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.
|Publication status||Published - 2023 Jan|
Bibliographical noteFunding Information:
This work was supported directly by National Research Foundation of Korea (NRF‐2018R1A5A1024958), Yonsei Signature Research Cluster Program of 2021 (2021‐22‐0003). SWY was also supported by Korea Environment Industry and Technology Institude (KEITI) through‐Climate Change R&D Project for New Climate Regime funded by Korea Ministry of Environment (MOE) (2022003560001).
© 2022 The Authors. Earth's Future published by Wiley Periodicals LLC on behalf of American Geophysical Union.
All Science Journal Classification (ASJC) codes
- Environmental Science(all)
- Earth and Planetary Sciences (miscellaneous)