Interactions of climate tipping elements and their associated basin stability in a conceptual model for tipping cascades

With progressing global warming, there is an increased risk that one or several climate tipping elements might cross a critical threshold, resulting in severe consequences for the global climate, ecosystems and human societies. Here, we study a subset of four tipping elements and their interactions in a conceptual and easily extendable framework: the Greenland Ice Sheet, the West Antarctic Ice Sheet, the Atlantic Meridional Overturning Circulation (AMOC) and the Amazon rainforest.

In a large-scale Monte-Carlo simulation, we explicitly investigate the domino effects triggered by each of the individual tipping elements under global warming in equilibrium experiments. Thereby, we reveal the roles of each of the individual tipping elements in cascading transitions. Further, we perform a comprehensive basin stability analysis to detect the stable states of the interacting system and discuss their associated Earth system resilience. Finally, we analyse whether additional internal temperature feedbacks of the tipping elements might be able to increase the risk of triggering tipping events and cascades.

In our model experiments, we find: (i) the Greenland and the West Antarctic Ice Sheet are often the initiators of tipping cascades, while the AMOC typically takes on the role as a mediator of cascades. (ii) The interactions between the tipping elements considered here overall have a destabilizing effect on the climate system as a whole. (iii) In our model, the large ice sheets are of particular importance for the resilience of the Earth system on long time scales, as found by basin stability measures. (iv) Additional internal temperature feedbacks of the tipping elements can slightly increase the risk of triggering tipping events.