Actor Leonardo Dicaprio has warned the world to act on climate change now, before it is too late. Speaking at the premiere of his documentary The 11th Hour at the Cannes Film Festival yesterday (19May07), the Departed star stressed the urgency of the global warming situation, and urged people around the globe to take action now. Directed by sisters Leila Conners Petersen and Nadia Conners, and narrated by DiCaprio, The 11th Hour looks at the state of the environment and explores what people can do to stop Earth's rapid deterioration. And the actor hopes documenting the problem on film will help to influence people's opinions, just like the former U.S. vice president Al Gore did on 2006's An Inconvenient Truth. DiCaprio says, "Global warming is a reality. It is happening. In the last year, people are taking this issue more seriously than they ever have, and it's a direct result of affecting people's emotions in a cinematic format. "I wanted to give (the scientific believers) a way of not being challenged about whether the science is correct or whether their opinions were valid. It was about them being able to express ideas and being able to give us, the public, solutions for the future. "(The United States is) the largest superpower in the world. We're are also the largest polluters. 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?"