Projections of Antarctic Ice Sheet Loss by 2100 Using CMIP6 Models for IPCC AR6

The Cryosphere, February 26

The contribution of Antarctica to global sea level rise by 2100 varies widely based on the many different models included in the new “ISMIP6” effort. This work is based on the CMIP6 earth systems models developed for the next IPCC Assessment Report, AR6, Part 1 of which will be released in August of this year.  Under the low greenhouse gas emissions scenario, the Antarctic ice sheet exhibits much less ice loss; some of the models even found that a low emissions scenario might even result in stabilization and growth of the ice sheet, though this appears unlikely given current observations of net loss at today’s 1.1°C of warming (low emissions scenarios will result in around 1.5°C globally by 2100).  High emissions in contrast resulted in loss ranging up to 150 mm (15 cm) by 2100 from Antarctica alone. Few of these models have been calibrated using paleo-climatic sea level data or dynamic ice sheet processes, especially in West Antarctica, which could result in much higher amounts and rates of sea-level rise from Antarctica, especially after 2100.

Compiled by Amy Imdieke.