Sea-ice-free Arctic during the Last Interglacial supports fast future loss
The Last Interglacial (LIG), a warmer period 130,000–116,000 years before present, is a potential analogue for future climate change. Stronger LIG summertime insolation at high northern latitudes drove Arctic land summer temperatures 4–5 °C higher than in the pre-industrial era. Climate model simulations have previously failed to capture these elevated temperatures, possibly because they were unable to correctly capture LIG sea-ice changes. Here, we show that the latest version of the fully coupled UK Hadley Center climate model (HadGEM3) simulates a more accurate Arctic LIG climate, including elevated temperatures. Improved model physics, including a sophisticated sea-ice melt-pond scheme, result in a complete simulated loss of Arctic sea ice in summer during the LIG, which has yet to be simulated in past generations of models. This ice-free Arctic yields a compelling solution to the long-standing puzzle of what drove LIG Arctic warmth and supports a fast retreat of future Arctic summer sea ice.
Authors: Guarino, Maria Vittoria ORCID record for Maria Vittoria Guarino, Sime, Louise C. ORCID record for Louise C. Sime, Schröeder, David, Malmierca Vallet, Irene, Rosenblum, Erica, Ringer, Mark, Ridley, Jeff, Feltham, Danny, Bitz, Cecilia, Steig, Eric J., Wolff, Eric, Stroeve, Julienne, Sellar, Alistair