Future Slower Reduction of Anthropogenic Aerosols Enhances Extratropical Ocean Surface Warming Trends

Abstract Global surface temperature short‐term trends fluctuate between cooling and fast‐warming under the combined action of external forcing and internal variability, significantly influencing the detectability of near‐term climate change. A key driver of these variations is anthropogenic aerosols...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Pingting Gu, Bolan Gan, Wenju Cai, Hai Wang, Lixin Wu
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2024
Subjects:
Online Access:https://doi.org/10.1029/2023GL107772
https://doaj.org/article/899fdb8cfb284a37a7338ddfcd374207
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Summary:Abstract Global surface temperature short‐term trends fluctuate between cooling and fast‐warming under the combined action of external forcing and internal variability, significantly influencing the detectability of near‐term climate change. A key driver of these variations is anthropogenic aerosols (AAs), which have undergone a non‐monotonic evolution with rapid reduction in recent decades. However, their reduction is projected to decelerate under a high carbon emission scenario, yet the impact on surface temperature trends remains unknown. Here, using initial‐perturbation large ensembles, we find that future slowdown in AA reduction over Europe and North America expedites the subpolar North Atlantic surface warming by intensifying the Atlantic meridional overturning circulation. Further, it accelerates the South Indian Ocean and Southern Ocean surface warming through positive low‐cloud feedback and oceanic dynamical adjustment, triggered by the poleward migration of westerlies under interhemispheric energy constraint. These AA‐driven warmings exacerbate greenhouse warming, significantly enhancing the detectability of local decadal warming trends.