Assessing the Efficacy of Municipal Green Bonds in Funding Climate Adaptation Infrastructure across Coastal Southeastern US Cities

As sea level rise and intensified storm surges threaten coastal municipalities across the Southeastern United States, local governments increasingly turn to municipal green bonds (MGBs) to finance climate adaptation infrastructure. This study empirically evaluates the financial performance, project deployment efficacy, and socio-spatial equity of 34 municipal green bond issuances totaling $2.84 billion issued by 12 coastal cities between 2015 and 2023. Integrating financial transaction data from the Electronic Municipal Market Access system with spatial GIS analyses and econometric modeling, we examine the degree to which MGB financing accelerates adaptive infrastructure construction and mitigates localized flood risks. Our findings indicate that MGBs achieved a modest pricing advantage—an average 'greenium' of 3.2 basis points—and substantially reduced project execution lags compared to conventional municipal debt. Econometric evaluation reveals a 18.4% reduction in annualized flood-related property damages within project catchment areas. However, spatial equity analysis uncovers significant disparities: capital deployment was disproportionately concentrated in commercial centers and high-value coastal residential zones, leaving socioeconomically vulnerable communities under-protected. We conclude that while municipal green bonds are a potent mechanism for mobilizing adaptation capital, institutional reforms—such as equity-weighted bond frameworks and state-level credit enhancements—are required to ensure just and comprehensive coastal climate resilience.