The Atlantic Meridional Overturning Circulation (AMOC) and the West Antarctic Ice Sheet (WAIS) are two crucial parts of Earth’s climate system, each vulnerable to abrupt change. But what happens when the destabilization of one affects the other?
This question is at the center of new research by Sacha Sinet (Utrecht University) who joined the ClimTip webinar series to explain how WAIS meltwater can either intensify AMOC instability or, under specific conditions, help keep it running. His team explored this overlooked interaction using conceptual theory and climate-model experiments, recently published in Science Advances.
Much of what we know about AMOC vulnerability comes from studies of Greenland meltwater, which consistently pushes the circulation toward a weaker state. Far less is known about how WAIS, itself a major tipping element, influences AMOC behaviour when it undergoes large or rapid mass loss.
Sinet’s results show that WAIS meltwater can have several distinct effects. Depending on how much, how fast, and when meltwater enters the ocean, it may accelerate AMOC weakening, delay an eventual collapse, or prevent collapse altogether in a narrow but plausible set of warming trajectories. Stabilization appears possible when WAIS meltwater reaches the ocean early and rapidly relative to Greenland’s melt, shifting density gradients and deep-water formation just enough to keep the AMOC in a weak but active state.
These dynamics also resonate with abrupt events in past climate, underscoring why the timing, magnitude and pathways of meltwater matter for assessing AMOC resilience under future greenhouse-gas emissions.
Watch the Webinar
The recording of this webinar is available on our YouTube.
Reference: Sacha Sinet et al., Meltwater from West Antarctic ice sheet tipping affects AMOC resilience. Sci. Adv.11, eadw3852 (2025). DOI: 10.1126/sciadv.adw3852
Find moret talks on the ClimTip YouTube channel to find more webinars on science of climate tipping points.
In Case You Missed It
Watch the October webinar with Jan Swierczek-Jereczek on the rate-induced tipping of the Antarctic Ice Sheet.
Thumbnail and opener design by Kuat Abeshev. Photo by NOAA on Unsplash.
