On Saturday at 8.30 pm the WWF wants 1 billion people to swich off their lights to show support for action to tackle climate change.
Businesses, official buildings and landmarks around the world are going to switch off the light for one hour. Here is the list of all the Spanish cities participating.
On the individual basis WWF suggests that you spread the word, switch of your lights, your computer or even host a candlelight dinner eg. You can find more ideas on their site.
Personally, I think I will light some candles and, if the weather permits it, sit on the terasse watching the sea and the sky in the company of nice people :-)