About Earth Hour

"Hundreds of millions of people, businesses and governments around the world unite each year to support the largest environmental event in history – Earth Hour.
More than 6,950 cities and towns in 152 countries and territories switched off their lights for Earth Hour 2012, sending a powerful message for action to save the planet. This year marked the continuation of the movement going Beyond the Hour, with more than 200,000 individuals accepting I Will If You Will challenges on YouTube to turn their symbolic action for the planet into an ongoing commitment to a sustainable future."
For more details check out the Earth Hour official website.