At 8.30 tonight it is hoped the earth will turn dark for one hour.
Dozens of high profile buildings all around the world will be switching off all electricity as part of the tenth anniversary celebrations of Earth Hour.
Earth Hour started back as a symbolic event in 2007 in Australia with the UK joining a year later and it has since spread around the world.
In the UK landmarks including Big Ben, Buckingham Palace and the Gherkin will be taking part and further afield at 8.30pm local time the Eiffel Tower, Empire State Building and the Sydney Opera House will also be taking part.
It’s all about helping to protect the planet and everyone doing their bit to reverse global warming.
Earth Hour, organised by conservation organisation WWF is supported across the world in 178 countries.
Whether you are sat watching Casualty or The Voice this evening remember 8.30 until 9.30pm switch everything off!
