TORONTO — Leonardo DiCaprio has unveiled his climate change documentary “Before the Flood” at the Toronto International Film Festival, saying the film is intended to “give the scientific community a voice.”

The film was directed by Fisher Stevens. It chronicles DiCaprio’s advocacy around the globe to raise awareness about climate change.

DiCaprio is a United Nations Ambassador of Peace.

The Academy Award-winning actor called climate change “the largest crisis we’ve ever faced.”

Stevens says the film’s release is timed to the presidential election. The film will air Oct. 31 on National Geographic.

– From news service reports