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Seven lanterns released over the City of Cape Town, Republic of South Africa, (in front of Table Mountain) symbolizing the seven continents taking part in this global call to action on climate change to mark Earth Hour 2010.

Lights off for Earth Hour

On Saturday, March 31 at 8:30pm get ready to turn off your lights for one hour to participate in the world’s largest voluntary environmental action: Earth Hour. Earth Hour acts as a platform to showcase to the world what measures individuals, businesses, and governments are taking to reduce their environmental impact to save the planet. During this 2012 Earth Hour, World Wildlife Fund is daring the world to take positive actions for the environment and to showcase them in the "I Will If You Will" campaign. Go to http://www.youtube.com/earthhour to see challenges and create your own! Click through the slideshow below to view photos of past participants and landmarks around the world that have “gone dark.”