QUANTIFYING CO2 EMISSION AND SEQUESTRATION ACROSS THE END-PERMIAN MASS EXTINCTION

The extensive volcanic eruption of the Siberian Traps large igneous province (STLIP) and the felsic volcanic activity in southwest China are thought to be responsible for the end-Permian mass extinction (EPME), during which the temperature rose by ~10 ^oC¹, surface ocean pH decreased by one unit², and large area of the seafloor became anoxic³. These environmental deteriorations are likely caused by massive amount of CO₂ emissions and associated carbon cycle feedbacks, with important implications for the ongoing climate change. The CO₂ emission patterns and their links to the ST LIP, however, are still poorly understood. Here we use the known degassing history of the ST LIP from the literature to force an Earth system model of intermediate complexity to reconstruct the carbon cycle dynamics during the EPME and compare the model output to an exceptionally high-resolution geochemical record from South China. CO2 emission and sequestration rates were quantified based on the observed patterns of global carbon isotopes, sea surface temperature, pH, and anoxic areas.

1 Joachimski, M. M. et al. Climate warming in the latest Permian and the Permian–Triassic mass extinction. Geology 40, 195-198, doi:10.1130/g32707.1 (2012).

2 Jurikova, H. et al. Permian–Triassic mass extinction pulses driven by major marine carbon cycle perturbations. Nature Geoscience, doi:10.1038/s41561-020-00646-4 (2020).

3 Zhang, F. et al. Congruent Permian-Triassic δ238U records at Panthalassic and Tethyan sites: Confirmation of global-oceanic anoxia and validation of the U-isotope paleoredox proxy. Geology 46, 327-330, doi:https://doi.org/10.1130/G39695.1(2018).