The Greenland ice sheet will continue to lose mass and contribute to sea-level rise in the future due to climate change. The main factors causing this are increased surface meltwater run-off and glacier retreat. Models project a sea-level rise contribution of 90±50 mm for a high emissions scenario and 32±17 mm for a lower emissions scenario by 2100. The biggest mass loss is expected in the south-west of Greenland. Uncertainties in the projections come from ice sheet models, climate models, and ocean forcing. The biggest gap in knowledge is understanding how the ice sheet interacts with the ocean.