From Oregon State University: Climate projections don’t accurately reflect soil carbon release
CORVALLIS, Ore. – A new study concludes that models may be predicting releases of atmospheric carbon dioxide that are either too high or too low, depending on the region, because they don’t adequately reflect variable temperatures that can affect the amount of carbon released from soil.
The study points out that many global models make estimates of greenhouse gas emissions from soils based on “average” projected temperatures. But temperatures vary widely from those averages. That variability, along with complex biological processes, makes the issue far more complicated.
Researchers said that climate projections, in general, don’t effectively incorporate into their calculations a major component of global warming – the enormous amounts of carbon found in dead, decaying organic matter, which represent up to three times the amount of carbon in the Earth’s live vegetation.
The study was just published in the journal Biogeosciences by scientists from the College of Forestry at Oregon State University and other institutions.
“We’ve done a pretty good job of determining how much carbon is getting absorbed by growing trees and vegetation, how much is coming in,” said Mark Harmon, professor and holder of the Richardson Chair in Forest Science at OSU, and one of the world’s leading experts on the effect of decomposition on the Earth’s carbon cycle.
“However, we know much less about how carbon is released to the atmosphere through the process of decomposition, how much is going out,” he said. “This is half of the equation, and there’s just a huge amount we don’t know about it.”
These findings don’t change the fact that atmospheric carbon dioxide and other greenhouse gas levels are increasing and global warming is a reality, Harmon said. But they do suggest that some of the projections, particularly those made by older models that incorporate even less variability into their analysis, may be flawed.
“This work is important because it brings attention to a component of climate change that was often ignored in the past,” said Carlos Sierra, previously an OSU doctoral student, lead author on the study and now a researcher with the Max-Planck-Institute for Biogeochemistry in Germany. “We can make better projections if we add changes in temperature variability to the equation.”
Researchers have understood, and have been concerned for some time, that warmer temperatures will speed up the rate of decomposition of stored organic matter in soils, a process that ordinarily is slow. This faster rate of decomposition, in turn, could further increase carbon released to the atmosphere and cause even greater global warming.
“This feedback loop is one of our biggest worries with global warming, simply because the amount of carbon stored in soil is so huge,” Harmon said. “Increased release of that soil carbon could offset much of what we’re trying to accomplish with increased growth of live vegetation in forests. And this is a special concern in northern latitudes.”
In the past, estimates of that process were usually based on average temperature increases that were expected, Harmon said. But in the real world, temperatures vary greatly, from day to night, season to season, through heat waves and cold spells. And that variability, researchers say, changes the biological equation considerably and can make averages misleading.
“If the response of soil respiration to temperature was a straight line, then temperature variability would not be important,” Harmon said. “However, the response is curved, which means that as temperature variability increases, so does the average response. This general phenomenon is known as Jensen’s inequality, but it had not previously been applied to soil respiration.”
In simple terms, less variability will equate to less soil carbon release. In the new analysis, considering the effects of variability, scientists found that temperature variability may be reduced in northern latitudes, in particular, and result in carbon releases that are lower than have been projected in one of the areas of the world where this phenomenon is of greatest concern.
The research was not able to precisely quantify this phenomenon and more work needs to be done in that area, the researchers said.
The study reports that:
- The amount of carbon stored in soils worldwide exceeds the amount of carbon in the atmosphere by a factor of two to three.
- There is concern that a large portion of this carbon will be released to the atmosphere as global average temperatures increase.
- Too little attention has been paid to the effect of temperature variability in this process.
- In high latitudes of the Northern Hemisphere, temperature variability is expected to decrease, and release of soil carbon will probably be lower than that predicted by changes in average temperature.
- At lower latitudes, where both average temperature and variability are expected to increase, the release of soil carbon will probably be higher than that predicted by changes in average temperature.
“The findings of this study can greatly modify past predictions about the effects of future average temperatures on ecosystem respiration,” the scientists wrote in their conclusion. “Changes in both temperature and precipitation variance would likely produce complex behaviors not incorporated in current model predictions.”
The research was done by scientists from OSU, the U.S. Geological Survey, and the National Ecological Observatory Network. The study used data from the Long Term Ecological Network Program of the National Science Foundation.
http://oregonstate.edu/ua/ncs/archives/2011/jun/climate-projections-don%E2%80%99t-accurately-reflect-soil-carbon-release
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Let me summarize. We don’t know what we’re doing, but we know we are right. If you give us some more grant money maybe we can figure it out.
It is certainly a step in the right direction. Simple idea that the more plants grow from increased CO2, the more biomass there is to decompose.
In the summary there is no acknowledgement of how bacteria feed on the released CO2.
The reason given for the greens hating cattle and other livestock was the release of methane. However, methanotrophs were not accounted for. In one study in the Australian Alps, the methanotrophs were fixing more methane than the cattle were releasing. Another study indicated in North Queensland, that cattle were only releasing 1/3rd of the estimated methane. That study did not account for methane loving bacteria either.
So the warmists rely on the tyranny of averages.
Another factor not accounting for is that for plants, the nutrient chains have to be converted to a form the plant can take up. Usually the organic molecules are to big to be taken up, so the plants rely on a symbiotic relationship with fungi/ bacteria that can breakdown the chain. So again we have another huge source of carbon and converted CO2 that is not accounted for by the models.
off topic — its logical to reframe the debate.
No one gave a rat’s ass about climate science until it sought to steal our pocket book.
Who cares if Climate Science decides to hi jack notions. As far as I’m concerned, they’re welcome to create a new SciFi flick on their own dollar.
Isn’t it time to reframe the debate into something more meaningful?
What options are on the table that make sense to save the taxpayer a few bucks and improve efficiency?
We’re tired of reading “he said, she said” crap — what’s the next step?
You must excuse my skepticism of scientists who espouse Global Warming. It may or may not be occurring. I certainly have my opinion after reading a library full of material on the subject. What I do know from experience is that science does not fund itself and scientists and governments have a conflict of interest when it comes to the funding of science, or anything else through grants. As a department head working on an a Native American Indian Reservation it was my responsibility to secure government funding to maintain our programs. Each year the government sent out the criteria for which grant applications would be judged worthy to fund. So, each year we were worked to mold our programs to fit into the government’s “flavor of the month” in order to maintain our funding. Science is funded in the same manner. How many times has the government sent out grant requirements which required a fundee’s program work to disprove global warming? Never happened, and never will happen. Instead, fundees are “required” (in order to receive funding) to do work which proves the existence and acceleration of global warming. As decided by our government (and other governments especially in Europe) Global Warming is the “flavor of the month” of our generation.
And here I thought the “science” was “settled”. Silly me.
umm.. The CO2 is released via the energy cycles of the fungi and bacteria breaking the starches (glucose chains)… to glucose(C6H12o6)… to alchohol(s)… absorbing the energy in the bonds through enzymatic digestion… eventually ending up with CO2 and H20. Krebs cycle if memory serves me correctly.
In a eukaryote the energy is released as a free oxygen radical is stepped through the mitochondria… an electron is released at each step, the energy going into the production of ATP. (again if memory is correct)
In prokaryote’s the process is a bit different, occuring on different cellular structures, but the basic principle is there all the same.
Really, this is basic. They show they didn’t receive much of an education from their elite universities. I’m 15 years away from learning this stuff and haven’t used it since.
There, we’ve answered their question as to how the CO2 is released, I’ll expect my $25,000.00 in the mail, along with royalty checks on the publication.
So CO2 follows temperature, huh.
Most organic gardeners soon learn that the key to maximizing land fertility, is not just adding more organic matter to the soil at increased depth, to effect better crumb structure, water percolation, aeration, and total usable nutrient content. But also to increase the mulch on the surface that protects the top soil from UV sterilization from sunlight, texture to prevent large rain drop compaction, but temperature insulation to keep the soil temperatures lower to slow the losses of nutrients from carbon out gassing.
Deep woods have a built in shade canopy structure from the diversity of the blend of the under growth to top of canopy size gradients that protect the floor litter to prolong the natural mulch that results in a thicker layer of small organisms, bugs, ants, worms, molds, yeasts, and fungi.
As soon as people start to farm they take away the shade canopy, till the top soil and incorporate the mulch into the top 6″, the commonly know smell of freshly tilled soil is due to the high death rates of soil bacteria being exposed to the killing effects of the full sunlight strength of its UV component. No till farming is a newer concept that avoids a lot of the problems associated with plowing the soil, it leaves the crop residue on the surface as a mulch, where it performs some of the shade and living organism support that forest litter did in the first place.
The problems due to erosion starts with loss of the surface mulch as well as the overhead canopy, that shelters the soil particles from rain drop impact that blasts particles loose from the soil, the organic matter loosened by this process is light and floats away on the runoff, while the fractured soil crumbs flow along the bottom, with the fine silt mixed thru out, along with the dissolved nutrients.
I think the person doing the plant cultivation for their own food sources is responsible for maintains the healthy soil structure that evolves naturally, by maintaining the surface mulch as well as adding organic matter to the top and sub soil horizons, thus effecting lower moisture loss, and more stable cooler soil temperatures, and as a result better more efficient nutrient to food conversion ratios as well as maintaining a healthy blend of soil bacteria, molds, yeasts, and fungi to effect good mycorrhizal symbiosis of the exchange of nutrients, with minimal loss of out gassed carbon compounds to the atmosphere.
The increased used of better farming practices in the USA is one of the mail reasons why as a country we are carbon emitting neutral, along with good landscaping practices in the suburban sprawl, and the preservation of wetlands filtration of run off, and increasing shade canopy in urban tree plantings.
Just my $.02 Richard Holle
DesertYote, don’t forget the basic premis is that human activities caused CO2 to increase which resulted in higher temps — now the (as this study seems to be implying) positive feed-back cycle in in play, i.e. “We’re all going to die” (sarc)
I would hypothesize that in general, the overall average response of soils to increased atmospheric CO2 would be an increase in biomass storage as would be predicted by LeChateliers principle.
So buried deep within the article is the most important point:
“In simple terms, less variability will equate to less soil carbon release. In the new analysis, considering the effects of variability, scientists found that temperature variability may be reduced in northern latitudes, in particular, and result in carbon releases that are lower than have been projected in one of the areas of the world where this phenomenon is of greatest concern.”
In other words, their research suggests that the “soil carbon feedback” is weaker than presently thought (remember that the soil carbon most commonly worried about is that in the Northern Latitudes, all the permafrost and such, they even say the phenomenon is most concerning in that area).
Read most of the article and you here “uh-oh! Uncertainty! That could mean things could be worse than we thought!” read far enough in (which many people do not, and the writers know they do not) and you realize that the “uncertainty” “added” by this analysis is in the opposite direction, it’s not as bad as we thought.
The study reports that:
“The amount of carbon stored in soils worldwide exceeds the amount of carbon in the atmosphere by a factor of two to three.”
=============
Yet doesn’t state, the amount of carbon stored in the ocean exceeds the amount in the soils by a factor of 24.
It is useful to have a study that confirms the limitations of knowledge about various components of the earth atmosphere interface. The IPCC acknowledged the limitations but glossed it over in their Summary for Policymakers and few have bothered to look at what the Science Report of Working Group I actually says. In my opinion the downplaying of severe limitations of data and process was the intent. Here is what they said about carbon to climate models.
“Several other groups have evaluated the impact of coupling specific models of carbon to climate models but clear results are difficult to obtain because of inevitable biases in both the terrestrial and atmospheric modules (e.g., Delire et al., 2003).”
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch8s8-3-4-3.html
There are similar problems with an even more important greenhouse gas, water vapour.
“Since the TAR, there have been few assessments of the capacity of climate models to simulate observed soil moisture. Despite the tremendous effort to collect and homogenise soil moisture measurements at global scales (Robock et al., 2000), discrepancies between large-scale estimates of observed soil moisture remain. The challenge of modelling soil moisture, which naturally varies at small scales, linked to landscape characteristics, soil processes, groundwater recharge, vegetation type, etc., within climate models in a way that facilitates comparison with observed data is considerable. It is not clear how to compare climate-model simulated soil moisture with point-based or remotely sensed soil moisture. This makes assessing how well climate models simulate soil moisture, or the change in soil moisture, difficult.”
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch8s8-2-3-2.html
“The climate models employed in the IPCC’s Fourth Assessment are clearly deficient in their ability to correctly simulate soil moisture trends, even when applied to the past and when driven by observed climate forcings. In other words, they fail the most basic type of test imaginable; and in the words of Li et al., this finding suggests that “global climate models should better integrate the biological, chemical, and physical components of the earth system.”
Li,H.,Robock, A. and Wild, M. 2007. “Evaluation of Intergovernmental Panel on Climate Change Fourth Assessment soil moisture simulations for the second half of the twentieth century.” Journal of Geophysical Research 112
I believe these limitations are adequate in themselves to give any credibility to outputs from the IPCC computer models. Despite this they are used as justification for global policies.
This helps explain the observed correlation that the detrended CO2 increases more quickly in detrended warmer years, which can’t be explained by the ocean warming alone. The magnitude is about a 1 ppm extra increase for a 0.2 degree warmer year, especially visible with the 1998 El Nino spike.
And don’t forget the CO2 that is released from Earth by volcanoes and the occasional CO2 burps from lakes.
Dr Harmon’s appointment at OSU is for lifetime; his conclusions are probably relatively objective with respect to global warming politics. He’s very difficult to pin down because it’s just not that simple to measure soil CO2, even within a biome, let alone globally.
Scott Covert says:
If this article sums up the paper correctly, there are gaping holes in it.>>>
Gaping? THEY’VE GOT THE FREAKIN’ DATA UPSIDE DOWN! From their last bullet:
“■At lower latitudes, where both average temperature and variability are expected to increase, the release of soil carbon will probably be higher than that predicted by changes in average temperature”
Well that’s going to be news to a lot of physicists, because the physics says the lower latitudes will have the LEAST temp increase and the LEAST variability. In fact, the IPCC says so too, that’s why they go on about “Polar Amplification” all the time. In fact they even publish the temperature record to show this!
Explanation here: http://knowledgedrift.wordpress.com/2011/06/02/variability-is-what-where/
Or if you are good with just the pictures, the graphs by latitude from the IPCC AR4 report showing the actual temperature trend over the decades by latitude:
http://knowledgedrift.files.wordpress.com/2010/05/ipcc-zonal.jpg
Or better still look at the temperature record from NASA/GISS broken down by latitude band. Lower latitudes are expected to increase in both temperature and variability more than the average my SELF SNIP!
http://knowledgedrift.files.wordpress.com/2010/05/polar-amplification.png
Hmm, a very interesting article. Maybe this is the reason why, in the historical record, changes in CO2 FOLLOW changes in temperature. Especially in the earlier geological eras where we had an abundance of CO2, plants, and dinosaurs.
Shun the myopic look at go for long term concepts, say 1,000 years. It will be approximately correct that the weight of carbon entering a soil over 1,000 years will equal the weight leaving the soil, mostly as CO2 Kreb’s cycle. It’s not really so important to climate research because it’s a near equilibrium equation.
More broadly, the weight of carbon on a grid cell of land, the sum of living mass plus dead mass, be it in soil or in biological material, will remain largely unchanged over 1,000 years. Thus, its integrated effect on atmospheric CO2 levels will be essentially nil.
On a shorter time scale, the weight of carbon decreases (as in desertification) or increases (because the vegetation was sparse in any case at the start, or reafforestation occurred). However, averaged over a millennium, the change will not be very significant. It follows that schemes to increase the carbon content of soils (sequestration) tend to revert to starting conditions unless managed. If follows further that tree planting cannot lead to permanent sequestration unless also managed for that millennium to prevent the land returning to its starting point of low carbon weight.
Presupposing that forest floors have the largest mass of decomposing vegetation in the soil, would not the temperature increase mean tree growth increased demanding more atmospheric CO2 producing a zero feedback?
Och don’t get me going on this nonsense! Studied agriculture 40 yrs ago @ur momisugly Uni; when politicians intervene on what you should grow and how it affects the Cost of growing = Min-till, no FYM incorporation = reduction in Soil Org Matter, etc-> water retention, Less use of Nitrogen early season being as good as adding water – flush of growth when water is usually in abundance in soil & prevents run off; Intensive agric using LESS fuel per ton food produced ( fewer acres to run over ( meaning to plough through to harvest ) ; Less setaside acres to grow weeds / non-productive areas which need horsepower spent on them for maintenance purposes ( C O 2 ? maybe perhaps ? )……………………….och mannie, the sun is shining still today and I better get back outside and DO SOMETHING for myself instead fo A L L this writing – reports reports reports – I MUst be in the wrong job !
OH! BBC says Scotland had the wettest May for some time – Argyll 3x Average – Rainfall and Cold winds for 4-5 weeks here daily , has set back much garden fruit & Veg…. oh I am going on again….
I’m like this close || to googling further and finding out what biogeochemistry is.
A former doctoral student is lead author. hmmm…
Did they factor in extra decomposition from the extra 7% of woody biomass estimated to have grown over the last 30 years since it got warmer. Sounds like the human contribution might be over=estimated…
I have always thought that the important temperature climate signal, would be found 6 to 10 inches below the soil. Here the temperature is less noisy and less subject to extraneous signals. After all, the most eco important life on the planet exist or takes its mineral requirements there. Agriculture has been monitoring soil temperatures for many years.
However, I have never heard of any climate collation of this data? Wonder why? GK
I’ve been watching something quite fascinating happening over the last year or so in the science world.
Two decades ago a paper of this sort above would get exposure in just one publication with a very limited circulation amongst the in crowd researchers of that discipline and it would be quietly read and if it had some veracity, discussed in some learned forums or workshops.
If it failed the grade it would disappear down that big black hole where all those lousy research papers that were so lovingly labored over by some not particularly able or astute researcher for many a long hour and day would go, for the most part never to be seen or referenced again.
With the rise of the Internet and World Wide Web many such papers, excellent, good, mediocre or stinkingly bad are getting their hour in the sun and are being analyzed and for the most part, torn apart by a whole galaxy of interested web participants from a huge range of professions, skills and accomplishments .
And many of those papers are really coming apart at the seams and are showing their authors to be at best somewhat lacking in a science based approach to being utterly ignorant and at worst just a propaganda piece laboring under the pretext that it is science that is being published.
Perhaps the saddest part for science in the longer term is the increasing skepticism being displayed over the last half a decade by this immensly diverse audience as it analyses and tears apart the various science and research papers put in front of it from various sources .
After WW2 and the atom bomb, penicillin, rockets, computers, radar and a whole gamut of exciting and very advanced developments, most of which were actually already in existence before the start of WW2, scientists and science were placed on a very high pedestal by the public and the politicos and through a reticence to get politically involved in any substantial way and through a careful approach to pronouncements on matters of science only , a very conservative approach that kept the publics respect for science as a dispassionate calling, science and scientists remained on that high public pedestal for all of the 60 plus years until perhaps the second half of this first decade.
Then came the so called climate science and a very obvious and heavy interference and a driving attempt by a small incestuous coterie of prominent self aggrandizing climate scientists with a developing ideology and agenda to coerce through their supposedly greater knowledge of climate science, the politicals to follow a particular line on global warming which they used in attempting to implant their own personal ideologically based catastrophic climate warming beliefs onto the body politic and onto the rest of society.
As anybody who knows a little about how individuals in a society like ours will react to pressure to conform to somebody else’s belief system, there has been a major blow back against these so called climate scientists and increasingly anybody who invokes a particular climate science claim of future catastrophic global warming as a part of or reason for his particular conclusions now knows or is rapidly getting the message that science now has to take account of the rise of Skepticism and those nasty Skeptics who harrowingly question everything that was hallowed and beyond question by any of the ignorant public for decades past but they now have the gall to doubt the lot of your research unless you can irrevocably prove your case.
Now that Skepticism is starting to spread to all branches of science as more and more covers are pulled aside, covers that for 6 decades have carefully concealed the huge amount of nefarious going ons in all branches of science but were carefully kept under wraps so as not to damage the image of science, scientists and science are being forced to come down off it’s high pedestal and increasingly it will find that it has to fully justify to the public the lavish publicly funded resources that have flowed it’s way in ever increasing amounts for decades past.
The one thing that a lot of scientists feared when climate science and the very high profile climate scientists started to swing their collective weight around in the political and public spheres was the possibility of a serious loss of respect for science by the public which for much of science would be the end game for a lot of research and in a lot of cases, the end of a lot of feather bedding rackets by universities sand various other publicly funded science organisations.
And a final note, the public at large are now starting to get sick of and fed up with the constant braying of ever promised, non eventuating climate catastrophes in the making so they are increasingly inclined to believe those who express doubts on scientists predictions in all science and rumor mongering about dire happenings in the immediate future.
The public at large are simply getting to the stage where science and scientists will have to take their lumps along with everybody else rather than remaining in that 60 year old protected golden cage where they could do what they wished and claim almost superhuman like powers over the rest of society who were paying their salaries and research grants.