Via commenter eggroll_jr in response to this post — “We’re in a planetary emergency” thanks to Arctic ice melt and Greenland permafrost — we find this article about the appearance of “methane plumes” now rising through the newly warmed Arctic ocean. From The Independent last December:
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.
We talked about methane here (scroll down) in reference to the methane trapped in Greenland permafrost and sealed from the atmosphere by now-disappearing ice sheets. This story is about methane shooting up through the Arctic ocean itself in vast torch-like plumes and headed straight for the surface and the atmosphere.
The scale of the phenomenon — as usual — is the big surprise:
“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.
“I was most impressed by the sheer scale and the high density of the plumes. Over a relatively small area we found more than 100, but over a wider area there should be thousands of them,” he said.
One thousand meters is a kilometer — more than half a mile. These are high-density methane columns, compressed tight by the high pressure of the ocean itself, many wider than a kilometer. And they think there are thousands of them. Add methane from the ocean depths, methane from the Greenland permafrost, and methane from the Siberian permafrost to the air, and we have unleashed a monster.
How big a monster? This big:
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.
And this big:
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[.]
I want to send you to the article for the rest; it’s fascinating in a data-rich way. There’s even a discussion about why methane is so dangerous, and why those estimates of its effect relative to CO2 move around — from 20 to 25 times more damaging — depending on who provides them.
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