CHRISTIANA FIGUERES and TOM RIVETT-CARNAC are the cofounders of Global Optimism, an organization focused on bringing about environmental and social change. They have worked closely with key campaigners supporting efforts to ameliorate the consequences of climate change, among them Greta Thunberg, Al Gore, Leonardo DiCaprio, His Holiness the Dalai Lama, Jane Goodall, David Attenborough, and Robert Redford.