Changing Permafrost in the Arctic and its Global Effects in the 21st Century (PAGE21): A very large international and integrated project to measure the impact of permafrost degradation on the climate system

摘要

The northern permafrost region contains approximately 50% of the estimated global below-ground organic carbon pool and more than twice as much as is contained in the current atmospheric carbon pool. The sheer size of this carbon pool, together with the large amplitude of predicted arctic climate change implies that there is a high potential for global-scale feedbacks from arctic climate change if these carbon reservoirs are destabilized. Nonetheless, significant gaps exist in our current state of knowledge that prevent us from producing accurate assessments of the vulnerability of the arctic permafrost to climate change, or of the implications of future climate change for global greenhouse gas (GHG) emissions. Specifically: Our understanding of the physical and biogeochemical processes at play in permafrost areas is still insufficient in some key aspects. Size estimates for the high latitude continental carbon and nitrogen stocks vary widely between regions and research groups. The representation of permafrost-related processes in global climate models still tends to be rudimentary, and is one reason for the frequently poor performances of climate models at high latitudes.