Al Gore appears in An Inconvenient Sequel by Bonni Cohen and Jon Shenk, an official selection of the Documentary Premieres program at the 2017 Sundance Film Festival. Courtesy of Sundance Institute.

Al Gore is the primary focus of “An Inconvenient Sequel,” but the new documentary, which debuted Thursday at the Sundance Film Festival, doesn’t feel like a vanity project.

Gore and his relentless passion to communicate the dangers of climate change and enact policy to diminish its global effects gives the film a through-line it otherwise wouldn’t have, as the actual climate change portions of the film jump from the science of the issue to the many other issues caught in the same complex political web.

The film is less invested in building a thorough scientific argument for climate change than it is in dramatizing efforts Gore has made over several decades to make the argument over and over again, through setbacks and hurdles of various kinds.

One strength of the documentary is the balance it strikes between despair and hope. The film, like Gore himself, has an abiding trust in the power of the slide show presentation as a means of enacting social change, and its optimism is infectious.

In the 10 years since the first film, “An Inconvenient Truth,” was released, Gore has continued to fight private and public battles for public awareness of the science of climate change and for regulations and investment in innovations that would curb its effects.

The film also succeeds at showing how climate change is not an isolated political issue, but one that is connected to issues of poverty, terrorism and faith.

The 2015 United Nations Climate Change Conference in Paris provides the longest piece of narrative drama in the film. The nitty gritty of the conference’s issues on the table are presented in a somewhat reduced form, so it’s not the most in-depth coverage of the conference, but tense behind-the-scenes moments of dealmaking that keep the stakes personal and interesting throughout.

India is shown to be a key player in the conference, having raised an argument that complicates the moral simplicity of the environmental position: That is, that after 150 years of nations like the United States building an empire off cheap, dirty energy, it is hypocritical to demand that less affluent countries pay to invest in green energy.

It’s an understandable argument, and one that Gore and the film effectively work to address in a satisfying way.

The best scene in the movie features Gore’s visit to a mayor of the “reddest town in the reddest county in Texas,” who nevertheless has made his city’s energy production 90 percent solar-produced. (My fellow Provoans may understand why I found a scene with a forward-thinking, conservative mayor so lovely and familiar.)

The GOP elephant in the room looming over the film is Donald Trump, and the film incorporates the presidential campaign in interesting, sparse, ways. News clips of Trump dismissing climate change during the campaign make a marked contrast to Gore’s slow-and-steady efforts to educate and convince the public of the imminent dangers.

Gore’s frustration that public understanding and opinion about climate change has not produced more progress during his decades of work on the subject is palpable, but the movie is able to avoid being, well, a bummer. It avoids fear-mongering while delivering its clear-eyed message.

The movie will certainly be released wide — opening with a Paramount logo, it has the rare distinction at Sundance of a film having a major distributor already on board.

It’s worth a look, not only as a piece of political history, but as a story of an immovable will persisting no matter the odds.