This Saturday 28 March at 8.30pm it's time to switch off for Earth Hour. The WWF (World Wide Fund for nature) are trying to get 1 billion people to power off for one hour. Already the campaign has enlisted companies, landmarks and individuals from over 900 cities across 80 countries.

The Eiffel Tower, London Eye, Christ the Redeemer statue in Rio de Janeiro and the Sydney Opera House are some of the famous landmarks going dark at Earth Hour. These big icons will certainly raise awareness for the cause but it's corporations like HSBC who are pledging to turn off all office lights in 33 countries that can save the most power.

Earth Hour started in one city - Sydney - but last year it swept the earth with an estimated 50 million people participating in places as barren as Antarctica. Watch this short film to watch countries across the world participating in the 2008 big switch off in an effort to raise awareness on climate change. WWF are running this global campaign to convince governments everywhere to ‘agree effective action' on climate change with particular focus on effecting decision made at the UN climate summit in Copenhagen this December.

You can participate by signing up on the Earth Hour website.

Vote with your light switch and tell the policy makers that we can all make a difference - especially if they help us!