Earth Hour, on Saturday 26th March at 8.30pm is a world event.
Lights will go off for for an hour. Private houses, business and public icons such as the Syndey Harbour Bridge and Toronto's CN Tower will become dark for just an hour. Switch on by switching off. Just so you know how to do it properly on the night, start practising at home right now. Find an empty room or hall that has a light on, and simply flick the switch off. It's that easy.
It's not a lot, but when millions of people join together, something changes.