Methodological pathways for circular economy in energy and environmental studies: a structured review toward sustainable development

The circular economy (CE) has become a major focus in energy and environmental (E&E) research, as it helps advance sustainable development, improve resource efficiency, and alleviate environmental pressure. Even so, the literature is still fragmented, particularly in the CE themes it explores, the levels of analysis it adopts, and the methods used to measure CE progress. This systematic review examines 93 peer-reviewed articles from the ScienceDirect database, published between 2009 and 2024, and classifies them by research field, data level, thematic focus, and analytical method. The results show that CE application and implementation are the most frequently studied topics, while quantitative research (48%) and mixed methods (45%) appear at almost the same rate. Among quantitative approaches, structural equation modelling and bibliometric analysis are the most widely used methods, while surveys and interviews are most common in mixed-method studies. Drawing on the resource-based view, resource-based theory/natural-resource-based view, and institutional theory, the review points to a clear methodological imbalance: macro-level benchmarking is relatively well developed, but firm-level circular transformation remains insufficiently explored. The paper contributes by proposing a model-selection framework that connects research objectives, theory-method alignment, data level, and managerial evidence needs across capability development, business model innovation, governance, partnerships, and performance evaluation