Earth Hour is WWF’s global environmental movement. As one of the first open-sourced climate change campaigns, Earth Hour has grown from a symbolic event in one city to the world’s largest grassroots movement for the environment. In 2014, Earth Hour engaged individuals, business and organisations in over 7,000 cites and 162 countries and territories during the hour and beyond. In 2015, Earth Hour aims to harness the power of its millions of supporters worldwide to change climate change.