Hollywood actor Leonardo DiCaprio says he rushed to release his upcoming climate change documentary Before the Flood ahead of November's US presidential elections to issue a clarion call to US voters in time to influence their decisions.
"We wanted this film to come out before the next election because ... the United States is the largest contributor to this issue," DiCaprio said to the audience after the film's world premiere at the Toronto International Film Festival on Friday.
"We cannot afford, at this critical moment in time, to have leaders in office that do not believe in the modern science of climate change," he added.
The film follows the Oscar-winning DiCaprio and actor-filmmaker Fisher Stevens as they travel from Canada's oil sands to tiny Pacific islands, interviewing world leaders such as the Catholic Church's Pope Francis and US President Barack Obama, climate scientists and academics.
DiCaprio's interview subjects discuss and document the negative impacts of industrialisation and increasing consumption on the health of the planet.
"The fact that we are still debating any of this is just utter insanity to me," DiCaprio said.
The actor, who won an Oscar this year for playing a fur trapper battling nature's elements in The Revenant, was an executive producer on 2014 Oscar-nominated documentary Virunga, about the threatened gorillas in the Democratic Republic of Congo.
This year, he is an executive producer on Netflix documentary The Ivory Game, about Africa's illegal ivory trade, also making its debut at the Toronto film festival.
Before the Flood is out in New York and Los Angeles theatres on October 21 and airs on National Geographic Channel globally on Oct. 30.