The Greenland Ice Sheet (GrIS) mass balance is examined with an Earth system/ice sheet model that interactively couples the GrIS to the land and atmosphere.

The simulation runs from 1850 to 2100, with historical and SSP5-8.5 forcing. By mid-21st century, the cumulative contribution to global mean sea level rise (SLR) is 23 mm.

Over the second half of the 21st century, the surface mass balance becomes negative in all drainage basins, and an additional 86 mm of SLR is contributed.

The annual mean GrIS mass loss in the last two decades is 2.7 mm sea level equivalent (SLE) yr-1. Strong decrease in SMB (3.1 mm SLE yr-1) is counteracted by a reduction in ice discharge from thinning and retreat of outlet glaciers.

The southern GrIS drainage basins contribute 73% of the mass loss by mid-century. This decreases to 55% by 2100, as surface runoff in the northern basins strongly increases.