Earth Hour 2012

Annual Earth Hour campaign was held around the world on March 31. Electricity was switched off at the main sights of many countries for 1 hour. Kazakhstan took part in the campaign as well.

The Great Wall before Earth Hour. ©REUTERS/Jason Lee

The Great Wall during Earth Hour. ©REUTERS/Jason Lee

Hong Kong's central financial district during Earth Hour. ©REUTERS/Siu Chiu

Palacio de los Capitanes during Earth Hour in the Central Place of Antigua, Guatemala. ©REUTERS/Jorge Lopez

People light candles during Earth Hour after lights were turned off in Cali, Colombia. ©REUTERS/Jaime Saldarriaga

Children light a candle while marching during Earth Hour in Lima, Peru. ©REUTERS/Enrique Castro-Mendivil

Combo picture shows Sydney Harbour Bridge and city skyline before and during Earth Hour. ©REUTERS/TIM WIMBORNE

Chilean volunteers hold up candles during Earth Hour in Valparaiso city. ©REUTERS/Eliseo Fernandez

Fire acrobats perform in front of Ivan Vazov national theatre during Earth Hour in Sofia, Bulgaria. ©REUTERS/Stoyan Nenov

The Empire State Building is seen with its lights turned off in participation of Earth Hour in New York, the U.S. ©REUTERS/Allison Joyce

An ice-cream cart is pictured next to the India Gate during Earth Hour in New Delhi, India. ©REUTERS/Parivartan Sharma

People hold candles during Earth Hour after lights were turned off in central Amman, Jordan. ©REUTERS/Ali Jarekji

Students hold candles as they attend Earth Hour in front of the monument Baiterek in Kazakhstan's capital Astana. ©REUTERS

A combination shows the 97-metre monument Baiterek before and during Earth Hour in Kazakhstan's capital Astana. ©REUTERS

Philippine police hold candles as they join the celebration of Earth Hour in Manila's Makati financial district. ©REUTERS/Cheryl Ravelo

A man poses with an iPhone during Earth Hour in the center of Brasilia, Brazil. ©REUTERS/Ueslei Marcelino