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

Sea level rise due to anthropogenic warming threatens coastal environments and human societies, but its regional reversibility under successful climate mitigation efforts remains unclear. Using idealized atmospheric CO₂ ramp-up and ramp-down experiments, the study investigates Subpolar North Atlantic (SPNA) sea level fluctuations. During ramp-up, the SPNA experiences sea level rise faster than the global mean; during ramp-down, it exhibits a more rapid sea level decline over several decades. These fluctuations are mainly driven by the Atlantic Meridional Overturning Circulation (AMOC) response to CO₂ forcing. Enhanced meridional salinity transport associated with rapid AMOC recovery plays a crucial role in regional sea level decline. The results highlight potential pronounced sea level changes in the SPNA and surrounding coasts under climate mitigation scenarios.