"An Inconvenient Truth," the 2006 film formed around Al Gore's powerful, science-based slideshow on global climate change, won an Oscar for best documentary. It also helped propel Gore to a Nobel Peace Prize the following year.
Now, comes the release of "An Inconvenient Sequel: Truth to Power." Is a follow-up really warranted?
Gore's continued efforts are a story worth telling, and filmmakers Bonni Cohen and Jon Shrenk have seamlessly updated it. They show him recounting what's been happening to the climate, and the technological advances and greater affordability of renewable energy sources providing real reasons for hope.
Gore's power-point presentation plays a big role once again, this time with powerful and compelling new slides and film footage that shows that what has happened to the weather around the globe in the years since the first film.
We see the acceleration of melting ice sheets, flooding of cities, extreme droughts and the increased frequency of extremely rare weather occurrences. We're reminded 14 of the planet's 15 hottest years on record have happened since 2001, something science deniers chalk up to something unrelated to increased carbon in the atmosphere.
Gore visits a flooded Miami Beach, a shrinking glacier in Greenland and presents footage of Storm Sandy flooding the site of the World Trade Center in Manhattan -- something his first film posited as a possibility, only to be scoffed at by detractors.
Yes, things are looking worse. But unlike when the first film came out, green energy sources are now more viable than ever. (Buffalo's sure banking on it with SolarCity.) The change in the marketplace is a big reason why Gore exudes optimism that the country and the world -- which are already making big strides away from fossil fuels -- could make far bigger advances in the not-too-distant future.
As Gore goes about speaking at climate leadership training sessions, meeting with politicians and talking to scientists, his remarkable transition from being a Supreme Court vote away from the presidency in 2000 becomes all the more apparent. There is something noble in his dedication, and his willingness to stick with the cause long after his fame and wealth could have led him in other directions.
Much of the film's second half focuses on Gore summoning his political skills behind the scenes at the 2015 Paris climate summit to broker a deal in which SolarCity, based in California, agrees to share technology in exchange for India's support of a major agreement.
Filming for "Inconvenient Sequel" was completed before Donald Trump withdrew the United States from that landmark accord. But Gore makes it clear -- and the actions of people and governments around the world since Trump's decision back it up -- that he believes people will continue to push en masse to make the right decisions even if elected leaders don't.
One of the film's most engaging scenes is when Gore goes to Georgetown, Texas to meet with Mayor Dale Ross. The community is on the verge of using 100 percent renewable energy, having reached 90 percent at the time of the filming.
"This is the reddest city in the reddest county in Texas, but going green makes sense because it's cheaper" as well as "just common sense," he tells the former vice president.
Is Gore just preaching to the choir? Leaving aside political satirist Barry Crimmins' assertion that "the choir needs a night out, too," Ross shows he's not. Lets hope so.
"An Inconvenient Sequel: Truth to Power"
3 stars (out of four)
Al Gore in the follow-up to the 2006 documentary that presented scientific evidence of man-made climate change. 98 minutes. Rated PG for thematic material and some troubling images.