Adaptation planning in large cities is unlikely to be effective

The assessment of public adaptation policies, strategies and plans to evaluate progress, effectiveness and long-term sustainability is challenging. The potential to develop an ex-post evaluation linked to outcomes is limited given the lack of policy implementation globally and the uncertainty related to when and how impacts will happen. Ex-ante evaluations, by contrast, seem more feasible when they focus on policy processes, contents and outputs. Yet, proxies that indicate credible outcomes need to be carefully selected. In both cases, how adaptation is integrated in local planning processes, and previous experience by governments seem to be crucial. In this paper we perform an ex-ante evaluation of adaptation planning in 59 cities, identified across a set of 136 coastal cities of over 1 million inhabitants located in developed and developing world regions. We assess 3 major areas: policy and economic credibility, science and technical credibility, and legitimacy. Overall, 53 metrics are used to assess how likely local adaptation policies are to be effective, implemented and sustained in the long-term. This global assessment reveals that current adaptation planning in big global cities has a significant space for improvement and is, overall, unlikely to be effective unless greater effort is invested in financing, regulatory context, monitoring and evaluation, and legitimacy aspects. We also discuss challenges and needs, assuming this sample is re-presentative of current progress of adaptation planning in large cities.