Adaptation planning in the context of a weakening and possibly collapsing Atlantic Meridional Overturning Circulation (AMOC)

Climate scientists have raised concerns about the weakening of the Atlantic Meridional Overturning Circulation (AMOC) or even its potential collapse in the future. Their messages should not hinder urgent adaptation to climate risks; rather, they underscore the growing need for adaptive planning across a range of possible futures, including high-impact, low-likelihood AMOC scenarios. There are five ways to consider the consequences of AMOC weakening or collapse in adaptation planning: (1) broaden the set of future adaptation scenarios considered; (2) develop adaptation pathways beyond the most likely range of possible outcomes; (3) create robustness and redundancy in adaptation portfolios; (4) expand the solution space, attuned to path dependencies and their implications; and (5) monitor emerging, weak signals of AMOC changes to inform adaptation planning. We argue that closer collaboration between climate scientists and the adaptation planning community is needed to generate timely, policy-relevant insights that can guide proactive and effective adaptation action.