YouTube - Nova: Permian Extinction
Over the last few decades, a growing body of evidence has come to light indicating that the Permian was not, like the much more recent extinction that killed the dinosaurs, the result of an asteroid strike, but rather, a volcanically kick-started Greenhouse event.
A few years ago,
Neil DeGrasse-Tyson, astrophysicist and Project Scientist at New York’s Hayden Planetarium, hosted a NOVA piece that outlined the major puzzle pieces of what we know about this catyclysm, and why it matters today.
YouTube - Climate Denial Crock of the Week: "The Earth is Carbon Starved."
The
Greatest Extinction event in Earth’s history, “The Great Dying” that killed almost every living creature some 250 million years ago, was a greenhouse event, brought on by volcanic eruptions that burned thru great deposits of coal, and created a perfect storm of toxic clouds and warming gases.
Science Daily:
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 University of Calgary’s Department of Geoscience and research scientist at Natural Resources Canada.
The new research, published in Nature Geoscience,
built on
previous research linking
prehistoric extinction events to warming from volcanism. With colleagues Dr. Benoit Beauchamp, a professor in the Department of Geoscience at the University of Calgary, and Dr. Hamed Sanei, they probed unusual layers of organic material at Buchanan Lake in northern Canada.
Researchers comb through sediments at Buchanan Lake in Northern Canada
“Our research is the first to show direct evidence that massive volcanic eruptions — the largest the world has ever witnessed — caused massive coal combustion, thus supporting models for significant generation of greenhouse gases at this time,” Steve Grasby of the university’s Department of Geoscience said.”
Science20.com continues:
Researchers at the University of Calgary believe they have discovered evidence for the hypothesis that volcanic eruptions burnt significant volumes of coal, producing ash clouds that had broad impact and was a direct factor in the late Permian extinction.
Unlike the end of dinosaurs 65 million years ago, where there is belief that the impact of a meteorite was at least one factor, the cause of the late Permian extinction is mostly speculation. Previous researchers have suggested massive volcanic eruptions through coal beds in Siberia would generate significant greenhouse gases causing global warming.
At the time of the extinction, the Earth contained one big land mass, a supercontinent known as Pangaea.
The location of volcanoes, known as the Siberian Traps, are now found in northern Russia, centred around the Siberian city Tura and also encompass Yakutsk, Noril’sk and Irkutsk. They cover an area just under two-million-square kilometers, a size greater than that of Europe. The ash plumes from the volcanoes traveled to regions now in Canada’s arctic where coal-ash layers where found.
“This could literally be the smoking gun that explains the latest Permian extinction,” says Dr. Steve Grasby, adjunct professor in the University of Calgary’s Department of Geoscience and research scientist at Natural Resources Canada.
Grasby and colleagues discovered layers of coal ash in rocks from the extinction boundary in Canada’s High Arctic that give the first direct proof to support this and have published their findings in
Nature Geoscience. ”Our research is the first to show direct evidence that massive volcanic eruptions – the largest the world has ever witnessed –caused massive coal combustion thus supporting models for significant generation of greenhouse gases at this time.”
The photos below show the comparison between the particles in deposits at Buchanan Lake, (left) and ash from modern coal fired power plants.(right)
The particles on the left are from the prehistoric deposits at Buchanan Lake. The ones on the right are from modern coal fired power plants.
The striking similarities between the two sets of ash bring to mind
warnings from NASA’s James Hansen, that modern fossil fuel burning is changing the atmosphere 10,000 times faster than natural processes.
Peter Ward’s book
“Under A Green Sky” kept me awake on a summer vacation 2 years ago. In it, Ward reviews the large and rapidly growing scientific literature tying mass extinctions of the past to natural volcanic warming events – in particular the Permian, which he described in a
Scientific American article that was the basis for the book.
Ward pointed out that since it became clear that the “dinosaur extinction” of 65 million years ago was shown to be caused primarily by an asteroid impact, the prevailing wisdom has been that eventually an impact would be linked to every major extinction event. But that evidence has not been found.
Instead, “New geochemical evidence is coming from the bands of stratified rock that delineate mass extinction events in the geologic record, including the exciting discovery of chemical residues, called organic biomarkers, produced by tiny life-forms that typically do not leave fossils. Together these data make it clear that cataclysmic impact as a cause of mass extinction was the exception, not the rule. In most cases, the earth itself appears to have become life’s worst enemy in a previously unimagined way. And current human activities may be putting the biosphere at risk once again.”
The story of how the Permian evolved from a slow warming event to a mass killer from the bottom of the ocean to the tops of mountains is a frightening hint of what a worst case global warming scenario could bring in coming centuries or millennia, one that I’ll cover in more detail in future posts.
