Scientists Shed New Light on Ancient Apocalypse That Affected the Entire Planet

Around 183 million years ago, during the Toarcian Oceanic Anoxic Event (T-OAE), volcanic eruptions in what is now South Africa released approximately 20,500 gigatons of carbon dioxide (CO2) into the atmosphere and oceans over a span of 300 to 500 thousand years. This significant influx of CO2 led to severe oxygen depletion in marine environments, resulting in a widespread extinction of marine life.

Human activity since the industrial revolution has already resulted in cumulative CO2 emissions representing 12 percent of the total CO2 released during the entire T-OAE, in less than 0.1 percent of the time. The T-OAE foreshadows what might happen to our oceans if greenhouse gas emissions continue to increase.

Scientific Analysis of Ocean Deoxygenation
“You can see lots of fossils within ocean sediments before the T-OAE, and then suddenly they disappear,” says Caltech’s Francois Tissot, Professor of Geochemistry and Heritage Medical Research Institute Investigator. Tissot is a co-author on a new study, appearing on June 24 in the journal Proceedings of the National Academy of Sciences, describing the extent of the ocean anoxia during the T-OAE.a