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.
This “finding” doesn’t change the overall balance of the carbon cycle: humans emit some 8 GtC/year as CO2 and the atmospheric increase is about 4 GtC/yr. So whatever the individual flows involved, the overall balance shows that nature as a whole is a net sink for CO2.
How that is distributed over the different compartiments is not easy to follow: temperature increases increase soil activity, releasing more/faster carbon that was captured in previous years by vegetation (leaves, stems, rotting wood/roots). But at the other side increases vegetation growth: the earth is greening. The balance between soil respiration and vegetation can be calculated from the oxygen trends: fossil oil burning uses oxygen, which can be calculated from fossil fuel sales and burning efficiency. The balance shows that slightly less oxygen is used that calculated from fossil fuel use.
This means that in balance there is more vegetation growth than decay (which produces resp. uses oxygen), including soil, human and animal respiration. Thus total biolife on earth is a net sink for CO2. The calculations can be found here:
http://www.sciencemag.org/cgi/content/abstract/287/5462/2467
and with free admission:
http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf
The amounts absorbed by biolife are around 1/3rd of total sink capacity, the rest of the balance in sink capacity is absorbed by the oceans…
AlexB (21:26:11) :
“Plants are famous for photosynthesis”
Yes indeedy, I was at the Plant Oscars years ago, I saw Daffodill get hers the very first time in Spring, then dear sweet Rose. Alas they died so young, Rose covered in greenfly, then brutally grassed up, so sad, Daff faded away as the months wore on, but she said she would return next Spring! Then the loon pretending to be a light bulb got released & I could no longer work at the bench in the dark! Woopie it’s medication time!!!!!!!!!!!!
Seriously this must have been a EU study, it has all the hallmarks of one. It’s always worse than was thought. However there is the tinge of doubt being sown, that could lead to a Get Out Of Jail/Gaol Free card for these guys, the simple fact as has been noted here, that they are sneakily admitting that as a race of beings, we know diddly squat about how the planet works! I wish the BBC would repeat “Earth Story”, (they do everything else), when in the last episode Aubrey Manning praises carbon & the carbon cycle, seeing carbon being subducted at a tectonic plate on the ocean floor then sitting atop a volcano watching the “same” carbon being emitted to the atmosphere, it’s so brilliant compared to the crap we get today, when the very mention of carbon raises hackles on many a neck! Any guess as to what Carbon Nanotubes will be called before too long so as to avoid the very mention of the word CARBON?
Interesting article. Sounds like good quality research and whilst it adds to the debate, unfortunately, it just reminds me how much the research has been slanted by funding to the “pro” lobby so that whilst individual research may try not be biased, the overall effect is to create biased results creating a biased environment which then becomes considered the “norm”.
What if the Heisenberg Principle of Uncertainty has “soil”ed the entire research?
Yes, the carbon cycle. The benefits of doubled CO2 are KNOWN, whereas the harm consists of what if and maybes..
We know that we will get worldwide increase in crop production of no less then 33%, given the same acreage devoted to such production. We know it will not take additional water to achieve this increase in yield. We know that vast tracts of newly available land will be open in to increased production in agriculture, further increasing crop yield. We know growing seasons will lengthen. We know that the benefits of increased CO2, up to at least 1000 ppm, continue at a linear or slightly higher pace. We know that the “projected” and questionable negative warming effects decrease exponentially.
This is why I ask some reasonable proponents of AGW, such as Mr Gates, to discuss the effects of doubled CO2.
Wondering Aloud (21:10:25) :
Wonder about the plants that ate C02 voraciously to produce the coal beds of the world. Wonder about the formations of limestone (CaC03) laid down by ages shellfish. The notion that the biosphere cannot handle the extra C02 is nonsense, and mightily proven wrong by the geologic past.
It’s called Life on Earth.
Great. So the ice core record that shows us that CO2 rises AFTER an increase in temperature is correct – ‘cos warmer weather makes soils release more CO2. Which means that when the ice core record tells us that elevated CO2 cannot prevent the temperature from falling – it’s right about that too.
The bottom line (both figuratively and literally) is.
“We identified an area where we need to do more work,” said Thomson.
JJ (23:51:16)
I was reading the posts with frustration as I was wanting to comment, and then I read your comment JJ now all I need to say is, THANK YOU SIR.
” 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.”
Duh. Neither can the earth’s heating/cooling/drought/flood or whatever the climate change word of the day is be simulated. These guys are really starting to grasp at anything like a drowning man(or rat).
A bit OT, but a question.
Today’s “Scotsman” newspaper reports that the UK’s carbon emissions were down by nearly 10% due to the recession. The recession didn’t just hit the UK, so presumably there was a similar effect in other countries.
Yet the atmospheric CO2 plot from Hawaii continues on an astonishingly smooth upward trend, as it has since these measurements started.
Is there ANY correlation between global economic conditions and this parameter? Surely, if the principal reason for the increase is anthropogenic, we should see the effect of economic downturns, and upturns; I find it very hard to believe that globally, our emissions average out to such a smooth trend.
(or 98 billion metric tons)
Anthony, dumb question. Is it 98 billion or 98 million? The title implies the latter.
From way back in my chemistry lab days I have a very solid appreciation of how readily CO_2 dissolves in water. A flask of CO_2 inverted into a tub of water will suck the water right up into the flask as the CO_2 rapidly goes into solution. Nobody who has ever seen this demonstration done is ever going to believe that CO_2 hangs around in the atmosphere for long.
MOST CO_2 quickly ends up as carbonate or bicarbonate in the oceans, and what happens to it there is not all that well understood. The carbon clearly gets taken up by algae and enters the food chain, and some of it eventually sinks and rots onto the ocean floor releasing methane and adding to clathrate deposits, a truly massive carbon sink. The rates of these processes are crucial for understanding global carbon balance as the amounts of carbon in the oceanic part of the carbon cycle dwarf the terrestrial quantities. I really don’t think we can claim to have a good handle on the carbon cycle until we understand what is going on with carbon in the oceans a lot better than we do today.
OT but…Congratulations!! 40 million hits at about 1030 UT
you are the best
John Cooke (03:34:45) :
Today’s “Scotsman” newspaper reports that the UK’s carbon emissions were down by nearly 10% due to the recession. The recession didn’t just hit the UK, so presumably there was a similar effect in other countries.
Yet the atmospheric CO2 plot from Hawaii continues on an astonishingly smooth upward trend, as it has since these measurements started.
John, the emissions were some 8 GtC per year in the last years. Even with a worldwide recession causing 10% less emissions, the emissions still are 7.2 GtC per year. With the current (supposed stable) sink rate of 4 GtC/yr, the increase still is 3.2 GtC/yr. If that holds for several years, some change in the trend would be seen, but still strongly going up (with 1.6 ppmv instead of 2 ppmv/yr).
Ian H (03:36:24) :
From way back in my chemistry lab days I have a very solid appreciation of how readily CO_2 dissolves in water. A flask of CO_2 inverted into a tub of water will suck the water right up into the flask as the CO_2 rapidly goes into solution. Nobody who has ever seen this demonstration done is ever going to believe that CO_2 hangs around in the atmosphere for long.
Two important differences with the lab test: seawater is not fresh water and the driving force (the pCO2 difference) is very, very much lower than in the labtest. We are speaking about a globally average difference of 7 microatm between atmosphere and ocean surfaces, not one (or several) atmosphere(s) as in the lab flask…
Further the diffusion speed between air and seawater and in seawater is slow, only enhanced by wind speed mixing. See for a lot of information:
http://www.pmel.noaa.gov/pubs/outstand/feel2331/exchange.shtml and following pages…
JJ (23:51:16) : Right on, but they do know that estimates of the potential size of the U.S. cap-and-trade market range from $300 billion to $2 trillion.
This is an important issue, with some very poor journalism. We talk about air, ground and sea temperature, but the earth, the ground under our feet is a huge biosphere. We know so little.
Can we change the term “sceptic” to “questioner” ?
Denier implies refusing a truth.
Sceptic implies being unconvinced of a truth.
But both these terms suggest there’s a truth out there. There isn’t.
There’s actually a big gaping hole where the truth, theory, data, and understanding should be. It’s a theatre of imaginary science.
The planet is so unknown that we’re still asking basic questions. We’re just learning what questions to ask.
I’m a questioner.
“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”
They can’t simply say that there have recently been warm periods, and carbon was also released then. So they can’t admit that until temperatures get warmer than they recently have been, the carbon being released now is part of the normal cycle of warming and cooling.
Anthony,
See
http://www.nytimes.com/2010/03/26/science/earth/26climate.html?hpw
‘Cap and Trade’ Loses Its Standing as Energy Policy of Choice
What an incredible turn of events over the last four months.
Well done to the forces of truth and justice!
As usual, everyone here gives widely different numbers for the flows of the carbon cycle, and even for the amount of carbon in the system. This is very confusing.
In the following two charts by IPCC and NASA they lump together soil and vegetation, and the flow give for this pair is about 120 petagrams (or gigatons) in both charts.
IPCC chart:
http://tinyurl.com/y8s4m6m
NASA chart:
http://tinyurl.com/624cbs
So now all of a sudden these researchers are saying that soil *alone* gives off 98 petagrams?? So this means that soil flows represent more than 80% of the soil-vegetation pair?? Or what exactly does it mean?? The more I look at all these ever changing numbers the more confused I become.
Ha! Vindication is sweet. Keeling and Calendar, your statues are toppled, wankers.
Next the fluence of the oceans. Please.
My cola does the same. Odd how science works.
May be something to this CO2 increase after temperature increases. Who knew the very stuff that drives the carbon cycle of life would do this. Warm good for life, cold not so good. Strange.
Sometimes science and scientists just need a time out from pushing the scam.
I bet that next they will be telling us that tilling the soil makes plants grow faster. Will wonders of science never cease.
OT and I’m sure not the first… 40,000,000+ reached; nice work Anthony et al.
Keep it up, the 50M milestone next :o)
Cheers
Mark.