Differentiated trajectories of ecosystem-based adaptation for urban coastal defence in the Asian-Pacific region: A biodiversity–climate–society nexus perspective

Many coastal cities already experience severe climate change impacts and are in urgent need of an immediate shift toward transformative adaptation. Ecosystem-based adaptation (EbA) measures for coastal defence have garnered increasing attention as a more sustainable and cost-effective approach to foster climate-resilient development in coastal areas. This study explores the current priorities, processes, and progress of EbA implementation for coastal defence in Asia Pacific cities. It uses the Biodiversity – Climate – Society (BCS) nexus lens popularised in the first joint report by the Intergovernmental Panel on Climate Change (IPCC) and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). Utilising case studies from Singapore, China, and Vietnam, we evaluate the current stage and status of EbA implementation and examine interacting outcomes, feedback loops, leverage points, and tipping points within the BCS nexus. The insights drawn here from multiple cities in Asia Pacific can offer insights that could be useful to similar coastal areas in other parts of the world as well as decision-makers and stakeholders within the broader climate change community. • Ecosystem-based adaptation (EbA) projects can protect coasts against climate change. • Comparative analysis of EbA adoption in Da Nang, Singapore and Xiamen. • Different EbA adoption trajectories, influencing factors and dynamics across cities. • Caution against one-size-fit-all EbA implementation approaches to guarantee success. • Transformative governance needed to activate leverage points for EbA implementation.