From the Pacific Northwest National Laboratory:
Soils release more carbon dioxide as globe warms
COLLEGE PARK, Md. – Twenty years of field studies reveal that as the Earth has gotten warmer, plants and microbes in the soil have given off more carbon dioxide. So-called soil respiration has increased about one-tenth of 1 percent per year since 1989, according to an analysis of past studies in today’s issue of Nature.
The scientists also calculated the total amount of carbon dioxide flowing from soils, which is about 10-15 percent higher than previous measurements. That number — about 98 petagrams of carbon a year (or 98 billion metric tons) — will help scientists build a better overall model of how carbon in its many forms cycles throughout the Earth. Understanding soil respiration is central to understanding how the global carbon cycle affects climate.
“There’s a big pulse of carbon dioxide coming off of the surface of the soil everywhere in the world,” said ecologist Ben Bond-Lamberty of the Department of Energy’s Pacific Northwest National Laboratory. “We weren’t sure if we’d be able to measure it going into this analysis, but we did find a response to temperature.”
The increase in carbon dioxide given off by soils — about 0.1 petagram (100 million metric tons) per year since 1989 — won’t contribute to the greenhouse effect unless it comes from carbon that had been locked away out of the system for a long time, such as in Arctic tundra. This analysis could not distinguish whether the carbon was coming from old stores or from vegetation growing faster due to a warmer climate. But other lines of evidence suggest warming is unlocking old carbon, said Bond-Lamberty, so it will be important to determine the sources of extra carbon.
The Opposite of Photosynthesis
Plants are famous for photosynthesis, the process that stores energy in sugars built from carbon dioxide and water. Photosynthesis produces the oxygen we breathe as a byproduct. But plants also use oxygen and release carbon dioxide in the same manner that people and animals do. Soil respiration includes carbon dioxide from both plants and soil microbes, and is a major component of the global carbon cycle.
Theoretically, the biochemical reactions that plants and soil microbes engage in to produce carbon dioxide suggest that higher temperatures should result in more carbon dioxide being released. But unlike the amount of sunlight reaching Earth, soil respiration can’t be measured from space and can’t yet be simulated effectively with computer models.
So, the researchers turned to previous studies to see if they could quantify changes in global soil respiration. PNNL’s Bond-Lamberty and his colleague Allison Thomson, working at the Joint Global Change Research Institute in College Park, Md., examined 439 soil respiration studies published between 1989 and 2008.
They compiled data about how much carbon dioxide has leaked from plants and microbes in soil in an openly available database. To maintain consistency, they selected only data that scientists collected via the now-standard methods of gas chromatography and infrared gas analysis. The duo compared 1,434 soil carbon data points from the studies with temperature and precipitation data in the geographic regions from other climate research databases.
After subjecting their comparisons to statistical analysis, the researchers found that the total amount of carbon dioxide being emitted from soil in 2008 was more than in 1989. In addition, the rise in global temperatures correlated with the rise in global carbon flux. However, they did not find a similar relation between precipitation and carbon.
Zooming In
Previous climate change research shows that Arctic zones have a lot more carbon locked away than other regions. Using the complete set of data collected from the studies, the team estimated that the carbon released in northern — also called boreal — and Arctic regions rose by about 7 percent; in temperate regions by about 2 percent; and in tropical regions by about 3 percent, showing a trend consistent with other work.
The researchers wanted to know if their data could provide more detailed information about each region. So they broke down the complete data set by regional climates and re-examined the smaller groups of data using different statistical methods. The regional data from the temperate and tropical climates produced results consistent with other results, such as more carbon being released at higher temperatures, but the boreal-Arctic climate data did not. In addition, removing only 10 percent of the boreal-Arctic data points was enough to invalidate the statistical significance of the boreal-Arctic result. Together, the results support the idea that more boreal data on regional climates is needed to reach statistical relevance.
“We identified an area where we need to do more work,” said Thomson.
The authors designed the database so that other researchers could contribute to it. The paper describing the database can be found online in Biogeosciences.
Reference: Bond-Lamberty and Thomson, 2010. Temperature-associated increases in the global soil respiration record, Nature March 25, 2009, doi:10.1038/nature08930.
This research was supported by Pacific Northwest National Laboratory and by the Office of Biological and Environmental Research within the Department of Energy’s Office of Science.
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This is a meta-study, meaning the authors conglomerated the studies of others (818 at last count). All meta-analyses have inherent problems including publication bias (authors are more likely to submit positive rather than inconclusive results). That kind of bias is likely in this area of study given the strong political/funding incentives to find climate change effects.
The 818 individual studies were limited in scope: location, duration, methodology. The methodologies including modeling studies as well as some empirical observations. Pooling the findings is equivalent to extending the individual study inferences beyond their respective scopes, a practice that weakens if not violates the scientific method.
Most of the studies were focused on temperate forests, and other vegetation/soil types are thus poorly represented. The authors of the meta-study characterized a percentage of the forests in the individual studies as “unmanipulated ecosystems,” but that is a stretch. No temperate forests are in truth unmanipulated within any historical context. Nor are temperate forests independent of current political trends in forest management.
For that matter, forest fires are also not independent of current political trends. Forest fires represent the most severe type of soil carbon and soil metabolic change (disturbance).
Given all that, the meta-study purported to find a minute trend in soil respiration that is so small that it is dwarfed by the large uncertainties and biases. Further, no purported trends in gross sequestration of carbon through photosynthesis were considered in this meta-study. A slight increase in photosynthesis would offset soil respiration increases, yielding no net change terrestrial in carbon sequestration.
The upshot is that the “findings” are extremely weak and apparently blown completely out of proportion by the media blitz accompanying the paper — the blitz representing, ironically, a meta-example of publication bias.
Water holds CO2. Cold water holds more CO2 than warm water. When cold water is heated, it can no longer hold as much CO2, and releases CO2.
Soil is moist, it is wet dirt. Soil has water.
Therefore soil holds CO2. Cold soil holds more CO2 than warm soil. When cold soil is heated…
How much more grant money will it take for them to figure out how much of this CO2 release from soil is just general chemistry and whether there even is a separate significant detectable biological factor?
OMG the Tipping Point!
We are all going to die!
OMG! Was this allowed for in the models!
These little chaos termites keep nibbling away at number crunchers!
The whole exercise is just downright soily. Next thing they will do is to connect this to Genesis and claim that since G*d made men out of clay this is really AGW.
You sure you have your units right?
In the Headline, you say: “Soils Add 100 million tonnes of Carbon per Year”, but in the text it says: “The scientists also calculated the total amount of carbon dioxide flowing from soils, which is about 10-15 percent higher than previous measurements. That number — about 98 petagrams of carbon a year (or 98 billion metric tons)”.
I think that what we have here is an estimate of total emissions of CO2 flowing from soils of 98 billion metric tonnes per year, but that it is increasing at 100 million tonnes per year. Do I have that right?
Nick Stokes (above) says: “100 million tons CO2 per year is equivalent to burning about 30 million tons C. We burn about 300 times more than that in fossil fuel.” But I think that the proper comparison should be (accepting Nick’s figures on fossil fuel) 98 billion tonnes coming from soils each year compared with 9 billion tonnes coming from burning fossil fuels.
We should anticipate a steady stream of these kind of ‘new findings’ and ‘breakthrough analyses’ stories from the popculture/polysci rags (Nature, Science, et al.) in advance of the impending push for cap ‘n trade legislation later this spring. Good thing for them that the parrots in the press have no clue about the other than man-made inputs to the carbon cycle. At least we’ll get a chuckle out of them!
fhsiv,
Concrete has a higher albedo than grass or trees and according to Trenberth the earth’s average surface evaporative/transpirative effect is roughly equivalent to an albedo of .39 so, doing the same math that I think goes into the models implies that new concrete at an albedo of .50 would break even and the new LEED white concrete (.7-.8) could cool down that hot old backyard of yours.
I can see it now… “Stop Global Warming – Pave the Planet”
davidmhoffer (21:59:17) :
I have yet to read a really good accounting of the modern-era carbon cycle that brings in the fossil carbon input without all sorts of hysteria tacked on!! Very frustrating.>>
Have you looked at this one?
http://www.antti-roine.com/viewtopic.php?f=10&t=73
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Thanks, that is helpful information!
This topic of atmospheric carbon & its effects seems to be changing day to day….This one just came up, about cattle methane:
http://blogs.telegraph.co.uk/news/geraldwarner/100031389/now-its-cowgate-expert-report-says-claims-of-livestock-causing-global-warming-are-false/
There is so much obfuscation and spin put onto the topic of the modern-era carbon cycle that it is difficult to ascertain the truth from the junk (same with Arctic ice trends etc.). However, I am most convinced by data showing an overall balance between carbon dioxide production and uptake in the oceans.
The great ecologist Paul Colinvaux was writing about oceanic uptake of carbon dioxide and subsequent formation of carbonates back in the early 1970’s. I still tend to believe he was correct.
It’s amazing to me we don’t all wake up dead every morning. With one climate catastrophe following on the heels of another, shouldn’t we be seeing piles of bodies? Or are the oil companies hiding the evidence? As a minimum I’d think there would be polar bear pelts aplenty for sale on Craig’s List. In fact, when I look for true fallout of all this climatic hell that embraces our time on this wobbly orb I don’t see the jetsam one would expect of such careless stewards of spaceship earth.
Any wide scale disaster as pervasive and destructive as global warming is claimed to be and that does not produce a reflexive signature in the defensive behavior of humanity is probably not what the progenitors imagined it to be.
This is such a …..doh! Yes. That is why CO2 is a lagging indicator. Biologic activity. And as the solar quiescence has a global effect it will diminish. Thank nature for absorbing billions of tons via plant growth. But it is also important to remember that the earths atmospheric density, the CO2 has a relatively limited ability to contain heat.
So lets get this straight. This research claims that more CO2 is given off by the soil than ‘previously thought’. About 15% more, amounting to 98GT per year.
So … if this research is correct … there is 13GT more C being added to the atmosphere every year that ‘previously thought’. That amount is approximately double the annual ‘evil fossil fuel anthropogenic Carbon’ release, which is somewhere on the order of 6GT per year.
No one knew that this 13GT of soil sourced C was entering the atmosphere, and still no one knows where it is going. There has been a large hole in our understanding of the Carbon cycle for a long time. It’s size was pegged at approximately 3GT, based on the assumption that observed C rise was anthropogenic. We keep adding what is assumed to be 6GT per year, but the measured atmospheric CO2 was only showing an increase equivalent to about 40% of that. Some ‘missing sink’ was swallowing up 3GT, and no one could find it. Now, that missing sink must be more than five times the ‘previously thought’ size, and is swallowing 13GT more C every year?
We dont understand $#!^ about this planet.
dp (23:32:55) :
I think it works like this… the bodies have been stealthed away at night and converted in huge human-to-oil factories and sold to you as premium fuel for your automobiles. We actually passed peak oil decades ago but the human-to-oil program has kept up the supply to meet the growing demand.
It’s kinda like soylent Green meets Fight Club /nod
NickB. (23:11:31);
Hey, not so fast! I think you may have missed some significant items in your calculations!
While your ‘new’ concrete may have a favorable albedo, it is carbon intensive to manufacture. All that blasting, mucking, hauling, crushing, and sorting requires the combustion of lots of fossil fuel. Not to mention the tremendous amounts of CO2 liberated in the calcining of portland cement.
I think you need to submit a grant request to study whether or not paving the planet will be carbon neutral!
Practically every day of the week we’re privy to another unanticipated “discovery” about how the earth interacts with its atmosphere and how that atmosphere interacts with outer space. Doesn’t that belie the contention that “the science of AGW is settled”?
Carbon dioxide slumping
There is a report about a development that has received mysteriously little attention: according to numbers from the Energy Information Agency, greenhouse gas emissions fell sharply in 2008 (by more than 2½%), are falling even more in 2009 (about 6%), and in the next few years are almost certain to remain easily below the levels of 2005.
The oil price spike in 2008 deserves some credit. Some might wish to try to give some credit to policy too. But there can be no doubt that the main reason for the sharp fall in emissions is the slump. A simple statistic for the uninitiated: although carbon dioxide emissions in an average year rise by 0.8%, they fell that much in both 1991 and 2001, the last two slump years, in addition to the much larger drop in the much larger recent slump. That’s not a coincidence.
How should one weigh a 9% fall in emissions against a 3.8% fall in real GDP (from the 2007Q4 peak to the 2009Q2 apparent-trough)? I strongly suspect that a majority of Americans, no matter how well-informed, would think that the output loss far more than outweighs the climate benefit. A minority, in favor of very drastic action on climate change, might implicitly choose the other way.
__________________________
Projected carbon dioxide (carbon dioxide) emissions from fossil fuels fall by 5.9% in 2009. Coal leads the drop in 2009 carbon dioxide emissions, falling by 10.1%. Changes in energy consumption in the industrial sector, a result of the weak economy, and changes in electricity generation sources are the primary factors for the decline in carbon dioxide emissions (U.S. Carbon Dioxide Emissions Growth Chart). The projected recovery in the economy contributes to an expected 1.1% increase in carbon dioxide emissions in 2010.
“A convergence of several factors has contributed to the projected decline in carbon dioxide emissions in 2009 (see STEO Supplement: Understanding the Decline in carbon dioxide Emissions in 2009). EIA estimates that the combined effects of the decline in consumption of coal and natural gas in the industrial, commercial, and residential sectors, the substitution of natural gas for coal in the electric power sector, and the forecast increase in non-carbon dioxide emitting electricity generation (hydroelectric, nuclear, wind, solar, wood and wood waste) reduce carbon dioxide emissions by 242 million metric tons, or 70% of the total projected 2009 decline. The projected reduction in petroleum consumption accounts for the remaining 30% of the decline in carbon dioxide emissions. Carbon dioxide emissions from petroleum are expected to fall by 102 million metric tons in 2009, with over two-thirds of the decline attributable to economy-related reductions in consumption of jet fuel and distillate fuel oil, including both diesel fuel and home heating oil. Reduced petroleum demand in industry also contribute to the overall reduction in petroleum use.”
http://www.eia.doe.gov/emeu/steo/pub/gifs/Fig24.gif
http://www.eia.doe.gov/emeu/steo/pub/contents.html#Carbon%20Dioxide%20Emissions
“dp (23:32:55) :
I think it works like this… the bodies have been stealthed away at night and converted in huge human-to-oil factories and sold to you as premium fuel for your automobiles. We actually passed peak oil decades ago but the human-to-oil program has kept up the supply to meet the growing demand.”
Anyone seen Big Al lately?
That there is a conspiracy to deny a public airing of the “debate” is clear. Russian scientists continue to report a mini Ice Age starting 2010 to 2020 and lasting past 2050 – despite the carbon dioxide content of the atmosphere. Such scientific theories are suppressed.
Humans contribute 0.03% of the total carbon dioxide in the ecosystem. There are 28,000 gigatonnes in the oceans, 8 gigatonnes in the air. Breathing by humans and all animal life is between 2 and 5 gigatonnes. Humans alone contribute almost 1 gigatonne through breathing out carbon dioxide. Plants absorb carbon dioxide as food.
To reduce the 0.03% to zero will not change the temperature of the Earth.
This is a challenge to all you carbon-dioxide-causes-global-warming people:
Show us the published “Theory of Anthropogenic Global Warming” and the raw data that underpins your Holy Grail of a Theory. The Theory does not exist in any published paper. Now the data has been mysteriously “lost.” How convenient for the political scientists at the CRU.
====================================
1 gigatonne = 10 to the 9 tonnes, or 1,000,000,000 tonnes
Human activity produces about 6 billion tons of carbon dioxide every year. The atmosphere contains 3,600 billion tons, so humans produce an insignificant amount of all “new” carbon dioxide (0.166666%).
The greatest greenhouse gas is water vapor and clouds, accounting for up to 90% of all effects. The other 10% is from C02, CH4, S02, N0x, fluorocarbons, SF6, and a few others.
150 billion tonnes of carbon dioxide go into the atmosphere from natural processes every year. This is almost 30 times the amount of carbon dioxide humans make.
“Together, the results support the idea that more boreal data on regional climates is needed to reach statistical relevance. “We identified an area where we need to do more work,” said Thomson.”
Cha-ching! (sound of the successful funding hook…)
On a more serious note: I’ve no doubt that the assumptions underpinning the statistical analysis could be torn to shreds by a realistic individual with the right combination of education; however, the (cultural, not scientific) convention among colleagues in the field is to “overlook” such things…
Despite agreeing with Mike D, JJ and Pat above that we’ve got to be careful (and we really don’t understand shit about this planet), this fits nicely with what I’ve been saying for years, viz., that as the surface warms more CO2 comes out of solution, soil bacteria ramp up their activity, peat bogs dry out and rot and permafrost melts and releases methane which oxidises to CO2.
What else do you need to explain the 4-800 year lag of CO2 behind temperature? The quantities are certainly not yet well enough constrained to disprove the hypothesis numerically, but they all seem to be in the right area.
In the lab, CO2 certainly absorbs IR, but its contribution in a real, turbulent, water-laden atmosphere is extremely dubious and from the fact that the ice cores show temperature falling while CO2 goes on rising (with no other apparent cause) makes it look as though any CO2 contribution to warming is trivial at best.
Interesting study. But it is actually way more important than first glance, and I’m sure that the modelers will be looking very closely at it. The whole chicken and egg argument is now alive again, i.e. CO2 follows temp or temp follows CO2.
http://www.nytimes.com/2010/03/26/science/earth/26climate.html?src=me
The Cantwell-Collins plan is almost exactly what Mr. Obama proposed in the campaign and after first taking office — a 100 percent auction of permits and a large tax rebate to the public.
“He called our bill ‘very elegant,’ ” Ms. Cantwell said. “Simplicity and having something people can understand is important.”
===
So why isn’t Obama looking at this option seriously, which is a much more taxpayer friendly option? Is it because he and his banker buddies won’t be able to make as much money from gullible taxpayers?
Would it be fair to say that in fact there is a view of the carbon cycle that is so simple as to be naive?
Folks who learned the water cycle at school, evaporation, rain, river, sea, evaporation… think there’s a similar carbon cycle. There is not. It is waaaay more complicated, and nobody has a real handle on it.
The flows are massive. 100 million tons is a drop in the bucket, far larger amounts are unaccounted for, get fixed for indeterminate periods, enter and leave the ‘cycle’. It’s not well-described anywhere, yet some speak of it as if it was.
This Nature study appears to directly contradict the findings of Emmett et al (2010) who found that soils in Great Britain have lost NO carbon in a huge study conducted between between 1978 and 2007. The summary is at http://www.countrysidesurvey.org.uk/news.html – links to technical documents are given on the website.
Emmett also thereby trashes a similarly alarmist paper by Bellamy et al, also in Nature, which reported that UK soils were losing carbon at rate 10x the level predicted by IPCC lead author Pete Smith’s models.
Emmett made the point that measuring such a tiny signal against the heterogeneity of hugely differing soil types and plant cover is very troublesome – so making claims of actually detecting a 0.1% change sounds like more alarmist bedwetting to me.
OMG. SOIL RESPIRES CO2. IT HAS GOT TO BE TAXED OR IT HAS GOT TO GO, OR BOTH!!! WHERE WILL IT END? CLEARLY THE WHOLE PLANET IS ADDICTED TO CO2 AND NEEDS TO GO INTO COLD TURKEY DETOX IMMEDIATELY!