NBS are defined as “actions to protect, sustainably manage, and restore natural or modified ecosystems that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits”5. This approach offers a way to tackle multiple urban issues concurrently, yielding environmental, social, and economic benefits6. From urban forests mitigating heat island effects to constructed wetlands managing stormwater and enhancing biodiversity, NBS have demonstrated potential to transform urban landscapes and improve city dwellers’ quality of life7. However, despite growing enthusiasm and increasing implementation, the effectiveness of NBS often falls short of expectations8. Several key factors contribute to this gap between potential and reality:

1. 1.Short-sighted planning: Many NBS projects are designed as one-off interventions, failing to consider long-term impacts or how they fit into the broader urban ecosystem9.

2. Limited stakeholder engagement: Top-down approaches often dominate, with experts and officials implementing solutions without meaningful input from local communities, resulting in projects that fail to resonate with or meet the needs of residents6.

    

    

3. Oversimplification of urban complexity: Cities are intricate systems with countless interconnected parts, and many NBS projects fail to account for this complexity, leading to unintended consequences or missed opportunities10.

4. .Rigid visions of the future: Urban planners and policymakers often work with a single, inflexible vision of the future, an approach that can lead to solutions that quickly become obsolete in our rapidly changing world11.

5. Siloed expertise: NBS projects often lack truly interdisciplinary teams, resulting in solutions that fail to fully integrate ecological, social, and technological considerations3,9.

These limitations reflect a broader challenge in environmental management: the disconnect between scientific approaches and local ways of knowing and interacting with nature12. This disconnect is particularly pronounced in urban areas, where diverse communities, each with their own relationship to the environment, coexist. Several frameworks have been proposed to enhance urban NBS. For example, Raymond et al.6 introduced a framework for assessing and implementing the co-benefits of NBS, Barker et al.13 explored the potential of strategic planning in implementing NBS, and the European Union has developed a roadmap emphasizing collaborative and scenario-based planning14. However, many of these approaches tend to focus on individual components. Recognizing both their innovative potential and their inherent challenges—such as the complexity of urban systems and resource requirements—the present work adopts a critical perspective that underlines the need for an integrated strategy.

Several participatory and adaptive governance frameworks have sought to address the challenges in NBS planning. Adaptive co-management15 emphasizes iterative decision-making based on stakeholder input, while transition management16 applies long-term visioning and experimentation in urban sustainability contexts. Additionally, urban living labs17 have been employed to pilot nature-based interventions with active citizen participation. However, these approaches often focus on either stakeholder engagement or future scenario development in isolation, lacking a mechanism to integrate visioning, design, and evaluation into one iterative process. In response to these limitations, the Adaptive Multifutures Framework (AMF) is introduced as a cohesive, iterative process that unifies participatory visioning, scenario planning, fractal design, and immersive visualization. By merging these components, the AMF not only bridges known implementation gaps but also provides a realistic assessment of the challenges associated with urban sustainability. The framework represents an integrated approach to conceptualize, design, and implement NBS. It embraces uncertainty, complexity, and diverse knowledge systems to pave the way for more effective, resilient, and socially just urban solutions18. As cities worldwide seek innovative approaches to address pressing environmental and social challenges, the AMF offers a timely and thought-provoking framework for reimagining urban futures in harmony with nature. 

By offering a framework that considers complexity, fosters genuine participation, and plans for multiple futures, the AMF contributes to transforming urban planning practices and NBS implementation, leading to more resilient, sustainable, and equitable cities. The AMF emerges as a response to the growing recognition of limitations in current NBS implementation. As urban environments face increasingly complex and interconnected challenges, the need for a more holistic, adaptive, and inclusive approach to NBS has become evident9. The components of the AMF are illustrated in Fig. 1, which shows the interplay between participatory visioning, scenario planning, fractal design, and immersive visualization. Each component is interconnected and supports the others to create a holistic approach to urban planning and NBS implementation.                                                          

Participatory visioning: beyond technical expertise......At the heart of the AMF lies the recognition that effective NBS require more than just technical expertise; they demand an understanding of local contexts, values, and potential future scenarios.