In 2007, 2.2 million people took part in the world's first Earth Hour in Sydney Australia.
Just three years later, 50 million people in 370 cities and towns, in more than 35 countries worldwide switched off their lights for Earth Hour.
Earth Hour 2011 aims to reach more than two billion people in 1000 cities around the world, inviting communities, business and governments to switch off lights for one hour at 8:30pm on March 26 2011, sending a powerful global message that we care enough about climate change to take action.
Join us for Earth Hour 2011 on March 26 at 8.30PM!  Find out more about Earth Hour