Earth Hour is now in its 10th year. It started in Sydney, Australia in 2007 and has grown to big a huge global event around the world since then.
Earth hour is where people switch off their lights for an hour, between 8.30PM and 9.30PM, to raise awareness about things such as Climate Change, and the Sixth Extinction.
To sign up for Earth Hour go to the links.
If you are in the United Kingdom, sign up for Earth Hour here:
If you are anywhere else in the World, sign up for Earth Hour here: https://www.earthhour.org/cop21-and-beyond