2012-12-09. 5 million-year hangover.

posted Dec 12, 2012, 4:00 PM by Alan Gould
| By  Spencer Hunt, The Columbus Dispatch. Relevant to Life and Climate, chapter 8. Excerpt:  Scientists say climate change slowed recovery after the world’s greatest extinction event 250 million years ago. …250 million years ago during a time that scientists call the Great Dying … world’s greatest extinction event wiped out 90 percent of life in the oceans and about 70 percent on land. Earth did recover, but it took about 5 million years, according to a team of earth scientists, including Ohio State University geologist Matthew Saltzman. “That’s a relatively long amount of time,” he said. “We see mass extinctions throughout Earth’s history and, in most cases, the recovery took place in about 1 million years or so.” …the mass extinction was triggered by a series of severe volcanic eruptions in a region called the Siberian Traps. After 1 million years of heavy volcanic activity, an area larger than Europe was covered in a layer of once-molten igneous rock 1 mile to 3 miles thick…. Researchers theorize that magma from the initial eruptions burned through an ancient coal bed. …Thomas Algeo, a University of Cincinnati geologist, said huge amounts of carbon dioxide and methane were released, killing off most remaining species.  …After the Great Dying, increases in global temperatures made life nearly impossible for plants and animals on land and heated the oceans to an average 100 degrees Fahrenheit. …Saltzman said the Great Dying offers a window on the effects of climate change. He and Algeo cautioned that the current predictions for climate change are far from the global catastrophe that occurred 250 million years ago. …the average temperature increase then was two to three times higher than the increase climatologists are forecasting. Still, Saltzman said reactions to climate change can be severe…. Read the full article: http://www.dispatch.com/content/stories/science/2012/12/09/5-million-year-hangover.html