The effects of a constructed closure of the Bering Strait on AMOC tipping behavior

Abstract

The Atlantic Meridional Overturning Circulation (AMOC) is a major tipping element in the present-day climate and could potentially collapse under sufficient freshwater or CO2 forcing. While the effect of the Bering Strait on AMOC stability has been well studied, it is unknown whether a constructed closure of this Strait can prevent an AMOC collapse under climate change. Here, we show in an Earth system Model of Intermediate Complexity that an artificial closure of the Strait can extend the safe carbon budget of the AMOC, provided that the AMOC is strong enough at the closure time. Specifically, an equilibrium AMOC under a sufficiently low additional freshwater flux has an increased safe carbon budget given a timely closure of the Strait, while for higher freshwater fluxes (and corresponding weaker AMOC), a closure reduces this budget. This indicates that constructing this closure could be a feasible climate intervention strategy to prevent an AMOC collapse.