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A 21st Century Warming Threshold for Sustained Greenland Ice Sheet Mass Loss
Author(s) -
Noël B.,
van Kampenhout L.,
Lenaerts J. T. M.,
van de Berg W. J.,
van den Broeke M. R.
Publication year - 2021
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl090471
Subject(s) - greenland ice sheet , meltwater , environmental science , climatology , glacier mass balance , future sea level , ice sheet , global warming , snow , climate model , climate change , atmospheric sciences , cryosphere , sea ice , geology , glacier , ice stream , physical geography , meteorology , oceanography , geography
Under anticipated future warming, the Greenland ice sheet (GrIS) will pass a threshold when meltwater runoff exceeds the accumulation of snow, resulting in a negative surface mass balance (SMB < 0) and sustained mass loss. Here, we dynamically and statistically downscale the outputs of an Earth system model to 1 km resolution to infer that a Greenland near‐surface atmospheric warming of 4.5 ± 0.3°C—relative to preindustrial—is required for GrIS SMB to become persistently negative. Climate models from CMIP5 and CMIP6 translate this regional temperature change to a global warming threshold of 2.7 ± 0.2°C. Under a high‐end warming scenario, this threshold may be reached around 2055, while for a strong mitigation scenario it will likely not be passed. Depending on the emissions scenario taken, our method estimates 6–13 cm sea level rise from GrIS SMB by the year 2100.