Effectiveness of renewable energy in reducing greenhouse gas emissions: a global systematic review

Abstract

Abstract- This study presents a global systematic review on the effectiveness of renewable energy in reducing greenhouse gas (GHG) emissions, analyzing 39 empirical studies published between 2015 and 2025. Through searches in databases such as Scopus, Web of Science, ScienceDirect, IEEE Xplore, and Google Scholar, relevant studies were identified according to rigorous inclusion and exclusion criteria. The findings confirm that the energy sector remains the largest emitter of GHGs, primarily due to the use of thermal sources and the exploitation of hydrocarbons. However, renewable technologies such as solar, wind, and hydropower have shown high effectiveness in mitigating emissions, especially when integrated with solutions such as Carbon Capture and Storage (CCS). The study highlights key technical challenges, such as intermittency and the integration of these sources into electricity grids. Furthermore, it underscores the importance of public policies—such as carbon taxes and incentives for clean energy—to accelerate the transition to a sustainable, low-carbon energy model. This review provides empirical evidence to the global debate on the strategic role of renewable energy in addressing climate change. Keywords: Renewable energy, Efficiency, Emission reduction, Greenhouse gases, Systematic review.