We begin with Anthony Kaufman, writing for Screen: "Former Vice President Al Gore’s hair is a little thinner, and it’s a lot whiter, but his message remains the same in this purposefully rousing follow-up to his 2006 documentary hit An Inconvenient Truth: climate change is a dangerous man-made reality and the world has a moral imperative to curtail it. Though audiences may have heard this one before, An Inconvenient Sequel: Truth to Power preaches effectively to its choir, with a decade of fresh data and increasing cataclysms—from harrowing typhoons and 'rain bombs' to heat-waves and flooding coastlines—to persuasively make its case."

"A decade ago, when An Inconvenient Truth made its own splash at Sundance," writes Variety's Owen Gleiberman, "the film may have been 'speaking truth to power,' yet there was every reason to suspect that, like too many socially conscious Sundance documentaries, it could wind up preaching to the choir. But An Inconvenient Truth was the rare documentary that actually achieved what these movies always set out to do: It didn’t just change hearts and minds—it shifted a paradigm. The movie presented Gore as a charming dweeb professor of dire environmental warning, but it did more than offer a message. It clanged the alarm bell and brought the news. It helped to free global warming from its pesky (and outdated) leftist underpinnings, establishing the issue as a mainstream concern in the same way that Occupy Wall Street would inject the meme of the one percent into the center of middle-class culture."

For Gleiberman, this is a "winning and impassioned, stirring and proudly wonkish follow-up." The AV Club's A.A. Dowd is less enthusiastic, but still: "Replacing Davis Guggenheim in the director’s seat, filmmakers Bonni Cohen and Jon Shenk, who made last year’s Sundance alum Audrie & Daisy, escape the lecture-hall format of the original by following Gore on a kind of world tour, as he meets with global leaders, shapes disciples into fellow climate-change activists, and continues to tour with his eye-opening slideshow. The footage of natural disasters from the last few years offer much more immediate, compelling evidence than charts and graphics—which is to say, rather perversely, that Gore’s awareness campaign benefits from some of his fears being realized."

Vulture's Jada Yuan finds it "impossible to watch without feeling immense sadness for how much ground the fight has lost without Gore in a position to enact policy. And how much more ground might still be lost, given that the new climate-change-denying president has nominated climate-change-denier Scott Pruitt to head the EPA." Gore's "message to the crowd at Sundance was surprisingly one of hope, regardless of who was set to move into the Oval Office the next day. 'We're going to win this,' said Gore; the only question was how fast. 'The reality has been that the maximum that's politically feasible has fallen short of the minimum the scientists tell us is necessary to save the planet balance, according to what the laws of physics dictate,' he said. We could despair, which would be another form of denial, or we could try to change the limits of what is politically possible."

"The idea was not to wallow in already-in-abundance despair," adds Rolling Stone's David Fear, "but to remember that this is a long, hard, tooth-and-nail fight. Civil rights, gender rights and LGBT rights were not won overnight, he reminded folks, and neither will environmental rights. 'For those of you who have so much doubt,' he said to the hushed audience, 'there are so many other folks who also want to make things better. The will to act is a renewable resource.'"

"The 2006 film was notably dry," grants Jordan Hoffman in the Guardian, but "its specificity gave it focus, tightly covering the audience with facts and visual reinforcements, like an atmospheric layer around our potentially doomed planet. Eleven years later, the follow-up… is uncomfortably desultory and surprisingly vainglorious. As shocking as it may seem, you may yearn for more of those dreary lectures."

For Flavorwire's Jason Bailey, "the whole thing feel more than a little disjointed. Gore comes off well, equal parts passion, disappointment, and Dad jokes, though he lands a few good zingers (A reporter notes that, due to its climate-denier governor, 'Florida is challenging'; Gore, without missing a beat, replies, 'I can confirm that')."

More from John DeFore (Hollywood Reporter), Eric Kohn (IndieWire, B), Richard Lawson (Vanity Fair), Dan Mecca (Film Stage, B+) and Mike Ryan (Uproxx). Ramin Setoodeh gets a few words with Gore for Variety, while Alessandra Potenza interviews Cohen and Shenk for the Verge.

Updates, 1/23: "What kind of message does premiering an Al Gore movie the night before Donald Trump’s inauguration send?" wonders Bilge Ebiri in the Voice. "Does Gore inspire resistance? Does he remind us of past heartbreak? Or does he merely symbolize helplessness and a possibly extinct brand of politics? Within the context of this film festival, one’s answer to that probably depends on how one sees the legacy of An Inconvenient Truth." Regardless, this new film "is a mess."

Gore "allows himself to get angrier these days (even if he apologizes for it afterward, like a decent Southern gentleman), and his change in tactics is palpable," notes Time Out's Joshua Rothkopf. "Alas, this is a film that builds to a backroom compromise on carbon emissions, not the most thrilling of climaxes. The serious issue of global warming won’t be minimized by a mediocre doc, but it has yet to find a filmmaker inflamed with rage and visual passion."

Update, 1/27: "Despair, Gore cautioned, is 'another form of denial,'" notes MTV's Amy Nicholson. "Sequel finds hope in an unexpected place: the heavily GOP area of Georgetown, Texas, where conservative mayor Dale Ross has already rewired his town to be 90 percent fueled by solar and wind. To Ross, ditching fossil fuels just makes sense. By the end of this year, Georgetown will be 100 percent green. And so, I came out of the movie inspired to do something I couldn't have imagined that morning: I went home and emailed a Trump voter a thank you letter."

For the full 2017 Sundance on Fandor experience, go here