Leonardo DiCaprio might not experience global warming in his new film, but stopping it is one of his personal goals. He met with Pope Francis in Vatican city on Thursday to discuss the issue.

DiCaprio first greeted the Pope in Italian and kissed the pope’s ring, reports The Associated Press. “Your Holiness, thank you for granting me this private audience with you,” the actor said.

DiCaprio also presented the Pope with a book of paintings by Hieronymus Bosch and pointed out the 15th Century Dutch painter’s triptych Garden of Earthly Delights. DiCaprio said that the image was hung over his crib when he was an infant. He linked the image to the modern day concern over global warming.

“As a child I didn't quite understand what it all meant, but through my child's eyes it represented a planet, the utopia we had been given, the overpopulation, excesses, and the third panel we see a blackened sky that represents so much to me of what's going on in the environment,” DiCaprio told the Pope in English.

DiCaprio has been a passionate advocate for environmentalism and recently gave an address at the World Economic Forum in Switzerland. There, he said that his foundation would donate $15 million to businesses that are making efforts to stop global warming.

DiCaprio is currently up for an Oscar for his performance in The Revenant.