Global warming leading to mass extinction?

Earlier this year, researchers offered a hypothesis aiming to solve one of science’s enduring mysteries: what happened at the end of the Permian period to cause the worst of the five mass extinctions in Earth’s history. Methane-spewing Microbe Blamed in Earth’s Worst Mass Extinction:

globe-earth-space-western-hemisphereA microbe that spewed humongous amounts of methane into Earth’s atmosphere triggered a global catastrophe 252 million years ago that wiped out upwards of 90 percent of marine species and 70 percent of land vertebrates.

The scale of this calamity made the one that doomed the dinosaurs 65 million years ago – a six-mile wide asteroid smacking the planet – seem like a picnic by comparison.

“I would say that the end-Permian extinction is the closest animal life has ever come to being totally wiped out, and it may have come pretty close,” said Massachusetts Institute of Technology biologist Greg Fournier, one of the researchers.

I don’t mean to alarm you, but it is happening again. Vast methane ‘plumes’ seen in Arctic ocean as sea ice retreats:

Dramatic and unprecedented plumes of methane – a greenhouse gas 20 times more potent than carbon dioxide – have been seen bubbling to the surface of the Arctic Ocean by scientists undertaking an extensive survey of the region.

The scale and volume of the methane release has astonished the head of the Russian research team who has been surveying the seabed of the East Siberian Arctic Shelf off northern Russia for nearly 20 years.

In an exclusive interview with The Independent, Igor Semiletov of the International Arctic Research Centre at the University of Alaska Fairbanks, who led the 8th joint US-Russia cruise of the East Siberian Arctic seas, said that he has never before witnessed the scale and force of the methane being released from beneath the Arctic seabed.

“Earlier we found torch-like structures like this but they were only tens of metres in diameter. This is the first time that we’ve found continuous, powerful and impressive seeping structures more than 1,000 metres in diameter. It’s amazing,” Dr Semiletov said.

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Scientists estimate that there are hundreds of millions of tons of methane gas locked away beneath the Arctic permafrost, which extends from the mainland into the seabed of the relatively shallow sea of the East Siberian Arctic Shelf.

One of the greatest fears is that with the disappearance of the Arctic sea ice in summer, and rapidly rising temperatures across the entire Arctic region, which are already melting the Siberian permafrost, the trapped methane could be suddenly released into the atmosphere leading to rapid and severe climate change.

Dr Semiletov’s team published a study in 2010 estimating that the methane emissions from this region were in the region of 8 million tons a year but the latest expedition suggests this is a significant underestimate of the true scale of the phenomenon.

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Dr Semiletov released his findings for the first time last week at the American Geophysical Union meeting in San Francisco. He is now preparing the study for publication in a scientific journal.

The total amount of methane stored beneath the Arctic is calculated to be greater than the overall quantity of carbon locked up in global coal reserves so there is intense interest in the stability of these deposits as the polar region warms at a faster rate than other places on earth.

Natalia Shakhova, a colleague at the International Arctic Research Centre at the University of Alaska Fairbanks, said that the Arctic is becoming a major source of atmospheric methane and the concentrations of the powerful greenhouse gas have risen dramatically since pre-industrial times, largely due to agriculture.

However, with the melting of Arctic sea ice and permafrost, the huge stores of methane that have been locked away underground for many thousands of years might be released over a relatively short period of time, Dr Shakhova said.

“I am concerned about this process, I am really concerned. But no-one can tell the timescale of catastrophic releases. There is a probability of future massive releases might occur within the decadal scale, but to be more accurate about how high that probability is, we just don’t know,” Dr Shakova said.

Dr. Jason Box, a widely published climatologist who has been following the expedition, sounded the alarm. If We Release a Small Fraction of Arctic Carbon, ‘We’re Fucked’:

This week, scientists made a disturbing discovery in the Arctic Ocean: They saw “vast methane plumes escaping from the seafloor,” as the Stockholm University put it in a release disclosing the observations. The plume of methane—a potent greenhouse gas that traps heat more powerfully than carbon dioxide, the chief driver of climate change—was unsettling to the scientists.

But it was even more unnerving to Dr. Jason Box, a widely published climatologist who had been following the expedition. As I was digging into the new development, I stumbled upon his tweet, which, coming from a scientist, was downright chilling:

Screenshot from 2014-08-05 13:13:59

It’s not just the Arctic sea floor either. In news you may have missed recently, the permafrost on land is releasing methane and leaving huge craters. The Really Scary Thing About Those Jaw-Dropping Siberian Craters:

Russian scientists have determined that a massive crater discovered in a remote part of Siberia was probably caused by thawing permafrost. The crater is in the Yamal Peninsula, which means “end of the world.” [That’s irony for you, folks.] It caught hold of the media spotlight in mid-July when it was spotted by oil and gas workers flying over the area. At roughly 200 feet wide and seemingly bottomless, speculation abounded about the cause[.]

Since this first discovery, two other smaller craters have been spotted in the surrounding regions, fueling even more armchair conjecture. Russian scientists sent to the site are now providing first-hand data showing that unusually high concentrations of methane of up to 9.6 percent were present at the bottom of the first large crater shortly after it was discovered on July 16. Andrei Plekhanov, an archaeologist at the Scientific Centre of Arctic Studies in Salekhard, Russia, who led an expedition to the crater, told The Journal Nature that air normally contains just 0.000179 percent methane.

According to Plekhanov, the last two summers in the Yamal have been exceptionally warm at about nine degrees Fahrenheit above average. Rising temperatures could have allowed the permafrost to thaw and collapse, releasing the methane previously trapped by the subterranean ice. Methane is the primary component of natural gas. The original crater is about 20 miles from a large natural gas plant and the entire Yamal Peninsula is rich in natural gas that is being extensively tapped to help fuel Russia’s natural gas boom.

Hans-Wolfgang Hubberten, a geochemist at the Alfred Wegener Institute in Potsdam, Germany, told Nature that climate change and the slow, steady thaw of the region could be to blame.

“Gas pressure increased until it was high enough to push away the overlying layers in a powerful injection, forming the crater,” he said. [Holy shit!]

Crater

This frame grab made Wednesday, July 16 shows the 200-foot wide crater discovered in the Yamal Peninsula. – CREDIT: Associated Press Television

While staring down into the abyss of these craters is a scary thought, the release of large quantities of greenhouse gases from melting permafrost is existentially daunting. A study from earlier this year found that melting permafrost soil, which typically remains frozen all year, is thawing and decomposing at an accelerating rate. This is releasing more methane into the atmosphere, causing the greenhouse effect to increase global temperatures and creating a positive feedback loop in which more permafrost melts.

“The world is getting warmer, and the additional release of gas would only add to our problems,” said Jeff Chanton, the John Widmer Winchester Professor of Oceanography at Florida State and researcher on the study. According to Chanton, if the permafrost completely melts, there would be five times the current amount of carbon equivalent in the atmosphere.

Kevin Schaefer, a permafrost scientist at the National Snow and Ice Data Center, told ThinkProgress that there are actually two sources of GHGs released by melting permafrost: methane hydrates that destabilize when permafrost temperatures rise, as has been the case in Siberia, and frozen organic matter.

“Note that the methane hydrate and the decaying organic matter emissions result from two completely different mechanisms,” said Schaefer. “Methane hydrate emissions come from deep permafrost due to purely physical processes. The decaying organic matter emissions come from near-surface permafrost due to purely biological processes.”

He said that as the permafrost thaws, the organic matter will also thaw and begin to decay, releasing CO2 and methane into the atmosphere. “Published estimates indicate 120 gigatons of carbon emissions from thawing permafrost by 2100, which would increase global temperatures by an additional 7.98 percent,” he said.

Schaefer said the phenomenon of the Siberian craters was a surprise to him because he thought the methane would leak out more slowly.

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Ted Schuur, a professor of ecosystem ecology at the University of Florida and leader of the Permafrost Carbon Network, told ThinkProgress that the Siberian craters remind him of ‘hot spots’ of methane bubbling that occur both in lakes and undersea in the permafrost zone.

“This could be a terrestrial version that was previously capped by ground ice in permafrost,” he said. “If indeed they are the result of warming permafrost they could be a significant pathway of greenhouse gas release to the atmosphere. As with other processes in the permafrost zone, abrupt changes appear to be as or perhaps more important than slow gradual change.”

Jason Box is right — we’re fucked.

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