Fast recovery of North Atlantic sea level in response to atmospheric CO2 removal

Abstract

Abstract Sea level rise (SLR) due to anthropogenic warming poses substantial threats to coastal environments and human societies. Despite successful climate mitigation efforts, regional reversibility of SLR in response to stabilization or reduction of atmospheric carbon dioxide (CO2) remains unclear. Here, we investigate sea level fluctuations in Subpolar North Atlantic (SPNA) using idealized CO2 ramp-up and -down experiments. We found that during ramp-up period, the SPNA experiences a faster SLR than the global mean, followed by a more rapid decline with decreasing CO2. These dramatic sea level fluctuations are mainly driven by the response of Atlantic Meridional Overturning Circulation (AMOC) to CO2 forcing. The enhanced meridional salinity transport triggered by the rapid AMOC recovery plays a crucial role in the recovery of the SPNA sea level. Our study highlights the potential for abrupt sea level changes in the SPNA and surrounding coastal areas under climate mitigation scenarios.