Global warming due to loss of large ice masses and Arctic summer sea ice

• Main Authors: Wunderling, Nico, Willeit, Matteo, Donges, Jonathan, Winkelmann, Ricarda
• Format: Article in Journal/Newspaper
• Language: English
• Published: Humboldt-Universität zu Berlin 2020
• Subjects: Climate and Earth system modelling; Cryospheric science; Projection and prediction; 550 Geowissenschaften; ddc:550; Antarctic; Arctic; Greenland; West Antarctic Ice Sheet; albedo; Antarc*; Global warming; Ice Sheet; Sea ice
• Online Access: http://edoc.hu-berlin.de/18452/27867; https://nbn-resolving.org/urn:nbn:de:kobv:11-110-18452/27867-9; https://doi.org/10.1038/s41467-020-18934-3; https://doi.org/10.18452/27211

Several large-scale cryosphere elements such as the Arctic summer sea ice, the mountain glaciers, the Greenland and West Antarctic Ice Sheet have changed substantially during the last century due to anthropogenic global warming. However, the impacts of their possible future disintegration on global mean temperature (GMT) and climate feedbacks have not yet been comprehensively evaluated. Here, we quantify this response using an Earth system model of intermediate complexity. Overall, we find a median additional global warming of 0.43 °C (interquartile range: 0.39−0.46 °C) at a CO2 concentration of 400 ppm. Most of this response (55%) is caused by albedo changes, but lapse rate together with water vapour (30%) and cloud feedbacks (15%) also contribute significantly. While a decay of the ice sheets would occur on centennial to millennial time scales, the Arctic might become ice-free during summer within the 21st century. Our findings imply an additional increase of the GMT on intermediate to long time scales. Deutsche Forschungsgemeinschaft (German Research Foundation) https://doi.org/10.13039/501100001659 Leibniz-Gemeinschaft (Leibniz Association) https://doi.org/10.13039/501100001664 Bundesministerium für Bildung und Forschung (Federal Ministry of Education and Research) https://doi.org/10.13039/501100002347 EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 European Research Council (H2020 Excellent Science - European Research Council) https://doi.org/10.13039/100010663 Earth League https://doi.org/10.13039/501100010065 Peer Reviewed