Implementing Nature-based Solutions: the role of experts in co-creation processes and in new governance structures

The environmental crisis of XXI century is increasingly manifesting its negative impacts, especially in cities. Air pollution, heat island effects, adverse events such as flooding are only some of the most recurrent issues affecting public health and quality of life in cities. At the same time, the challenges but also the opportunities related to urbanisation have encouraged a global effort to re-think urban environments in an innovative way, especially through new solutions that address multiple issues and wide societal challenges (environmental, social, economic) at the same time. In this context, the concept of nature-based solutions (NBS) is receiving more and more attention, with various research studies and applications in several cities. Particularly in Europe, the European Commission is funding various projects and initiatives, becoming a global leader in innovating with nature to achieve more sustainable and resilient societies. NBS projects are often associated with the concept of ecosystem services and they are usually considered more complex and uncertain than traditional grey infrastructure projects. In fact, NBS are essentially dynamic (natural features evolve over time), they present a character of multiplicity (in terms of stakeholders involved, design solutions considered and co-benefits provided), and they are adaptive (tailored to the conditions of the local context without a one-fits-all solutions). These intrinsic features raise relevant issues and demand more flexible governance models and participatory processes as inclusive as possible. The complexity of nature-based solutions is also reflected in the multiple barriers to implementation, not only financial; these usually include the lack of adequate knowledge and experience, difficulties in capturing the multiple benefits of NBS, possible trade-offs and conflicts between the groups involved. Experts can support both local authorities and local communities along the process, thus playing an important role in the successful implementation of projects. Our contribution focuses on the inclusion of expert knowledge in the design, implementation and monitoring of NBS. Drawing from the latest European projects and reports and literature, the paper will underline some of the main challenges and criticalities related to the involvement of experts in green policy-making. More specifically, the paper briefly illustrates three macro-themes that deserve particular attention: the tensions between local and expert knowledge in the participative co-creation of NBS; the political legitimacy of expert knowledge; and the local financial and administrative capacity to cope with NBS implementation, monitoring, maintenance and management in the medium-long term.