The actor has been a longtime supporter of climate change awareness, recently pledging over $15 million to aid environmental groups, including Ocean and the Rainforest.
"We simply cannot afford to allow the corporate greed of the coal, oil and gas industries to determine the future of humanity," he said in a speech at the Davos Crystal Award Ceremony on Jan. 20.
Pope Francis, for his part, has addressed climate change and global warming numerous times over the course of his papacy. He issued a 180 page document this past summer and discussed climate policies on his recent visit with President Obama.