Photo taken on June 2, 2012 shows the Sabu glacier and its glacial lake in Biru County, southwest China's Tibet Autonomous Region. The northern parts of the autonomous region have one of China's richiest glacier distributions, which are increasingly under the threat of global warming. (Xinhua/Chogo)

Photo taken on June 2, 2012 shows a melting glacier in southwest China's Tibet Autonomous Region. The northern parts of the autonomous region have one of China's richiest glacier distributions, which are increasingly under the threat of global warming. (Xinhua/Chogo)

Photo taken on May 31, 2012 shows a glacial lake in Biru County, southwest China's Tibet Autonomous Region. The northern parts of the autonomous region have one of China's richiest glacier distributions, which are increasingly under the threat of global warming. (Xinhua/Chogo)

Photo taken on June 2, 2012 shows the Sabu glacier in Biru County, southwest China's Tibet Autonomous Region. The northern parts of the autonomous region have one of China's richiest glacier distributions, which are increasingly under the threat of global warming. (Xinhua/Chogo)

Photo taken on June 2, 2012 shows the Sabu glacier and its glacial lake in Biru County, southwest China's Tibet Autonomous Region. The northern parts of the autonomous region have one of China's richiest glacier distributions, which are increasingly under the threat of global warming. (Xinhua/Chogo)

Photo taken on June 2, 2012 shows a glacial river in southwest China's Tibet Autonomous Region. The northern parts of the autonomous region have one of China's richiest glacier distributions, which are increasingly under the threat of global warming. (Xinhua/Chogo)

Photo taken on June 2, 2012 shows the Sabu glacier and its glacial lake in Biru County, southwest China's Tibet Autonomous Region. The northern parts of the autonomous region have one of China's richiest glacier distributions, which are increasingly under the threat of global warming.