CO2 emission changes in two Italian regions: progress toward 2050 climate neutrality under the Covenant of Mayors

In 2008, the European Commission established the Covenant of Mayors (CoM), a voluntary initiative to involve and support local authorities in pursuing the European Union's climate change mitigation and adaptation goals. This study proposes a methodology to evaluate the effectiveness of Sustainable Energy Action Plans (SEAPs) and Sustainable Energy and Climate Action Plans (SECAPs) in terms of reducing carbon dioxide emissions in the regions of Apulia and Sicily. The CO2 emissions are analyzed at the provincial level, before and after the approval of the plans by the municipal council, using homogeneous consumption data from national sources, rather than from data declared by the CoM signatories themselves. The methodology adopted combines the analysis of variance and compound annual growth rate (CAGR) of emissions, both total and per capita, with an assessment of the level of involvement of municipalities and the population in CoM plans. Through Pearson's coefficient, the correlation between the spread of plans and emissions at the provincial level was also assessed. The main results show that Apulia and Sicily, with a share of approved plans of 45.5% and 87.7%, respectively, experienced a reduction in total emissions of 12.1% and 21.2%, and per capita of 9.3% and 18.7%, in the period after municipalities submitted their SEAPs or SECAPs. A greater effectiveness of the plans is denoted in Sicilian provinces than in Apulian ones. These findings underscore the importance of emissions monitoring by signatory local governments, particularly through a uniform methodology, as well as monitoring at the provincial and regional levels, implemented by the Covenant Territorial Coordinators (CTCs), to assess the implementation of the action plans and ensure that regional and national emission reduction targets are met. © The Author(s) 2025.