Two hundred fifty million years ago the CO2 levels shot up in the atmosphere, the oceans turned into acid, temperatures skyrocketed and death embraced the earth, killing over 90% of marine species and 70% of terrestrial species. The prime suspect has long been a series of massive volcanic eruptions in Russia known as the Siberian Traps eruptions. One of the other suspected causes was a meteorite impact, because basaltic volcanic eruptions don't emit enough CO2 to cause a global catastrophe. The cause of the massive spike in CO2 has been a mystery.
About 250 million years ago, about 95 percent of life was wiped out in the sea and 70 percent on land. Researchers at the University of Calgary believe they have discovered evidence to support massive volcanic eruptions burnt significant volumes of coal, producing ash clouds that had broad impact on global oceans.
"This could literally be the smoking gun that explains the latest Permian extinction," says Dr. Steve Grasby, adjunct professor in the U of C's geoscience department and research scientist at Natural Resources Canada.
Apparently, the huge volume of basaltic flood volcanism, erupted through massive coal deposits in Siberia, setting them on fire. This has been a suspected cause for a number of years, but no evidence has been found until this discovery was made. The fires were so large that the coal ash was deposited thousands of miles away in Canada. (At the end Permian the Atlantic had not yet opened up. Eastern Canada was attached to Greenland and Europe. Siberia was thousands of miles from the site where the coal ash was found.)
The Permian extinction, known as the great dying, was the largest extinction in earth's history.
The Permian–Triassic (P–Tr) extinction event, informally known as the Great Dying, was an extinction event that occurred 251.4
million years ago, forming the boundary between the Permian and Triassic geologic periods. It was the Earth's most severe extinction event, with up to 96% of all marine species and 70% of terrestrial vertebrate species becoming extinct It is the only known mass extinction of insects. Some 57% of all families and 83% of all genera were killed. Because so much biodiversity was lost, the recovery of life on Earth took significantly longer than after other extinction events. This event has been described as the "mother of all mass extinctions".
The massive natural CO2 emissions from the Siberian traps' coal fires are analogous to the man-made CO2 emissions from burning coal for power and cement production. Humans are in the process of recreating the conditions that led to the greatest mass extinction event in earth's history.