BBC writes about Cities dim lights for environment.

Residents in towns and cities around the world are preparing to turn out the lights for an hour, to highlight the threat of climate change.

“Earth Hour” begins in Sydney, Australia, at 2000 (0900GMT), when lights on landmarks such as the Opera House and Harbour Bridge will go out. Other participants around the world will follow suit when clocks reach 2000 local time on Saturday. Bangkok, London and Chicago are among the cities that have signed up. The initiative, first held in Sydney last year, has now been taken up by more than 35 countries.

Earth Hour is an interesting concept and the way it spreads shows that the climate change makes people care and act. I just hope their actions not are limited to just this one hour of the year.