Global warming threat seen in fertile soil of northeastern US forests
In ‘vicious cycle,’ heat may boost carbon release into atmosphere, UCI-led study finds
— Irvine, Calif., June 11, 2012 —
Vast stores of carbon in U.S. forest soils could be released by rising global temperatures, according to a study by UC Irvine and other researchers in today’s online Proceedings of the National Academy of Sciences in Washington, D.C.
The scientists found that heating soil in Wisconsin and North Carolina woodlands by 10 and 20 degrees increased the release of carbon dioxide by up to eight times. They showed for the first time that most carbon in topsoil is vulnerable to this warming effect.
“We found that decades-old carbon in surface soils is released to the atmosphere faster when temperatures become warmer,” said lead author Francesca Hopkins, a doctoral researcher in UCI’s Earth system science department. “This suggests that soils could accelerate global warming through a vicious cycle in which man-made warming releases carbon from soils to the atmosphere, which, in turn, would warm the planet more.”
Soil, which takes its rich, brown color from large amounts of carbon in decaying leaves and roots, stores more than twice as much of the element as does the atmosphere, according to United Nations reports. Previously, it wasn’t known whether carbon housed in soil for a decade or longer would be released faster under higher temperatures, because it’s difficult to measure. The team, using carbon isotopes, discovered that older soil carbon is indeed susceptible to warming.
Forest lands, which contain about 104 billion tons of carbon reserves, have been one of the biggest unknowns in climate change predictions. Northeastern woodlands that were once farm fields are currently one of the Earth’s beneficial carbon sinks, holding nearly 26 billion tons. But climate scientists worry that trees and soils could become sources of greenhouse gas emissions rather than repositories.
“Our results suggest that large stores of carbon that built up over the last century as forests recovered will erode with rising temperatures,” said Susan Trumbore of the Max Planck Institute for Biogeochemistry and UCI, who led the research team, which also included Margaret Torn, head of the Climate & Carbon Sciences Program at Lawrence Berkeley National Laboratory.
Microbes in soil near tree roots, in particular, eat carbon, and it’s then diffused into the air as carbon dioxide, already the largest greenhouse gas in the atmosphere.
“These are carbon dioxide sources that, in effect, we can’t control,” Hopkins said. “We could control how much gasoline we burn, how much coal we burn, but we don’t have control over how much carbon the soil will release once this gets going.”
Hopkins, who is also a visiting researcher at the Max Planck Institute, received funding from the National Science Foundation, the ARCS Foundation, and a Ralph J. & Carol M. Cicerone Graduate Fellowship. Additional support was provided by the U.S. Department of Energy, the U.S. Forest Service, Michigan Technological University and the Canadian Forest Service.
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First, this really isn’t surprising. Anyone that has ever worked with bacteria and petri dishes can tell you the bacteria are far more active at warmer temperatures. That’s why cultures are incubated to enhance growth.
I think the thing really missing from this study is the fact that the surrounding flora will likely utilize much of the CO2 released from the forest floor. They make no mention of where it goes, only that heating the soil allows for more bio-action by CO2 producing microbes.
The CO2 then gets sequestered in the trees and plants, until such time they die and decay.
I really can’t get too worked up about this.
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Cut down the forests and concrete them over.
But wait a minute! Isn’t rising temperature also supposed to promote tree growth? Isn’t that what tree ring proxies are all about? So if the forest warms up, more CO2 is released from the forest floor AND more CO2 is taken up by the trees. Which effect is bigger?
This is good. The warm-mongers are getting more and more ludicrous all the time.
Try as I might, I could not find the accepted scientific definition of vicious. I did find:
but I don’t think trees or leaves can (yet) be classified as animals or are cruel or violent towards humans.
Also, when has anyone suggested that CAGW was going to cause “heating soil in Wisconsin and North Carolina woodlands by 10 and 20 degrees”. This is what they> did, not what is necessarily likely to happen.
No dummy. Pave them over with asphalt.
Is that 10 and 20 degrees C or F?
I would be curious to know how they determined that the temperature has become warmer and where they did the study. Did they measure this in the field or bring soil into the lab and heat it? Any chance we could get hold of the paper?
Surely these researchers deserve the Nobel Peace Prize (but not the Nobel Biochemistry prize as it still has some credibility).
Wow. If their study had merit, then we would expect the lowest carbon levels in soil to occurr in tropical rain forests where consistant high temps ought to expel the stuff from the soil, and the lowest in frozen wastelands. We get the opposite. Shame on those ignorant plants for scraping CO2 ought of the atmosphere and depositing it in the soil when they die at higher rate than the soil bacteria can release it.
Bad trees. Fooled Mann and Briffa into thinking they were thermometers (except after 1960) and now they fooled some soil scientists into thinking that carbon levels in soil will go down instead of up due to warmer temperatures. Bad tress. Bad, bad, bad.
This bit confuses me “Microbes in soil near tree roots, in particular, eat carbon, and it’s then diffused into the air as carbon dioxide, already the largest greenhouse gas in the atmosphere.”
I thought water vapor was the biggest ghg.
“These are carbon dioxide sources that, in effect, we can’t control,” Hopkins said. “We could control how much gasoline we burn, how much coal we burn, but we don’t have control over how much carbon the soil will release once this gets going.”
News flash for Mizz Hopkins: you don’t have control over carbon release from the soil *now*, let alone “once this gets going.”
One decent bushfire would release umpteen hundreds of tons/ years of CO2. As it does in some parts of Australia’s noth west every year. Makes any attempt to sequester it a joke.
If you heat water it releases dissolved CO2.
Another example of the back to front IPCC, Al Gore pseudoscience.
CO2 is the lagging not leading factor in the geological record.
The last twenty years of rising CO2 yet flat temperatures shows CO2 is not a temperature driver.
Still its nice to know that the ‘scientists’ are leaving their computer models to do some experiments.
10 or 20 degrees ? More moronic conclusions based on fantasy strawmen.
I sugest they actually measure soil temperatures longterm – and do it properly with replicated random samples. If the net delta air temperature is point 8 degrees C (and that is likely doubtful), then my bet is the delta soil temperature change is likely close to zero, especially in soils with a large organic insulating layer.
More straining at gnats, as usual. Make a model why don’t you ?
“and it’s then diffused into the air as carbon dioxide, already the largest greenhouse gas in the atmosphere.”
Largest? I guess a molecule of CO2 is somewhat larger than say, a molecule of H2O or N2.
Is this what passes for scientific statements?
Water vapour is not a greenhouse gas and its effect is not greater than CO2 ?
And they heated the soil by 10 – 20 degrees ? How does that relate to global warming over the last century ?
I am appalled.
Is it a coincidence this and all the other scare stories start to appear in the run up to an environment conference (rio 2012); ramp up the scare tactics to get the msm interested.
As for 10 degree rise in soil temperatures, doesn’t that happen every year after winter?
OMG, the sky is falling and God forbid the topsoil might be warmed up by several degrees.
Guess what? This happens every day starting soon after sunrise.
And what’s with the control freaks at Irvine? Jeeze there’s a ton of things we can’t control and yet these silly people want to get all worried about CO2 release from topsoil. Listen up Irviners — we can’t control solar variations either and THAT is scary!
Pathetic. My primary school kids do better science than this!
Er – “by 10 and 20 degrees” – even the wildest alarmist predictions don’t expect a rise of the former, never mind the latter.
Alex Heyworth says:
June 12, 2012 at 12:08 am
But wait a minute! Isn’t rising temperature also supposed to promote tree growth? Isn’t that what tree ring proxies are all about? So if the forest warms up, more CO2 is released from the forest floor AND more CO2 is taken up by the trees. Which effect is bigger?
>>>>>>>>>>>>>>>
Oh don’t be silly. CO2 levels don’t affect tree ring growth, Hansen and Briffa said so. Never mind all those studies about increased growth from high levels of CO2 in greenhouses, that’s just greenhouses, not the “real world”. Other things that don’t affect tree growth in the real world include precipitation, soil nutrients, pestilence, disease, competiion from other species, changes in migration patterns of birds and animals that leave, uhm, soil nutrient precursors, behind in large quantities, late frosts, early frosts, variations in insect population that stunt or promote seed production, and of course the temperature during the non growing season is exactly the same from one year to the next so as to make the growing season representative of the whole year.Just ignore all that, The trees only respond to temperture. Oh and don’t forget that 12 trees in Siberia represent the temperature of the earth for 1,000 years oh a blobal basis. Well, actually as it turns out, only one of them. How it got the local temps wrong and the global temps right is beyond me. Well until 1960, after which the all got it wrong. We can’t compare to temps recorded before 1900 or so, but given there;s a few decades in their where they sorta correlate if we discard the 11 other trees, then obviously there’s not question they were accurate for the 900 years prior to the temperature record beginning.
I knew a caprenter who said he could make anything out of wood and I now I know what he meant.
carbon dioxide, already the largest greenhouse gas in the atmosphere
No it isn’t. Water vapour is.
If this study is correct and warmer temperatures increase CO2 emissions from soil, then this is strong evidence that the greenhouse warming effect of CO2 is weak to non-existent.
This is a positive feedback and will cause runaway warming. As this hasn’t happened in the past, we can safely conclude that increased CO2 emissions from warmer soils has no effect on the climate.
I can’t get worked up at *all* about this. What rot –literally and figuratively. Their lead author is a “doctoral researcher” which sounds like “this is my Ph.D thesis, and I hope someday to know what I’m doing.”. Their work “suggests” that this mechanism might exist, and under huge changes on the input side (10 or 20 degrees of temperature increase) the mechanism might produce an attention-getting increase on the output side (8x release from soil? Really?). Did they observe this? Did they attempt to falsify their hypothesis? Can they explain why this seemingly-catastrophic release of carbon has not occurred over and over in the planet’s history, because surely those input conditions have existed time and time again?
Me, I think we’re seeing a tsunami of tripe, timed for publication before the cut-off date for citation by the IPCC in AR5. If somebody could eavesdrop on the IPCC’s “leadership” they might show a deliberate coordinated program of generating such papers by marginal players, to be pushed through friendly review and dumped on the world at just the right moment. But such a notion on my part is, like this paper, pure speculation.
“In ‘vicious cycle,’ heat may boost carbon release into atmosphere”
Yippee !! bring on a more SUSTAINABLE atmosphere, one that is not so near barely a plant survival level.
SUSTAINABLE is the “NEW” word isn’t it. 😉 So let’s boost that CO2 level !!!
It’s been “going” pretty well as long as the planet has supported life.
Do these post-normal, teenage “scientists” really believe they’ve just discovered the carbon cycle?
They showed for the first time that most carbon in topsoil is vulnerable to this warming effect.
They really do believe we’re stupid, don’t they?
From 2001 — “Seasonal dynamics of soil carbon dioxide efflux and simulated rhizosphere respiration in a beech forest…”
http://treephys.oxfordjournals.org/content/21/2-3/145.full.pdf
— through 2009 — “Abstract: Laboratory and field CO2 efflux measurements were used to investigate the influence of soil organic C (SOC) decomposability and soil microclimate on summer SOC dynamics in seasonally dry montane forest and rangeland soils at the T.W. Daniel Experimental Forest in northern Utah.”
http://www.mendeley.com/research/factors-affecting-carbon-dioxide-release-forest-rangeland-soils-northern-utah/
— there must have been fifty papers published on the subject.
“This suggests that soils could accelerate global warming through a vicious cycle in which man-made warming releases carbon from soils to the atmosphere, which, in turn, would warm the planet more.”
JK—Shouldn’t they first prove that CO2 really does cause warming in a real atmosphere, with air circulation, and overlapping absorption bands?
Thanks
JK]
davidmhoffer said in part:
June 12, 2012 at 12:52 am
“I knew a caprenter who said he could make anything out of wood and I now I know what he meant.”
I had one of his Sirloin steaks he made the other day………
Surely this extra CO2 [ my trees/ plants say “bring it on!”] is all for digestion in Rio and to support the inevitable Media Green Garbage overhype?