A documentary by Bonni Cohen and John Shenk. Rated PG

During the presidential race of 1952, candidate Adlai Stevenson famously said of Republicans, “If they will stop telling lies about the Democrats, we will stop telling the truth about them.” Despite this and many other bon mots, Stevenson lost to Dwight D. Eisenhower. Twice.

Al Gore knows something about that. But he put the passion he may have been lacking in campaign style into his concern for the environment. Released in 2006, An Inconvenient Truth was a wake-up call for a First World population sleeping through its own demise. Where that was a feature-length extrapolation of his touring slide show, this Sequel is a validation of the earlier film’s projections, most of which show the biosphere much worse off than expected 11 years later—especially when it comes to melting polar ice. That’s familiar territory to directors Bonni Cohen and John Shenk—best known for The Island President, which detailed the effects of rising tides on the Maldives—who take over from Davis Guggenheim here.

They concentrate more on the drama of Gore’s sometimes quixotic journey, occasionally to the doc’s detriment. We spend much time with this veteran glad-hander working with grassroots foot soldiers, and prepping for the Paris Agreement of 2015. That’s fine, but Jeff Beal’s music works too hard ennobling our protagonist when a grittier, less admiring tone would be more effective. And the ending reaches for optimism that can be hard to justify.

The movie is on surer ground when it points out that war contributes to global warming, and that climate change—drought, wildfires, flooding—feeds both war and mass migration. It also makes the case that the anti-science lobby, in ascension since last November, has moved from merely smearing the messenger (“Look. Al Gore’s using a coal-powered cellphone!”) to covering up the falling costs of alternative energy. It’s clear that Trump’s big-oil buddies aren’t going to stop lying anytime soon. So we’ll need lots more serious truth—win, lose, or draw.