Less climatic resilience in the Arctic

Abstract

Twenty years ago the Arctic system was more resilient than now as sea ice was three times thicker than today. Heavier and more persistent sea ice provided a buffer against the influence of short-term climate fluctuations. Such recent increases in sea ice/atmospheric interactions lead to revisiting the concept of abrupt change. The Arctic climate is stabilized by a negative radiative feedback, as increased temperatures of the surface and atmospheric lose more long wave energy. However, through new shifts in albedo feedback, open ocean areas are absorbing more of the incoming solar heat. Recent multi-year environmental extremes, potential albedo instabilities, and increased sensitivity of sea ice to storms in marginal seas, are overcoming negative radiative feedback, which point to passing impending climatic and ecosystem thresholds. Unless CO2 emissions are reduced, further Arctic extremes are expected in the next decades with environmental and societal impacts spreading through the Arctic and beyond.