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

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 pCO(2) and caused global warming. However, the magnitude of pCO(2) changes during the PTME has not yet been estimated. Here, we present a continuous pCO(2) record across the PTME reconstructed from high-resolution delta C-13 of C-3 plants from southwestern China. We show that pCO(2) increased from 426 +133/-96ppmv in the latest Permian to 2507 +4764/-1193ppmv at the PTME within about 75 kyr, and that the reconstructed pCO(2) significantly correlates with sea surface temperatures. Mass balance modelling suggests that volcanic CO2 is probably not the only trigger of the carbon cycle perturbation, and that large quantities of C-13-depleted carbon emission from organic matter and methane were likely required during complex interactions with the Siberian Traps volcanism. The Permian-Triassic mass extinction was accompanied by a massive release of carbon into the ocean-atmosphere system, but the magnitude of change is not well known. Here, the authors present a new record of C-3 plants from southwestern China which shows that atmospheric pCO(2) increased by a factor of six during this event.

Automated summary

The Permian-Triassic mass extinction was characterized by a massive release of carbon into the ocean-atmosphere system, with atmospheric pCO2 increasing by a factor of six during this event as shown by a new record of C-3 plants from southwestern China.