北极气候反应：全球性影响.pdf

for a living planet Arctic climAte FeedbAcks: GlobAl implicAtions executive summAry ver the pAst Few decAdes , the Arctic has warmed at about twice the rate of the rest of the globe. human-induced climate change ohas affected the Arctic earlier than expected. As a result, climate change is already destabilising important “Human-induced arctic systems including sea ice, the Greenland ice sheet, mountain glaciers, and aspects of the arctic carbon cycle climate change has including altering patterns of frozen soils and vegetation and affected the Arctic increasing methane release from soils, lakes, and wetlands. earlier than expected” the impact of these changes on the Arctic’s physical systems, biological systems, and human inhabitants is large and projected to grow throughout this century and beyond. in addition to the regional consequences of arctic climate change are its global impacts. Acting as the northern hemisphere’s refrigerator, a frozen Arctic plays a central role in regulating earth’s climate system. A number of critical arctic climate feedbacks affect the global climate system, and many of these are now being altered in a rapidly warming Arctic. there is emerging evidence “There is emerging and growing concern that these evidence and growing feedbacks are beginning to accelerate concern that arctic climate global warming significantly beyond feedbacks affecting the the projections currently being considered by policymakers. recent global climate system are observations stro