Thousands of landmarks are to switch off their lights for an hour this month, while millions of people around world will stage fundraisers
This year marks the tenth Earth Hour - the world’s biggest environmental event.
Hundreds of millions of people in countries and territories around the world will show they care about our planet by switching their lights off at 8.30pm for one hour.
What is Earth Hour?
Earth Hour is the world's largest grassroots movement for the environment, organised by WWF.