Moving Nbs from Concept to Action in Sub-saharan Africa: Strategic Pathways for Scaling Implementation

Sub-Saharan Africa (SSA) is facing major threats from climate change and rapid urbanization, particularly increasing hydro-meteorological risks, environmental degradation, and the proliferation of informal settlements. Medium and small cities, which are urbanizing the fastest and make up over two-thirds of SSA cities, remain under researched despite facing mounting vulnerabilities. Nature-based Solutions (NbS) hold a promise as a sustainable solution to these socio-ecological challenges and can deliver co-benefits for climate adaptation, risk mitigation, and urban liveability. This paper synthesizes findings on NbS planning and implementation in SSA, drawing on literature and empirical insights from a doctoral study in Ghana's Greater Kumasi Metropolitan Area. It identifies barriers at multiple scales includimg macro/meso (e.g.policy and governance, institutional coordination) and micro (e.g.community participation and financing) that hinder implementation. Using TELEMAC-2D hydrological modelling, the study assesses the flood mitigation potential of different NbS scenarios, which demonstrate that integrated interventions combining river restoration and wetland creation significantly reduce peak flows in both short and long duration storms. Additionally, stakeholder surveys and workshops highlight governance fragmentation, financial constraints, and limited public awareness as key impediments to scaling NbS. Building on these findings, the paper proposes strategic, multi-scalar pathways to overcome these barriers, including policy mainstreaming, participatory governance, innovative financing mechanisms, and integrated monitoring frameworks. By combining localized insights with global best practices, the paper provides insights for scaling NbS across diff erent urban contexts in SSA, closing the gap between concept and implementation. The paper concludes with a call for policymakers and stakeholders to prioritize NbS as a transformative approach to urban resilience, climate adaptation, and inclusive sustainable development in the region.