EGU2020-1399, updated on 10 Jan 2023
EGU General Assembly 2020
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

A sea ice-free Arctic during the Last Interglacial supports fast future loss

Maria Vittoria Guarino1, Louise Sime1, David Schroeder2, Irene Malmierca-Vallet1, Erica Rosenblum6, Mark Ringer3, Jeff Ridley3, Danny Feltham2, Cecilia Bitz5, Eric Steig5, Eric Wolff4, Julienne Stroeve6, and Alistair Sellar3
Maria Vittoria Guarino et al.
  • 1British Antarctic Survey, Cambridge, United Kingdom (
  • 2Department of Meteorology, University of Reading, United Kingdom
  • 3The Met Office, Exeter, United Kingdom
  • 4University of Cambridge, Cambridge, United Kingdom
  • 5University of Washington, US
  • 6Centre of Earth Observation Science, University of Manitoba, Canada

The Last Interglacial (LIG) is a period of great importance as an analog for future climate change. Global sea level was 6-9 m higher than present. Stronger LIG summertime insolation at high northern latitudes drove Arctic land summer temperatures around 4-5 K higher than during the preindustrial era. Climate-model simulations have previously failed to capture these elevated temperatures. This may be because these models failed to correctly capture LIG sea ice changes.

Here, we show that the latest version of the UK Hadley Center coupled ocean-atmosphere climate model (HadGEM3) simulates a much improved Arctic LIG climate, including the observed high temperatures. Improved model physics in HadGEM3, including a sophisticated sea ice melt-pond scheme, results in the first-ever simulation of the complete loss of Arctic sea ice in summer during the LIG.

Our ice-free Arctic yields a compelling solution to the long-standing puzzle of what drove LIG Arctic warmth. The LIG simulation result is a new independent constraint on the strength of Arctic sea ice decline in climate-model projections, and provides support for a fast retreat of Arctic summer sea ice in the future.

How to cite: Guarino, M. V., Sime, L., Schroeder, D., Malmierca-Vallet, I., Rosenblum, E., Ringer, M., Ridley, J., Feltham, D., Bitz, C., Steig, E., Wolff, E., Stroeve, J., and Sellar, A.: A sea ice-free Arctic during the Last Interglacial supports fast future loss, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-1399,, 2020.