More than 99% of the earth's ice is found in the ice sheets covering Antarctica and Greenland. Under the effect of climate change, their melting, even partial, will contribute significantly to a rise in sea level. By how much?
For the first time, glaciologists, oceanographers and climatologists from 13 countries have joined forces to produce new projections under CMIP5 and CMIP6 scenarios (see below). Their simulations are organized as part of the Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6).

Simulations indicate that the melting of the Antarctic ice sheet could contribute up to 30 cm to sea level rise from 2015 to 2100 but could also mitigate it by up to 7.8 cm at best. Indeed, certain models and scenarios predict that snow accumulation could exceed the loss due to ice melt.
This very significant uncertainty is explained by the melting of the lower extensions of the ice sheet over the ocean (ice shelves) - a poorly understood mechanism governed by changes in the ocean. These floating extensions, whose surface areas can be as large as half that of France, are contrary to the melting of the cap. Assuming their imminent disappearance, projections indicate a sea level rise of several meters over 500 years!
For the Arctic, over 2015-2100, the Greenland ice sheet would contribute between 1.5 cm and 14 cm, depending on the trajectory of greenhouse gas emissions due to human activity.

To refine these estimates, scientists are working on a new generation of climate models that will describe the cryosphere, along with the atmosphere, ocean and biogeochemistry. 

CMIP5 and CMIP6