Can the ocean survive a melting ice sheet?

Like dominoes, the fall of one thing can lead to a cascade of other effects. In science, this can be found in climate systems and is known as cascading tipping — something that occurs when a subsystem crosses its tipping point and pushes another beyond its own threshold.

Previous work has shown that crossing a tipping threshold does not necessarily cause a system to tip. Sinet et al. extended this understanding to interacting systems by determining when one subsystem can push another beyond its tipping point without triggering a cascade and applied it to coupled climate systems.

The researchers found that whether the second subsystem tips or recovers mainly depends on how strongly the two subsystems interact and how quickly each responds.

One example of a coupled system is the Greenland Ice Sheet and the Atlantic Meridional Overturning Circulation (AMOC), which are linked by meltwater.

“[As] the Greenland Ice Sheet melts, it releases freshwater into the North Atlantic, which weakens the AMOC and can temporarily push it beyond its tipping point,” author Sacha Sinet said. “In the simplified model considered in the paper, our criterion identifies a fairly large range of Greenland Ice Sheet collapse durations for which the overshoot remains safe: The AMOC crosses its tipping threshold but recovers before a full collapse occurs.”

The researchers cautioned that these results should not be interpreted as predictions. Instead, the examples in the paper are used to demonstrate whether their model and criterion can be used to assess whether a coupled system will tip into a domino effect.

Their next step is to test the criterion in more complex climate models.

“Testing whether the criterion remains useful under those more realistic conditions will show how far it can be applied to assessing cascading tipping risks in the climate system,” Sinet said.

Source: “A criterion for safe overshoot in coupled tipping systems,” by S. Sinet, N. A. M. Delmeire, P. D. L. Ritchie, H. A. Dijkstra, and A. S. von der Heydt, Chaos (2026). The article can be accessed at https://doi.org/10.1063/5.0332433 .