People hold candles during an event attempting to establish a Guinness World of Record for "Blowing out the most number of candles simultaneously" during Earth Hour in Shanghai March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Carlos Barria (CHINA - Tags: ENERGY ENVIRONMENT SOCIETY CITYSCAPE TPX IMAGES OF THE DAY) 

A combination picture shows the India Gate before (bottom) and during Earth Hour in New Delhi March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Mansi Thapliyal (INDIA - Tags: ENERGY SOCIETY TPX IMAGES OF THE DAY) 

Heavy traffic moves in front of the India Gate before Earth Hour in New Delhi March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Mansi Thapliyal (INDIA - Tags: ENERGY SOCIETY) 

Heavy traffic moves in front of the India Gate during Earth Hour in New Delhi March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Mansi Thapliyal (INDIA - Tags: ENERGY SOCIETY) 

The Chicago skyline is seen before (top) and during Earth Hour in Chicago, Illinois, in this combination picture made March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for action to confront climate change. REUTERS/Jim Young (UNITED STATES - Tags: ENVIRONMENT CITYSCAPE ENERGY) 

A photo of the Chicago skyline during Earth Hour in Chicago, Illinois, March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for action to confront climate change. REUTERS/Jim Young (UNITED STATES) 

The Chicago skyline is seen before Earth Hour in Chicago, Illinois March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for action to confront climate change. REUTERS/Jim Young (UNITED STATES - Tags: ENVIRONMENT CITYSCAPE ENERGY) 

A combination picture shows the Lions Gate Bridge before (L) and during Earth Hour in Vancouver, British Columbia March 23, 2013. The World Wildlife Fund crowned Vancouver the title of Global Earth Hour Capital for 2013. REUTERS/Andy Clark (CANADA - Tags: SOCIETY ENVIRONMENT ENERGY) 

The lights on Lions Gate Bridge are on before Earth Hour in Vancouver, British Columbia March 23, 2013. The World Wildlife Fund crowned Vancouver the title of Global Earth Hour Capital for 2013. REUTERS/Andy Clark (CANADA - Tags: SOCIETY ENVIRONMENT ENERGY) 

The lights on Lions Gate Bridge are turned off during Earth Hour in Vancouver, British Columbia March 23, 2013. The World Wildlife Fund crowned Vancouver the title of Global Earth Hour Capital for 2013. REUTERS/Andy Clark (CANADA - Tags: SOCIETY ENVIRONMENT ENERGY) 

A combination photo shows the Marina Bay Sands hotel and the ArtScience Museum (R), before (top) and during Earth Hour in Singapore March 23, 2013. Earth Hour, when everyone around the world is asked to turn off the lights for an hour from 8.30 pm local time, is meant as a show of support for tougher actions to combat climate change. REUTERS/Natashia Lee (SINGAPORE - Tags: ENVIRONMENT CITYSCAPE TRAVEL) 

The Marina Bay Sands hotel and ArtScience Museum (R) is seen before Earth Hour in Singapore March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 pm local time, is meant as a show of support for tougher actions to combat climate change. REUTERS/Natashia Lee (SINGAPORE - Tags: ENVIRONMENT CITYSCAPE TRAVEL) 

The Marina Bay Sands hotel and ArtScience Museum (R) is seen before Earth Hour in Singapore March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 pm local time, is meant as a show of support for tougher actions to combat climate change. REUTERS/Natashia Lee (SINGAPORE - Tags: ENVIRONMENT CITYSCAPE TRAVEL) 

A combination picture shows a general view of the Parilament Building and the Sukhbaatar statue before (top) and during the Earth Hour at Sukhbaatar Square in Ulan Bator, March 23, 2013. REUTERS/B. Rentsendorj (MONGOLIA - Tags: SOCIETY ENVIRONMENT ANNIVERSARY) 

People celebrate Earth Hour at Sukhbaatar Square with lights-off on the Parilament Building (R) and the Sukhbaatar statue in Ulan Bator, March 23, 2013. REUTERS/B. Rentsendorj (MONGOLIA - Tags: SOCIETY ENVIRONMENT ANNIVERSARY) 

People celebrate ahead of the Earth Hour at Sukhbaatar Square with lights-on on the Parilament Building (R) and the Sukhbaatar statue in Ulan Bator, March 23, 2013. REUTERS/B. Rentsendorj (MONGOLIA - Tags: SOCIETY ENVIRONMENT ANNIVERSARY) 

The Angel Independence Monument is seen before (top) and during (bottom) Earth Hour in Mexico City, in this combination picture taken March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for action to confront climate change. REUTERS/Henry Romero (MEXICO - Tags: ENVIRONMENT ENERGY SOCIETY) 

The Angel Independence Monument is seen before Earth Hour in Mexico City March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for action to confront climate change. REUTERS/Henry Romero (MEXICO - Tags: ENVIRONMENT ENERGY SOCIETY) 

The Angel Independence Monument is seen during Earth Hour in Mexico City March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for action to confront climate change. REUTERS/Henry Romero (MEXICO - Tags: ENVIRONMENT ENERGY SOCIETY) 

Members of the World Wildlife Fund (WWF), Defenders of Wildlife and the G-22 organisations, sit around 22 candles to represent the 22 municipalities of Guatemala and meditate during Earth Hour, in Guatemala City March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change.
REUTERS/Jorge Dan Lopez (GUATEMALA - Tags: ENVIRONMENT ANNIVERSARY POLITICS) 

The Empire State Building (right) is seen before the lights were turned off during Earth Hour in New York, March 23, 2013. Earth Hour, when everyone around the world is asked to turn off the lights for an hour from 8.30 pm local time, is meant as a show of support for tougher action to combat climate change. REUTERS/Carlo Allegri (UNITED STATES) 

The Empire State Building (left) is seen after the lights were turned off during Earth Hour as the streak of lights from an airplane landing at La Guardia airport streaks across the sky in New York, March 23, 2013. Earth Hour, when everyone around the world is asked to turn off the lights for an hour from 8.30 pm local time, is meant as a show of support for tougher action to combat climate change. REUTERS/Carlo Allegri (UNITED STATES - Tags: SOCIETY ENERGY ENVIRONMENT) 

A combination photograph shows the skyline with the Empire State Building on the right before (top) and during (bottom) Earth Hour in New York, March 23, 2013. Earth Hour, when everyone around the world is asked to turn off the lights for an hour from 8.30 pm local time, is meant as a show of support for tougher action to combat climate change. REUTERS/Carlo Allegri (UNITED STATES - Tags: SOCIETY ENVIRONMENT ENERGY) 

A combination photo shows the "Puente Nuevo" (New Bridge) seen from the terrace of a house with a statue of a cow in the day (top), at night (C) and during Earth Hour in Ronda, near Malaga March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher actions to confront climate change. REUTERS/Jon Nazca (SPAIN - Tags: ENERGY ENVIRONMENT TRAVEL) 

The "Puente Nuevo" (New Bridge) is seen from a terrace of a house with the statue of a cow, before the Earth Hour in Ronda, near Malaga March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher actions to confront climate change. REUTERS/Jon Nazca (SPAIN - Tags: ENERGY ENVIRONMENT TRAVEL) 

The "Puente Nuevo" (New Bridge) is seen from a terrace of a house with the statue of a cow during the Earth Hour in Ronda, near Malaga March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher actions to confront climate change. REUTERS/Jon Nazca (SPAIN - Tags: ENERGY ENVIRONMENT TRAVEL) 

The "Puente Nuevo" (New Bridge) is seen illuminated by artistic lights at night from a terrace of a house with the statue of a cow before the Earth Hour in Ronda, near Malaga March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher actions to confront climate change. REUTERS/Jon Nazca (SPAIN - Tags: ENERGY ENVIRONMENT TRAVEL) 

Earth Hour is observed at Berlin's Brandenburg Gate, the Cologne Cathedral and in Frankfurt's city centre (L-R) during (top) and before the lights were switched off, in this combination picture taken March 23, 2013. Earth Hour, when everyone around the world is asked to turn off the lights for an hour from 8.30 pm local time, is meant as a show of support for tougher actions to combat climate change. REUTERS/Tobias Schwarz/Wolfgang Rattay/Lisi Niesner (GERMANY - Tags: ENVIRONMENT TRAVEL SOCIETY ENERGY) 

A combination picture shows the Sydney Opera House on March 21, 2013 (top) before Earth Hour, and during Earth Hour March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Daniel Munoz (AUSTRALIA - Tags: ENERGY ENVIRONMENT SOCIETY CITYSCAPE) 

A combination picture shows the entrance to the Sydney amusement park "Luna Park" on March 21, 2013 (top) before Earth Hour, and during Earth Hour March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/David Gray (AUSTRALIA - Tags: ENERGY ENVIRONMENT SOCIETY) 

Leifeng Pagoda is seen behind the West Lake before (L) and during the Earth Hour in Hangzhou, Zhejiang province, March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher action to confront climate change. REUTERS/Chance Chan (CHINA - Tags: SOCIETY ENVIRONMENT ANNIVERSARY TPX IMAGES OF THE DAY) 

People ignite candles during Earth Hour in the city centre of Frankfurt March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for action to confront climate change. REUTERS/Lisi Niesner (GERMANY - Tags: ENVIRONMENT CITYSCAPE SOCIETY) 

Emiratis light candles to mark Earth Hour near Burj Khalifa in Dubai, March 23, 2013. Earth Hour, when everyone around the world is asked to turn off the lights for an hour from 8.30pm local time, is meant as a show of support for tougher actions to combat climate change. REUTERS/Jumana El Heloueh (UNITED ARAB EMIRATES - Tags: SOCIETY ENERGY TPX IMAGES OF THE DAY) 

Children hold candles during Earth Hour after the lights were turned off in central Amman March 23, 2013. Earth Hour, when everyone around the world is asked to turn off lights for an hour from 8.30 p.m. local time, is meant as a show of support for tougher actions to confront climate change. REUTERS/Ali Jarekji (JORDAN - Tags: POLITICS ENVIRONMENT TPX IMAGES OF THE DAY)