Scientists investigate at the foot of Purog Kangri Glacier in the Qiangtang nature reserve, southwest China's Tibet Autonomous Region, July 9, 2017. China began its second scientific expedition to the Qinghai-Tibet Plateau this June to study changes in climate, biodiversity and environment over the past decades. The last expedition of similar scale was conducted in the 1970s. (Xinhua/Liu Dongjun)
