By Kaye Coholan
A University of Calgary research team has found evidence of what caused the world’s biggest extinction 250 million years ago which set the stage for dinosaurs to evolve.
Stephen Grasby, adjunct professor of geoscience at the U of C, said his team focused on the causes of the Permean extinction, the largest extinction in the history of the earth which wiped out up to 95 per cent of life in the sea and 70 per cent on land. The extinction was caused by a volcanic eruption, burning coal and greenhouse gases.
“There was a series of bad events at this time,” Grasby said. “Coal burning, runaway global warming, lots of stresses on the environmental system dumping toxic ash into the oceans.”
The team of researchers found layers of coal ash in the Canadian arctic which had traveled from volcanoes in northern Russia.
“We showed the first direct evidence of layers of coal ash at sites of eruptions,” he said. “It’s a double whammy, not only having a big volcanic eruption, but also combusting a huge amount of coal.”
The extinction did see the production of greenhouse gases, though on a much larger scale than what may exist today.
According to U of C geoscience professor and Grasby’s colleague on the study, Benoit Beauchamp, research like this can warn of the potential end results of releasing large amounts of carbon dioxide.
“The earth has gone through past episodes of global warming with devastating results,” said Beauchamp, who is also the U of C Arctic Institute of North America executive director. “When [the eruptions were] over it was a completely different world. Life forms no longer existed, it was just microbes. Perhaps it’s a sobering thought for our appetite for burning fossil fuels.”
The significance of the research was recognized by the publication of the team’s findings in Nature Geoscience magazine in January.
“Publishing in the magazine Nature Geoscience is not something we do every day,” Beauchamp said. “The rejection rate is over 95 per cent.”
The next step for the research team will be to look at other aspects of the extinction and research the timing of these events, as well as other environmental aspects related to burning of coal in Siberia.
“You never know really what the earth has in store for us,” Grasby said.