全球变暖:global warming

　　冰川融化:the melting of glaciers

　　永久冻土:permafrost

　　北极冰山:Arctic iceberg

　　青藏高原:Qinghai-Tibetan Plateau

　　上游:headwaters

　　过度开发:excessive exploitation

　　生态灾难:ecological disaster

　　沙漠化:desertification

　　人为的:human-induced