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Science

Scientists Study Permian Mass Extinction Event As Lesson For 21st Century 235

Hugh Pickens DOT Com writes "About 252 million years ago, cracks in the Earth's crust in Siberia caused vast amounts of lava to spill out and blanket the region with about 6,000,000 cubic kilometers of molten material—enough to cover the continental U.S. at a one mile depth. It triggered a huge change in climate, causing a mass extinction event that killed roughly 90 percent of life on earth. Now Helen Thompson writes in the Smithsonian that a team at MIT has focused its efforts on this major extinction event, which marks the end of the Permian period and the beginning of the Triassic period. Their results suggest that the die-out happened a lot faster than previously thought — perhaps over a span of only 60,000 years. The shorter time scale means that organisms would have had less time to react and adapt to changes in climate, atmospheric CO2 and ocean acidity. Without the ability to adapt, they died. Other mass extinction events have also been narrowed down to short timeframes. The asteroid impact that killed the dinosaurs at the end of the Cretaceous period only took about 32,000 years. A similar study of another mass extinction triggered by volcanic eruptions at the end of the Triassic period suggests it lasted less than 5,000 years. Even though all of these extinction events were caused by different things, the ecosystem collapse happened very quickly. 'Whatever the causes of the extinctions may be, and it looks like there are very different causes for some of them, the biosphere may collapse in very similar ways once it gets beyond a tipping point,' says Doug Erwin. Some scientists see the end of the Permian as a lesson for the 21st century (PDF) and say that understanding the conditions leading up to, within, and after a mass extinction event may help us to avoid human-induced ecosystem collapses in the future. As Erwin puts it, 'you don't want to start a mass extinction, because once a mass extinction begins, the prognosis is pretty grim.'"
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Scientists Study Permian Mass Extinction Event As Lesson For 21st Century

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  • by TeachingMachines ( 519187 ) on Wednesday February 19, 2014 @05:26PM (#46290025) Homepage Journal

    If you aren't concerned about this subject, you should be. It is possible that a 4C increase would lead to a 10C increase, wiping out nearly everyone and everything. A good BBC summary of the Permian mass extinction can be found here:
    http://www.youtube.com/watch?v... [youtube.com]

    For a really unsettling update:
    http://guymcpherson.com/2013/0... [guymcpherson.com]

  • Re:I should be? (Score:4, Informative)

    by TeachingMachines ( 519187 ) on Wednesday February 19, 2014 @05:49PM (#46290233) Homepage Journal

    I'll bite. The video describes the problem of a 4C increase in temperature that then causes methane trapped as ice in the permafrost and oceans to melt and go into the atmosphere. It's a positive feedback loop that results in at least a 10C increase (methane being a much more efficient greenhouse gas than CO2). The first step is warming by CO2, which then results in warming by methane. Several scientists are predicting a 20C increase by 2050 if the methane is allowed to escape into the atmosphere, which is essentially a planetary extinction event. The only thing that seems likely to prevent this scenario is total economic collapse, immediately. More details available in the second link. Hope that helps.

  • Re:Comparable? (Score:4, Informative)

    by ColdWetDog ( 752185 ) on Wednesday February 19, 2014 @06:43PM (#46290677) Homepage

    Don't you liberals like evolution? Why would you actively work against it?

    Depends on whether or not you're one of the survivors. Hard to know which side of the fence you will fall on when the shit hits the fan. Evolution changes the biosphere, evolution doesn't care whether your DNA and the rest of your corporal assets happen to get passed along.

    There are lots of losers in evolution. You just might be one of them.

  • by stjobe ( 78285 ) on Wednesday February 19, 2014 @06:53PM (#46290761) Homepage

    At the end of the Permian era, 250m years ago, the global temperature rose by six degrees. That wiped out 95% of all life on earth.

    That's why people come to that conclusion; it has happened before.

    That, and the fact that just a few degrees may well kill off just about all marine life, raise sea levels, create deserts where there's currently farmland, melt the permafrost (releasing massive amounts of methane into the atmosphere, further accelerating global warming), melt the polar ice caps and the glaciers, deforest the rain forests, and basically make the world a hell-hole.

    Sure, humanity could possibly survive; but at what cost and what kind of life would it be? We can't build AC and heating for the whole ecosystem...

    Here's an interesting doomsday summary, degree by degree, from one to six degrees: http://globalwarming.berrens.nl/globalwarming.htm [berrens.nl]

The key elements in human thinking are not numbers but labels of fuzzy sets. -- L. Zadeh

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