Observation-based selection of climate models projects Arctic ice-free summers around 2035

• Published in: Communications Earth & Environment
• Main Authors: Docquier, David, Koenigk, Torben
• Other Authors: EC | Horizon 2020 Framework Programme, NordForsk
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2021
• Subjects: General Earth and Planetary Sciences; General Environmental Science; Arctic; Arctic Ocean; Sea ice
• Online Access: http://dx.doi.org/10.1038/s43247-021-00214-7; http://www.nature.com/articles/s43247-021-00214-7.pdf; http://www.nature.com/articles/s43247-021-00214-7

Abstract Arctic sea ice has been retreating at an accelerating pace over the past decades. Model projections show that the Arctic Ocean could be almost ice free in summer by the middle of this century. However, the uncertainties related to these projections are relatively large. Here we use 33 global climate models from the Coupled Model Intercomparison Project 6 (CMIP6) and select models that best capture the observed Arctic sea-ice area and volume and northward ocean heat transport to refine model projections of Arctic sea ice. This model selection leads to lower Arctic sea-ice area and volume relative to the multi-model mean without model selection and summer ice-free conditions could occur as early as around 2035. These results highlight a potential underestimation of future Arctic sea-ice loss when including all CMIP6 models.