Philippine police hold candles as they join the celebration of Earth Hour in Manila's Makati financial district March 31, 2012. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 pm local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Cheryl Ravelo (PHILIPPINES - Tags: SOCIETY ENVIRONMENT)
Participants hold candles as they join the celebration of Earth Hour in Manila's Makati financial district March 31, 2012. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 pm local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Cheryl Ravelo (PHILIPPINES - Tags: SOCIETY ENVIRONMENT)
China's National Stadium (R), also known as the "Bird's Nest", and the National Aquatics Center, also known as the "Water Cube", are seen before Earth Hour in Beijing March 31, 2012. Homes, office towers and landmarks in cities around the world turned off their lights from 8:30 pm local time for one hour to raise awareness about climate change and the threat from rising greenhouse gas emissions. REUTERS/David Gray (CHINA - Tags: ENERGY ENVIRONMENT SOCIETY SPORT)