Reversible Atlantic overturning despite continued Greenland Ice Sheet melt
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The Atlantic Meridional Overturning Circulation (AMOC), a key component of the Earth’s climate system, has long been considered vulnerable to irreversible weakening or collapse under anthropogenic forcing and related Greenland Ice Sheet (GrIS) melt. However, its resilience remains uncertain. Here, we use a CO2-emission-driven Earth system model with an interactive GrIS to assess AMOC reversibility under idealised CO2 emission pathways that produce near-linear global warming, stabilisation at multiple warming levels, and subsequent cooling. We find that AMOC weakens quasi-linearly with global mean temperature increase up to 7 K without collapse, remains stable during temperature stabilisation, and recovers during cooling. In contrast, the GrIS mass loss accelerates under warming and continues through stabilisations; cooling slows the loss toward near balance, but does not restore the ice already lost, committing the planet to long-term sea-level rise. These results reveal a striking asymmetry in Earth-system resilience: the AMOC remains dynamically reversible under transient CO2 forcing — even under continued meltwater input from Greenland, whereas the GrIS is locked into long-term decline. Our findings underscore the urgency of rapid emission cuts to limit climate overshoot, AMOC weakening, and irreversible ice loss.