Is it possible for a movie to be too timely? With the earth’s temperature hitting a record high for the third year in a row, a sequel to Al Gore’s Oscar-winning climate change documentary An Inconvenient Truth couldn’t be more relevant. But watching it open the Sundance Film Festial the night before Donald Trump’s inauguration, it was difficult to come away with the message Gore relayed to the crowd from the stage after the lights came up: “We are going to win this.”
Sundance has a strong midnight movies section, but this is more terrifying than The Babadook
An Inconvenient Sequel: Truth to Power, directed by Bonni Cohen and Jon Shenk, offers glimpses of the Keynote presentation made famous by its Oscar-winning predecessor, updated with freshly alarming statistics and footage from the intervening decade. One graph, showing the proportion of days per year in five different temperature categories, starts out as a comforting bell curve, with an even distribution of cooler- and hotter-than-average days on either side. But as Gore progresses through the years, the central hump lurches toward the hot end of the scale like a drunken porcupine. Sundance has a strong midnight movies section, but that slouching form is more terrifying than the Babadook. (There are feel-good slides, too, showing the growth of renewable energy sources in scattered spots around the world, but they don’t hit with the same force.)
Gore has always approached the fight for climate change as a political actor, calculating the precise dosages of hope and despair to shock his audience’s conscience without short-circuiting their minds. But there are people whom no jolt can move, including the man who will be president of the US by the time this review is published, and who turns up periodically in An Inconvenient Sequel as a televised image or a disembodied voice suggesting that Obama’s focus on climate change is a dereliction of his duty, that he should “get back to work” and “solve the Isis problem.”
Although it has fierce competition, climate policy may be the best illustration of how poisonously partisan US political culture has become. Gore tells the story of Dscovr, a satellite developed during Bill Clinton’s presidency that would have provided detailed images showing precisely how the earth’s climate was shifting. When George W Bush took over the White House, the project was scrapped, until the energy companies who were counting on the satellite’s sensors to help them guard against the damages caused by solar storms protested. The Bush administration then agreed to launch Dscovr, but only after all the devices pertaining to measuring earth’s climate had been stripped away. And then, after all that, they failed to launch it at all.
Gore, this sequel shows us, has been building an army, training thousands of climate advocates to deliver his presentation all over the world. But while ordinary people can encourage their leaders to act, only those leaders can make the kinds of widespread changes necessary. So after following Gore around the world, where he surveys melting ice sheets and slogs through the flooded streets of Miami, the movie ends up at the 2015 climate conference in Paris. The mood in the weeks beforehand is cautiously optimistic, until it’s shattered by the terrorist attacks that left 130 dead. But in the wake of that tragedy, the nations of the world came together – with a little help from Al Gore – and signed a historic agreement. It’s a heartwarming story of humanity’s disparate factions coming together in the wake of something terrible and rising above it.
Gore calmly lectures audiences in a voice that drifts between reassuring and soporific
In much of An Inconvenient Sequel, Gore is in his familiar professorial mode, calmly lecturing audiences in a voice that drifts between reassuring and soporific. But on a few occasions, his emotions get the better of him, and that voice develops an exasperated rasp. Gore apologizes for getting carried away, but his anger, rare as it is, is the most galvanising thing in the movie, suggesting that, on some level, Gore knows there are times when you have to stop trying to persuade everyone and simply fight those you feel are on the wrong side of history. At a rally, Gore quotes Martin Luther King Jr’s famous statement that “the moral arc of the universe is long, but it bends towards justice.” In truth, though, that arc only bends if we bend it.
An Inconvenient Sequel comes close to sanctifying Gore; while he says he sometimes views the lack of global progress on climate change as “a personal failure,” the film never encourages us to agree with him. The most important figure in the movie isn’t Al Gore, but the mayor of Georgetown, Texas, a midsized town that is in the process of shifting all of its energy to renewable source. The mayor is a self-proclaimed conservative Republican, the elected leader of “the reddest city in the reddest county” in the state. He frames the shift as a simple matter of dollars and cents, but it’s also clear that he believes a person should leave the earth in better shape than they found it – an idea that ought to be simple enough to transcend the differences between political parties. A small town in Texas isn’t where you’d expect to find hope for the future of the planet, but with a storm this menacing, any port will do.
If you would like to comment on this story or anything else you have seen on BBC Culture, head over to our Facebook page or message us on Twitter.
And if you liked this story, sign up for the weekly bbc.com features newsletter, called “If You Only Read 6 Things This Week”. A handpicked selection of stories from BBC Future, Earth, Culture, Capital, Travel and Autos, delivered to your inbox every Friday.