Co-creating Scenario Narratives for Future Risk Landscapes in the Context of Interconnected Climate Hazards

A central challenge in climate change adaptation is the temporal mismatch between short-term planning and long-term changing risks. Most strategies focus on ex-post adaptation to current climate impacts rather than on anticipatory strategies that address future risks. This challenge is particularly difficult for systemic climate risks related to interconnected hazards, such as floods and droughts. Flood and drought risks, and their adaptation solutions, are usually analysed in isolation, overlooking their coupled dynamics within hydrological cycles and possible win-wins for adaptation to hydrological extremes. A key tool used in adaptation planning are climate change scenarios. These represent structured narratives about plausible futures, and can help to understand future hazards, supporting the exploration of future risk trajectories linked to hydrological extremes. However, effective adaptation planning for systemic risks at the local level requires downscaled climate projections and locally contextualised socioeconomic trajectories to effectively co-develop adaptation options with local actors. This study addresses this need by co-creating scenario narratives based on hybrid localized Shared Socioeconomic Pathway–Representative Concentration Pathway (SSP-RCP) projections and introduces an approach to explore systemic future risk landscapes of interconnected hazards.

We coupled downscaled RCP2.6 and RCP8.5 scenarios with localized SSP1 and SSP5 scenarios and integrated these with co-created visions and systemic risk models to generate one hopeful (SSP1-RCP2.6) and one apprehensive (SSP5-RCP8.5) scenario narrative, informed by both local actor expertise and localized projections for the Erft Basin in Germany. We applied the two scenarios that illuminate divergent potential futures in a participatory workshop setting to review systemic future risk landscapes, prioritize future risks linked to floods and droughts, and define risk tolerance thresholds. Participating actors prioritized a combination of societal and biophysical risks, helping to develop a clearer understanding of risk landscapes from a systemic lens. The risk tolerance thresholds defined in this process are embedded in local realities and reflect the priorities and potential commitment of the actors. Our findings suggest that co-created scenario narratives prompt actors to recognize future systemic risks in a broader range of contexts, thereby enabling them to consider linked future risks in cross-sectoral risk landscapes, potentially enabling more robust and differentiated decision-making. By explicitly linking locally calibrated hybrid scenarios with actor participation, this approach promotes and facilitates forward-looking adaptation planning, such as adaptation pathways, and enhances actors' capacity to prioritize systemic future risk in the context of interconnected climate hazards.