Icy wilderness, towering wildlife, hair-raising escapes: Nope, they’re not scenes from Leonardo DiCaprio‘s Oscar-winning drama The Revenant. Rather, they’re all-too-real interludes from a sprawling global jaunt to sound the alarm on an escalating crisis.
The actor and environmental activist has produced and appears in a documentary on climate change titled Before the Flood, which is directed by Fisher Stevens and had its world premiere Thursday at the United Nations headquarters in New York City.
“I mean, there were definitely some hairy moments,” the actor told PEOPLE at the premiere as he looked back on shooting the documentary, which did not come without its dangers. DiCaprio and Stevens traveled to remote, perilous places, where they witnessed icebergs collapse, communed with elephants, and, in one terrifying instance, were in a “[helicopter] flying over the fires of Sumatra” — a near-death experience that Stevens chronicled recently to GQ.
Still, the actor said, “for the most part it was an eye-opening experience for all of us.”
More alarming, the actor explained, is the lack of urgency with which some approach the climate crisis.
“People always talk about climate change in the distant future, this intangible thing that we can’t control,” the 41-year-old actor said. “But it’s happening right now, you know? It’s happening — to go to the Arctic and see that these ice shelves are disappearing, that Greenland is melting decades ahead of scientific predictions. That’s the terrifying stuff, truly.”
DiCaprio, who was named a U.N. Messenger of Peace in 2014, said an ongoing fallout from the catastrophe remains inevitable.
“Climate refugees, freak hurricanes and storms that are going to continue — wildfires, droughts. That is terrifying, and I continue to be terrified about the future, really,” he said.
That’s not to say the actor is resigned to a doomsday scenario. “You know, I’m slightly optimistic that we could do something about it because we’ve finally come together,” he explained, citing last year’s U.N. climate change conference COP 21 in Paris, where delegates reached the most significant agreement to date to address climate change by putting an end to fossil-fuel use and reducing greenhouse gas emissions.
“But,” DiCaprio added, “the world needs to take action. Otherwise, we’re in for some very bad news.”
Before the Flood opens in theaters in New York and Los Angeles on Friday, and will be televised globally, in 171 countries and 45 languages, on the National Geographic Channel starting Oct. 30.
- Reporting by BLAKE BAKKILA