Methane bubbles up from the bottom of Esieh Lake, Alaska. Photo: Jonathan Newton / The Washington Post

By Chris Mooney
25 September 2018

(The Washington Post) – "The lake, about 20 football fields in size, looked as if it was boiling. Its waters hissed, bubbled and popped as a powerful greenhouse gas escaped from the lake bed. Some bubbles grew as big as grapefruits, visibly lifting the water’s surface several inches and carrying up bits of mud from below."

That's the picture I painted in my latest dispatch from the Arctic, where ecologist Katey Walter Anthony discovered Esieh Lake, which is emitting a large amount of methane gas for a single Arctic lake. It's a volume that could pose a significant threat to the climate if lakes like this one turn out to be common.

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.”

There are already a number of  so-called "thermokarst" lakes growing in the deep muck of the thawing Arctic permafrost that are emitting methane, a greenhouse gas that hits the climate system hard and fast. It's more potent than carbon dioxide in the short term, though without the same long term impact.

Accelerating carbon emissions in Alaska due to permafront thaw, in metric tons of CO2-equivalent emissions per year. Graphic: The Washington Post

But for sheer volume, Esieh Lake seems to be emitting more methane gas than those lakes.  (A rough estimate: It's emitting as much gas daily – two tons of methane – as about 6,000 dairy cows.)

And Walter Anthony worries there's a feedback loop in which bubbling lakes like Esieh create more warming which in turn could create more lakes that emit methane, significantly increasing the risks of climate warming. “These lakes speed up permafrost thaw,” Walter Anthony told  me. “It’s an acceleration.” [more]

The Energy 202: Something strange is happening with Arctic lakes



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