Environmental justice in urban planning through post-implementation governance of nature-based solutions

This study presents insights from the EU Biodiversa+ NatureScape project (2025–2028). The project offers a new perspective for understanding nature-based solutions (NBS) in cities by focusing on the post-implementation phase, in which environmental justice in urban planning is put to the test.In recent years, cities have increasingly pursued NBS in urban development projects such as community gardens, green roofs, and temporary green spaces to support biodiversity while simultaneously improving human well-being. Despite growing recognition of NBS in urban planning, their potential for cities' socio-ecological transformation remains constrained by overlooked post-implementation challenges. While the planning and implementation of NBS already receive considerable attention, critical dimensions of environmental justice – distributive equity, accessibility, and procedural justice for continuous public participation and stakeholder engagement – become apparent only in the post-implementation phase. This phase is characterized by dynamic interactions between social and ecological components, shaping whether NBS are consolidated and sustained in ways that contribute in the long term to transformative effects and environmental justice, or whether they instead undermine these aims.NatureScape addresses this critical transition and its challenges in urban planning. Through transformation laboratories (T-Labs) in seven cities (Oslo, Dublin, Riga, Milan, Lisbon, Lublin, and St. Gallen), the research team explores two central questions: (1) What enablers and barriers in urban planning shape the post-implementation stewardship of urban NBS? (2) What governance mechanisms, strategies, and measures lead to the successful integration of urban NBS into urban planning to unfold their transformative potential for biodiversity-positive transitions and environmental justice?Initial findings from the T-Labs reveal crucial barriers. The post-implementation phase is often reduced to technical maintenance. Insufficient incorporation of NBS into urban planning is associated with fragmented institutions and responsibilities, weak strategic and instrumental anchoring, financial insecurity, and the erosion of institutional and political support.The project identifies interconnected governance mechanisms that could successfully integrate NBS into urban planning: adaptive planning processes, institutional anchoring that fosters shared ownership among stakeholders, co-management approaches with formal agreements, public planning frameworks, and institutional structures that support integrated action. Together, these mechanisms highlight stewardship as a pivotal principle for achieving just and biodiversity-positive urban futures.