In 2007, 2.2 million people took part in the world's first Earth Hour in Sydney Australia. Just one year later, 50 million people in 370 cities and towns, in more than 35 countries worldwide switched off their lights for Earth Hour.

Earth Hour 2009 aims to reach more than one billion people in 1000 cities around the world, inviting communities, business and governments to switch off lights for one hour at 8:30pm on Saturday March 28 and sending a powerful global message that we care enough about climate change to take action.

 Visit Earthhour.org for more info.