A cross-scale worldwide analysis of coastal adaptation planning

The Paris Agreement requires measurement of the progress made on adaptation. Tracking the progress made by governments through analysis of policies provides insight into the goals and means to achieve adaptation targets. Here we show the current state-of-the-art in public adaptation planning affecting 136 of the largest coastal port urban agglomerations, covering 68 countries. We identify 226 adaptation policies: 88 at national level, 57 at regional/state level and 81 at city/metropolitan level. This set of adaptation policies can be considered the latest, most up-to-date database of governmental and public-led adaptations. Our analyses show that (1) in one half of cases, there is no evidence of policy implementation, (2) in almost 85% of cases, planned adaptation actions are not driven by present or future climatic impacts or risks, and (3) formal adaptation planning is relatively recent and is concentrated in more developed areas and countries.