Bill McKibben helped found the first global grassroots climate campaign, which has organized protests on every continent, including Antarctica, for climate action. He played a leading role in launching the opposition to big oil pipeline projects like Keystone XL, and the fossil fuel divestment campaign. He is founder of Third Act, which organizes people over the age of 60 for action on climate and justice. His 1989 book The End of Nature is regarded as the first book for a general audience about climate change, and has appeared in 24 languages. Foreign Policy named him to its inaugural list of the world’s 100 most important global thinkers.