Seven lessons for planning nature-based solutions in cities

Nature-based solutions are proliferating in European cities over the past years as viable solutions to urban challenges such as climate change, urban degeneration and aging infrastructures. With evidence amounting about nature-based solutions, there is a need to translate knowledge about nature-based solutions to future policy and planning. In this paper, we analysed fifteen cases of nature-based solutions’ experiments across 11 European cities. What makes our case studies stand out is the balanced focus between ecosystem and social benefits in contrast to many published cases on nature-based solutions that have a weighted focus on the climate benefits. From a cross-case comparative analysis we draw seven overarching lessons related to all stages of proof-of-concept and implementation of nature-based solutions in cities: (a) nature-based solutions need to be aesthetically appealing to citizens, (b) nature-based solutions create new green urban commons, (c) experimenting with nature-based solutions requires trust in the local government and in experimentation process itself, (d) co-creation of nature-based solutions requires diversity and learning from social innovation, (e) nature-based solutions require collaborative governance, (f) an inclusive narrative of mission for nature-based solutions can enable integration to many urban agendas and (g) design nature-based solutions so as to learn and replicate them on the long-term. The lessons we draw show that nature-based solutions require multiple disciplines for their design, diversity (of settings) for co-creation and recognition of the place-based transformative potential of nature-based solutions as 'superior’ to grey infrastructure. We further discern that urban planners need to have an open approach to collaborative governance of nature-based solutions that allows learning with and about new appealing designs, perceptions and images of nature from different urban actors, allows forming of new institutions for operating and maintaining nature-based solutions to ensure inclusivity, livability and resilience.