Connecting biodiversity and climate transformative action: Clashing of tough choices on nature-based solutions implementation?

Nature-based Solutions are increasingly promoted as a means to tackle the intertwined crises of biodiversity loss and climate change. Their implementation, though, continues to lag behind political ambition. While existing reviews highlight a broad set of barriers, from financial and political constraints to entrenched practices and fragmented governance, much less is known about how these barriers play out across different ecosystems and institutional contexts. This contribution presents results from a series of mixed-method research activities conducted within the Biodiversa+ BiodivClim Knowledge Hub to better understand where and why Nature-based Solutions implementation efforts encounter friction, and what kinds of solutions stakeholders believe should be sought.First, we report findings from a survey completed by researchers, practitioners, and policymakers from across Europe and beyond. Respondents assessed the importance of twelve commonly cited barriers and suggested concrete actions to overcome them. Across ecosystems and stakeholder groups, political will, long-term commitment, and financial resources emerged as the most pressing obstacles, followed closely by difficulties in breaking away from established norms and conventional grey-infrastructure preferences. Interestingly, and not totally unexpectedly, the perceived importance of several barriers varied by ecosystem type. For example, researchers and practitioners engaged in coastal ecosystems highlighted land availability as a dominant constraint, whereas those working in urban settings emphasised public awareness and competing interests.Second, we draw on insights from two participatory “House of Commons” debate sessions that explored tensions and value clashes arising when aligning biodiversity and climate objectives through Nature-based Solutions. These debates made visible a divide around issues such as investment priorities, distributional fairness, and the balance between restoration and conservation. They also highlighted the potential of deliberative formats to unmask deeply held assumptions and open space for more flexible and inclusive governance approaches. This is precisely the type of collective reflection we aim to spark in the session, encouraging participants to engage with these tensions and consider what is needed for successful to move Nature-based Solutions implementation forward in practice.