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.
If you heat the soil enough for the trees to combust spontaneously you get even more CO2 released.
@David An artificial Lake Nyos event, preferably in an area where executives of Big Green have their country estates?
First, there is an annual cycle in which the trees accumulate carbon in their leavesall spring ans summer, to drop it on the ground each fall. The microflora on the florest floor break down the elaves and return it to the air as CO2 *continually*.
Then there is the irregular cycle of fire, which is the ONLY known source that can heat the soil 10-20° C and release the CO2 to the air in one large pules. This cannot happen in successive years for any given location, but happens randomly in intervals of several years to a few centuries.
This whole myopic piece strikes me as a rent-seeking report.
Ian Middleton says:
June 12, 2012 at 12:37 am
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.
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You are correct it is but the IPCC never ever speaks of water because then the whole scam will crash around their ears. Water, as vapor, clouds, oceans, ice, rain and snow, is the huge elephant in the Global Warminst’s room.
Here is the graphs of Atmospheric Transmission and Absorption
@Philip Bradley
“What was there?”
He replied, “Que nada”.
++++
Love it! We have little shrines in each sports bar where in mid-summer we offer a little corn to Manitou thanking Him for not allowing the Portuguese to land first.
So the ice core data are correct that first comes the heat then comes the CO2. But what causes the heat? Somewhere in the world of climate science there is a chicken missing its egg.
Bill Illis says:
June 12, 2012 at 5:27 am
These papers are becoming scarier and scarier as time goes on as well farther divorced from reality as time goes on. Why do they need to do this?
It’s their mindset. When people don’t buy into their message, they don’t believe their message is wrong, they think that people just aren’t aware of Teh Revelation. So, they think that shouting will get it across — kind of like that old Sam Kinison sketch;
Sam [to immigrant convenience store clerk]: “Do you have any cigarettes?”
AICSC: [shrugs] “????”
Sam: “DO. YOU. HAVE. ANY. CIGARETTES?!?”
tadchem says:
June 12, 2012 at 6:51 am
This whole myopic piece strikes me as a rent-seeking report.
“No actual science was used during the production of this report.”
We already know that CO2 levels in the atmosphere follow temperature swings by about 800 years. Thank you for detailing one possible mechanism.
Now, how does this cause global warming?
“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.”
For peace of mind, resign as general manager of the universe. ~Author Unknown
garymount says:
June 12, 2012 at 5:24 am
On the front page of The Vancouver Sun today:
“Drier summers in the Lower Mainland”
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Anyone that actually lives in Vancouver would vote in a instant for drier summers. Vancouver is a rain forest. Today it is cold and rainy. Most of the past 10 months it has been cold and rainy. Most of the past 100 years it has been cold and rainy. A heat wave in Vancouver is when it reaches 24C (75F).
Vancouver is situated on the ocean at 49+ degrees north. 700 miles closer to the North Pole than to the equator. The city sits right smack dab in the middle of the North Pacific storm track. There are 5000 foot high mountains immediately behind the city that ring every drop of water out of the clouds and rain it down in the city in a near constant drizzle that starts in September and ends in July. Occasionally we get a break from the drizzle – when it rains.
There are wetter places on earth than Vancouver, but most human beings have the good sense not to live there. Anyone that thinks drier summers are a negative in Vancouver hasn’t lived in Vancouver. Or an insurance company looking for reasons to boost rates.
Mike Smith says:
June 12, 2012 at 12:49 am
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….
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What is really laughable is the fact it happens in every organic farmer’s compost heap! (Those veggies the Politically Correct at OSU and UVa eat.)
…above 55°C (131°F)… sounds like that is where they got that ” 10 and 20 degrees increased” Think they are now going to start banning compost heaps and manure piles?
OH THE HORROR! Where will all politically correct Academia get their food?
The fundamental problem with this is that it assumes that since there has been rise in global temperatures that there is also a rise in the continental US but this is not the case. The continental US has seen a significant downtrend in temperatures since 1998.
While it is certainly warmer now than it was in 1975, it is slightly cooler today than it was in the early 1930’s. With all the hype about how warm this May was, it was still cooler than May 1934.
A new high resolution CO2 series from the Antarctic ice cores for the last 1,000 years was recently released. CO2 as high as 287.5 at 1203 AD (Medieval Warm Period).
A comparison of the 3 high resolution ice core series shows MWP and the LIA feedback of temperature on CO2 levels. They can’t rewrite this record now.
http://www.agu.org/journals/gb/gb1202/2011GB004247/2011gb004247-op02.jpg
http://www.agu.org/pubs/crossref/2012/2011GB004247.shtml
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/wais2012co2.txt
They can’t see the forest behind YAD06.
David says:
June 12, 2012 at 6:23 am
Ah – but BURYING CO2 under pressure, as the British government is determined to make a condition of any new fossil-fuelled power stations, is bound to work, isn’t it..?
What could possibly go wrong..?
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Can let that pass…
In 1986, a tremendous explosion of CO2 from the lake Nyos, West of Cameroon, killed more than 1700 people and livestock up to 25 km away.
So just make sure the “BURYING CO2 under pressure” is right next to parliament and other seats of government… That is the best way to make sure the engineering is done correctly by the Son-in-Law of the big wig in office. (tongue firmly in cheek)
10 to 20 degree increase is bad for soils – now I am scared. I’m also amazed that forest fire areas can begin to grow back in a couple of years. I guess the carbon is just about gone from the Amazon jungle.
Someone make them stop, please!!!!
This is embarrassing to read.
> heating soil in Wisconsin and North Carolina woodlands by 10 and 20 degrees increased the release of carbon dioxide by up to eight times
I didn’t notice anyone ask this… 10 to 20 degrees from… where? What was the starting temp of the soil? Ditto for the release of CO2 – what’s the baseline release rate?
Just for fun, I looked up vicious cycle (circle) on wikipedia:
A virtuous circle and a vicious circle (also referred to as virtuous cycle and vicious cycle) are economic terms. They refer to a complex of events that reinforces itself through a feedback loop. A virtuous circle has favorable results, while a vicious circle has detrimental results.
Bob Shapiro says:
June 12, 2012 at 7:37 am
We already know that CO2 levels in the atmosphere follow temperature swings by about 800 years. Thank you for detailing one possible mechanism.
Now, how does this cause global warming?
One step at a time. First off, we invent time travel…
I inadvertently performed a similar experiment behind my patio digging a barrier to a fire pit. Several worms emerged and a strange looking beetle surfaced and flew away. And that was prior to starting the fire. It would be difficult to contemplate the bio-disruption to the forest floor with a 10 to 20 degree temperature increase.
“Francesca Hopkins of the University of California at Irvine collected soil from the two forests in jars and then measured how much carbon dioxide the soil emitted as she warmed the containers.”
Sorry, but I won’t get all exercised about a test like this. Small samples that have an increased surface area to volume ratio will allow for better heat flow in the sample. You then would expect more microbial activity than in a real forest environment environment. That this got published is a testament to their belief in AGW.
As I have said before, as a general rule, atmospheric CO2 is directly related to the rate of eukariote metabolism; the rate of eukariote metabolism is directly related to temperature, thus CO2 follows temperature.
But because I don’t have a PhD, no one believes me. All I have is 30 years experience duplicating aquatic eco-systems in big glass boxes.
New title proposed: Published paper opportunity found under every rock and behind every tree!
Is there nothing left of this paper? Let me offer Figure 1. By ocular estimation, it appears that the atmospheric residence time of carbon-14 dioxide (and by extension CO2) is 5 to 10 years. That is what I recollect from other studies and substantially less than the decades to eons required to fulfill CAGW prophecy. Now I must go out to the yard and turn over my compost pile.