Projections of 21st-century sea-level fall along coastal Greenland.

Abstract

The Greenland Ice Sheet will significantly contribute to global mean sea-level rise this century. However, glacial isostatic adjustment is expected to cause regional sea-level fall around Greenland as the land rebounds and the gravitational pull of the shrinking ice sheet decreases. A fall in local sea level has implications for Greenlandic communities whose economy, near-shore infrastructure, and food security are vulnerable to coastal changes, and for the dynamics of marine-terminating glaciers. In this study, we use a glacial isostatic model paired with sea-level and vertical land motion observations to predict future sea-level change in this region. We find that local sea level will fall around the island by 2100 CE (relative to 2017 CE) reaching a median value and likely range (17th-83rd percentile) of  - 0.9 m [ - 1.2 m to  - 0.66 m] and  - 2.5 m [ - 3.8 m to  - 1.7 m] for Representative Concentration Pathways 2.6 and 8.5, respectively, with viscous effects contributing 20-40% of the predicted local sea-level signal associated with future ice change.