U.S. actor Leonardo DiCaprio (2ndL) looks on as he speaks on stage next to (From L) Paris mayor Anne Hidalgo, U.S. director Fisher Stevens, French Environment Minister Segolene Royal and Managing Director, National Geographic Partners France, Olivier Bramly during the Paris premiere of the documentary film "Before the Flood" on October 17, 2016 at the Theatre du Chatelet in Paris, France. REUTERS/Christophe Archambault/Pool