Southern Ocean Control of 2°C Global Warming in Climate Models
Abstract Global warming will soon reach the Paris Agreement targets of 1.5°C/2°C temperature increase above pre‐industrial levels. Under a business‐as‐usual scenario, the time to reach these targets varies widely among climate models. Using Coupled Model Intercomparison Project Phase 5 and 6, we sho...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Wiley
2023-01-01
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| Series: | Earth's Future |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2022EF003212 |
| Summary: | Abstract Global warming will soon reach the Paris Agreement targets of 1.5°C/2°C temperature increase above pre‐industrial levels. Under a business‐as‐usual scenario, the time to reach these targets varies widely among climate models. Using Coupled Model Intercomparison Project Phase 5 and 6, we show that a 2°C global warming is determined by Southern Ocean (SO) state closely tied with a low‐level cloud (LLC) amount feedback strength during reference (1861–1900) period; climate models with cold SO tend to accompany more low‐level cloudiness and Antarctic sea ice concentration due to a strong LLC amount feedback. Consequently, initially cold SO models tend to simulate a fast global warming by absorbing more downward shortwave radiation compared to initially warm SO models because more LLC disappears due to a strong LLC amount feedback during the 2°C rise. Our results demonstrate that climate models that correctly simulate initial SO state can improve 2°C warming projections with reduced uncertainties. |
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| ISSN: | 2328-4277 |