Earth Hour campaign observed around globe Italian musician Niccolo Fabi performs at a pedal-powered concert near the Castel Sant'Angel...

Earth Hour campaign observed around globe

Italian musician Niccolo Fabi performs at a pedal-powered concert near the Castel Sant'Angelo (Saint Angel Castle) during Earth Hour in Rome, Italy, March 31, 2012. (Xinhua/Wang Qingqin)

WWF International Director General James Leape attends the Earth Hour event at the Castel Sant'Angelo (Saint Angel Castle) in Rome, Italy, March 31, 2012.(Xinhua/Wang Qingqin)

The Combination photo taken on March 31, 2012 shows the Castel Sant'Angelo (Saint Angel Castle) before (top) and during Earth Hour in Rome, Italy.(Xinhua/Wang Qingqin)

Volunteers pedals bicycles to power a concert near the Castel Sant'Angelo (Saint Angel Castle) during Earth Hour in Rome, Italy, March 31, 2012.(Xinhua/Wang Qingqin)

People talk in front of the main building of Moscow State University during the "Earth Hour" in Moscow, Russia, March 31, 2012. The "Earth Hour", initiated by the World Wild Fund for Nature in 2007, calls on families and buildings to turn off the lights for one hour on the last Saturday night of March. (Xinhua/Jiang Kehong)

A combination photo shows the main building of Moscow State University before (top), and during the "Earth Hour" in Moscow, Russia, March 31, 2012. (Xinhua/Wang Qingqin)

The Combination photo taken on March 31, 2012 shows the Hungarian Royal Palace (Rear) and the Chain Bridge (Front) before (Top) and during Earth Hour in Budapest, Hungary.(Xinhua/Attila Volgyi)

The "Earth Hour", initiated by the World Wild Fund for Nature in 2007, calls on families and buildings to turn off the lights for one hour on the last Saturday night of March. 

Earth Hour is the world's largest environmental movement which encourages individuals, businesses and communities around the world to turn off their lights for one hour on last Saturday of March.