Photo taken on July 15, 2014 shows the melting ice of Purog Kangri Glacier in Shuanghu County, Nagqu, southwest China's Tibet Autonomous Region. As the highest terrain in the world's mid-latitude regions, China's Qinghai-Tibet Plateau is now under negative influence of the global warming. Purog Kangri Glacier, the third largest in the world, has shrunk by 50 meters over the past 30 years. [Photo/Xinhua]