Chicago Theatre "featuring" Earth Hour 2010 with lights on...& off.

Parliament buildings in Ottawa, Canada before and after lights off #earthhour © WWF-Canada/Patrick Doyle

Birds Nest in Beijing before and after.

Big Ben switched off for Earth Hour.

Sphinx and Pyramids before and after lights off for Earth Hour.

The North gate of Beijing's Forbidden City, switched off in support of #EarthHour 2010

Chris Gorman took this photo of the unlit skyline of Auckland, NZ, during #earthhour. #wwf

Earth Hour is top in Twitter! YOU have made this happen, tx! Other ways you can help: http://bit.ly/cfoReO

#WWF inside #climate conference: Civil society removed from negotiations #Copenhagen

How #WWF & NGOs are being treated at the #Copenhagen #climate conference as seen by Biggerpicture.dk

2nd week of the UN #Climate conference starts with people freezing for hours in line, around 2C outside today #cop15 #wwf

Ugghh. Train delays on the way to the Bella Centre. Being stuck in a tunnel is no fun. #wwf #COP15 #climate

Early mornings and late nights for everyone at COP15. Thank goodness for comfy sofas. #wwf #climate #COP15

An army of 100 cooks prepare mad hot dishes to keep bellies of #climate negotiatior's warm at #Copenhagen #wwf

Rich countries: Tuvalu is fighting for survival in #Copenhagen #cop15 #wwf #climate

#WWF asks delegates to choose their path in the entrance to the #Copenhagen conf, 96% choose a legally binding deal :) #cop15

Finding your coat in the sea of 35000 is a lot of stress, 5C in #Copenhagen #wwf #climate

End of day 2 at #copenhagen #climate summit #wwf

#Cop15 logistics: Hanging 35000 coats takes time and space... #wwf #climate #copenhagen

"We must deliver", Yvo de Boer, opening the Copenhagen climate conference #wwf #incop15 #climate