At nights, most of Africa is dark, but wherever you are, if you use artificially generated light - join and turn off your lights for Earth Hour. Starting in New Zealand's remote Chatham Islands, thousands of cities, towns, and landmarks around the world will start to go dark for Earth Hour on Saturday evening.
Up to a billion people worldwide are expected to participate in this global voluntary blackout by switching off their lights from 8:30 p.m. to 9:30 p.m. local time. The movement, sponsored by the conservation nonprofit WWF, is designed as a symbolic gesture in support of action against global warming. Read more from the National Geographic.