"Global warming is not only the number one environmental challenge we face today, but one of the most important issues facing all of humanity," DiCaprio said.

"We all have to do our part to raise awareness about global warming and the problems we as a people face in promoting a sustainable environmental future for our planet," the "Titanic" star said.

The feature-length documentary, titled "11th Hour," will "examine the state of the global environment, and includes visionary and practical solutions for restoring the planet's beleaguered ecosystems," the statement said.

The documentary takes a "renewed urgency in the wake of recent natural disasters, and as increasing global abuse brings the future of our environment into greater question," the statement said.

DiCaprio, 31, will produce, co-write and narrate the project, which is already in production.

The actor, who has established an environmental foundation, has bought himself an idyllic island that he plans to turn into an environmentally-friendly resort, People magazine reported in July.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.