How can overshoot risks be included in long-term adaptation planning?

As climate change intensifies, it is essential to take a wide range of climate scenarios and their consequential impacts into account for adaptation planning. Overshoot scenarios, during which global warming will temporarily exceed the 1.5°C Paris Agreement target before it is brought down again in the following decades, are increasingly likely under current emissions trajectories. They would result in complex risks such as limits to adaptation and irreversible impacts and stress the need to prepare long-term adaptation plans under deep uncertainty.

Here, we introduce the latest version of the Overshooting Proofing Methodology, a self-assessment tool designed to guide adaptation planners and policy-makers to integrate overshoot risks into planning processes, and present novel insights from its application with key stakeholders at city and regional levels. We also reflect on how adaptation pathways can allow to adequately plan a sequence of adaptation measures over time based on information collected through this tool. Its initial implementation in selected cities/regions reflects its applicability in varied climatic settings together with a range of climate related challenges. This work provides insights on key data gaps, capacity building needs and avenues for future adaptation planning, policy-making and research.