Impact assessment is a key step in mainstreaming urban nature-based solutions (NBS). Yet, it remains unclear if and how assessment frameworks influence urban planning, design and management. We contend that the potential of current NBS assessment frameworks is not fully exploited due to: (1) limited contextualisation of monitoring and assessment to place-specific contexts and (2) the depoliticisation of co-production. To address this, we present a practical five-step action framework to guide inclusive participation across different stages of monitoring and assessment of urban NBS, including indicator selection. Unlike previous approaches, applying selection criteria at the level of individual indicators, we also use criteria at the aggregate level of the indicator set. We conclude that participatory assessment contributes to mainstreaming urban NBS for sustainable and just cities, provided data is contextualised to local decision-making contexts and the process is designed to amplify marginalised voices.

Nature-Based Solutions concepts and practices are being used worldwide as part of attempts to address societal challenges but have also been criticised for not dealing with deeper transformations needed to face urgent issues including biodiversity loss, climate change and inclusion. In this paper, we explore how an inclusive, integrated and long-sighted approach, emphasising a more radical integration of nature within cities, might support the transformations needed to endure major contemporary challenges. Addressing important emerging critiques of Nature-Based Solutions, we consider the potential of a more incisive form of Nature-Based Thinking (NBT) in cities, based on more holistic perspectives. The paper draws on a reflective and iterative research process that engaged both the research and practice communities through a symposium and a series of futures workshops that together explored the potential of NBT to develop future nature-cities relations in Europe and Latin America. The results of the reflective process suggest that notions of nature with people—not for people— new organisational structures, and the intention and capacity to apply long-term perspectives, are needed when planning for NBS interventions aimed at sustainable urban development. This includes developing a cultural-structural change based on new and inclusive understandings of human–nature relations, and novel governance paradigms that allow cross-sectoral coordination and engagement of local stakeholders beyond formal organisational structures.

Concepts such as green infrastructure, nature-based solutions, and ecosystem services gained popularity in recent discourses on urban planning. Despite their recognition as innovative concepts, all of them share a degree of ambiguity. Fuzziness can be a weakness but also an opportunity to shape novel concepts together with the stakeholders that are supposed to implement them in the planning practice. The paper traces concept development processes of green infrastructure through transdisciplinary knowledge exchange in three different projects, a European and a national research project and a local city-regional project as part of an EU regional cooperation project. In all projects, the green infrastructure concept evolved in different stages. Stakeholder involvement during these stages span from consultation to co-creation. The cases reveal two different approaches: concepts that are developed “for planning practice” might be based on a plethora of insight via consultation, while those “with planning practice” foster co-creation and might result in high acceptance among the involved stakeholders. Depending on the purpose of the novel concept, each approach can be beneficial and result in practice-related and operational products, such as guidance documents or planning strategies. However, the cases also show that in any new context an exchange about fuzzy concepts is not only needed but also a chance to stimulate cooperation and joint understanding about urban challenges and how to address them.

Growing cities face severe land use conflicts. Urban expansion and the densification of existing built areas are increasing the pressure on green spaces, which are key for climate change adaptation. Planning procedures embroiled in these land use conflicts are often complicated and slow. This is due to the increasing complexity in planning processes, which involve a multitude of stakeholders and decision-makers, whose responsibilities are not always entirely clear. Governance-oriented forms of decision making with horizontal structures are often required, but these also entail challenges. In our study, we ask how climate adaptation through urban green spaces can be integrated into planning processes. The study is based on a methodological combination, including document analysis and qualitative interviews with administrative staff. The City of Munich, a rapidly growing German city, serves as a case study. The results show different collaborative arrangements in four planning arenas and demonstrate how these structures support or hinder climate change adaptation mainstreaming. We conclude that hierarchical structures impede horizontal collaborative arrangements and shed lights on mechanisms reinforcing these structures. For large administrations, informal meetings and coordinating units are effective in fostering interdepartmental cooperation.