Entertainment Movies WATCH: Leonardo DiCaprio Is a Warrior for Climate Change in 'Before the Flood' Documentary Trailer The Oscar winner wants us all to understand the importance of saving the climate for future generations By Kara Warner Published on September 26, 2016 01:30 PM Share Tweet Pin Email Photo: George Pimentel/WireImage If you aren’t aware that Leonardo DiCaprio cares deeply about climate change, then you haven’t been paying attention to the Oscar winner’s many awareness efforts. DiCaprio’s latest project is the documentary Before the Flood directed by Fisher Stevens, in which the actor – who appears in the film and serves as executive producer – examines how much damage we have caused to the planet and whether or not we’ll be able to reverse it. “We’ve known about this for decades. For half a century,” DiCaprio narrates in the trailer. “Try to have a conversation with anyone about climate change, people just tune out.” The two minute preview is full of beautiful aerial footage of environmental landmarks and polluted cities, which we see DiCaprio exploring. He is also shown meeting politicians like President Obama and the Pope and speaking at the U.N.. “We’re knowingly doing this,” DiCaprio says in the trailer. “I just want to know how far we’ve gone and if there’s anything we can do to stop it.” Of his passion for and commitment to the environment, DiCaprio told PEOPLE “we are at a real turning point,” at the Toronto International Film Festival, where the documentary recently premiered. “Each year is getting hotter than the next and now is the time to act on this issue,” he said. “We are at a real turning point, not only in human history but as far as the manipulation of our planet is concerned due to global emissions. We need political leaders to really take a stand.” Before the Flood will be in theaters in New York and Los Angeles starting Oct. 21, and airs globally (in 171 countries and 45 languages) on the National Geographic Channel starting Oct. 30.