Structured expert judgement projections of the ice-sheet contribution to future sea-level rise
Structured expert judgement (SEJ) is an established method for estimating the likelihood of deeply uncertain outcomes, such as century-to-multicentury ice-sheet changes. We used SEJ to estimate ice-sheet changes through 2300 under scenarios stabilizing in 2100 at 2°C, 3.5°C, and 5°C of global warming. Under a 2°C scenario, the projected median (5th–95th percentile) ice-sheet contribution to GMSL change is 23 (-16 to 76) cm by 2100 and 131 (-45 to 420) cm by 2300; under a 5°C scenario, these values rise to 42 (-34 to 181) cm by 2100 and 365 (10 to 1120) cm by 2300. Relative to a comparable 2018 study, upper-end projections are similar while low-end projections reflect a greater probability of a significant increase in Antarctic accumulation. Combining elicitation results with probabilistic interpolation indicates a GMSL contribution from the Greenland ice sheet under SSP2-4.5 of 16 (-4 to 43) cm by 2100, 33 (-6 to 93) cm by 2150, and 77 (-17 to 234) cm by 2300, exceeding corresponding Intergovernmental Panel on Climate Change Sixth Assessment Report (AR6) medium-confidence estimates in uncertainty and, for 2100 and 2150, median values. For Antarctica, projections of 11 (-34 to 85) cm by 2100, 26 (-54 to 191) cm by 2150, and 105 (-84 to 532) cm by 2300 are more uncertain than AR6 medium-confidence projections. Accounting for tail dependence, 95th-percentile total ice-sheet contributions reach 1.1 m by 2100 and 2.5 m by 2150 under SSP2-4.5, highlighting the potential for multi-meter GMSL rise in the 22nd century under intermediate emissions.
Authors
- Luke D. Trusel (ORCID: https://orcid.org/0000-0002-7792-6173)
- Chris R. Stokes (ORCID: https://orcid.org/0000-0003-3355-1573)
- Willy P. Aspinall (ORCID: https://orcid.org/0000-0001-6014-6042)
- Anders Levermann (ORCID: https://orcid.org/0000-0003-4432-4704)
- Helene L. Seroussi (ORCID: https://orcid.org/0000-0001-9201-1644)
- Eric J. Rignot (ORCID: https://orcid.org/0000-0002-3366-0481)
- Edward Hanna (ORCID: https://orcid.org/0000-0002-8683-182X)
- Robert E. Kopp (ORCID: https://orcid.org/0000-0003-4016-9428)
- I. Velicogna (ORCID: https://orcid.org/0000-0002-9020-1898)
- Gabriela F. Nane (ORCID: https://orcid.org/0000-0002-3614-1820)
- Jonathan Louis Bamber (ORCID: https://orcid.org/0000-0002-2280-2819)
- T. A. Scambos (ORCID: https://orcid.org/0000-0003-4268-6322)
- Ronja Reese (ORCID: https://orcid.org/0000-0001-7625-040X)
- Surendra Adhikari (ORCID: https://orcid.org/0000-0003-1021-6860)
- Michael Oppenheimer (ORCID: https://orcid.org/0000-0002-9708-5914)
- Elizabeth Davis (ORCID: https://orcid.org/0000-0001-9468-8990)
- Trevor R. Hillebrand (ORCID: https://orcid.org/0000-0003-3535-1540)
- Mathieu Morlighem (ORCID: https://orcid.org/0000-0001-5219-1310)
- Denis Felikson (ORCID: https://orcid.org/0000-0002-3785-5112)
- Roger Cooke
Institutions
- Rutgers, The State University of New Jersey (US)
- Dartmouth College (US)
- Goddard Space Flight Center (US)
- Pennsylvania State University (US)
- Jet Propulsion Laboratory (US)
- Los Alamos National Laboratory (US)
- Cooperative Institute for Research in Environmental Sciences (US)
- University of Colorado Boulder (US)
- Durham University (GB)
- Princeton University (US)
- University of California, Irvine (US)
- Resources For The Future (US)
- Northumbria University (GB)
- University of Bristol (GB)
- High Meadows Environmental Institute (US)
- University of Lincoln (GB)
- Potsdam Institute for Climate Impact Research (DE)
- Delft University of Technology (NL)
Publication Details
- Published
- 2026-11-06
- DOI
- https://doi.org/10.22541/essoar.15011810/v1
- Primary Topic
- Cryospheric studies and observations
- Type
- preprint