The European Commission launched the Covenant of Mayors (CoM) in 2008, an initiative that aims to coordinate, promote and incentivize thousands of local authorities to pursue the European Union's goals of reducing emissions and adapting to climate change. By voluntarily joining this movement, signatories committed to submit Sustainable Energy Action Plans (SEAPs) with the aim of reducing CO2 emissions by at least 20% by 2020 compared to 1990 levels. In 2015, the Covenant merged with the Mayors Adapt initiative to form the new Covenant for Climate and Energy, introducing the theme of adaptation to climate change. Following the Paris Agreement and the launch of the European Green Deal, the Covenant has undergone significant adjustments. To meet the goals of these agreements, a further increase in CO2 emission reductions of at least 55% by 2030 is required. In line with these targets, signatories have renewed their commitment by developing Sustainable Energy and Climate Action Plans (SECAPs). In Italy, the initiative has seen a growing number of participants. Despite its success, the plans face a number of problems related to the quality of emission inventories, the implementation of measures and the completion of monitoring by the signatories. The present study proposes a methodology to evaluate the effectiveness of emission reduction plans in the context of the Apulia region, statistically comparing the results achieved by the municipalities participating in the CoM initiative.