The governance paradox: Renewable energy, institutional quality, and cross-border CO₂ spillovers in Sub-Saharan Africa

National climate policies in Sub-Saharan Africa (SSA) are potentially challenged by cross-border pollution spillovers that shift environmental impacts to neighboring countries. Using spatial econometric models applied to panel data for 38 SSA countries over the period 1996–2021, this study examines the interaction between renewable energy adoption, governance quality, and CO₂ emissions. The results reveal a governance paradox. Improvements in institutional quality are associated with a negative but statistically insignificant domestic effect, while stronger governance is associated with higher emissions in neighboring countries, a pattern consistent with pollution displacement (indirect effect: +0.308, p < 0.01). In contrast, renewable energy consumption generates a significant negative cross-border externality, lowering emissions both domestically and in neighboring countries (indirect effect: −0.142, p < 0.05). These findings highlight the limitations of nationally isolated mitigation strategies in a region characterized by strong spatial interdependence and underscore the importance of coordinated regional approaches to clean energy deployment and environmental governance in SSA.