"Earth Hour" is a sustainable global activity initiated by WWF in response to global climate change. It calls on individuals, communities, enterprises and cities to turn off their lights for one hour from 20: 30 to 2 1: 30 on the last Saturday of March every year, aiming to make people around the world pay attention to climate change and advocate a low-carbon lifestyle through a small action-a small change that may have a far-reaching impact. "Earth Hour" was put forward by the World Wide Fund for Nature (WWF) to cope with global climate change. Earth Hour is such an activity. "Earth Hour" is an activity of WWF to protect the earth, save energy and reduce emissions. It is an environmental protection activity, aiming at awakening the public's awareness of energy conservation and emission reduction.