Leonardo DiCaprio is urging young people to only vote for political candidates who will combat climate change.
The Hollywood superstar, 41, has previously said politicians who do not believe in manmade global warming should be removed from office.
Now, The Revenant actor has called on young people around the world to use their vote to kick out their leaders if they refuse to take steps to save the environment.
"This is going to be something that affects young people for decades and decades," he told the BBC. "It will affect their children and their grandchildren and their life. It is a long-term problem and we need long term solutions.
"But we need an entire generation out there that is going to be focused on this issue, use their vote to put people in their office that are going to take action on this issue and get involved."
Leonardo was in London over the weekend (15-16Oct16) to promote his new climate change documentary Before the Flood. Directed by Fisher Stevens, the film follows the star's travels around the world talking to leaders, scientists and those likely to be affected by climate change.
The actor warns that if people do not vote out politicians who refuse to take urgent environment saving measures, the planet and humanity will be ruined.
"It really boils down to their vote, if we have political leaders in office that do not want to take fundamental steps to combat this issue we are ultimately doomed," he explained. "And the best way you can do that in a democracy is by putting people in office that are going to take action."
Leonardo himself has faced criticism recently, when the head of a rainforest preservation charity called on him to step down from his United Nations (UN) Messenger of Peace role.
Lukas Straumann, director of the Bruno Manser Fonds, spoke out following allegations Leonardo and his environmental charity received funds from individuals connected to a Department of Justice investigation into the misappropriation of funds from a Malaysian sovereign wealth fund.