I attended a WWF Earth Hour event a while ago to learn more about the campaign which highlights efforts to tackle climate change.

Here is a description of the event from the Earth Hour website .

"In 2009 hundreds of millions of people around the world showed their support by turning off their lights for one hour.

Earth Hour 2010 will continue to be a global call to action to every individual, every business and every community. A call to stand up, to show leadership and be responsible for our future.

Whether you are an individual, a business, a school or a city, you can show your support for Earth Hour by turning off your lights at 8.30PM on March 27 wherever you are on the planet."