Coproduced assessments of climate change adaptation to flood risk reveal equity challenges in locally led approaches 

Robust evaluation of climate change adaptation is essential for tracking progress and informing decision-making, yet existing assessment methods often overlook local priorities, social outcomes, and contextual complexity. We introduce a coproduced, quantitative framework for evaluating adaptation effectiveness that explicitly incorporates local knowledge, values, and success criteria. The approach is applied to locally led adaptation to flood risk in Tamale, Ghana, providing one of the first quantitative evaluations of this rapidly expanding adaptation approach.The assessment draws on a multi-year participatory process combining community ranking exercises, focus group discussions, and household surveys to evaluate 11 locally led adaptation interventions. Effectiveness was measured against criteria identified by local people, capturing dimensions frequently absent from conventional technical assessments, including diverse risk-reduction pathways, equity considerations, long-term sustainability, and social and environmental co-benefits. Community-based and behavioural measures - such as collective action and tree planting - were consistently rated as more effective than predominantly structural or technical interventions.By embedding the coproduced assessment results within a flood risk modelling framework, we find that locally led adaptation interventions can substantially reduce overall flood risk but struggle to address existing social inequalities. The findings demonstrate how coproduction can broaden and strengthen adaptation assessment whilst also revealing the practical challenges of fully realising locally led adaptation principles in implementation.