“2100 –The Fateful Year” –Earth’s Final Extinction Event (WATCH Today’s ‘Galaxy’ Stream)

 

Animals_Beasts_Polar_bear_on_ice_floe_024666_

 

In the past 540 million years, the Earth has endured five mass extinction events, each involving processes that upended the normal cycling of carbon through the atmosphere and oceans. These globally fatal perturbations in carbon each unfolded over thousands to millions of years, and are coincident with the widespread extermination of marine species around the world.


“How can you really compare these great events in the geologic past, which occur over such vast timescales, to what’s going on today, which is centuries at the longest?” says MIT geophysicist Daniel Rothman. “So I sat down one summer day and tried to think about how one might go about this systematically.”

 

“This is not saying that disaster occurs the next day,” says Rothman about his new study. “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.”

In the fascinating video below Thom Hartman talks with Daniel Rothman on the point of no return for climate change, at what point will we not be able to turn things around (ignore the landline phone!).

Now Rothman, professor of geophysics in the MIT Department of Earth, Atmospheric and Planetary Sciences and co-director of MIT’s Lorenz Center, has analyzed significant changes in the carbon cycle over the last 540 million years, including the five mass extinction events.

 

 

He has identified “thresholds of catastrophe” in the carbon cycle that, if exceeded, would lead to an unstable environment, and ultimately, mass extinction.

In a paper published in Science Advances, he proposes that mass extinction occurs if one of two thresholds are crossed: For changes in the carbon cycle that occur over long timescales, extinctions will follow if those changes occur at rates faster than global ecosystems can adapt. For carbon perturbations that take place over shorter timescales, the pace of carbon-cycle changes will not matter; instead, the size or magnitude of the change will determine the likelihood of an extinction event.

Taking this reasoning forward in time, Rothman predicts that, given the recent rise in carbon dioxide emissions over a relatively short timescale, a sixth extinction will depend on whether a critical amount of carbon is added to the oceans. That amount, he calculates, is about 310 gigatons, which he estimates to be roughly equivalent to the amount of carbon that human activities will have added to the world’s oceans by the year 2100.

Does this mean that mass extinction will soon follow at the turn of the century? Rothman says it would take some time — about 10,000 years — for such ecological disasters to play out. However, he says that by 2100 the world may have tipped into “unknown territory.”

“This is not saying that disaster occurs the next day,” Rothman says. “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.”

Continue reading… 

 

Recommended Space & Science Headlines

"Alien Minds" –'Artificial Intelligence Is Already Out There, and It's Billions of Years Old' (VIDEO)

 "300-Million Nuclear Bombs" –New Insights Into Global Impact of Titanic Chicxulub Mass-Extinction Event

Stephen Hawking: Wake Up, Science Deniers! –"Earth is Morphing into Venus" (WATCH Today's 'Galaxy' Stream)

"Evolutionary Leap?" AI is Mimicing the Human Brain –"But Several Orders of Magnitude Faster and More Efficiently

China Creates a Laser of Mind-Boggling Power –"Could Rip Space Asunder, Breaking the Vacuum"

"Stop Saying That Dinosaurs Went Extinct. They Didn't"

 

"The Galaxy" in Your Inbox, Free, Daily