Greenland ice sheet climate disequilibrium and committed sea-level rise
Jason E. Box (Geological Survey of Denmark and Greenland)
Alun Hubbard (University of Oulu, University of Tromsø)
David B. Bahr (University of Colorado - Boulder)
William T. Colgan (Geological Survey of Denmark and Greenland)
Xavier Fettweis (Université de Liège)
Kenneth D. Mankoff (Geological Survey of Denmark and Greenland)
Adrien Wehrlé (Universitat Zurich)
Brice Noël (Universiteit Utrecht)
Bert Wouters (TU Delft - Physical and Space Geodesy, Universiteit Utrecht)
undefined More Authors (External organisation)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Ice loss from the Greenland ice sheet is one of the largest sources of contemporary sea-level rise (SLR). While process-based models place timescales on Greenland’s deglaciation, their confidence is obscured by model shortcomings including imprecise atmospheric and oceanic couplings. Here, we present a complementary approach resolving ice sheet disequilibrium with climate constrained by satellite-derived bare-ice extent, tidewater sector ice flow discharge and surface mass balance data. We find that Greenland ice imbalance with the recent (2000–2019) climate commits at least 274 ± 68 mm SLR from 59 ± 15 × 103 km2 ice retreat, equivalent to 3.3 ± 0.9% volume loss, regardless of twenty-first-century climate pathways. This is a result of increasing mass turnover from precipitation, ice flow discharge and meltwater run-off. The high-melt year of 2012 applied in perpetuity yields an ice loss commitment of 782 ± 135 mm SLR, serving as an ominous prognosis for Greenland’s trajectory through a twenty-first century of warming.
help_outline