Six-fold increase of atmospheric pCO2 during the Permian–Triassic mass extinction

Abstract The Permian–Triassic mass extinction was marked by a massive release of carbon into the ocean-atmosphere system, evidenced by a sharp negative carbon isotope excursion. Large carbon emissions would have increased atmospheric p CO 2 and caused global warming. However, the magnitude of p CO 2 changes during the PTME has not yet been estimated. Here, we present a continuous p CO 2 record across the PTME reconstructed from high-resolution δ 13 C of C 3 plants from southwestern China. We show that p CO 2 increased from 426 +133/−96 ppmv in the latest Permian to 2507 +4764/−1193 ppmv at the PTME within about 75 kyr, and that the reconstructed p CO 2 significantly correlates with sea surface temperatures. Mass balance modelling suggests that volcanic CO 2 is probably not the only trigger of the carbon cycle perturbation, and that large quantities of 13 C-depleted carbon emission from organic matter and methane were likely required during complex interactions with the Siberian Traps volcanism.