Inconvenient Sequel: Truth to Power ★★★★ out of 4 stars

Rating: PG for thematic elements and some troubling images.

Theater: Uptown.