Permian Triassic extinction event is the one most similar to current situation.

The level of atmospheric carbon dioxide rose from around 400 ppm to 2,500 ppm with approximately 3,900 to 12,000 gigatonnes of carbon being added to the ocean-atmosphere system during this period.[22] Several other contributing factors have been proposed, including the emission of carbon dioxide from the burning of oil and coal deposits ignited by the eruptions;[27][28] emissions of methane from the gasification of methane clathrates;[29] emissions of methane by novel methanogenic microorganisms nourished by minerals dispersed in the eruptions;