MIT Scientists Predict Sixth Mass Extinction On Earth By 2100

Posted: Sep 23 2017, 6:03am CDT | by , in News | Latest Science News

 

MIT Scientists Predict Sixth Mass Extinction on Earth by 2100
Credit: Massachusetts Institute of Technology (MIT)
 

By 2100, oceans may hold enough carbon to trigger a major die-off, researchers predict

Over the last half-billion years, there have been five mass extinctions events on Earth in which a large number of species suddenly died off. By closely analyzing those previous major wipeouts, researchers predict a sixth mass extinction by the end of the century. MIT researchers believe that oceans will likely hold so much carbon by 2100 that it will trigger a mass extinction event on Earth.

Since the 19th century, carbon dioxide emissions have risen at an alarming rate, but deciphering whether this increase in carbon has reached a tipping point has been challenging. That’s mainly because it is difficult to link ancient carbon elevations to recent spike, which have taken place almost over a century.

To solve this problem, researchers analyzed significant changes in the carbon cycle over the last 540 million years, including the five mass extinction events and identified "thresholds of catastrophe" in the carbon cycle that would lead to an extreme environment and ultimately mass extinction if exceeded. 

Using precise calculations, researchers suggest that a sixth extinction will depend on how much carbon is added to the oceans. By the end of year 2100, about 310 gigatons of carbon will have added to the oceans, which they believe is the critical amount to cause the sixth mass extinction on Earth.

“This is not saying that disaster occurs the next day,” said Daniel Rothman, professor of geophysics in the MIT Department of Earth, Atmospheric and Planetary Sciences. "It's saying that, if left unchecked, the carbon cycle would move into a realm which would be no longer stable, and would behave in a way that would be difficult to predict. In the geologic past, this type of behavior is associated with mass extinction.”

Researches came to this conclusion after searching through hundreds of published geochemistry papers. As a result, they identified 31 events in the past 500 million years in which a significant shift was observed in Earth’s carbon cycle. Then, they derived a mathematical formula based on basic physical principles and hypothesized that this formula should predict whether a critical amount of carbon is added to the oceans and could lead to mass extinction event. The amount, they calculate, is about 310 gigaton, which is equal to the amount of carbon that human activities will potentially add to the world's oceans by the year 2100.

"It became evident that there was a characteristic rate of change that the system basically didn't like to go past," said Rothman.

"There should be ways of pulling back (emissions of carbon dioxide). But this work points out reasons why we need to be careful, and it gives more reasons for studying the past to inform the present."

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Hira Bashir covers daily affairs around the world.

 

 

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