Ticking Arctic Carbon Bomb May Be Bigger Than Thought


SAN FRANCISCO, CALIFORNIA—Scientists are expressing fresh concerns about the carbon locked in the Arctic’s vast expanse of frozen soil. New field studies, presented here this week at the fall meeting of the American Geophysical Union, quantify the amount of soil carbon at 1.9 trillion metric tons, suggesting that previous estimates underestimated the climate risk if this carbon is liberated. Meanwhile, a new analysis of laboratory experiments that simulate carbon release by thawed soil is bolstering worries that continued carbon emissions could unleash a massive Arctic carbon wallop.

Disappearing Arctic ice, which gets most of the attention from climate scientists, is an effect of humanmade climate change. By contrast, the melting of frozen soil, or permafrost, can drive warming. As it thaws, microbes devour carbon previously locked inside, unleashing carbon dioxide—a potent greenhouse gas—in the process. The carbon dioxide amplifies the warming power of carbon pollution in a vicious feedback loop.

Scientists have struggled, however, to quantify this threat. Permafrost occurs on a quarter of the Northern Hemisphere landmass—from Alaska to Canada and across Siberia—but researchers have taken far too few readings to feel very confident about the risk. “We are working on really large landmasses with limited data,” says physical geographer Gustaf Hugelius of Stockholm University. Measuring the carbon content of permafrost requires muddy field work with heavy drilling machinery, operated in remote areas, and satellite data help little.

Those logistical constraints have largely limited researchers’ previous estimates of carbon to the top meter of permafrost. But scientists think that carbon down to a depth of 3 meters is susceptible to thawing and release as well. An influential 2009 estimate that Arctic permafrost held 1.6 trillion metric tons of carbon included only 45 field sites analyzed down to that depth. In the new study, Hugelius added 405 new analyses of field sites that went to 3 meters, some through new field work he and colleagues performed, some from archived data. Adding up the carbon found in different soil types he says, yields an initial new estimate of 1894 billion metric tons of carbon locked into permafrost across the Arctic, 13% more than the previous estimate.

Written By: Eli Kintisch
continue to source article at news.sciencemag.org


  1. One of the hardest things to get across to people who have no understanding of how science as a process works is getting them to understand science’s usual conservatism.  Trouble is media is usually over-hyping and there is a tenancy to believe scientists do the same.  Global warming it is becoming clear is very much a case in point.  As more evidence comes in and scientists become more confident they have covered all the variables the actual estimates of damage we are likely causing will go up.  Getting people to see that what we can be highly confident will happen is very likely an underestimate is one of the truly frightening aspects of this.

  2. One of my junior creatives announced, the other day, that she didn’t believe in global warming. “I don’t believe in global warming; the earth goes through cycles”, she told us. I was very happy my IT guy spoke up and said “I believe people who don’t believe in global warming are delusional”. I tried to calm the situation (I know, can you believe it) by saying “we can’t control the earth’s cycles so the next best thing we can do is control ourselves. Besides, science doesn’t care what we believe, it cares what we can prove. Global warming is a fact.” I actually quoted one of my brother’s t-shirts to this girl. 

    I’ve had a lot of friends and others up here in Canada laugh it off with a casual “no more winter, alright. We’ll be fine.” Perhaps some of us but you won’t stop 300 million United States Americans from migrating north.

  3. A little warming might trigger the end of the Holocene and a Northern Hemisphere glacial period. So most of Canada could be under several miles of ice for several hundred thousand years before things stablise. So Canadians should be OK with the reduced risk of an American invasion. It’s all about quantifying risk. US has never yet invaded any non-penguin sovereign nation that’s covered by several thousand feet of ice.

    Recent precedents involving Italian geologists whose risk estimates were too conservative and uncertain might be a useful guide on this latest greenhouse gas situation.

    What would be the appropriate length of prison sentence to be imposed on climate scientists for failing to convince non-scientists of the dangerous risks?

  4. According to numbers I find in http://en.wikipedia.org/wiki/C… estimate for the amount of carbon in the permafrost to 3m depth is equivalent to:2.4 * carbon in total terrestrial vegetation in 1990 (7.8*10^11 tons)It’s quite impressive that so much carbon is stored.If it were all combusted to form CO2, this would be equivalent toover 200 years of human-caused CO2 emissions (2010 estimate: 9.14*10^9 tons of carbon)

  5. I’ve had a lot of friends and others up here in Canada laugh it off with
    a casual “no more winter, alright. We’ll be fine.” Perhaps some of us
    but you won’t stop 300 million United States Americans from migrating

    If I knew that Toronto’s winters are a bit less severe/similar to where I live, I probably would have headed up north twenty years ago.  It’s starting to look like another mild winter this year again. I worry about the trees come March if we have another storm after all the trees bud.

    I think we are all screwed. People will not change. Africa will be hit with high temperatures in our lifetime. Considering the level of superstition with many of the people, I expect rampant violence.

  6. “Carbon bomb” puts me in mind of the old BBC series Oppenheimer which I watched the other night about the making and deploying of that other lethal bomb we have so far barely kept in check and that puts me in mind of Christopher Hitchens in this rare comment on climate change …

    “The argument about global warming is not whether there is any warming but whether or not and to what extent human activity is responsible for it. My line on that is that we should act as if it is, for this reason, which I borrowed from Jonathan Schell’s book on the nuclear
    question, The Fate of the Earth: We don’t have another planet on which
    to run the experiment. Just as we don’t have a right to run an experiment in
    nuclear exchange on this planet, we have no right to run an experiment in
    warming it either. So if it turned out to be that there was no severe global
    warming threat or that it wasn’t man-made, then all we would have done would be
    make a mistake in analysis – which we could correct from. But if it turned out
    that there was and we didn’t do anything about it, then it would be too late to
    do anything at all. And that would lead to disaster”

    Aren’t both experiments up and running and now irreversible?

  7. Pete H
    A little warming might trigger the end of the Holocene and a Northern Hemisphere glacial period. So most of Canada could be under several miles of ice for several hundred thousand years before things stablise.

    Alternatively, and more likely in the foreseable future, it could just be subjected to unpredictable intermittent fierce snow-storms, as the previously frozen ground, thaws, rots, turns to mush and ponds, and belches methane into the air to increase the feed-backs!

    The thawing and disappearance of permafrost has accelerated in recent decades1, damaging buildings and infrastructure and causing public concern2.
    Here we offer a geographic overview of the hazard potential associated with thawing permafrost in the Northern Hemisphere which indicates that vulnerability to subsidence is widespread. Much of the existing
    infrastructure erected in northern regions is located in areas of high hazard potential and could be affected by thaw subsidence under conditions of global warming. – http://www.nature.com/nature/j



    A railroad in Alaska (left) and building (right), both buckled due to thawing permafrost. Image credit: (left) NASA and U.S. Geological Survey, (right) Vladimir Romanovsky, Geophysical Institute, University of Alaska Fairbanks. –

  8. I see dozy-Dave Cameron’s carbon-industry-stooge government has given the go-ahead for gas fracking in England.   If there are any economic benefits from fracking, remains uncertain, but Dozy Dave just could not pass up a chance which might reduce gas prices enough in the short term, to discourage investment in nuclear or renewable power generation, while adding to atmospheric CO2 and leaking methane! 

    I see they “might” also “look at” plans for a Severn tidal barrage some time! Apparently, it could “only” generate about a fifth of UK electricity requirements – so no urgency to get started!!!

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