NASA: New Pathway for Methane Emissions from Arctic Lakes?

September 25, 2018

Newsweek:

Lakes across Alaska and Siberia have started to bubble with methane, and the release of this highly potent greenhouse gas has scientists worried.

Last month NASA released footage showing the bubbling Arctic lakes, which are the result of a little known phenomenon called “abrupt thawing.” It occurs when the permafrost—ground that has been frozen for potentially thousands of years—thaws faster than expected.

Scientists have long known that the thawing permafrost has the potential to release large amounts of methane into the atmosphere. As the organic matter that has been locked up in the ground defrosts it decomposes, releasing carbon and methane (a hydrocarbon) in the process.

If all this was released into the atmosphere, the impact on climate change would be huge. In total there is about 1,500 billion tons of carbon locked up in the permafrost—almost double the amount of carbon in the atmosphere right now.

Thawing permafrost has currently been causing problems across the Arctic. In Siberia, huge craters have opened up across the tundra. While not confirmed, it is believed that as the permafrost thaws, pockets of methane are formed. When the pressure gets too high, these pockets explode.

Methane was also thought to be causing the ground to wobble—video released in 2016 showed patches of grassland bobbing up and down when researchers stood on it.

As the thawing continues, it will eventually cause major problems for the towns and cities located in these northern regions—as the ground becomes softer, roads warp and buildings start sinking into the ground.

In a NASA-funded study published in Nature Communications, scientists have now discovered a source of methane that has not been accounted for in climate models—methane coming from “thermokarst” lakes.

These lakes form when the permafrost thaws at a faster rate and deeper into the ground than normal. The thawing creates a depression, which then fills with rain water, ice and snow melt. The water then speeds up the rate of the permafrost thaw at the shores of the lake.

The process—abrupt thawing—could speed up the release of methane into the atmosphere.

“Within decades you can get very deep thaw holes, meters to tens of meters of vertical thaw,” Katey Walter Anthony, from the University of Alaska Fairbanks, said in a statement. “So you’re flash thawing the permafrost under these lakes. And we have very easily measured ancient greenhouse gases coming out.”

Washington Post:

The first time Walter Anthony saw Esieh Lake, she was afraid it might explode — and she is no stranger to the danger, or the theatrics, of methane. In 2010, the University of Alaska at Fairbanks posted a video of the media-savvy ecologist standing on the frozen surface of an Arctic lake, then lighting a methane stream on fire to create a tower of flame as tall as she is. It got nearly half a million views on YouTube.

So now, in the Arctic’s August warmth, she had come back to this isolated spot with a small research team, along with her husband and two young sons, to see what secrets Esieh Lake might yield. Was it simply a bizarre anomaly? Or was it a sign that the thawing Arctic had begun to release an ancient source of methane that could worsen climate change?

One thing she was sure of: If the warming Arctic releases more planet-warming methane, that could lead to. . . more warming. Scientists call this a feedback loop.

“These lakes speed up permafrost thaw,” Walter Anthony said. “It’s an acceleration.”

Her sounding devices picked up huge holes in the bottom of the lake. Pockmarks, she called them, “unlike anything I’ve ever seen in any Arctic lake.”

Most of Esieh is quite shallow, averaging only a little more than three feet deep. But where the gas bubbles cluster, the floor drops suddenly, a plunge marked by the vanishing of all visible plant life.

Measurements showed that the lake dips to about 50 feet deep in one area and nearly 15 feet in another. When they first studied them, Walter Anthony and her graduate student Janelle Sharp named these two seep clusters W1 and W2, short for “Wow 1” and “Wow 2.”

The next discovery came from the lab.

When the scientists examined samples of the gases, they found the chemical signature of a “geologic” origin. In other words, the methane venting from the lake seemed to be emerging not from the direct thawing of frozen Arctic soil, or permafrost, but rather from a reservoir of far older fossil fuels.

If that were happening all over the Arctic, Walter Anthony figured — if fossil fuels that had been buried for millennia were now being exposed to the atmosphere — the planet could be in even deeper peril.

Scientists have been puzzling over a dramatic spike in atmospheric methane levels, which since 2006 have averaged 25 million tons more of the gas per year. Walter Anthony’s study found that Arctic lakes could more than double this increase as well.

Overall, if Walter Anthony’s findings are correct, the total impact from thawing permafrost could be similar to adding a couple of large fossil-fuel-emitting economies — say, two more Germanys — to the planet. And that does not take into account the possibility of more lakes like Esieh, which appears to be a different phenomenon from thermokarst lakes, emitting gases faster.

Another scientist, Frederic Thalasso, had traveled from Mexico City and spent days taking gas measurements around the lake. His initial results: Emissions from Esieh were very high — and clearly had something to do with fossil fuels.

The lakes where he had witnessed similar bubbling activity were in the tropics and polluted — ideal conditions for the production of methane, said Thalasso, a scientist with the Center for Research and Advanced Studies at the National Polytechnic Institute in Mexico.

But those lakes have gas flows that are “probably 100 times lower than in this lake,” he said.

His instruments also detected ethane, butane and propane — classic signatures of a fossil origin.

Later, after processing his data, he produced an initial estimate that the lake was producing two tons of methane gas every day — the equivalent of the methane gas emissions from about 6,000 dairy cows (one of the globe’s biggest methane sources). That’s not enough to be a big climate problem on its own, but if there are many more lakes like this one — well, that’s another story.

The holes in the bottom of Esieh Lake could therefore be an underwater cousin of odd craters that have appeared in the Siberian tundra in recent years, suspected to have been caused by underground gas explosions.

If this is right, then Esieh Lake becomes a kind of hybrid — and a worrying one.

It’s not a pure thermokarst lake, though some thermokarst appears to be forming around the lake’s expanding edges, tipping shoreline trees as the ice in the permafrost melts and the ground destabilizes. But the thawing of permafrost at the lake bed might also have unleashed older fossil gases from a reserve that had been sealed — creating another kind of worrisome lake.

“This is an additional source,” Walter Anthony said.

Carolyn Ruppel, who leads the Gas Hydrates Project at the U.S. Geological Survey, said Walter Anthony’s theory makes sense. Permafrost thawing could indeed release ancient fossil fuels in areas where they intersect.

But it would take more study to prove that this phenomenon is leading to widespread emissions across the Arctic, she cautioned.

 

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19 Responses to “NASA: New Pathway for Methane Emissions from Arctic Lakes?”

  1. indy222 Says:

    I’ve worried about thermo-karst ever since I read the papers of MacDougall a few years ago, even warning in my “Future Climate” presentation that it may double CO2e release, but little was known and I left it out of my own back-of-envelope graphing of the future. I may have to change that now.

    It staggers me to see the sheer magnitude of betrayal being committed by my own species (granting for argument’s sake that the Trumpsters are members of the my same species).

    • dumboldguy Says:

      Betrayal and evil intent are indeed primary characteristics of the Trumpsters (Heard a new one today—Trump Presides in the Offal Office), but ALL members of the species are to blame for the present situation—-we are simply not psychologically evolved enough to deal with AGW or the other looming catastrophes. Mother Nature bats last and makes up the rules for the game. If we are found wanting as a species and become extinct, we won’t be the first or the last, and the “good” will die with the “bad”.

      (And you should definitely include what’s happening with thermokarst in your “future climate” lessons—-it’s just part of the worsening picture in the Arctic, but it’s not going to get any better and there’s a LOT of it on the planet).

    • dumboldguy Says:

      DUH!

    • Gingerbaker Says:

      The EPA uses a figure of 25, not 100, for valid reasons. This is a complicated topic, and the EPA are not dummies. Please, can we stop trying to exaggerate the science?

      • dumboldguy Says:

        Actually, the most common recent figure seems to be “roughly 30 times more potent” as a GHG than CO2, and there is also some small disagreement over how long it tales methane to be converted to CO2—-8 to 12 years. No matter—this is very bad news—-if we start to hear giant “burps” from over the northern horizon, we will know that another tipping point has been passed.

        Using my favorite “loaves of bread CO2 equivalent” (burning one gallon of gas is like giving the world 20 loaves of stale bread to dispose of), burning one “gallon” of methane leaves ~2000+ loaves in its wake.

        Sir Chucky is not trying to exaggerate the science, he barely understands it—-he is nothing more here than a “blog tagger”—-like an urban graffiti artist trying to get his name on the wall as often as possible. He picked the highest number he could find because he doesn’t understand the science and wants to be dramatic. Pity him.

      • Sir Charles Says:

        You obviously don’t bother reading the link I provided, Ginger. Your EPA figure is outdated. Here from the last IPCC report:

        • dumboldguy Says:

          Chucky’s link was to a Shale Gas Ireland piece, and neither there nor on the IPCC chart is there any reference to “Methane can be 100 times as potent as CO2 in terms of global warming”. Not unless 86= 100. My “DUH” was a reaction to Chucky’s “Doctor Obvious” need to tell us that CH4 was a more potent GHG than CO2, as if we didn’t know that.

          Why don’t you give up trying to keep up with the science, Chucky, and just stick to your childish and obsessive attention seeking and links to sites most of us are already subscribed to?

          For anyone who is interested, here’s a site that is inactive but has some good info about methane:

          http://methane-hydrates.blogspot.com/2013/04/methane-hydrates.html

  2. Sir Charles Says:

    In a study published Monday, scientists estimate for the first time how much each country around the world will suffer in future economic damage from each new ton of carbon dioxide pumped into the atmosphere. What they found may come as a surprise: the future economic costs within the U.S. borders are the second-highest in the world, behind only India.

    The results suggest that the U.S. has been underestimating how much it benefits from reducing its greenhouse gas emissions and that the country has far more to gain from international climate agreements than the Trump administration is willing to admit.

    => Climate Change Will Cost U.S. More in Economic Damage Than Almost Any Other Country

  3. indy222 Says:

    You mean the Trump administration has been incorrect in its thinking? Wow. Who’d have ever thought… /s

  4. indy222 Says:

    For newbies, the Greenhouse Warming Potential of methane is very time-dependent. A kg of methane emitted today is about 123x as powerful a warmer as is a kg of CO2 emitted today. But that methane oxidizes to water vapor (rains out) and CO2 with a half-life of 10 years or so, and so after 10 years it’s only about 60x as powerful, and downward roughly as an exponential as time goes on. But for continuous methane emission, such as we see from leaks we refuse to fix, and from the permafrost and cows etc, then a steady state equilibrium will eventually be reached for the GWP. I’ll spare the math, but it depends on the leakage rate as to what value you apply. It’s a very squishy number. You’re all wrong. And you’re all right. Depends on what you want to assume.


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