Sun Apr 26, 2015, 08:13 PM

Skeptical Science: Permafrost feedback update 2015: is it good or bad news?

We have good reason to be concerned about the potential for nasty climate feedbacks from thawing permafrost in the Arctic. Consider:

The Arctic contains huge stores of plant matter in its frozen soils. Over one-third of all the carbon stored in all of the soils of the Earth are found in this region, which hosts just 15% of the planet's soil-covered area.
The Arctic is warming at twice the rate of the rest of the planet. The vegetable matter in the soils is being taken out of the northern freezer and placed on the global kitchen counter to decompose. Microbes will take full advantage of this exceptional dining opportunity and will convert part of these plant remains into carbon dioxide and methane.
These gases will add to the already enhanced greenhouse effect that caused the Arctic warming, providing a further boost to warming. There's plenty of scope for these emissions to cause significant climatic mischief: the amount of carbon in the permafrost is double the amount currently in the air.
But exactly how bad will it be, and how quickly will it cause problems for us? Does the latest research bring good news or bad?

Ted Schuur and sixteen other permafrost experts have just published a review paper in Nature: Climate change and the permafrost feedback (paywalled). This long and authoritative article (7 pages of text, plus 97 references) provides a state-of-the-art update on the expected response of permafrost thawing to man-made climate change. Much of the work reported on in this paper has been published since the 2013 IPCC AR5 report. It covers new observations of permafrost thickness and carbon content, along with laboratory experiments on permafrost decomposition and the results of several modelling exercises.

The overall conclusion is that, although the permafrost feedback is unlikely to cause abrupt climate change in the near future, the feedback is going to make climate change worse over the second half of this century and beyond. The emissions quantities are still uncertain, but the central estimate would be like adding an additional country with the unmitigated emissions the current size of the United States' for at least the rest of the century. This will not cause a climate catastrophe by itself, but it will make preventing dangerous climate change that much more difficult. As if it wasn't hard enough already.

The original paper is here:

But as they point out, it's paywalled. That's why Skeptical Science did a very thorough job explaining the paper at their site. The top link will take you there.

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Reply Skeptical Science: Permafrost feedback update 2015: is it good or bad news? (Original post)
JosephNobles Apr 2015 OP
Gamle-ged Apr 2015 #1

Response to JosephNobles (Original post)

Sun Apr 26, 2015, 09:02 PM

1. I had a very small part in permafrost thawing in Greenland, long ago. Contractors were drilling...

... under a heated building to install pipes to pump a refrigerant to prevent the building from sinking down. I took a core from a discard heap, as a souvenir, and left it in a garage until the end of my shift. When I retrieved it, it had thawed to a pile of damp rubble.

I'd like to take this moment to apologize for my part in Global Warming...

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