Earth Hour, organized by WWF, is a global grassroots movement uniting people to take action on environmental issues and protect the planet. Engaging a massive mainstream community, Earth Hour was famously started as a lights out event in Sydney, Australia in 2007. Since then, it has grown to engage millions of supporters in more than 185 countries and territories, inspiring individuals and organizations worldwide to take action for the environment, and driving major legislative changes by harnessing the power of the crowd. As the movement grows, the one-hour lights out event continues to be the symbol of a broader commitment toward nature and our planet.