"So, Earth Hour is nearly here! With just two days to go it’s not too late for you to register and show you care about tackling climate change and protecting the natural world. Then on Saturday night just turn your lights out at 8.30pm and enjoy your special hour. But please don't forget to tell us you're taking part.

We've already got more countries worldwide involved than last year - 131 are taking part in Earth Hour 2011, across all seven continents. And that means millions of us will see iconic landmarks such as the Sydney Opera House, Big Ben, Edinburgh and Caenarfon Castles, the Empire State Building and even Niagara Falls plunge into darkness.

Please register and help us make this year's Earth Hour the best yet. By signing up you'll join with millions of people around the world and help us send an important message to world leaders that we need urgent action to protect our planet.

And finally… have you heard the news? The Prime Minister is supporting Earth Hour because he agrees it's important. You can watch his Earth Hour video on the our website."

Read more here