“Financing urban Nature-based Solutions (NBS): A literature review from the perspective of funders”

Nature-based Solutions (NBS) are increasingly recognized as relevant strategies for mitigating the pressures coming from urbanization and climate change to build resilient and sustainable cities. However, securing financing for urban NBS is a persistent barrier for their widespread implementation. Therefore, understanding how to realize (co-)finance and funding by attracting resources from specific stakeholders – namely those that benefit from NBS - is essential to their expansion. While the need for NBS co-finance has been acknowledged, the funders' perspective on NBS has remained largely conceptual. Through a systematic review of the scientific literature this study identifies barriers and corresponding strategies for financing urban NBS from the funders'-oriented perspective. Knowledge sharing, fostering of innovative and alternative financing models and collaboration, also for co-financing, are among the most cited strategies to leverage other financial resources for NBS implementation and overcoming the budget shortfalls generally affecting public actors. We conclude by proposing future research avenues. Particularly, we suggest that the role of specific classes of stakeholders, namely corporations, the insurance sector, real estate firms and water utilities, should be investigated further since their contributions is likely to be relevant for the upscaling of NBS.