<p>This study investigates the pivotal role of local governance in mitigating CO₂ emissions, a cornerstone for achieving sustainable development and fulfilling the mandate of SDG 13 (Climate Action). Despite the acknowledged importance of the public sector in implementing sustainability policies, a significant void exists in the literature regarding the specific influence of local government characteristics on climate outcomes. To address this gap, our research analyzes 55 Spanish municipalities through a comprehensive analysis to identify how different municipal attributes impact CO₂ emission levels. Our findings reveal compelling insights: municipalities characterized by higher political competition, those operating under coalition governments, and those led by female mayors consistently demonstrate superior performance in emission reduction efforts. Conversely, an increase in population income correlates with higher CO₂ generation, suggesting that affluence may contribute to increased consumption patterns. In contrast, higher population density is associated with lower emissions, likely due to the efficiencies and economies of scale inherent in more concentrated urban environments. These results offer critical implications for policymakers aiming to leverage local administrative structures for effective climate action.</p>