Pathways for mainstreaming nature-based solutions for climate adaptation: grounding, capitalising, embedding and anticipating across 12 Mediterranean cities

Abstract The implementation of urban nature-based solutions (NbS) is gaining momentum, with significant efforts to advance the use of green walls, constructed wetlands, raingardens and other solutions in Europe. We examine nine case studies across the Mediterranean to analyse different mechanisms that contribute to institutional mainstreaming of NbS for climate resilience in urban and peri-urban areas. Drawing on targeted interviews and workshops with representatives of academia, governments and project managers, we offer insights into how these solutions can gain scale through different pathways that account for both disruptive and anchoring mechanisms by (i) adapting existing processes and gradually changing institutions (embedding), (ii) leveraging gaps in institutions and finding opportunities to build momentum from previous initiatives (capitalising), (iii) convincing actors and proving the effectiveness of NbS (grounding), and (iv) creating knowledge to respond to future demands (anticipating). Responding to unique policy landscapes and geo-climatic and cultural contexts, the cases offer insights into how different pathways can create institutional space for climate adaptation or leverage existing institutions to consolidate transformative change for implementing NbS in the Mediterranean and beyond.