摘要
在过去几个世纪,人类活动已经从根本上影响了整个地球系统的功能。这些变化在北半球的高纬度地区尤为明显,那里的环境变化一直是明显而迅速的。这些变化的影响远远超出本区域,因为它们可以导致两个重要的反馈过程:冰反照率的反馈和陆地碳循环气候反馈。这些过程在地球系统功能中发挥着异常重要的作用,特别是,在本世纪,它们可能从抑制人为环境变化的影响一转而为加速这些影响。在高纬度地区快速的环境变化会影响那些对人类有直接重要关系的事物,尤其是水资源。
Human activities over the past few centuries have profoundly changed the functioning of the earth system as a whole.These changes are particularly evident in the high latitudes of the Northern Hemisphere,where environmental change has been pronounced and rapid. Such changes have implications beyond the region,as they can lead to two important feedback processes:the icealbedo feedback and the terrestrial carbon cycle-climate feedback.These processes play an exceptionally important role in earth system functioning, particularly because they may switch this century from damping the effects of anthropogenic climate change to accelerating them.Rapid environmental change in the high latitudes also has consequences for issues of direct importance to humans,particularly water resources.
