GREENLAND TIMESCALES

The Greenland ice sheet could potentially contribute up to 7 m to sea level rise in the coming millennia due to anthropogenic global warming. As temperatures increase, the ice sheet experiences more surface melt and will eventually no longer be able to sustain its current size. It is generally believed that if the global Earth's temperature will exceed a certain threshold value, the Greenland ice sheet will eventually melt completely. However, the magnitude of global warming which will lead to crossing this threshold is not well known. The sensitivity of the ice sheet to climate change on long timescales will largely depend on surface mass balance change. In this project, a novel approach will be developed for modeling the surface mass balance of the Greenland ice sheet by using a regional climate model of intermediate complexity coupled to an ice sheet model via a physically-based surface energy and mass balance interface. Such an approach will allow us to perform a large ensemble of long-term simulations of the Greenland ice sheet under different climate change scenarios to refine estimates of the Greenland ice sheet sensitivity to climate change and the critical climate thresholds leading to its complete melting. With this project, we will contribute to a better understanding of the Greenland Ice Sheet contribution to future sea level rise and to the assessment of the probability of irreversible changes in the Earth system.