Earth Hour

The Petronas Twin Towers in Kuala Lumpur, a Malaysian landmark, are pictured after lights were turned on after the Earth Hour March 31, 2012. REUTERS/Bazuki Muhammad

The Petronas Twin Towers in Kuala Lumpur, a Malaysian landmark, are pictured after lights were turned off for Earth Hour March 31, 2012. REUTERS/Bazuki Muhammad

Hong Kong's central financial district's (L-R) Bank of China Tower, Cheung Kong Centre, HSBC headquarters, Standard Chartered Bank and Legislative Council (front L) are pictured lighted up before Earth Hour March 31, 2012. REUTERS/Tyrone Siu

Hong Kong's central financial district's (L-R) Bank of China Tower, Cheung Kong Centre, HSBC headquarters, Standard Chartered Bank and Legislative Council (front L) are pictured with most of their lights switched off during Earth Hour March 31,...more

The Bund on the banks of the Huangpu River is pictured before Earth Hour in Shanghai March 31, 2012. REUTERS/Aly Song

The Bund on the banks of the Huangpu River is pictured during Earth Hour in Shanghai March 31, 2012. REUTERS/Aly Song

China's National Stadium (R), also known as the "Bird's Nest", and the National Aquatics Center, also known as the "Water Cube", are seen before Earth Hour in Beijing March 31, 2012. REUTERS/David Gray

China's National Stadium (R), also known as the "Bird's Nest", and the National Aquatics Center, also known as the "Water Cube", are seen during Earth Hour in Beijing March 31, 2012. REUTERS/David Gray

The Welcome Statue (C) is seen before Earth Hour in Jakarta March 31, 2012. REUTERS/Supri

The Welcome Statue (C) is seen during Earth Hour in Jakarta March 31, 2012. REUTERS/Supri

China's National Stadium (R), also known as the "Bird's Nest", and the National Aquatics Center, also known as the "Water Cube", can be seen before Earth Hour in Beijing March 31, 2012. REUTERS/David Gray

China's National Stadium (R), also known as the "Bird's Nest", and the National Aquatics Center, also known as the "Water Cube", can be seen during Earth Hour in Beijing March 31, 2012. REUTERS/David Gray

A general view of the Leifeng Pagoda before Earth Hour in Hangzhou, Zhejiang province March 31, 2012. REUTERS/Steven Shi

A general view of the Leifeng Pagoda during Earth Hour in Hangzhou, Zhejiang province March 31, 2012. REUTERS/Steven Shi

Prambanan temple is seen before Earth Hour outside Yogyakarta city, Central Java March 31, 2012. REUTERS/Dwi Oblo

Prambanan temple is seen during Earth Hour outside Yogyakarta city, Central Java March 31, 2012. REUTERS/Dwi Oblo

The "Ham Ca Map" building is seen before Earth Hour in Hanoi March 31, 2012. REUTERS/Kham

The "Ham Ca Map" building is seen during Earth Hour in Hanoi March 31, 2012. REUTERS/Kham

An ice-cream cart is pictured next to the India Gate before Earth Hour in New Delhi March 31, 2012. REUTERS/Parivartan Sharma

An ice-cream cart is pictured next to the India Gate during Earth Hour in New Delhi March 31, 2012. REUTERS/Parivartan Sharma

An historical part of Tbilisi is seen before Earth Hour, March 31, 2012. REUTERS/David Mdzinarishvili

An historical part of Tbilisi is seen during Earth Hour, March 31, 2012. REUTERS/David Mdzinarishvili

The Ivan Vazov national theatre is seen before Earth Hour in Sofia March 31, 2012. REUTERS/Stoyan Nenov

The Ivan Vazov national theatre is seen during Earth Hour in Sofia March 31, 2012. REUTERS/Stoyan Nenov

A view shows the University embankment after Earth Hour in St. Petersburg March 31, 2012. REUTERS/Alexander Demianchuk

A view shows the University embankment during Earth Hour in St. Petersburg March 31, 2012. REUTERS/Alexander Demianchuk

St. Sava church is seen before Earth Hour in Belgrade March 31, 2012. REUTERS/Marko Djurica

St. Sava church is seen during Earth Hour in Belgrade March 31, 2012. REUTERS/Marko Djurica

The Palace of Culture is pictured after Earth Hour in Warsaw March 31, 2012. REUTERS/Kacper Pempel

The Palace of Culture is pictured during Earth Hour in Warsaw March 31, 2012. REUTERS/Kacper Pempel

A combination photo shows the Empire State Building with the lights turned off, and with the lights switched back on in participation with Earth Hour, in New York, March 31, 2012. REUTERS/Andrew Burton

The Empire State Building and Brooklyn Bridge are seen with its lights turned off, in participation with Earth Hour, in New York March 31, 2012. REUTERS/Allison Joyce

People hold candles during the Earth Hour in the Central Place of Antigua, Guatemala,March 31, 2012. REUTERS/Jorge Dan Lopez