Nature-based solutions (NbS) represent a critical umbrella concept encompassing measures that employ nature's properties to systemically address societal challenges, potentially providing benefits for biodiversity, climate and people. NbS are accordingly emerging on an ever-expanding number of policy agendas, such as the Kunming-Montreal Global Biodiversity Framework and multiple European Union strategies. However, despite this increasing political traction, NbS implementation (that is, the design, planning, construction, monitoring and maintenance of NbS) remains fragmented and is often too context-specific for their wider upscaling and mainstreaming, creating an 'NbS implementation gap' between ambitions and on-the-ground operationalization. Based on a systematic review of grey- and peer-reviewed literature and workshop results (N = 34), we identify and discuss the institutional, legal, regulatory, social and economic enablers (N = 301) and barriers (N = 307) to NbS implementation. Our results highlight the governance factors that currently facilitate or limit NbS implementation and mainstreaming, which are often homologous. These include inclusive stakeholder engagement processes and true co-design; an evidence base on NbS performance and their co-benefits, including quantitative cost-benefit analyses; the existence of or lack of knowledge products and NbS-specific expertise; and available funds earmarked for NbS. We find that polycentric governance arrangements may act as a critical enabler for NbS implementation, yet path dependencies significantly limit NbS by still favouring grey alternatives. By providing an overview of NbS implementation enablers and barriers across literature and workshop findings, this analysis represents a first step towards understanding key pitfalls and leverage points for enhancing NbS implementation and mainstreaming.

There is growing recognition that using the properties of nature through nature-based solutions (NBS) can help to provide viable and cost-effective solutions to a wide range of societal challenges, including disaster risk reduction (DRR). However, NBS realization depends critically on the governance framework that enables the NBS policy process. Drawing from three case studies in Nocera Inferiore (Italy), Munich (Germany), and Wolong (China), we identify key governance enablers—the contextual preconditions, policy processes, and institutions—that proved essential for NBS initiation, planning, design, and implementation. In the three cases, interviews confirm the success of the NBS measures and their benefits in terms not only of DRR but of multiple ecological and social–economic co-benefits. Results highlight critical governance enablers of NBS, including: polycentric governance (novel arrangements in the public administration that involved multiple institutional scales and/or sectors); co-design (innovative stakeholder participatory processes that influenced the final NBS); pro-NBS interest and coalition groups (organized pressure groups that advocated for an NBS); and financial incentives (financing community-based implementation and monitoring of NBS). Findings show that the transition to NBS can contribute to multiple global agendas, including DRR, climate change adaptation, and sustainable development.

This paper explores how claims for transformative adaptation toward more equitable and sustainable societies can be assessed. We build on a theoretical framework describing transformative adaptation as it manifests across four core elements of the public-sector adaptation lifecycle: vision, planning, institutional frameworks, and interventions. For each element, we identify characteristics that can help track adaptation as transformative. Our purpose is to identify how governance systems can constrain or support transformative choices and thus enable targeted interventions. We demonstrate and test the usefulness of the framework with reference to three government-led adaptation projects of nature-based solutions (NBS): river restoration (Germany), forest conservation (China), and landslide risk reduction (Italy). Building on a desktop study and open-ended interviews, our analysis adds evidence to the view that transformation is not an abrupt system change, but a dynamic complex process that evolves over time. While each of the NBS cases fails to fulfill all the transformation characteristics, there are important transformative elements in their visions, planning, and interventions. There is a deficit, however, in the transformation of institutional frameworks. The cases show institutional commonalities in multi-scale and cross-sectoral (polycentric) collaboration as well as innovative processes for inclusive stakeholder engagement; yet, these arrangements are ad hoc, short-term, dependent on local champions, and lacking the permanency needed for upscaling. For the public sector, this result highlights the potential for establishing cross-competing priorities among agencies, cross-sectoral formal mechanisms, new dedicated institutions, and programmatic and regulatory mainstreaming.

In this report, we present the analysis of the different available biodiversity data streams at the EU and national level, both baseline biodiversity data and monitoring data. We assess how these biodiversity data inform and trigger policy action and identify the related challenges the different European countries and relevant EU agencies face and the solutions to overcome them. To do this, we consulted with more than 350 expert stakeholders from policy, research and practice. The assessment identified a fragmented biodiversity data landscape that cannot currently easily answer all relevant policy questions. Quantity and quality of biodiversity baseline datasets differ for the different countries, ranging from non-existent biodiversity monitoring due to capacity issues, to regular monitoring of ecosystem processes and state. By engaging stakeholders and experts in both member states and non-member states and from several EU bodies, we identified key challenges and ways to address these with targeted solutions towards building a joint European Biodiversity Monitoring Network. Solutions include focussing on cooperation and coordination, enhanced data standardisation and sharing, as well as the use of models and new technologies. These solutions can however only be realised with dedicated funding and capacity building, in coordination with all stakeholders in partnership.