The Green Deal, a cornerstone of the European Union’s climate goals, sets out to achieve a substantial 55% reduction in greenhouse gas emissions by 2030 compared to 1990 levels. The EU’s decarbonization strategies revolve around three pivotal avenues. First, there is a focus on enhancing energy efficiency and decreasing the energy intensity of economies. Second, concerted efforts are made to diminish the reliance on fossil fuels, particularly within industrial sectors. Lastly, there is a deliberate push to augment the share of renewable energy sources in the final energy consumption mix. These measures collectively aim to propel the decarbonization of EU economies, establishing EU member countries as global leaders in implementing these transformative processes. This manuscript seeks to evaluate the efficacy of three primary decarbonization strategies adopted by EU economies, namely the enhancement in energy efficiency, the promotion of renewable energy consumption and the reduction in fossil fuel consumption. The objective is to discern which strategies wield a decisive influence in achieving decarbonization goals across EU countries. The analysis encompasses all 27 member states of the European Union, spanning from 1990 to 2022, with data sourced from reputable outlets, including Eurostat, Our World in Data and the Energy Institute. Research findings underscore that, in the realm of decarbonization policies, statistically significant impacts on carbon dioxide emission reduction are attributable to the strategies of improving energy efficiency and augmenting the share of renewables in energy consumption across almost all EU countries. Conversely, the strategy with the least impact, embraced by a minority of EU member states, revolves around diminishing the share of fossil fuels in primary energy consumption. This approach, while statistically less impactful, is intricately linked with transitioning the economies toward renewable energy sources, thus playing a contributory role in the broader decarbonization landscape. The uniqueness of this research lies not only in its discernment of overarching trends but also in its fervent advocacy for a comprehensive and adaptive approach to EU decarbonization policy. It underscores the enduring significance of prioritizing energy efficiency, endorsing the integration of renewable energy and acknowledging the distinctive dynamics inherent in diverse regions. The study accentuates the necessity for nuanced, region-specific strategies, challenging the conventional wisdom of a uniform approach to decarbonization. In doing so, it accentuates the critical importance of tailoring policies to the varied energy landscapes and transition strategies evident in different EU member states.