Scientists at the Helmholtz Center for Ocean Studies in Germany have uncovered a detailed picture of the worst global catastrophe that destroyed almost all life on Earth 252 million years ago, on the border between the Permian and Triassic periods. As a result of global extinction due to volcanic activity in Siberia, three quarters of land and 95 marine animal species have become extinct. This was announced in a press release on EurekAlert !.
Researchers analyzed boron isotopes in the calcareous shells of fossil brachiopods, determining the degree of ocean acidification during the global extinction. The pH level of seawater is closely related to the content of carbon dioxide in the atmosphere, which has made it possible to track global climate changes. The scientists then used the latest geochemical model to assess the environmental impact of excess carbon dioxide.
It turned out that extensive outpouring of magma in Siberia released a huge amount of greenhouse gas. Its accumulation in the atmosphere lasted for several millennia, which caused severe warming and acidification of the ocean. The dramatic changes in chemical weathering on land affected the productivity and nutrient cycling of the ocean, causing the proliferation of dead zones deprived of oxygen. The impact of several factors simultaneously destroyed a wide variety of groups of animals.
Fortunately, such a scenario is nearly impossible at this time. Human burning of all fossil fuels on Earth will not lead to the same increase in carbon dioxide in the atmosphere as at the end of the Permian period. However, it is of concern that the rate of accumulation of greenhouse gas is now 14 times faster than that observed during the mass extinction.