Today’s Policies Determine the Rate of Sea Level Rise from Antarctica: Improved Ice Loss Projections Over Coming Centuries

Earth’s Future, 4 September 2024

An updated model comparison experiment (ISMIP6 Antarctica 2300) has provided the first multi-model and multi-century projections of Antarctic Ice Sheet loss to the year 2300. Using 16 different ice sheet models, authors highlight the sharp risk of triggering large increases in Antarctic ice loss accelerating after the year 2100 if the world continues on its current high emissions pathway. The models suggest that Antarctica alone could contribute up to 28 centimetres to sea-level rise by 2100 — but with up to 1.7 meters by 2200, and nearly 7 meters (6.9m) by 2300 if the peripheral ice shelves around Antarctica begin to collapse in response to global warming. Up to 40% of the models predict that the West Antarctic Ice Sheet will collapse by 2300. The simulations highlight the importance of rapidly lowering emissions to slow down sea-level rise from ice loss to rates that are within adaptation limits. While ice losses from low- and high-emission scenarios therefore remain relatively similar in this century, the resulting sea-level rise rates diverge sharply after 2100, underscoring the importance of emission reductions today for long-term Antarctic Ice Sheet stability; and for the continued viability for coastal communities worldwide, with several hundreds of millions living at or below 7 meters worldwide, including in many major cities.

Full paper: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024EF004561
News briefing published by iC3 (Centre for Ice, Cryosphere, Carbon, and Climate): https://ic3.uit.no/news/antarctica-sea-level