The Arctic cryosphere at the Last Interglacial; an analogue for the future?

The Arctic is warming at double the rate as the rest of the world, in large because of the positive feedback of the sea-ice albedo. Adaption to sea-level rise is hindered by uncertainty in the contribution from the shrinking Greenland ice-sheet (GIS).

To gain a better understanding of the stability of the GIS and the Arctic sea-ice, scientists have turned to the Last Interglacial (LIG) as the last period significantly warmer than today.

The problem is that both data and models paint a conflicting picture of the Artic cryosphere at the LIG and that the applicability of the lessons drawn from the LIG (forced by higher solar insolation) to the future (forced by higher greenhouse gas concentrations) is not well understood.

Here we propose a true inter-disciplinary approach to the problem by a team of experts on paleoclimate data, paleoclimate modelling, and future climate modelling.

We will develop a new LIG model that will be state-of-the-art in paleoclimate research with a resolution surpassing any previous studies of the period.

Unlike previous studies, which typically compared the LIG climate to the pre-industrial climate, we will compare its mean state and variability directly to a future greenhouse world of comparable warmth. We will simulate the LIG climate with and without a GIS to evaluate which state fits the proxies best.

For this purpose we will develop an up-to-date synthesis of climate proxies for the LIG, including 9 new sea-ice records developed in this project.