About a decade ago, when Leonardo DiCaprio was on the cusp of megastardom and Al Gore was the U.S. vice president, the two talked together about global warming.
Now an all-out environmental activist, DiCaprio has followed Gore's lead by bringing a climate change documentary to the Cannes Film Festival. DiCaprio co-produced and co-wrote "The 11th Hour," which explains how humans have changed the climate and how to fix the damage.
As DiCaprio tells it in the documentary, which debuted Saturday, people are living in the last minutes of the final hour before it may be too late to do anything about global warming.
"It's such an amazingly large issue, and you suddenly you feel like, what can I do? What can I do? It's too big for me to deal with," the 32-year-old actor told reporters Saturday in a beach cabana overlooking the Mediterranean.
DiCaprio said the environmental movement owed a great debt to Gore, whose "An Inconvenient Truth," was shown at Cannes and won an Academy Award for best documentary feature.
"I think that movie, through the cinematic format, was able to convey science to the public and to the media in a way that it had never done before," DiCaprio said.
He said at their meeting about 10 years ago, Gore "took his time to talk to me about the issue of global warming, which I didn't really understand very much about, and from then on I've kind of been more active."
Hawking, Gorbachev in film
While "An Inconvenient Truth" laid out the science behind global warming and its impact, DiCaprio's film doesn't try to prove that global warming exists — it accepts that it does and goes from there. It asks and responds to philosophical questions such as, how did mankind let nature deteriorate to this point?
DiCaprio also narrates the movie, which was directed by sisters Leila Conners Petersen and Nadia Conners and includes commentary by visionaries from physicist Stephen Hawking to former Soviet President Mikhail Gorbachev.
Acting much like a guide for audiences, DiCaprio poses questions everyday people might ask. Then, well known scientists provide answers.
"I wanted to give (the scientific believers) a way of not being challenged about whether the science is correct or whether their were opinions were valid," DiCaprio said. "It was about them being able to express ideas and being able to give us, the public, solutions for the future."
The scientists warn that the ultimate end point of extreme climate change is human extinction, but they also give examples of what can be done to stop it, from simply changing lightbulbs to electing "green" leaders or buying "green" products.
DiCaprio and the directors said they tried to stay away from partisan politics because the global warming affects all people, regardless of being liberal or conservative.
Message for U.S.
But "The 11th Hour" does aim squarely at the United States and its industries.
"We are the largest superpower in the world. We're are also the largest polluters," DiCaprio said.
"It's ultimately us as the largest democracy in the world to be the ones to set an example ... if we don't do it, how is the rest of the world supposed to follow?"
For a new project, DiCaprio is looking for a script with an environmental theme.
"It can't be just a film about the environment for the sake of doing it," he said. "It's got to be powerful and moving. ... It's got to be good."