Earth Hour is a global environmental initiative to improve energy efficiency. What started in Australia five years ago, now involves 6,000 cities and some of the world's most famous landmarks.This year’s Earth Hour is the sixth consecutive event to take place
In 2012, the event organized by the WWF (World Wide Fund for Nature) and supported by the United Nations has spilled into space. The crew of the International Space Station is also part of the global green action. European astronaut and WWF ambassador André Kuipers is taking photos and video footage of the Earth from orbit.
According to WWF ,it is the world's largest demonstration of support for action on carbon pollution.
Sydney's Opera House is scheduled to go dark, followed by Asian landmarks such as the Great Wall of China, the Tokyo Tower, Taipei 101 and the India Gate. In Dubai, the world's tallest building, the Burj Khalifa, will switch off its lights.
Other landmarks pledged to switch off: The Eiffel Tower in Paris, London's Big Ben, the Brandenburg Gate in Berlin, the Christ the Redeemer statue in Rio de Janeiro and the Empire State Building in New York.
In 2011, more than 5,200 cities and towns in 135 countries worldwide switched off their lights for Earth Hour to show support for action on climate change