epaselect epa04683568 A composite photo of two images with lights on (top) and off (below) showing the National Stadium (Bird’s Nest) in Beijing city, China, 28 March 2015. Many landmark buildings in Chinese cities take part in the Earth Hour 2015 event to light off. Earth Hour takes place worldwide at 8.30 p.m. local time and is a global call to turn off lights for 60 minutes to raise awareness of the danger of global climatic change. EPA/WU HONG
