Sydney Earth Hour

SYDNEY, AUSTRALIA - MARCH 31: The Milky Way and the Southern Cross become visible above the Sydney Opera House during Earth Hour March 31, in Sydney, Australia. The entire city of Sydney, including companies, government departments, individuals and families have been urged to switch off their lights for one hour. The event is the launch of a 12 month campaign organised by WWF (World Wide Fund for Nature) Australia to reduce Sydney's greenhouse gas emissions by 5%. (Photo by Ian Waldie/Getty Images)