China: lights out for Earth Hour The combined photo shows the China's National Stadium before Earth Hour (upper) and during Earth Hour...

China: lights out for Earth Hour

The combined photo shows the China's National Stadium before Earth Hour (upper) and during Earth Hour in Beijing, capital of China, March 31, 2012. Main buildings and areas in many cities of China participated in the Earth Hour on Saturday evening. Earth Hour is the world's largest environmental movement which encourages individuals, businesses and communities around the world to turn off their lights for one hour on the last Saturday of March in a bid to raise awareness on climate change. (Xinhua/Zhang Yuwei)

The combined photo shows the Leifeng Pagoda before Earth Hour (L) and during Earth Hour in Hangzhou, capital of east China's Zhejiang Province, March 31, 2012. Main buildings and areas in many cities of China participated in the Earth Hour on Saturday evening. Earth Hour is the world's largest environmental movement which encourages individuals, businesses and communities around the world to turn off their lights for one hour on the last Saturday of March in a bid to raise awareness on climate change. (Xinhua/Han Chuanhao)

The combined photo shows the Badaling section of the Great Wall before Earth Hour (upper) and during Earth Hour in Beijing, capital of China, March 31, 2012. Main buildings and areas in many cities of China participated in the Earth Hour on Saturday evening. Earth Hour is the world's largest environmental movement which encourages individuals, businesses and communities around the world to turn off their lights for one hour on the last Saturday of March in a bid to raise awareness on climate change. (Xinhua/Gong Lei)

Citizens sign on the promotion board of Earth Hour event at Hezhong Square in Jiujiang City, east China's Jiangxi Province, March 31, 2012. Earth Hour is the world's largest environmental movement which encourages individuals, businesses and communities around the world to turn off their lights for one hour on the last Saturday of March in a bid to raise awareness on climate change. (Xinhua)

Photo taken on March 31, 2012 shows the Earth Hour activity held on Xinghai Square in Dalian, northeast China's Liaoning Province, March 31, 2012. Main buildings and areas in many cities of China participated in the Earth Hour on Saturday evening. Earth Hour is the world's largest environmental movement which encourages individuals, businesses and communities around the world to turn off their lights for one hour on the last Saturday of March in a bid to raise awareness on climate change. (Xinhua/Pan Yulong)

Main buildings and areas in many cities of China participated in the Earth Hour on Saturday evening. Earth Hour is the world's largest environmental movement which encourages individuals, businesses and communities around the world to turn off their lights for one hour on the last Saturday of March in a bid to raise awareness on climate change.