Principles of Carbon Isotope Tracing and Its Applications in Energy Geology and Carbon Cycling: Progress, Challenges, and Prospects

Over the past several decades, the conceptual basis for carbon isotope tracing has steadily matured. The method’s high specificity and sensitivity have established it as a robust, widely adopted tool across soil, vegetation, ecology, and environmental research. This paper surveys the underlying principles of carbon isotope tracing and the state of current research, highlighting its range of applications. Using stable carbon isotope technology, the genetic source of natural organic matter such as coal, oil and natural gas can be effectively identified. Global climate change can be effectively retrieved through the changes of carbon isotope composition in different geological bodies such as cave stalagmites, loess sediments, lake sediments, tree rings, marine carbonate rocks and ice cores. In addition, carbon stable isotopes are also used to trace the geochemical cycle of soil organic carbon and solve the problem of inorganic carbon sink transformation in arid and semi-arid areas. We propose that a comprehensive understanding of the fundamental mechanisms controlling DIC’s chemical and isotopic compositions, coupled with extensive measurements across diverse conditions, would substantially improve our comprehension of the dynamic interplay between carbon cycling and climate change. By providing a structured, cross-disciplinary mapping of principles, analytical platforms, and applications, this integrative review aims to serve as a practical reference for researchers navigating the increasingly diverse and fragmented landscape of carbon isotope tracing.