Science News: Data show no sign of methane boost from thawing permafrost.

[Buckeye_Democrat]

https://www.sciencenews.org/article/data-show-no-sign-methane-boost-thawing-permafrost

SAN FRANCISCO — One climate doomsday scenario can be downgraded, new research suggests.

Decades of atmospheric measurements from a site in northern Alaska show that rapidly rising temperatures there have not significantly increased methane emissions from the neighboring permafrost-covered landscape, researchers reported December 15 at the American Geophysical Union’s fall meeting.

Some scientists feared that Arctic warming would unleash large amounts of methane, a potent greenhouse gas, into the atmosphere, worsening global warming. “The ticking time bomb of methane has clearly not manifested itself yet,” said study coauthor Colm Sweeney, an atmospheric scientist at the University of Colorado Boulder. Emissions of carbon dioxide — a less potent greenhouse gas — did increase over that period, the researchers found.

The CO2 rise “is still bad, it’s just not as bad” as a rise in methane, said Franz Meyer, a remote sensing scientist at the University of Alaska Fairbanks who was not involved in the research. The measurements were taken at just one site, though, so Meyer cautions against applying the results to the entire Arctic just yet. “This location might not be representative,” he said.

Across the Arctic, the top three meters of permafrost contain 2.5 times as much carbon as the CO2 released into the atmosphere by human activities since the start of the Industrial Revolution. As the Arctic rapidly warms, these thick layers of frozen soil will thaw and some of the carbon will be converted by hungry microbes into methane and CO2, studies that artificially warmed permafrost have suggested. That carbon will have a bigger impact on Earth’s climate as methane than it will as CO2. Over a 100-year period, a ton of methane will cause about 25 times as much warming as a ton of CO2.

A research station in Alaska’s northernmost city, Barrow, has been monitoring methane concentrations in the Arctic air since 1986 and CO2 since 1973. An air intake on a tower about 16.5 meters off the ground constantly sniffs the air, taking measurements. Barrow has warmed more than twice as fast as the rest of the Arctic over the last 29 years. This rapid warming “makes this region of the Arctic a great little incubation test to see what happens when we have everything heating up much faster,” Sweeney said.

Over the course of a year, methane concentrations in winds wafting from the nearby tundra rise and fall with temperatures, the Barrow data show. Since 1986, though, seasonal methane emissions have remained largely stable overall. But concentrations of CO2 in air coming from over the tundra, compared with over the nearby Arctic Ocean, have increased by about 0.02 parts per million per year since 1973, the researchers reported.

The lack of an increase in methane concentrations could be caused by the thawing permafrost allowing water to escape and drying the Arctic soil, Sweeney proposed. This drying would limit the productivity of methane-producing microbes, potentially counteracting the effects of warming.

Tracking Arctic wetness will be crucial for predicting future methane emissions in the region, said Susan Natali, an Arctic scientist at the Woods Hole Research Center in Falmouth, Mass. Studies have shown increased methane emissions from growing Arctic lakes, she points out. “We’re going to get both carbon dioxide and methane,” she said. “It depends on whether areas are getting wetter or drier.”

Fingers crossed! Methane is a much stronger greenhouse gas than CO2 (and it stays in the atmosphere longer than greenhouse gases like water vapor that quickly precipitates as rain) , so let's hope our rising CO2 levels at least avoids the positive feedback of faster warming from methane no longer trapped by permafrost! I'd prefer that we don't "test the planet" with more CO2-related warming, though!

[Warpy]

1. The worry is mostly about methane sequestered as methane hydrate

AKA "methane ice." That's the stuff that caused the Deepwater Horizon explosion. It's nasty stuff and it won't take much warming for it to be released from shallower seabeds.

CO2 would continue to warm us slowly. Rapid release of even a portion of this frozen methane would cook the whole planet.

[cstanleytech]

3. Arent those hydrates in deep water and kept there by a combination of

water pressure and how cold it is at that depth? If so I personally wouldnt worry to much about it unless they start trying to mine it as a replacement for oil and coal.

[Warpy]

4. Watch the weasel words

but there's a pretty good description of the mechanism here: https://www.theguardian.com/environment/earth-insight/2013/aug/05/7-facts-need-to-know-arctic-methane-time-bomb

It's so plausible that scientists are close to consensus on its being the mechanism for the permian-triassic extinction event. What is in doubt is whether it was a methane hydrate release or from a massive, planet wide bacterial bloom.

The fact remains that methane is a much worse greenhouse gas than CO2 and that a rise in global temperature from industrial CO2 production could initiate its release.

[cstanleytech]

5. Ahh I thought those hydrates only were in the deep ocean due to the water pressure

I didnt realize they were also in the permafrost at the surface.

[eppur_se_muova]

2. Worth posting in Environment/Energy. nt

[NickB79]

6. Yet methane is currently blowing holes in the Siberian tundra

http://www.ibtimes.co.uk/siberian-mystery-craters-explained-dragon-breath-methane-spikes-above-russia-linked-climate-1458971

Using data from a ground-based climate observing station in Tiksi, a small town in the Sakha Republic on the Arctic Ocean coast, Dr Box discovered "high end" levels of methane. The readings were backed up by data from similar stations in Alaska and Canada, according to News.com.au.

The spikes, which Dr Box calls "dragon breaths", may well be connected to the unusual holes that have appeared in the Siberia landscape over the last month.

And as the article in the OP stated about the Alaska methane study:

The measurements were taken at just one site, though, so Meyer cautions against applying the results to the entire Arctic just yet. “This location might not be representative,” he said.

[Warren DeMontague]

7. well, that's good.