Arctic Climate Feedbacks: Global Implications, Executive SumaryOver the past few decades, the Arctic has warmed at about twice the rate of the rest of the globe. Human-induced climate change has affected the Arctic earlier than expected. As a result, climate change is already destabilising important arctic systems including sea ice, the Greenland Ice Sheet, mountain glaciers, and aspects of the arctic carbon cycle including altering patterns of frozen soils and vegetation and increasing methane release from soils, lakes, and wetlands.
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.
Important aspects of the global climate system, which directly affect many people, are already seeing the effects of arctic climate change. This assessment of the most recent science shows that numerous arctic climate feedbacks will make climate change more severe than indicated by other recent projections, including those of the IPC 2007 assessment. Some of these feedbacks may even interact with each other. Up-to-date analyses of the global consequences of arctic change highlight the need for ongoing critical review of the thresholds of dangerous human interference with the climate system, and demand increased rigour to stay below these thresholds through an ambitious global effort to reduce atmospheric greenhouse gases.