Worst extinction ever linked to massive CO2 spill

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Scientists finally know the date — and hence the likely cause — of a massive extinction that wiped out 95 per cent of life in the oceans and 70 per cent of life on land more than 200 million years ago.

The end-Permian mass extinction — the most severe mass extinction ever — peaked 252.28 million years ago, reports a new study published Thursday in Science.

Most affected species met their demise within 20,000 years — a blink of an eye on the geological timescale. In all, the mass extinction lasted less than 200,000 years, wiping out huge forests of conifer trees, tree ferns, big amphibians, large reptiles such as dimetrodons, mammal ancestors called synapsids and a huge diversity of fish and shellfish.


The precise timing coincides with a huge outpouring of carbon dioxide and methane from volcanic lava flows in northwest Asia known as the Siberian traps.

"That led to cascading effect — global warming, aridity in various areas, giant wildfires, acidification of the ocean," said Charles Henderson, a geosciences professor at the University of Calgary who co-authored the paper with a large international team.

"All of these things led to a very inhospitable world."

The study also showed that marine and land animals went extinct at the same time, ending a long-held scientific debate.

http://www.cbc.ca/news/technology/story/2011/11/17/science-mass-extinction.html