{"id":479022,"date":"2026-10-14T12:05:51","date_gmt":"2026-10-14T19:05:51","guid":{"rendered":"https:\/\/climatescience.press\/?p=479022"},"modified":"2026-10-14T12:05:53","modified_gmt":"2026-10-14T19:05:53","slug":"thwaites-glacier-could-contribute-twice-as-much-sea-level-rise-by-2100-new-model-shows","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=479022","title":{"rendered":"Thwaites Glacier Could Contribute Twice as Much Sea-Level Rise by 2100, New Model Shows"},"content":{"rendered":"\n
\"Aerial
AI generated by Grok<\/figcaption><\/figure>\n\n\n\n

A new UC Irvine and NASA JPL study finds that Thwaites Glacier (West Antarctica) could contribute up to ~30 mm (1.2 inches) of global sea- level rise by 2100, roughly twice prior estimates, even under constant recent climate conditions (no additional warming).<\/strong><\/p>\n\n\n\n

The research, led by Mattia Poinelli (then at UC Irvine, now UCLA) with Eric Rignot (UC Irvine) and colleagues from NASA\u2019s Jet Propulsion Laboratory and other institutions, was published in Nature Communications<\/em> (October 2026). The paper is titled \u201cSea- level contribution from Thwaites Glacier doubles in an observation- constrained ice- sheet model.\u201d<\/p>\n\n\n\n

Key advance: modeling a \u201cgrounding zone\u201d instead of a simple \u201cgrounding line\u201d<\/strong><\/h3>\n\n\n\n

Traditional ice- sheet models treat the transition from grounded ice to floating ice shelf as a narrow, discrete grounding line<\/em>. Satellite radar data (including from the ICEYE constellation) show a broader grounding zone<\/em>, often several kilometers wide, where warm, pressurized seawater repeatedly intrudes under ice that models previously treated as firmly grounded. This causes vigorous basal melting during tidal cycles.<\/p>\n\n\n\n

By incorporating a grounding zone (typically 2- 5 and more km wide) into the Ice- sheet and Sea- level System Model (ISSM) <\/strong>and calibrating it against more than 20 years of observations (ice speed, thinning, and grounding-line position from the mid-1990s to 2023), the model much better reproduces the glacier\u2019s rapid historical retreat, thinning, and acceleration. Without the zone, historical mass loss is under-reproduced by a factor of about four.<\/p>\n\n\n\n

Projections<\/strong><\/h3>\n\n\n\n

Under climate conditions held at the recent average:<\/p>\n\n\n\n