IN 2006, SELF-DESCRIBED recovering politician Al Gore put climate change squarely on humanity's doorstep with An Inconvenient Truth. The breakthrough documentary netted $49.8 million and two Academy Awards along with accusations that Gore had veered into hyperbole. Critics, including politicians, panned an animated sequence suggesting that melting ice sheets would one day leave New York City's September 11 memorial submerged. (Fast-forward to 2012's Hurricane Sandy, which passed through ocean waters nine degrees warmer than normal before flooding the World Trade Center site.) 

A self-assured Gore returns in the noticeably more fired-up An Inconvenient Sequel: Truth to Power. Our nightly news reports—laden with fires and droughts—amount to "a nature hike through the Book of Revelation," according to Gore. Even so, we still have trouble hearing what "Mother Nature [is] screaming." 

Sequel is sophisticated compared with its slideshow-driven predecessor. Directors Bonni Cohen and Jon Shenk trail the former vice president as he leads climate-activist trainings and negotiates his way through the 2015 Paris climate talks. His exchanges with global leaders about the role first-world countries must play in mitigating the crisis send a clear message: Climate change disproportionately affects the developing world.

Gore meets with Filipino climate refugees reeling from Super Typhoon Haiyan in hopes of translating an excruciatingly painful experience into policy. He explains how record-breaking drought displaced thousands of Syrians before civil war broke out and why, for the first time in history, pregnant women have been advised against visiting parts of the United States. (Warmer temperatures help incubate disease, leading, in this case, to possible Zika transmissions.)

Total bummer, right? Not quite. Sequel offers more optimism than Truth, thanks to its coverage of renewable energy. The plot centers on a high-stakes bit of global progress at the Paris climate summit: an agreement by Indian prime minister Narendra Modi to transition his country's power-generation plants to clean energy sources. On-screen, Gore works to secure the low-interest loans and deliver the new technology necessary for the developing country to make that commitment, insisting that solutions lie in what he has referred to in speeches as "expanding the limits of what is politically possible." Along the way, the film documents how the cost of solar and wind has gone down in the last 10 years, defying critics who have dismissed such energy sources as too expensive.

The push toward renewable energy has, of course, run into a bit of a snag. Though the film never refers to "45" by name, Gore, scrolling through November 10 "Trumpquake" headlines, quotes Mike Tyson: "Everyone has a plan until he gets punched in the face." Hence, the film's subtitle. There's never been a more important time to speak truth to power. Climate change activism, Gore insists, is in the "tradition of every great moral movement that has advanced the cause of humankind." He reminds viewers that civil rights, women's rights, and LGBTQ rights weren't won overnight, and the rights of those most vulnerable to the destructive consequences of global climate change won't be either.

An Inconvenient Sequel at times feels like a commercial for Gore's star-powered Climate Leadership Training program and perhaps misses opportunities to credit other grassroots advocates for their own powerful work. Still, Gore's two-pronged moral comes across louder and with more clarity than ever: Climate activism is a movement in its own right, and for it to succeed, we have to address the social and diplomatic dilemmas at the heart of the climate crisis.

This article appeared in the July/August 2017 edition with the headline, "Truth Be Told."