北极变暖速度是世界其他地区的四倍

Communications Earth & Environment, 11 August 2022

Climate models typically estimate that the Arctic is warming 2.5 times faster than the global average, but decades of observational records now suggest that the true rate of “Arctic amplification” is nearly double these estimations. The Arctic warms faster than any other region on Earth due to Arctic amplification, a phenomenon in which rising temperatures create feedback loops that increase the warming experienced in far northern regions. Arctic sea ice loss drives this cycle, increasing the amount of heat absorbed by the dark surface of the ocean. These feedback loops are most prominent in the Barents and Kara seas, where ocean warming accelerates sea ice loss to unprecedented levels. The Arctic contains a delicately balanced climate system that is extremely sensitive to warming. Higher temperatures also threaten high-latitude regions with frozen permafrost, pushing them to thaw in processes that release carbon dioxide and methane, and accelerate warming on a global scale. Since the observed pace of Arctic warming is far higher than the models implied, the findings from this study suggest that current climate models may not fully capture the many feedback loops responsible for Arctic amplification. Authors underscore the urgency in reducing emissions to keep temperatures within 1.5°C, and avoid tipping delicate Arctic systems across thresholds of irreversible loss.

https://www.nature.com/articles/s43247-022-00498-3