气候变化领域集成服务门户(CCPortal): Critical slowing down suggests that the western Greenland Ice Sheet is close to a tipping point

CCPortal

DOI	10.1073/pnas.2024192118
	Critical slowing down suggests that the western Greenland Ice Sheet is close to a tipping point
	Boers N.; Rypdal M.
发表日期	2021
ISSN	0027-8424
卷号	118 期号:21
英文摘要	The Greenland Ice Sheet (GrIS) is a potentially unstable component of the Earth system and may exhibit a critical transition under ongoing global warming. Mass reductions of the GrIS have substantial impacts on global sea level and the speed of the Atlantic Meridional Overturning Circulation, due to the additional freshwater caused by increased meltwater runoff into the northern Atlantic. The stability of the GrIS depends crucially on the positive melt-elevation feedback (MEF), by which melt rates increase as the overall ice sheet height decreases under rising temperatures. Melting rates across Greenland have accelerated nonlinearly in recent decades, and models predict a critical temperature threshold beyond which the current ice sheet state is not maintainable. Here, we investigate long-term melt rate and ice sheet height reconstructions from the central-western GrIS in combination with model simulations to quantify the stability of this part of the GrIS. We reveal significant early-warning signals (EWS) indicating that the central-western GrIS is close to a critical transition. By relating the statistical EWS to underlying physical processes, our results suggest that the MEF plays a dominant role in the observed, ongoing destabilization of the central-western GrIS. Our results suggest substantial further GrIS mass loss in the near future and call for urgent, observation-constrained stability assessments of other parts of the GrIS. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Critical slowing down; Early-warning signals; Greenland Ice Sheet; Tipping points
语种	英语
scopus关键词	article; body weight; critical temperature; Greenland; ice sheet; melting point; simulation
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/238732
作者单位	Department of Mathematics and Computer Science, Freie Universität Berlin, Berlin, 14195, Germany; Potsdam Institute for Climate Impact Research, Potsdam, 14473, Germany; Department of Mathematics, University of Exeter, Exeter, EX4 4QF, United Kingdom; Global Systems Institute, University of Exeter, Exeter, EX4 4QE, United Kingdom; Department of Mathematics and Statistics, UiT The Arctic University of Norway, Tromsø, 9037, Norway
推荐引用方式 GB/T 7714	Boers N.,Rypdal M.. Critical slowing down suggests that the western Greenland Ice Sheet is close to a tipping point[J],2021,118(21).
APA	Boers N.,&Rypdal M..(2021).Critical slowing down suggests that the western Greenland Ice Sheet is close to a tipping point.Proceedings of the National Academy of Sciences of the United States of America,118(21).
MLA	Boers N.,et al."Critical slowing down suggests that the western Greenland Ice Sheet is close to a tipping point".Proceedings of the National Academy of Sciences of the United States of America 118.21(2021).