From the Helmholtz Association of German Research Centres a clear indication for those “CO2 is plant food” scoffers that the plants don’t care what they think.
Productivity of land plants may be greater than previously thought
Researchers recommend the reworking of global carbon models in Nature
This press release is available in German.
London – The global uptake of carbon by land plants may be up to 45 per cent more than previously thought. This is the conclusion of an international team of scientists, based on the variability of heavy oxygen atoms in the carbon dioxide of the atmosphere driven by the El Niño effect. As the oxygen atoms in carbon dioxide were converted faster than expected during the El Niño years, current estimates for the uptake of carbon by plants are probably too low. These should be corrected upwards, say the researchers in the current issue of the scientific journal NATURE. Instead of 120 petagrams of carbon, the annual global vegetation uptake probably lies between 150 and 175 petagrams of carbon. This value is a kind of gross national product for land plants and indicates how productive the biosphere of the Earth is. The reworking of this so-called global primary productivity would have significant consequences for the coupled carbon cycle-climate model used in climate research to predict future climate change.
Lisa Welp of the Scripps Institution of Oceanography at the University of California in San Diego and her colleagues evaluated the data for the global isotopic composition of the greenhouse gas CO2 over the last 30 years. This analysis indicated regular fluctuations between years and a connection with the El Niño phenomenon in the Pacific. Overall, El Niño years are warmer. They are also characterised by greater precipitation in South America and less intensive monsoons in Southeast Asia.
The researchers found a more rapid recovery of the
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  IMAGE:The global uptake of carbon by land plants may be up to 45 per cent more than previously thought. This is the conclusion of an international team of scientists, based…Click here for more information. |
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isotopic ratios following the El Niño events than assumed, indicating a shorter conversion time for CO2 in the terrestrial biosphere. On the basis of these data, the authors calculate the so-called global primary productivity (GPP). They now propose correcting this in the global models from 120 to 150-175 petagrams) of carbon annually.
Since 1977 the isotopic ratios in the carbon dioxide of the atmosphere (18O/16O und 13C/12C) have been measured in order to better understand the global carbon cycle, as the exchange processes between the biosphere, the atmosphere and the oceans are reflected in these values. “We assume that the redistribution of moisture and rain in the tropics during El Niño raises the 18O/16O ratio in precipitation and plant water and then signals this to the atmospheric carbon dioxide”, explains Lisa Welp the new approach of the researchers.
“Our atmosphere is a perfect blender. Changes in its levels of trace gases – such as carbon dioxide – reflect the overall release and uptake of trace gases from all sources. So if you measure the carbon exchange of a forest ecosystem, for example, you “only” get the net exchange of all the carbon taken up by the trees for photosynthesis and all the carbon released by the trees and soil “, writes Dr. Matthias Cuntz of the Helmholtz Centre for Environmental Research (UFZ) in his commentary in the same issue of NATURE. The gross-exchange fluxes, such as photosynthesis, are however accessible only with difficulty. “Global estimates therefore depend upon a number of assumptions. This includes, for example, how many of the CO2 molecules entering a plant are actually fixed by photosynthesis. The researchers of Lisa Welp’s team assume that around 43 per cent of all CO2 molecules entering a plant are taken up by the plant. If this were only 34%, the estimate would fall to about 120 billion tons of carbon – that is, to the currently accepted value”, for Matthias Cuntz reason of thought. In his opinion, the new findings do not completely upset the research to date. Nevertheless, they demonstrate an interesting new method for the determination of plant productivity over large areas. In future, the combination of several isotopic methods with conventional measurements represents a promising approach.
The now published study was carried out under the direction of Ralph F. Keeling, a professor of oceanography and the son of the late Charles David Keeling, after whom the so-called Keeling curve was named. This graph shows the concentration of CO2 of the volcano Mauna Loa on Hawaii since the year 1957. In the 1950s the CO2 fraction in the earth’s atmosphere was still around 315 ppm. In 2011, by comparison, it has already increased to 390 ppm. With his measurements Keeling was able to show for the first time that the concentration of the greenhouse gas increases in relation to changing land use and the combustion of fossil fuels. This new study underscores the importance of long-term measurements of the isotope 18O in the carbon dioxide of the atmosphere from the scientific point of view, as this occupies a key position between the carbon cycle and the hydrogen cycle.
Publications:
Lisa R. Welp, Ralph F. Keeling, Harro A. J. Meijer, Alane F. Bollenbacher, Stephen C. Piper, KeiYoshimura, Roger J. Francey, Colin E. Allison & Martin Wahlen (2011): Interannual variability in the oxygen isotopes of atmospheric CO2 driven by El Niño.
29 September 2011, Vol. 477, Nature 579, 579-582. doi:10.1038/nature10421
Matthias Cuntz (2011): A dent in carbon´s gold standard.
29 September 2011, Vol. 477, Nature 579, 547-548.
Links:
CO2- and Isotopic Measurement Program of the Scripps Institution of Oceanography, USA:
http://scrippsco2.ucsd.edu/data/atmospheric_co2.html
Atmospheric Measurement Program of the National Oceanic & Atmospheric Administration, USA:
Cape Grim Baseline Air Pollution Station, Tasmania, Australia:
http://www.csiro.au/places/Cape-Grim.html
El Niño – Southern Oscillation (ENSO):
http://de.wikipedia.org/wiki/El_Ni%C3%B1o
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Here’s an interesting illustration of the effect increased CO2 has on plants, and unlike Mr. Gores’s faked high school physics experiment, you can see this one in time lapse from start to finish as it actually occurred.
Can the carbon credit market go negative? Based on this study it should be possible for investors in agriculture to begin paying people to emit more CO2. That’d be a hoot.
Thanks to CO2 Science for the Time-lapse movie: It was beautiful, but (spoiler alert) it has a very sad ending if you tend to root for the underdog. The undernourished little cowpea loses, while the one fed on obscene quantities of CO2 wins. The modernist anti-hero triumphal and all that.
The expansive score was elegant and subtly supported the movie’s heroic themes. Lighting, brilliant (so to speak); direction masterful. Camerawork a tad static in places, but the two main characters were well-played and their lives, so bitterly uprooted in the end, revealed the universality of our fate. So must we all end
A suggestion: a third cowpea? a bit of a love rivalry next time? Ah well. Perhaps that’s just me.
Bill Parsons says:
September 29, 2011 at 6:59 pm
Plant trees? I have planted lots of trees. Maybe it is a good touchy feely thing to do but if 90% of the carbon is exchanged in oceans and fresh water and only 10% is exchanged on land; and the boreal forests are net emitters with only the tropical forests being good carbon absorbers … what effect will planting a tree have other than providing us with future timber or firewood? Certainly that has worked in Ethiopia where the denuded hillsides were planted with Eucalyptus trees – so they have firewood again for making charcoal for cooking — carbon cycling. Not much different from me growing wood and heating my house with here in sunny cold Alberta. More carbon cycling and more CO2 to help grow more trees for me to burn. Reduced fossil fuel consumption but more CO2. Bad or good. My guess is that no one really knows.
I disagree with
A perfect blender would instantly redistribute the gases evenly throughout the whole atmosphere. Which doesn’t even happen approximately over significant periods of time.
e.g. Observations (re-)documented by the late Ernst-Georg Beck (it’s been a year since he died) indicate that the near-surface distribution of CO2 is both temporally and spatially diverse around the world, throughout the day and the seasons. By around a hundred ppm. In e.g. tropical waters, the concentration is much higher than in cold, polar waters.
An “average”, supported by, in this case; assumed, perfect blending is invalid because of the non-linearity of thermodynamics. A model based on averages cannot adequately describe a complex, non-linear system. Certainly not one used to support ravaging the wallets of taxpayers to the tune of billions of dollars every year.
The new fudge-factor is too expensive.
I have a new hypothesis regarding CO2.
From many observations of humans entering/leaving ‘fast food’ restaurants and many that I know, there is a likelyhood that CO2 causes obesity. There seems to be a correlation between people drinking carbonated sodas and obesity. It seems that most with a ‘big gulp’ are obese.
My research findings are not available to the public as my research is protected by … due to future economic and academic concerns. Financial considerations may be sought from carbonated beverage producers and are therefore protected. CO2 may be absorbed by the human body efficiently and stored similar to plants.
Obesity can be tracked directly correlating to the increase in CO2 in the atmosphere and in increased consumption of carbonated beverages. Humans clearly increase in size with the increase in CO2 in their environment. It’s not their fault, but society has a stigmaization on one who weighs in at 300 lbs plus. Would you not be proud of a pumpkin weighing in at 300 lbs. Society need to reevaluate the norms. Big is now good, or CO2 is bad. There should be laws passed to promote the consensus viewpoint, whatever could be most promoted. Tax considerations must be evaluated before determining the direction of government policies.
CO2 and dihydrogen monoxide need to be regulated for the well being of human society.
Regarding boreal forests as “net emitters” (I don’t really know, but):
http://www.noaanews.noaa.gov/stories2007/s2823.htm
Of course, I realize that if CO2 is a supernutrient to the existing forests, there may be no point in planting any additional trees anywhere. Reforestation will occur naturally. But Colorado has had massive pine forest die-offs, which should provide lots of acreage, if it comes to that.
What harm can it do?
Did I hear someone say “Nobody understands the carbon cycle.” I know that my geochemistry professor said it all the time.
Both ways, HTML tags and character entities usually work okay.
Copy/Paste the left side here to get the result on the right side …
CO₂ … result: … CO₂
CO<SUB>2</SUB> … result: … CO2
Spoke too soon! In the first example, WordPress ignored the entity & translating it to a character and then translating the whole word to subscript 2! I see Rick Werme had the same thing happen. I’ll try again.
Copy/Paste the left side here to get the result on the right side …
CO₂ … result: … CO₂
CO<SUB>2</SUB> … result: … CO2
Optimum temperature for photosynthesis is 25°C. The El Nino years result in more carbon consumed because they are closer to the optimum. If the globe were two or three degrees warmer more life could be supported. Sad to say, many are worried about it warming up. Bit silly really.
Yes the plants will suck the CO2 down to 200ppm (where growth stops) within about 20 mins of sunrise in a greenhouse that does not have CO2 raised to 1000ppm to 15000ppm artificially. Another study indicated the same thing happens in open fields. The CO2 in the air near the leaves also drops to 200ppm.
The conventional wisdom is trees grow taller to gain more access to sunlight.
It occurs to me that it would be to access more CO2.
I remarked a few days ago in response to a study that had found an trend of increasing wind speeds at 10 meters above the ground, but decreasing wind speed at 2 meters that the authors had found a proxy for measuring average tree height in Australia.
Latitude says:
September 29, 2011 at 3:08 pm
Gail Combs says:
“Yes the plants will suck the CO2 down to 200ppm (where growth stops) within about 20 mins of sunrise in a greenhouse
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Gail, Co2 is reduced 10 ppm every six months….just going from winter to summer
In my work I have to do a lot of cultures, plankton, phyto, etc without artificially injecting CO2 it would be impossible…
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Ferdinand Engelbeen says @ur momisugly September 29, 2011 at 2:50 pm
The 5-7 years is how long a certain CO2 molecule (whatever its origin) resides in the atmosphere before being exchanged by another CO2 molecule from the oceans or vegetation…. The residence time is in/outflux divided by total mass or 150/800 or ~18% which gives a residence time of over 5 years. Not to be confused with an excess decay time, that is how long it takes to remove some extra injection of CO2 out of the atmosphere again.
The 100+ years is based on how long it takes to remove an excess amount of CO2 (whatever its origin) in the atmosphere back to “equilibrium”….. The half life time of that process is about 38 years (e-folding time = excess CO2 divided by the current sink rate = 220/4 or 55 years). Far longer than the empirical evidence (which is for a complete different item), but far shorter than the IPCC’s thousands of years for some fractions. The latter is based on an expected saturation of the (deep) oceans, of which there is no sign up to today.”
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The IPCC also seems to ignore the temperature dependence of the uptake of CO2 by water. The solubility of CO2 in cold water is much greater than in warm water but that little factoid would confuse the issue in the minds of their worshipers.
NASA says “……contrary to prior assumptions, carbon dioxide is not well mixed in the troposphere, but is rather “lumpy.” Until now, models of carbon dioxide transport have assumed its distribution was uniform. “
The interesting part of that new revelation is the large band of CO2 in the southern hemisphere in the mid-latitudes. and in the northern hemisphere in the mid-latitudes especially over the USA & Canada indicating lots of coal/oil burning in those areas…./sarc Or perhaps it is instead showing that the biosphere (ocean and land) in the tropics is sucking up CO2 as fast as it can while the CO2 uptake is a lot slower in winter over the USA (the article is Dec 2009) The removal of “excess” CO2 from the air in the tropics would also be thanks to Willis’ thunderstorm thermostat since CO2 is absorbed by water droplets in the air to form Carbonic Acid. You can see the water vapor band in the image to the left.
The wind would also play a large part in the distribution but that is not shown. Instead the animation shows the large amount of CO2 over Europe and the middle east (Huh??) the mid west of the USA while the heavily populated east coast is left relatively clear. To me this indicates that large masses of CO2 could be traveling around the world on the wind from China perhaps??? I have certainly heard complains about the smog blowing across the pacific to the west coast of the USA.
Given the objective of the IPCC (and NASA) is to stampede THE GREAT UNWASHED into forking over even more of their wealth, I am sure much time was taken to see that the animation fingered the right “culprits” The USA and EU before it was approved for release to the public. With the closing of the space program NASA knows they are skating on thin ice and would not be interested in rocking the boat by annoying Pres. Obama.
Tom V. Segalstad has a lot of information that puts large question marks around the IPCC version of CO2 “science” at his website: http://www.co2web.info/
Bill Parsons says:
September 29, 2011 at 6:59 pm
“….I guess you could look a this, roll your eyes, and say, “Here we go… another massive government expenditure.” My own thought is that it might be undertaken as some kind of joint public-private venture, with some sort of harvesting rights way down the road.
It seems a productive solution that would please greens and have proven benefits….
Al Gore beat you to it. All it takes is burning kids in grass huts….. Check out Anthony’s They had to burn the village to save it from global warming
and the money making deal for GMOs: Genetically Modified Forest Planned for U.S. Southeast
and how nasty the tree is they have chosen (worst for fire hazard, gobbles H2O and nutrients, invasive monoculture that is inedible and very hard to kill) see http://www.hear.org/pier/wra/pacific/eucalyptus_globulus_htmlwra.htm
(1)”Blue gum typically grows in dense monospecific stands.” (2)”The loss of biodiversity and habitat is a great threat from the Tasmanian Blue Gum tree, as it is from any eucalyptus. It creates virtual monocultures and can rapidly take over surrounding compatible areas, completely changing the ecosystem. That monoculture creates a loss of habitats for many species that relied on the previous system. Due to its great capacity for taking over a wide variety of habitats, the Blue Gum eucalyptus could possibly spread to a great range of systems where there is enough water content and create huge monocultures.”
There is also information that if the stump is left with established roots the tree will just resprout, and can grow 20 feet in one year.
How the heck they can make something a simple as planting trees “EVIL” I do not know but Al Gore sure as heck accomplished it. He is Chairman of the company tossing African natives off their land so he can reap the profits from CAGW carbon trading. He is also picking a tree that makes sure the Africans can not reclaim their land easily in the future setting the stage for starvation in the future as these trees spread.
….the ‘scientific’ journal NATURE? – WRONG!
The journal NATURE (as well as Scientific American), abdicated their responsibility to honestly report on science issues long ago. From now on, let’s all please refrain from referring to these fish wrappers as scientific journals. They don’t deserve the title.
Response to an up tread comment about residence time -> the units of residence time = Time.
The calculation is done as (Total amount) / (Amount /time) .. which gives the result in Time units.
Hence for the atmosphere of roughly 800 GT CO2 as carbon (Total Amount), and Annual turnover estimated at 150 GT/year, this gives
(800 GT) / (150 GT/yr) = 5.3 years as the atmospheric residence time of CO2.
So the up thread comment at September 29, 2011 at 2:50 pm notes 5 years as the answer, but the calculation, as shown, is upside down and stating the result as 18% has no meaning – “The residence time is in/outflux divided by total mass or 150/800 or ~18% which gives a residence time of over 5 years.”
If we take this to the next step, as it relates to the posted article, the higher annual uptake of carbon into the biomass would suggest a lower value of residence time (hence faster turnover) for CO2 in the atmosphere. If the old in/out flux value was 150 GT/yr and the new estimated value is 175 GT/yr, then the estimated atmospheric CO2 residence time would change from
800/150 = 5.3 years
down to
800/175 = 4.6 years
Lastly, there was a comment about ‘folding time’ for going back to 290 ppm, but I say –
Why in the world would we want to go back to 290 ppm CO2 and the Little Ice Age?
That tends to happen when your equation is designed to give you the same answer no matter what variables are used.
[(∑CO2bio + ∑CO2sea + ∑CO2man) – (∑SINKbio + ∑SINKsea)] = 0.45*∑CO2man
Whenever ∑CO2man increases or decreases some or all of the other variables are forced to change… This makes the Warmists’ willful disregard of Nyquist look like an honest mistake by comparison.
Dave in Delaware says:
September 30, 2011 at 6:29 am
Lastly, there was a comment about ‘folding time’ for going back to 290 ppm, but I say –
Why in the world would we want to go back to 290 ppm CO2 and the Little Ice Age?
I don’t want to go back to 274 ppmv (LIA), but 280 ppmv during the Medieval Warm Period was not that bad.
The main problem here is that many confuse residence time with excess decay time. That are two very different items which have nothing in common.
The first is how long a certain molecule of CO2 (whatever it’s origin) in average stays in the atmosphere, before being exchanged with a molecule from another reservoir. That is about 5 years, now a little shorter based on the new research (the 18% is the refresh rate BTW). But the residence time doesn’t say anything about a change in total CO2 in the atmosphere. If the in/out flows are equal, then the total amount of CO2 in the atmosphere remains the same over the years.
The second is how long it takes to reduce an injection of extra CO2 (whatever the source) back to the old equilibrium. To assure DocMartyn, with “equilibrium” I mean the pre-industrial dynamic equilibrium between all continuous and seasonal CO2 sources and sinks, which resulted in a quite linear ratio between atmospheric CO2 levels and temperature over the past 800,000 years and beyond. Or to be accurate, the “steady-state” which shows a rather fixed CO2 ratio with temperature of about 8 ppmv/°C.
Based on the past, for the current temperature we should have a steady state CO2 level of around 280 ppmv, but we measure 390 ppmv, whatever the cause.
If the source of the extra CO2 would stop emitting today, how long will it take for nature to reach the steady state again? The answer has nothing to do with the residence time, because that doesn’t change the total mass of CO2 in the atmosphere. The “folding time” in this case is based on what nature removes in a year at the current extra atmospheric CO2 pressure which moves more CO2 into plants and oceans. That is currently 4 GtC/year (the difference between natural inflows and outflows), while the excess amount in the atmosphere is about 220 GtC (~110 ppmv). Thus the e-folding time which really removes the extra amount of CO2 above steady state is 220/4 = 55 years. That gives a half life time of about 38 years.
The IPCC takes different folding times for different reservoirs, the ocean surface e.g. is very fast mixing with the atmosphere (1.5 years), but that is for only 10% of the extra CO2, due to the Revelle factor (a 100% increase of CO2 in the atmosphere gives only 10% more CO2 in the ocean surface waters, due to equilibrium reactions, mainly pH reduction). The deep oceans are relative fast, with the above folding time, and other reservoirs like oceanic organic and calcite deposits are much slower. Some 10% of the increased CO2 level remains in the atmosphere for thousands of years, according to the IPCC. That is based on saturation of the deep oceans, for which is no proof whatsoever at the current and near future emission scenario’s.
Gail Combs says:
September 30, 2011 at 4:01 am
contrary to prior assumptions, carbon dioxide is not well mixed in the troposphere
The NASA wants to show how good their satellites are. Please have a look at the scale of the differences: +/- 5 ppmv over the seasons, that is less than what some baseline stations show (Barrow, Alaska +/- 8 ppmv over the seasons). And have a look at the full animation
http://www.nasa.gov/wmv/411602main_AIRS_2_CO2%20Faster.wmv
That makes it clear that the source is in the NH and that CO2 levels are increasing steadily.
For yearly averages, that doesn’t make a damn difference, only that there is a lag between near ground and altitude and between the NH and the SH. The NH still is the main source of the extra CO2:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/co2_trends_1995_2004.jpg
David Middleton says:
September 30, 2011 at 8:19 am
[(∑CO2bio + ∑CO2sea + ∑CO2man) – (∑SINKbio + ∑SINKsea)] = 0.45*∑CO2man
Whenever ∑CO2man increases or decreases some or all of the other variables are forced to change… This makes the Warmists’ willful disregard of Nyquist look like an honest mistake by comparison.
Sorry David, nothing to do with some suspect conspiracy in this case…
∑CO2man is calculated from fossil fuel use.
0.45*∑CO2man is measured in the atmosphere, already 50+ years.
That, besides the temporarely influence of temperature on the sink rate, is a remarkable linear ratio over the full 50 years (and even beyond).
That means that the main sink processes involved are responding quite linear to the increase of partial pressure of CO2 in the atmosphere. For the oceans, that is obvious, but it seems that the uptake of plants also is rather linear for increased CO2 levels.
Ferdinand
Do you have a graph that- in your opinion- correctly shows the logarithmic curve and the relationship between increasing concentrations of Co2 (above a certain base level) having a limited effect on temperature increase
tonyb
Decadal- centennial- and millennial-scale fluctuations in atmospheric CO2 from 270-360 ppmv have been the norm throughout the Holocene. The natural source-sink ratio is far more variable than indicated by the ice cores. This was occurring long before man ever discovered how to burn things.
Wagner et al., 1999. Century-Scale Shifts in Early Holocene Atmospheric CO2 Concentration. Science 18 June 1999: Vol. 284 no. 5422 pp. 1971-1973…
The ice cores cannot resolve CO2 shifts that occur over periods of time shorter than twice the bubble enclosure period. This is basic Nyquist Sampling Theorem. The assertion of a stable pre-industrial 270-280 ppmv is flat-out wrong.
McElwain et al., 2001. Stomatal evidence for a decline in atmospheric CO2 concentration during the Younger Dryas stadial: a comparison with Antarctic ice core records. J. Quaternary Sci., Vol. 17 pp. 21–29. ISSN 0267-8179…
Not even the highest resolution ice cores, like Law Dome, have adequate resolution to correctly image the MLO instrumental record.
Kouwenberg et al., 2005. Atmospheric CO2 fluctuations during the last millennium reconstructed by stomatal frequency analysis ofTsuga heterophylla needles . Geology; January 2005; v. 33; no. 1; p. 33–36…
Stomatal reconstructions are reproducible over at least the Northern Hemisphere, throughout the Holocene and consistently demonstrate that the pre-industrial natural carbon flux was far more variable than indicated by the ice cores.
Wagner et al., 2004. Reproducibility of Holocene atmospheric CO2 records based on stomatal frequency. Quaternary Science Reviews. 23 (2004) 1947–1954…
The Antarctic ice cores lack adequate resolution because the firn densification process acts like a low-pass filter.
Van Hoof et al., 2005. Atmospheric CO2 during the 13th century AD: reconciliation of data from ice core measurements and stomatal frequency analysis. Tellus 57B (2005), 4…
Any estimate of the pre-industrial relationship between atmospheric CO2 and temperature derived from Antarctic ice cores is wrong… Because the ice core temperature and CO2 time series have vastly different resolutions.
Ferdinand Engelbeen says: September 30, 2011 at 8:30 am
I don’t want to go back to 274 ppmv (LIA), but 280 ppmv during the Medieval Warm Period was not that bad.
Not if you look at plant stoma studies which show very different numbers than your ice core ones.
Plant stomata data show much greater variability of atmospheric CO2 over the last 1,000 years than the ice cores and that CO2 levels have often been between 300 and 340ppmv over the last millennium, including a 120ppmv rise from the late 12th Century through the mid 14th Century. The stomata data also indicate higher CO2 levels than the Mauna Loa instrumental record; but a 5-point moving average ties into the instrumental record quite nicely…
http://debunkhouse.wordpress.com/2010/03/28/co2-ice-cores-vs-plant-stomata/
DocMartyn says:
September 29, 2011 at 5:52 pm
“There is about 700 GtC in the water, Co2, carbonate and organic matter (living and dead). A 150 GtC soft layer of mud/detritus and at least 20,000,000 GtC of compressed organic Kerogen at the bottom of the ocean. We don’t actually know how much. What we do know is that all this crap came from living biotic sources and was fixed at the top of the ocean.”
That is probably where we will all end up, in the end.
Long before this discussion is over, it may seem.
Interstellar Bill says:
September 29, 2011 at 3:40 pm
The Warmistas studiously ignore the rapid drop-off of C14O2 after the 60′s nuclear testing
The 14CO2 decline is only in part from the direct removal of CO2 in general. Most of it is by replacement and dilution:
1. the 14CO2 level is reduced by the general increase of total CO2 since the 1960’s
2. the 14CO2 level is reduced by the addition of 14CO2-free fossil fuel burning
3. the 14CO2 level is reduced by deep ocean exchanges: what is going into the deep oceans is the current 14C/12C ratio (with some fractionation), what comes out is mainly the pre-bomb ratio. For e.g. the 13C/12C ratio that makes that the decline in the atmosphere is only 1/3rd of what is expected from the use of 13C depleted fossil fuels.
Thus the real excess CO2 decay rate is much longer than what the 14C decline shows…
David Middleton says:
September 30, 2011 at 10:06 am
and
DD More says:
September 30, 2011 at 10:07 am
I had some discussion with Tom Van Hoof about stomata data. The main advantage is the better resolution, the main disadvantage is that it is a proxy taken over land, not in “background” atmosphere. Stomata data are directly linked to the average CO2 concentration in the previous year, according to Van Hoof. Local CO2 levels over land in average are higher than background, mainly due to buildup of CO2 from soil bacteria (and nowadays traffic and heating) in low wind conditions. See here the difference in monthly averages from modern continuous measurements at Giessen (Germany), where the late Ernst Beck used its longest historical series from 1940-1942, which is at the base of his 1942 “peak” value of 400 ppmv:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/giessen_mlo_monthly.jpg
Any local bias from where the stomata data are taken is resolved by calibrating the stomata data against… ice cores, firn and direct measurements over the past century. Which incidently doesn’t show any peak value around 1942…
The main problem now is that we have not the slightest knowledge of what the local bias did over the previous centuries. One of the main findings of historical stomata data around the MWP/LIA is in SE Netherlands, based on oak leaves. The landscape in The Netherlands (and Belgium) in the current (!) main wind direction has changed tremendously over the centuries: from sea and marshes and forests to dikes with agriculture and back to forests (for coal mining), increased population and industrialisation. Even the main wind direction and its strength may have changed between the MWP and LIA and back: according to Mörner, the Gulf Stream changed direction more southly to Portugal and North Africa during the LIA.
That all can have consequences for the local CO2 bias…
Thus please, take the stomata data with a grain of salt, they are not that absolute as the stomata people would like to convince us…
Further, we have different ice cores with different resolution. Over the past 150 years, the high resolution Law Dome ice cores have a resolution of less than a decade. Any sustained change of 2 ppmv over a period of 20 years or a peak of 20 ppmv in one year would show up in the ice core.
Over the past 1000 years, the resolution is 21 years for the third Law Dome ice core. Thus any sustained change of 2 ppmv over a period of 40 years or a peak value of 40 ppmv in one year would be noticed in the ice core. Thus it is very unlikely that a sustained (over a few years) peak or drop of 34 ppmv wouldn’t have been noticed in the ice core.
Further, since the measurements at the South Pole (before Mauna Loa) started, no yearly average variability of more than a few tenths of a ppmv was noticed over the past 50 years…