The Effects of a Constructed Closure of the Bering Strait on AMOC Tipping Behavior

TL;DR

This study uses an Earth system model to explore how artificially closing the Bering Strait could prevent the collapse of the Atlantic Meridional Overturning Circulation (AMOC) under climate change, potentially extending its safe carbon budget.

Contribution

It demonstrates that a constructed closure of the Bering Strait can serve as a climate intervention to delay or prevent AMOC collapse, depending on the AMOC's strength at closure time.

Findings

Closure can extend the AMOC's safe carbon budget by up to 500PgC.

Effectiveness depends on the AMOC's strength at the time of closure.

Early closure is more beneficial for stronger AMOC states.

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, for this model, an equilibrium AMOC with a reduction below (6.1 +/- 0.5)% from pre-industrial has an additional budget up to 500PgC given a sufficiently early closure, while for a 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.