New Study Uncovers Cause of End-Permian Mass Extinction

A new study, led by a Montclair State University researcher and PhD student and published in the journal Science Advances, sheds additional light on the cause of the largest mass extinction in Earth’s history.

Led by Assistant Professor of Earth and Environmental Studies Ying Cui and visiting PhD student Yuyang Wu, the study, titled “Volcanic CO2 degassing postdates thermogenic carbon emission during the end-Permian mass extinction,” shows there were actually two separate phases of carbon dioxide emissions instead of one signature event – and that the second wave is responsible for the extinction in which Earth lost 80% of marine and 70% of terrestrial species.

“We looked at the end-Permian mass extinction because it is thought to be an ancient analogue for the 21st century,” says Cui. “This research breaks new ground on our understanding of exactly how the events leading up to the end-Permian mass extinction unfolded, and gives us a new window into how carbon emissions can change our world today.”

Using Data to Solve the End-Permian Mass Extinction

Using a new version of data assimilation called “double inversion” in which stable carbon isotope data and atmospheric CO2 concentrations are used to diagnose continuously varying carbon emissions, the research team discovered that two separate and distinct phases of carbon emissions occurred; one with a small emission rate, and one with a significantly larger emission rate.

The cumulative carbon emitted during the second phase, which coincides with the main extinction, amounted to 21 trillion metric tons of carbon – 30 times more than the cumulative carbon emitted between 1750 and 2020 (690 billion metric tons of carbon) – enough to cause ocean acidification and mass extinction.

Implications for Present Day

Although the cumulative carbon dioxide emissions during the last 270 years are much smaller than the levels during the extinction, the rate at which it is being emitted is significantly faster. To prevent another mass extinction, carbon dioxide emissions must be significantly reduced.

“Our study differs from previous work in that it uses a novel inversion approach that includes stable carbon isotopes and ocean pH in an Earth system model to diagnose the evolution of the carbon emissions during the largest mass extinction of all time,” says Cui. “This technique will be far-reaching; we now have the ability to apply it to other geologic time periods in which rapid global warming occurred to see if similar patterns were evident. This can teach us even more about how our planet is changing based on carbon emissions, and what the end results could look like if we do not make significant changes.”

Other researchers on the study include Andy Ridgwell from University of California, Riverside, and Daoliang Chu, Haijun Song, Jinnan Tong and Jacopo Dal Corso from China University of Geosciences, China.

To learn more about the Earth and Environmental Studies program at Montclair State University, visit montclair.edu/earth-and-environmental-studies/.