Smart carbon–neutral development: Embracing complexity with multi-level governance and convolution

• The EU Missions framework drives transformative and systemic changes essential for achieving both mitigation and adaptation outcomes. • Thessaloniki’s Net Zero Plan uses tech, governance and management solutions across sectors, applying a systems-innovation approach and multiple levers to cut emissions. • Enhancing our understanding of spatial impacts requires continuous recalibration of governance strategies to ensure effective policy implementation. • Path-dependence in both actions and governance models poses limitations, highlighting the need for a systems perspective in smart carbon–neutral development. • Policy design should be seen as a convolution process—where actions and governance models merge—rather than as separate entities that need to be linked or combined. This paper delves into the current EU policy and strategy for advancing smart, carbon–neutral development across Europe, as outlined by the EU Missions framework. This framework aims to boost the resilience to climate change of at least 150 European regions and communities and facilitate the transformation of 100 cities into climate-neutral and smart urban centers by 2030. Our primary objective is to explore potential synergies between theoretical concepts and their practical application in realizing smart carbon–neutral development. Specifically, we examine the challenges associated with scaling processes inherent in smart carbon–neutral development alongside the transformative and systemic changes required to achieve significant levels of both mitigation and adaptation. Using the Net Zero Action Plan for Thessaloniki as a case study, we examine the efficacy of designing policies at both the operational and governance levels. We argue that a complexity-based approach is applicable in this context: as we refine our understanding of the spatial impact of interventions, our certainty regarding the necessary governance level diminishes, and vice versa. Finally, we discuss the potential for realizing the ambitious objectives of the EU Missions framework through a convolution perspective and the challenges associated with bridging the gap between theoretical concepts and practical implementation.