Ruptures in perceived solution spaces for adaptation to flood risk: Actor-specific insights from Mumbai’s flood risk reduction and general lessons

Adaptation to the increasing impacts of climate change will require societies to design portfolios of risk management solutions by selecting from an array of available adaptation options. A major step on the way toward a strong social contract for adaptation is understanding how different actors view different adaptation options as well as what adaptation goals they have and for whom. Here we adopt an actor-oriented multi-dimensional framework to understand how different actors evaluate their perceived adaptation solution space. The aim is to understand who identifies which adaptation options and how they are assessed as well as what desired objectives are and for whom they are targeted. In other words, what works, how, for what, and for whom. We build on the feasibility and effectiveness assessments used in IPCC’s sixth assessment report and explore the framework by applying it to the solution space for flood risk in Mumbai. We draw on empirical data collected through key informant interviews with state, civil society, and academic actors. Our findings show that, overall, actors see the need for institutional changes and green infrastructure measures. In terms of the factors perceived to enable or constrain adaptation, actors agree on the pivotal role of institutional aspects as even more important than financial or technical factors. However, the assessment revealed stark disparities between state and non-state actors, in particular on the objective of efficiency, largely emphasized by state actors for physical infrastructure measures. Other contested objectives included ecosystem protection and fairness for vulnerable populations. This study makes an empirical and analytical contribution to advance feasibility and effectiveness assessments by including actor perceptions in the evaluation of solution spaces for adaptation in real-world settings. It aims to inform decision-making processes for more effective and equitable adaptation.