On March 26th 2011, at exactly 8:30p.m., hundreds of people in cities around the world switched off their lights in honor of “Earth Hour,” allowing spectators to see the night sky clearly. In 2007, the World Wildlife Fund began this campaign as an international statement towards climate change.
According to WWF, participants send a powerful and visual message demanding action. Since its inception, Earth Hour has become a global movement including 4,000 cities in 87 countries.
In addition, according to National Geographic, this year’s record breaking Earth Hour had more participants than ever. However, despite efforts, light pollution continues to remain as a major form of pollution. Light pollution, or photopollution, is excessive artificial light.
View more photos of Earth Hour from National Geographic.