Carbon Isotope Excursions and Environmental Perturbations in the Late Permian

The Late Permian represents one of the most critical intervals in Earth’s history, marked by profound environmental instability and the largest mass extinction event at the Permian–Triassic boundary. Carbon isotope excursions recorded in marine carbonates and organic matter provide crucial evidence for disruptions in the global carbon cycle during this time. Significant negative δ¹³C shifts suggest rapid injections of isotopically light carbon into the atmosphere–ocean system, likely driven by extensive volcanic activity associated with the Siberian Traps, methane release from gas hydrates, and widespread oxidation of organic carbon. These perturbations were closely linked to extreme greenhouse warming, ocean acidification, marine anoxia, and ecosystem collapse. Stratigraphic records from various Late Permian basins demonstrate that carbon isotope fluctuations were not isolated events but part of a prolonged phase of environmental stress. The resulting biotic crisis culminated in the Permian–Triassic extinction event, during which a substantial proportion of marine and terrestrial species disappeared. By integrating isotope geochemistry with sedimentological and paleontological data, this study highlights how carbon isotope excursions serve as sensitive proxies for reconstructing paleoenvironmental change. Understanding these ancient carbon cycle disruptions offers valuable insight into the mechanisms linking volcanic forcing, climate feedbacks, and mass extinction, with implications for interpreting present-day anthropogenic carbon emissions and global climate change.