Sixty-six million years ago, an asteroid smashed into the Earth caused the extinction of over 70 percent of life on Earth. The Cretaceous-Paleogene extinction event, as it is known, wiped out the dominant species on Earth at the time – the dinosaurs.
Yet, the deadly event is relatively tame compared to another little-known mass extinction event which occurred some twenty million years before the first dinosaurs appeared.
The end-Permian mass extinction occurred some 252 million years ago. The largest known mass extinction event in the history of the planet, over 90 percent of all marine life and over 70 percent of all life on land were wiped out.
This time, it wasn’t an extra-terrestrial rock that caused the event. Instead, it was the sudden release of a deadly substance into the atmosphere by volcanic traps in Siberia.
The deadly substance was carbon.
The same greenhouse gas, that is threatening the world in the present day, was the cause behind the biggest event of mass extinction in the planet’s history.
The startling revelation comes from a new paper by researchers at Montclair State University in New Jersey, United States.
For years, scientists have been trying to better understand the massive event that changed the world., yet solid data has been lacking.
Various hypotheses for the cause of the extinction were previously put forward, including mass volcanic eruption in Siberian Traps, and the resultant acid rain, or the burning of coal due to volcanic activity, and the resultant release of greenhouse gases, and a rapid reduction of oxygen availability in the atmosphere, and more.
Using previously unused data and modeling, the study has found that over 36,000 gigatons of carbon were released into the atmosphere, mostly from volcanic sources, within a short span of 15,000 years.
The result of such huge quantities of carbon in the atmosphere was a spike in the average temperatures from 25ºC to over 40ºC.
An increase in average temperatures by over 15 ºC was deadly to most life on Earth at the time. For comparison, over the last two hundred years, carbon emissions have resulted in an increase in average temperatures by over 1 ºC across the world, resulting in extreme weather events.
Researchers studied compound-specific carbon isotopes, from samples collected from sediments extracted from the Finnmark Platform in Norway, on the eastern part of the Barents Sea Shelf.
According to Ying Cui, co-author of the paper and a professor at Montclair State University’s Department of Earth and Environmental Studies, the sediment samples from Barents Sea Shelf were well-preserved and allowed them to look at biomarker compounds from life on land and the ocean during that period.
Cover Photo: Shutterstock