Set your alarm for 8.30pm this evening, when buildings across the UK will turn dark for Earth Hour.
Big Ben, Harrods, the Gherkin and Piccadilly Circus will be among the famous British buildings taking part – and elsewhere, the Eiffel Tower, Sidney Opera House and Bangkok Grand Palace are also joining in.
Organised by the World Wildlife Fund, the point of turning off electricity for an hour is to remind people of just how much we rely on it.
It’s a symbolic way of reminding people to protect the planet.
How can I take part?
It’s up to you, but the easiest thing to do is just switch off your lights and stop using electronic things like computers and iPads as much as you can. (Not as easy as it sounds, probably.)
Get out some candles or small torches – or just watch the sky, with hopefully a little less light pollution.
Lights that are on for safety reasons, like traffic lights, street lights or emergency exit signs obviously need to stay on.
Where is it marked?
The movement started in Sydney, Australia, ten years ago. It now involves more than 100 countries and millions of people.
Countries further east than us have already switched off for this year’s Earth Hour. The picture below shows Tokyo (not Paris), lights dimmed:
Aren’t you just using more fuel by burning candles?
Well, firstly no-one says you have to light a candle. And the event isn’t really about the small amount of energy you could save in just one hour.
It’s more about reminding people how much electricity they normally use – and maybe convincing them they don’t need to use that much throughout the rest of the year.
It’s also to raise awareness that issues like climate chance and deforestation haven’t gone away.
Follow #EarthHourUK for people’s photos in Britain this evening.