Earth Hour 2007Sydney, Australia
The first Earth Hour inspires 2.2million individuals and more than 2,000 businesses to turn off their lights for one hour.
Earth Hour 2008Celebrated on all seven continents, with 35 countries participating as flagship cities; over 400 others support the hour
Landmarks such as Sydney Opera House, Empire State Building, The Colosseum, and London's City Hall go dark; as does the Google home page
Earth Hour 200988 countries and 4,159 cities turned off their lights for Earth Hour 2009, 10 times the number that participated in 2008. Estimates suggest 80,000,000 people participated in the USA alone.
The UN headquarters in New York particpated for the first time.
Earth Hour 2010Earth Hour 2010 was the biggest Earth Hour yet. 126 countries participated and landmarks such as The Parthenon and London's Big Ben went dark. Many companies and cities considered how they could make Earth Hour part of their everyday routine.
Earth Hour 2011Participation in this years Earth Hour is expected to exceed one billion people in 128 countries.
Certain Television channels plan to cease transmission during the hour.
This year Earth Hour is asking supporters to Go Beyond The Pledge and commit to further sustainable measures.