YES-27-A-14: When the Ocean Tips: Observing, Governing, and Acting on North Atlantic Circulation Change Across Generations

The Atlantic Meridional Overturning Circulation (AMOC) is a critical component of the Earth system redistributing heat across the Atlantic Ocean and strongly influences climate in northwestern Europe. Evidence suggests that the AMOC may be weakening and could approach a tipping point beyond which circulation changes become abrupt and potentially irreversible. Such a transition could alter regional temperature patterns, storm tracks, precipitation regimes and climate variability, with profound implications for society. While effort is being devoted to improving observations, modelling and early warning indicators of AMOC change, less attention has been paid to how this emerging knowledge can inform decision-making under deep uncertainty.

This project addresses a fundamental challenge for environmental governance: how should societies act on evidence of a potentially transformative Earth system change when its timing, likelihood and consequences remain uncertain? Existing climate risk assessments are largely designed to manage gradual and relatively well-characterised hazards. AMOC tipping presents a different challenge because it may involve abrupt change with consequences that unfold across timescales extending beyond conventional planning horizons.

Political decision-making is often measured in years, infrastructure planning in decades, and climate adaptation in mid and end-of-century projections. In contrast, the processes leading to AMOC tipping and many of its consequences may span multiple generations, creating a mismatch between the timescales of Earth system change and those of contemporary governance. The project will investigate how long-term tipping risks can be meaningfully incorporated into present-day decision-making when future social, political and economic conditions remain uncertain.

The research will examine how AMOC-related risks are currently represented and communicated within climate adaptation, national risk assessment and resilience planning across northwestern Europe. Through comparative analysis of Climate Change Risk Assessments, adaptation strategies and relevant resilience frameworks in countries including for example the United Kingdom, Ireland, Iceland and the Nordic region, the project will explore how institutions account for low-probability but potentially transformative climate risks and identify barriers that limit consideration of risks extending beyond current planning horizons.

A second focus will explore how observations of AMOC change can become meaningful for decision-makers. Existing research has concentrated on detecting early warning signals of tipping, yet there may never be a single moment at which a tipping process can be definitively observed. Instead, decision-makers are likely to face multiple and evolving indicators of change. The project will investigate what constitutes decision-relevant evidence, how scientific uncertainty can be communicated effectively, and how observational indicators might support precautionary action before certainty is achieved.

The project will also examine how actionable knowledge can be co-produced for future generations. Current approaches to co-production typically assume direct engagement between researchers and contemporary decision-makers. However, AMOC tipping raises the challenge of creating knowledge that remains useful across multiple generations, institutions and socio-economic futures. The research will explore how monitoring systems, observational records and warning frameworks can be designed not only to inform present governance but also to support decision-making in futures we can only partially imagine.

By connecting Earth system observations, tipping-point science, decision-making and governance, the research will develop new approaches for translating long-term environmental change into actionable knowledge, contributing to resilience and preparedness for one of the most profound and uncertain risks associated with future climate change.