What would you do if your job was to save the planet? When Christiana Figueres was tapped by the UN to lead the Paris climate conference (COP 21) in December 2015, she reacted the way many people would: she thought it would be impossible to bring the leaders of 195 countries into agreement on how to slow climate change. Find out how she turned her skepticism into optimism ? and helped the world achieve the most important climate agreement in history.