Asymmetric response of Northern Hemisphere near-surface wind speed to CO2 removal

Abstract

Understanding changes in near-surface wind speed (NSWS) is crucial for weather extremes prediction and wind energy management. This study examines the response of NSWS to atmospheric carbon dioxide (CO2) removal using large ensemble simulations of the Community Earth System Model version 1.2 (CESM1.2) and the models participating in the Carbon Dioxide Removal Model Intercomparison Project. Our results reveal that increasing CO2 concentrations lead to an overall weakening in the Northern Hemisphere (NH) extratropical NSWS over land. During the initial stage of CO2 removal (early ramp-down period), NH NSWS rapidly recovers. However, this recovery stalls and transitions into a declining trend during the late ramp-down period, mainly driven by pronounced negative NSWS trends in Europe. We find that a concurrent rapid recovery of the Atlantic Meridional Overturning Circulation (AMOC) counteracts the global cooling-induced recovery of the North Atlantic meridional air temperature gradient and associated westerly jet, thus prolonging NSWS weakening in NH mid-latitudes. Our findings underscore the pivotal role of AMOC in regulating NH extratropical NSWS variability under varying CO2 concentrations, offering valuable insights for future climate adaptation strategies.