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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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.
If plants keep sucking up all that heat-inducing CO2, my veggies will cook right on the vine; convenient. The popped corn is going to be messy though.
What impact will this have on Salby’s upcomming paper?
http://judithcurry.com/2011/08/04/carbon-cycle-questions/
Now they need to quantify the rates of uptake of the ocean’s greater biomass. Then they will find that natural processes control the atmospheric concentration of CO2 not anthropogenic.
So… We humans emit ~8.5 GtC worth of CO2 per year… And according to the Hockey Team, the rise in atmospheric CO2 since 1850 is attributed to humans because of a “simple accounting” of the natural carbon flux plus our emissions… And now we find out that all this time, plants were taking up 30 to 55 more GtC per year than the Hockey Team had accounted for…
It’s becoming increasingly obvious that the Hockey Team defines the natural carbon flux as whatever it needs to be in order for their simple accounting to work.
Next thing you know, we’ll find out that the d13C depletion since 1850 is actually a rebound from the d13C enrichment of the Little Ice Age.
This means that the European CO2 market will be flooded with CDM credits and the prize for a CO2 permit will drop to zero real soon now… (more supply than demand).
(Just guessing – I don’t know how many Ugandans have actually been evicted for such CDM credits and whether it will affect that market severely. But I would expect it. So every careful investor will run for cover RIGHT NOW.)
Who would have thought???
Give plants more CO2 and they “fix” it more effectively!!!!!!!!!!!
However a nice piece of work, using existing measurements in a novel way.
REAL SCIENCE!
duh…………..
Why do they think CO2 levels are so low in the first place
Plants, algae, bacteria, plankton, etc take up fertilizer until it becomes limiting
I posted yesterday some investigation from Portuguese scientists where they demonstrated that Port vines love that extra CO2! Two of their main conclusions:
“The elevated [CO2] concentration increased net photosynthetic rate (A), intrinsic water use efficiency (A/gs), leaf thickness, (…) Yield, cluster weight and vigour showed an increase in elevated [CO2] treatment but yield to pruning mass ratio was unaffected.”
“This study showed that the predicted rise in [CO2] did not produce negative effects on the quality of grapes and red wine. Although some of the compounds were slightly affected, the red wine quality remained almost unaffected.”
Post, mainly in Portuguese:
http://ecotretas.blogspot.com/2011/09/vinho-do-porto-com-mais-co2.html
As if any data will really change their beliefs….
Mr. Bussjaeger, we are 200 years and maybe 1C away from the year without a summer. Don’t worry about your vegetables cooking on the vine.
It’s funny how proper forest and farming management can help suck up EPA defined bad stuff. Ever since we started going away from crappy socialist forest and farming management techniques by using certain types of fast growing grass, crops and trees, to suck all that really bad stuff out of the ground they also suck more CO2 out of the air.
Although it is quite weird, the communist hippies want everything to just lay were it falls and no branch, tree or hindu kush bush is to be harvested for green energy production even, all the while promoting green energy and less EPA toxic stuff like CO2 in the air. 0_o
“They now propose correcting this in the global models from 120 to 150-175 petagrams) of carbon annually.”
Nuh-uh! The science is already settled so move along and get with the program already.
This value is a kind of gross national product for land plants and indicates how productive the biosphere of the Earth is.
=================================================================
Algae, phyto, bacteria, etc take up a lot more…….
If this “adjustment” is just for land plants, and it’s that far off…………
You don’t say.
Suppose this might have something to do with the world’s rising agricultural productivi… Nah. Crazy idea.
REPLY: Actually NASA has documented that the entire biosphere is booming.
http://wattsupwiththat.com/2011/03/24/the-earths-biosphere-is-booming-data-suggests-that-co2-is-the-cause-part-2/
-Anthony
David Middleton says:
September 29, 2011 at 10:25 am
And according to the Hockey Team, the rise in atmospheric CO2 since 1850 is attributed to humans because of a “simple accounting” of the natural carbon flux plus our emissions…
The new finding only shows that the total flux in and out is larger than expected, but that is only throughput and not of the slightest interest for the material balance. It is the difference between what the biosphere takes away and what the biosphere emits that makes the balance.
And that is known, be it with large margins of error, based on the oxygen balance. When plants grow, they produce oxygen (about 1.2 molecule for 1 molecule of CO2 captured). Conversely, when in fall leaves and plant parts are decaying or soil bacteria at work the whole year round, that uses oxygen.
The net result of the oxygen balance is that the whole biosphere (including ocean plants, animals, insects, bacteria) takes about 1.0 +/- 0.6 GtC/yr out of the atmosphere. That is in quantity about 1/6th of what humans emitted in the same period. The oceans take about 1.6 GtC/yr, that is about 1/3rd of the human emissions. Both together thus take about halve the human emissions (as mass) out of the atmosphere. The rest of the human emissions (as mass) accumulates in the atmosphere, already 150 years…
See: http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf
Does this study call into question the assumptions regarding the half-life of atmospheric CO2 emissions? As I recall the GCMs assume that CO2 resides in the atmosphere for 100+ to 200+ years after emission. I recall that there are also empirical ch studies that conclude the CO2 half-life is 5 to 7 years. Which is correct or closer to actuality?
I must confess that I would feel very guilty if I tried to STARVE the plants of the Earth by reducing my CO2 footprint. I therefore will plan to increase my production of CO2 many-fold by stocking up on my wood pellets, which will be burned this winter to produce heat (for me) and lots of CO2 for the plants. Its a win-win scenario for the biosphere!
Ferdinand
This is the classic IPCC view of the carbon cycle.
http://www.skepticalscience.com/human-co2-smaller-than-natural-emissions.htm
Has anything we have learnt since AR4-including this latest study-changed the totals or the proportions?
tonyb
So, it’s worse than we thought.
We thought we were only putting out so much CO2 and now we find it was 45% more than what we thought because the bushes were cleaning up 45% more than we thought. I knew it would turn out to be Bush’s fault. And for sure, it’s worse than we thought.
Sweet!
Everyone plant a couple fast growing trees problem solved. Or is it? With all the extra trees we now sink more carbon and by the AGW theory I have just thrown us into an ICE AGE. I won’t be able to sleep tonight knowing that I may have ended the world..
All silliness aside how many trees would you have to plant to bring atmospheric CO2 levels down to the ever changing (Norm) of around 300ppm?
Latitude says:
September 29, 2011 at 11:00 am
‘If this “adjustment” is just for land plants, and it’s that far off…………’
And, who is to say that the “adjustment” is the final word?
All that had been done to date was to create a narrative with which the data at hand superficially agreed, to a rough order of approximation. I expect the warming plank of AGW to fall first, as Global Cooling kicks into high gear in the next decade. Eventually, the subsequent decline in CO2 concentrations will drive the final stake through the heart of the entire scientific farce.
Ferdinand Engelbeen says:
September 29, 2011 at 11:13 am
“”The new finding only shows that the total flux in and out is larger than expected, but that is only throughput and not of the slightest interest for the material balance.”
Thanks for the clarification, Ferdinand!
So, just like plants in a greenhouse where CO2 is artificially raised, the plants “in the wild” will also take advantage of an increased CO2 level.
Now, I don’t like the “c” word (“conspiracy”), but it sure looks like this activity by planet-wide flora is more than mere coincidence.
We need to be vigilant. That extra fruit hanging from a tree maybe be part of their grand scheme.
Are the Triffids on the march?
Jeff says:
September 29, 2011 at 11:44 am
Sweet!
Trees! Many trees have brown/black trunks and dark green leaves. Plant them at a mid-to-high latitude (say the northern tier of US states and farther north) and the intercepted energy can raise the temperature more so than light colored plants (say dead grass in fall and winter), reflecting water, and snow.
About 10 years ago planting trees was the thing that was going to save the planet. Then studies were done. We haven’t heard much about it since.
http://usgovinfo.about.com/b/2006/12/18/trees-in-wrong-places-could-hasten-global-warming.htm
“And that is known, be it with large margins of error, based on the oxygen balance.”
Uh, when the (undoubtedly underestimated) margins of error are approximately the same size as the measurement, dont you think that throwing the word ‘known’ around is a bit cheeky?
When plants grow, they produce oxygen (about 1.2 molecule for 1 molecule of CO2 captured). Conversely, when in fall leaves and plant parts are decaying or soil bacteria at work the whole year round, that uses oxygen.
“Both together thus take about halve the human emissions (as mass) out of the atmosphere. The rest of the human emissions (as mass) accumulates in the atmosphere,”
Uh, no it doesnt. Currently, the carbon budget is not closed. The rate of increase in the atmospheric CO2 concentration cannot be accounted for – it is much slower than would be expected according to the accounting you propose. By about 50%. Currently, we cannot even pretend to account for an amount of anthropogenic carbon equal to the amount we think we see as an increase in atmospheric concentration.
The issue of the carbon budget is nowhere near ‘known’.
Whoa, look at how happy that plant in 1270 ppm CO2 was, it was positively dancing! (yes, actually, plants do move and that wasn’t a wind, it was the plant moving itself around. Such motions are usually much slower than we can have the perception to watch in real time)
That was really cool watching–what struck me was the huge reduction in germination time: that would make an enormous impact on agriculture.
@Ferdinand Engelbeen says:
September 29, 2011 at 11:13 am
Ferdinand, they aren’t measuring the natural flux in Bender et al.,2005. They are calculating it based on assumptions from the measured rise in CO2. The O2/N2 ratio matches the CO2 rise… Which is not diagnostic of CO2 sourcing.
“The O2/N2 ratio of air is falling because combustion of fossil fuel and biomass both consume O2. The observed rate of decrease is less than the calculated rate of O2 consumption by combustion. The difference is due almost entirely to net O2 production (and corresponding CO2 uptake) associated with the growth of the land biosphere.”
The observed decrease in O2 “decrease is less than the calculated rate of O2 consumption by combustion” and presumably much less than the calculated rate of fossil fuel consumption and biomass consumption. However, the rates of biomass O2 consumption and biospheric O2 production are essentially guesses based on the presumptively well-known rate of O2 consumption from fossil fuels.
If half, or more, of the CO2 was the result of oceanic out-gassing related to the warm up from the Little Ice Age, the O2/N2 ratio could very easily behave the same way.
Unbelievable…
People who profess to be Science Professionals do not understand one of the most fundamental characteristics of life itself.
Life seeks food. Availability of food is the limiting factor of life. Plant life is no different. In fact, plants, unlike animals, can usually live to reproduce at amazing extremes of size… either really small or really, really large.
This is the main reason I personally have always laughed at the CO2 hand-wringers. As CO2 levels rise, for whatever reason they are rising (no, the science is not “settled” on that), the flora of the world benefits hugely and does its level best to reduce the level. As long as food increases, plants will grow. And not just forests, but all plant life, everywhere. Plant absorption of CO2 could double or triple within 24 hours if it was beneficial. Think about it: what if all those tiny little seeds that you know will become weeds in your garden suddenly burst into life? What if every dandelion or grass seed actually started growing into a plant?
Which is why ANY scheme to reduce CO2, including dumping crap in the oceans or CO2 scrubbers or, outright dangerous and directly wasteful and harmful: sequestration, is a stupid, stupid thing to do.
Limiting CO2 emission is stupid, and believing that limiting CO2 emission is a good thing to do belies a fundamental ignorance of everything to do with Science and Nature.
Paddy ,
I suspect that the empirical observations are closer to reality .
Chuck,
No, it’s better than we thought.
How long before they want to pump oxygen into the ground and then hydrogen?
Ferdinand Engelbeen says:
September 29, 2011 at 11:13 am
The new finding only shows that the total flux in and out is larger than expected,
=============================================================
They are not talking about flux……
They are talking about CO2 incorporated into the plant mass
“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.”
I can’t tell if this finding is good or bad for my potential carbon credits………..
Do any of the climate models incorporate a variable for the biomass CO2 sink?
climatereason says:
September 29, 2011 at 11:36 am
Has anything we have learnt since AR4-including this latest study-changed the totals or the proportions?
Hi Tony,
One of the points is a better indication of the distribution of CO2 between the main sinks: the oxygen balance is at the edge of the analytical possibilities of the method (1 ppmv change in 200,000 ppmv!), but the longer the time frame, the more accurate the results become.
The main result is that the biosphere before the 1990’s probably were a net source of CO2 (based on a few samples of ancient air taken in flasks), but since then an increasing sink. The oceans also increase in sink capacity, but plant uptake increases faster.
More detailed work is underway with tall towers, where fluxes over larger areas are measured. And the satellites are at work, the Japanese one is looking at the total air column to the surface, but I haven’t seen anything beyond some preliminary results.
What’s good for General Plant, is good for the U. S. of Animals.
======================
The plants are wrong! The models tell me that CO2 uptake is 120. Someone tell the plants the truth!
JJ says:
September 29, 2011 at 12:33 pm
Uh, when the (undoubtedly underestimated) margins of error are approximately the same size as the measurement, dont you think that throwing the word ‘known’ around is a bit cheeky?
The magins of error are huge, because of the accuracy of the oxygen measurements, but nevertheless, one can say that the world is “greening”, as the biosphere is a net sink for between 0.4 and 1.6 GtC/year. Which in general is confirmed by satellites.
Currently, the carbon budget is not closed. The rate of increase in the atmospheric CO2 concentration cannot be accounted for – it is much slower than would be expected according to the accounting you propose. By about 50%.
I don’t see the problem here. As long as the increase in the atmosphere is less than the human emissions, then nature is a net sink for the difference. No CO2 escapes to space, thus as no carbon can be destroyed or made, the oceans and/or vegetation take the difference away. It is only of academic interest what the distribution between these two main sinks is, even if vegetation was a net source, that only means that the oceans are a larger sink, as these must remove halve the human emissions and what vegetation emits.
It would be different if the increase in the atmosphere was larger than the human emissions. In that case, both humans and nature add to the atmospheric CO2 increase.
Matthias Cuntz? That name sounds familiar. I think he may have been related to an old girlfriend of mine.
Geez, that is an even worse last name than Bastardi.
Ferdinand Engelbeen says:
September 29, 2011 at 11:13 am
“”The new finding only shows that the total flux in and out is larger than expected, but that is only throughput and not of the slightest interest for the material balance.”
A question, where did all these supposedly harmfull hydrocarbon feuls come from, anyway? Did they just magically appear? No, they started out as mostly plants. This shows that carbon going into plants does not nessissarily all return to the atmosphere, as we can see that a considerable amount ended up in the ground and stayed there. Therefore, your statement is proven false by the existance of hydrocarbon feuls. Note also that huge amounts of gas type fossil feuls have recently been discovered, enough for many hundreds, perhaps even thosuands, of years, all that carbon had to come from somewhere.
Howwever, there is throughput, WE are doing the throughput. We are returning to the air all the carbon that those nasty greedy plants stole and hid away in their secret stash.
RE: David Middleton says:
September 29, 2011 at 10:25 am
Thanks, Dave, for that link.
It would be very interesting if the d13C increase, which is seen by Alarmists as a humanity-caused effect, truely did occur during the last warm-period before the last ice age, because humanity could not have caused it back then.
This would focus true scientists upon other possible causes of d13C increases and decreases, and increase our scientific understanding. I really do think that these studies of isotope differences give us a really neat tracer to use as a tool.
The problem with some Alarmists is that they are so eager to prove mankind is the culprit that they develop a sort of blind spot, and are unable to see other options.
This sure is very interesting research asi it shows that not as much CO2 might be getting dissolved in water as thought. It doesn’t change the global CO2 air concentration trend though.
I guess its main message is that we should plant more trees?
The arguments demonizing “carbon” sound exactly like Malthus’ warning against population growth.
More CO2 is better. The biosphere is starved of it.
There is no evidence of any global damage or harm as a result of the rise in CO2. Therefore CO2 is harmless. But there is ample evidence of increased agricultural production due to more CO2. Therefore CO2 is beneficial.
Thus, CO2 is harmless and beneficial at current and projected levels. More is better, and there is zero evidence of any downside to increasing this essential trace gas.
I wonder how many extra petajoules of solar energy the biosphere (both land and water based) is consuming to produce this observed increase in growth rate???
No wonder global temperatures have flat-lined over the last twelve years!
David Middleton says:
September 29, 2011 at 12:34 pm
Ferdinand, they aren’t measuring the natural flux in Bender et al.,2005. They are calculating it based on assumptions from the measured rise in CO2. The O2/N2 ratio matches the CO2 rise… Which is not diagnostic of CO2 sourcing.
They don’t calculate the natural fluxes at all, because that is not of interest. They calculate the difference between the total natural uptake and the total natural release. That is what the oxygen balance gives. Fossil fuel consumption is reasonably known (maybe underestimated) from sales (taxes!). Combustion efficiency is known from most processes, so one can calculate how much oxygen fossil fuel burning uses. In reality, the amount of oxygen used is less than that, thus the whole biosphere is a net producer of oxygen. That includes all known and unknown fluxes, including forest fires, rotting wood, ocean plants, food eten by animals, etc…
Thus without knowing any natural flux in detail , we know that the biosphere as a whole is a net absorber of CO2. And preferentially 12CO2. Thus enriching the atmosphere in 13CO2, but we see a steep decrease in 13C/12C ratio.
Ocean CO2 uptake or release doesn’t change the O2 balance, as that is a matter of simple direct solubility, but it changes the 13C/12C ratio, because of fractionation at the surface. The current ocean releases would increase the 13C/12C ratio of the atmosphere, but we see a steep decrease…
The simple conclusion: both oceans and vegetation are net sinks for CO2, sequestering about halve the human emissions (as mass, not as original molecules).
ChE says: @ September 29, 2011 at 11:11 am
You don’t say.
Suppose this might have something to do with the world’s rising agricultural productivi… Nah. Crazy idea.
____________________________________________________________________
REPLY: Actually NASA has documented that the entire biosphere is booming.
http://wattsupwiththat.com/2011/03/24/the-earths-biosphere-is-booming-data-suggests-that-co2-is-the-cause-part-2/
-Anthony
_______________________________________________________________________
BUT,But, but Monsanto claims the increased productivity is because of THEIR GM plants…..
Smokey says:
September 29, 2011 at 1:42 pm
“More CO2 is better. The biosphere is starved of it.”
It is a wonderful feeling each morning to commute to work and see the trees flourish under the healthy influence of my car’s exhaust, I tell ya. Soon they’ll be rivaling the wind turbines in height!
Legatus says:
September 29, 2011 at 1:34 pm
This shows that carbon going into plants does not nessissarily all return to the atmosphere, as we can see that a considerable amount ended up in the ground and stayed there.
That is what I said too: some 1 GtC/year of CO2 is sequestered in more permanent carbon storage (peat, roots,…) . No matter how high the seasonal fluxes in the biosphere are: 120 GtC or 155 GtC back and forth between plants – atmosphere – oceans and back. The height of the fluxes is not important, only the net difference between the fluxes is important.
The point is that we burn carbon buried millions of years ago from an atmosphere at that time which had 10-12 times more CO2 than today. Thus we are enriching the atmosphere of today with extra CO2. No problem for plants, to the contrary, but it has some effect on temperature. How much, that is a matter of debate (my opinion is that the effect is modest and mostly beneficial). But there is very little doubt left that humans are the cause of the increase of CO2 in the atmosphere over the past 160 years…
JohnWho says: @ September 29, 2011 at 12:13 pm
So, just like plants in a greenhouse where CO2 is artificially raised, the plants “in the wild” will also take advantage of an increased CO2 level.
________________________________________________________________
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. (If some one wants I could try to dig out the studies)
It would seem that WIND bring in fresh CO2 may be the actual limiting factor. I wonder if anyone has bothered to do the study.
The idea that the CO2 is “Well mixed” in the air is a bit misleading but what else is new in IPCC “science”
Paddy says:
September 29, 2011 at 11:29 am
As I recall the GCMs assume that CO2 resides in the atmosphere for 100+ to 200+ years after emission. I recall that there are also empirical ch studies that conclude the CO2 half-life is 5 to 7 years. Which is correct or closer to actuality?
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. That doesn’t change the total amount of CO2 in the atmosphere, only changes the origin of the CO2. 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”. That takes much longer than 5-7 years, as the current amount which is sequestered is only 4 GtC/year, while humans still emit 8 GtC/year. If we stop all emissions today, the next year would see a drop of 4 GtC (2 ppmv), then 3.8 GtC the year after, etc. until we reach the old “equilibrium” level of 290 ppmv in the atmosphere. 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.
“Plants gobbling up CO2 – 45% more than thought”
And the end result of this ‘discovery’ will most likely be that developed countries will be sending 45% more of their wealth to nations with huge forests under REDD.
Yea, but how much CO2 are they soaking up?
Moderator: wordpress does not recognize superscripts and subscripts in HTML so my last post should read … Oh yea? How much CO^2 are they soaking up?
REPLY: I left this alone, because if you use ^ then you get “squared”, and that would be no better than the label on the bottle in Al Gore’s Climate 101 video. – Anthony
Gail Combs says:
September 29, 2011 at 2:23 pm
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.
==============================================
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…
Instead of 120 petagrams of carbon, the annual global vegetation uptake probably lies between 150 and 175 petagrams of carbon.
————
The research described has nothing to do with “CO2 is plant food” debating point.
The article is about the CO2 turn over rate as being higher than previously estimated. In other words the amount consumed by plants and also later returned to the air by decomposition. The decomposition rate is also higher than previously estimated.
This is a separate issue from whether increased CO2 will increase crop production.
Paddy says:
September 29, 2011 at 11:29 am
Does this study call into question the assumptions regarding the half-life of atmospheric CO2 emissions?
REPLY:
The Warmistas studiously ignore the rapid drop-off of C14O2 after the 60’s nuclear testing by the always-cheating Commies (their Slave-Empire’s long-overdue demise still mourned by all Watermelons).
At least now a few Warmistas begudgingly admit that a newly generated CO2 molecule only resides in the atmosphere for 5 years before it encounters a chloroplast.
Their so-called models (fantasies, actually) deliberately underplay the major plantgrowth-stimulus due to rising CO2.
Warmistas have become the champion-maximizers of confirmation bias: CO2 is evil , therefore discussion of its multiple benefits is downplayed, scorned, or outright censored. Ditto for how every past warming benefited civilization, how past coldings had dreadful sociological effects, including famines, miltant migrations, and endless wars.
It’s immense fun to ask a Warmista about how much plants like CO2, then watch the foam curdle on their lying lips. The more ‘sincere’ a Warmista, the more fun it is to expose the immense holes in his/her pathetic pseudo-arguments, which in the final analysis are nothing but special pleading for a statist dictatorship by a self-anointed elite of hardened Lefties.
“Fred H. Haynie
Now they need to quantify the rates of uptake of the ocean’s greater biomass. ”
Fred, there will be no major change in the oceans biomass due to the nature of the aquatic biosphere. At the moment the yearly amount of carbon fixed is approximately 10 times the total biomass.
A large fraction of this carbon mass is politely termed ‘snow’, but is really shit.
It rains down from the surface and starts toward the bottom. A range of creatures/micro-organisms feast on it on the way down, but a fair fraction makes it to the bottom.
This process denudes the surface of CO2. The argument that CO2 in the oceans was at ‘equilibrium’ prior to us burning fossil fuels is as stupid as claiming that oxygen is in equilibrium.
Here is the distribution of dissolved oxygen in the ocean
http://files.myopera.com/nielsol/blog/MeHg_O2_v_DepthGraph_l.png
As you can see, where there is little light flux, and so little marine photosynthesis, hypoxic conditions occur close to the surface. in colder water, the hypoxic region is closer to the surface.
Now, at the bottom of the oxygen organic carbon is either converted into methane or CO2 by the microoganisms, or it mineralizes, to become oil in the distant future.
The oceanic carbon cycle is the opposite of the oxygen one, Oceans are high in carbon at the bottom, and very low at the surface. The denuded surface waters must get their carbon from the atmosphere or from the very slow migration of CO2 (including as carbonates), from the bottom.
All we are doing by burning fossil fuel, is increasing the amount of snow that falls.
The Hare-Brained physicist who post here is a great proponent of a pre-Industrial [CO2] ‘equilibrium’, but has never heard of a steady state.
DirkH says:
September 29, 2011 at 10:32 am
“This means that the European CO2 market will be flooded with CDM credits and the prize for a CO2 permit will drop to zero real soon now… (more supply than demand).”
From the original article:
“This value is a kind of gross national product for land plants and indicates how productive the biosphere of the Earth is.”
I’m just wondering if someone might like to investigate any possible relationship between the collapse of the carbon market/”consensus science” VIEW with the collapse of the Eurozone economies? My understanding of economics theory (very limited) is that the big chaotic factor that underlies the health of an economy is the psychological motivations of various groups. Such as traders, politicians, consumers, business leaders etc. Very hard to model :-).
I don’t have the requisite skills to do this – but just thinkin’. Willis? Roy Spencer?
Ferdinand Engelbeen says:
September 29, 2011 at 11:13 am
Ferdinand,
Your argument based on mass balance assumes that the long-term behavior of sources and sinks does not change significantly. The C13/C12 data tell us otherwise. Try this exercise. Assume that all the atmospheric CO2 from organic origins has an index value of -27.3 (graphite standard) and all the CO2 from inorganic origins has an index value of the PDB standard. Now divide the measured index values by -27.3 to get an estimate of the fraction of the total CO2 concentration that is from organic origins. I find this fraction has increased from about 28% in 1990 to about 31% in 2010. That 3% change is possibly attributable to anthropogenic emissions. If there are long-term natural fractionation processes at work, the anthropogenic contribution would be even less. To put this in graphical perspective, multiply the calculated fraction by the measured total calculation and subtract that value from the total to get the amount that has inorganic origins and plot the results with time. This should show you that this natural inorganic CO2 has been steadily increasing at only a slightly lower rate than the organic CO2 and amounts to more than 2/3 of the total increase.
Its raining in texas
Don’t know where else to post it
DocMartyn says:
September 29, 2011 at 3:43 pm
How much of that “snow” is depleted in C13 (organic) and how much inorganic? How long does it take that fractionation process to recycle into the atmosphere in the form of upwelling that starts a la-Nina? Clouds and rain are also involved in a fractionation process but on a much shorter time scale.
” the plants don’t care what they think”
Time to send the plants to the re-education camps in the North.
// SATIRE //
STUPID Plants, here we are pumping more CO2 and the plants just gobble it up!
I believe this is PROOF that the plants are being paid off by the Oil Companies to do this!!!
Kevin Kilty says:
September 29, 2011 at 3:08 pm
You can use superscript and subscript characters built into the font at hand.
See my Guide to WUWT, down at the bottom. You can write CO₂ as CO₂ Often you can cut and paste the hard to type character from there, as I do here with ² and °.
Oops – WordPress goofed. I’m shocked, shocked! This might work:
You can write CO₂ as CO₂
CO, ampersand, hash, 8322, semi-colon.
“Fred H. Haynie says:
How much of that “snow” is depleted in C13 (organic) and how much inorganic? ”
It is mostly organic. On the way down it is eaten by aerobics, which is why there is not oxygen. O2 is not at equilibrium, because carbon isn’t at equilibrium. When the PO2 drops, the anaerobes take over, they oxidize the carbon, releasing methane and CO2.
You cannot point to a depth and do a 14C measurement as say it is this old. The carbon at any depth is a mix for fresh carbon (from organic carbon on the way down being converted to CO2) and old carbon on the way up, either as CO2 or CH4 being oxidized by aerobics.
Unlike Ferdinande constant pleas, the oceans are not, nor have they ever been, since live arose, in equilibrium with respect to carbon. They cannot be.
Do you know the ration of organic carbon at the bottom of the oceans compared with dissolved carbon?
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.
The EPA of the United States says that co2 is a pollutant. Plants are gobbling pollution.
But don’t be a dope and call it CO².
Yes like Gore did in his video
These new numbers just make the Carbon cycle more complicated.
It is a little strange that our 3.8% of Carbon emissions seem to be so consistently balanced out by a 1.9% increase in the net absorption by Plants and Oceans, just like when our emissions were 0.1% of the total emissions, Plants and Ocean absorbed 0.05% of them.
The difference in the numbers is getting too large now (237 billion tons emitted by Plants and Oceans versus Humans at 9.5 billion tons) for this to be so consistent. It is almost too coincidental.
How the heck can the Science be settled when they don’t even know the basics.
There was a biology resource book for teachers (classroom demonstrations, experiments, background info., etc.) published by the State of California in 1967. In the chapter for plants and photosynthesis was this paragraph: “It is estimated that around 200 billion tons of CO2 annually are photosynthesized by green plants globally. About 10% is by terrestrial plants and 90% by aquatic plants–both fresh water and marine.
I converted 175 petagrams to tons and the result was approximately 193 billion tons. Not bad for a forty-four year old estimate back when no one thought about global warming.
Jeff says:
September 29, 2011 at 11:44 am
Freeman Dyson http://en.wikipedia.org/wiki/Freeman_Dyson has some ideas on this subject. He says that CO2 levels in the atmosphere could be controlled by planting fast-growing trees. He figures it would take a trillion trees to “remove” all carbon from the atmosphere.
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.
DocMartyn says:
September 29, 2011 at 5:52 pm
Unlike Ferdinande constant pleas, the oceans are not, nor have they ever been, since live arose, in equilibrium with respect to carbon. They cannot be.
=================================================================
otherwise they would die……………………..
Negative feedback?
any serious grower of marijuana knows those particular plants will use 1500PPM CO2 and show vigorous signs of increased growth.
this site is great. a huge help.
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
==============================================
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…
==============================================
Ferdinand Engelbeen says @ 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.”
=============================================================
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…
@Ferdinand Engelbeen says:
It is physically impossible for Law Dome to have a resolution better than 60 years. The differential between the ice age and gas age is at least 30 years…
Ice cores cannot resolve CO2 shifts that occur over time periods less than twice the bubble enclosure time. That is basic Nyquist Sampling Theorem.
At the time the cores were taken, the sealing depth ranged from 66-72 m at an ice age of 40-68 years. None of those cores have the resolution to properly image the MLO instrumental record.
@Gail,
Maybe not…
Executive Summary, Chapter 3 of the IPCC Third Assessment Report, The Carbon Cycle and Atmospheric Carbon Dioxide
There are more details on the temperature dependence (and pressure, salinity, Ph) of CO2 solubility in the oceans deeper in the chapter, and again in the Fourth Assessment Report.
David Middleton says:
September 30, 2011 at 12:50 pm
It is physically impossible for Law Dome to have a resolution better than 60 years. The differential between the ice age and gas age is at least 30 years…
David, the resolution of the ice core CO2 measurements have nothing to do with the IGA (ice – gas age difference). As long as the pores are wide enough, there is free exchange between the air in the atmosphere and in the pores. The deeper one goes, the slower the exchanges are, but at 72 m depth for the Law Dome ice cores the ice is 40 years old, so the diffusion has 40 years the time to mix in and out. At that depth the enclosed air is only 10 years older in average than in the atmosphere.
At Law Dome, the CO2 levels in firn top down were measured. At sealing depth, the CO2 levels in firn and ice were equal, but it costs about 8 years to close all bubbles, so different bubbles may contain air of different average ages, in this case about a decade, with the average at 30 years difference between ice age and gas age.
More info about the diffusion and fractionation of gases in ice cores can be found at:
http://www.pnas.org/content/94/16/8343.full
And more interesting for this discussion, a diffusion model (confirmed by direct measurements in firn) shows that a one-year peak in CO2 for Law Dome diffuses down over time and causes a peak trapped in the sealed ice layer with an amplitude of 10% of the original peak at 11 years:
http://courses.washington.edu/proxies/GHG.pdf
For the high resolution Law Dome cores that means that a peak of 20 ppmv in the atmosphere during one year is measurable in the ice core as an increase of maximum 2 ppmv over a period of 8 years (8-16 years after the atmospheric peak).
None of those cores have the resolution to properly image the MLO instrumental record.
To the contrary, the Law Dome ice cores have an overlap of about 20 years with the direct measurements at the South Pole, with a perfect match for that period, within the accuracy of the measurements (1.2 ppmv – one sigma):
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_sp_co2.jpg
More about the work of Etheridge e.a. on the Law Dome ice cores, unfortunately behind a paywall:
http://www.agu.org/pubs/crossref/1996/95JD03410.shtml
CodeTech says:
People who profess to be Science Professionals do not understand one of the most fundamental characteristics of life itself.
Life seeks food. Availability of food is the limiting factor of life. Plant life is no different. In fact, plants, unlike animals, can usually live to reproduce at amazing extremes of size… either really small or really, really large.
IIRC the current level of carbon dioxide in the atmosphere is actually towards the low end of what plants can handle.
Which is why ANY scheme to reduce CO2, including dumping crap in the oceans or CO2 scrubbers or, outright dangerous and directly wasteful and harmful: sequestration, is a stupid, stupid thing to do.
There are actually devices to increase carbon dioxide levels in greenhouses. The obvious solution is, instead of using complex scrubbers, feed the exhaust from CO2 producing processes into greenhouses.
Even raising it to 20 times current atmospheric levels is perfectly safe for humans. It dosn’t make sense to claim that current levels are “too high” when they appear to be way below optimal for many plants and way below dangerous to animals. Instead it implies that at times in the past the level is likely to have been considerably higher than at present for organisms to evolve the biochemical mechanisms they have…
Ferdinand Engelbeen
I have two problems with the Ice Core data aside from the disagreement with the stomata data.
1. The grahps show CO2 at or below 180-200ppm. An old paper since removed from the internet stated trees stop growing at 220ppm. Other sources indicate plants run into trouble at 180 to 200 ppm.
2. The diffusion of CO2 through the ice.
http://www.geocraft.com/WVFossils/Reference_Docs/CO2_diffusion_in_polar_ice_2008.pdf
http://robertkernodle.hubpages.com/hub/ICE-Core-CO2-Records-Ancient-Atmospheres-Or-Geophysical-Artifacts
GRAPHS
Wiki: http://upload.wikimedia.org/wikipedia/en/6/63/Co2-temperature-plot.svg
http://joannenova.com.au/globalwarming/graphs/ice-cores/vostok-ice-core-petit-web.gif
http://joannenova.com.au/global-warming/ice-core-graph/
I am also well aware that scientists and lab techs will come up with the “correct” answers as Jaworowski suggests. I have certainly seen enough real life examples after more than thirty years in labs to know that “mavericks” like Jaworowski and Alan Carlin, who consider the truth to be more important than their careers are few and far between. Money trumps ethics especially when you have a family to feed and a mortgage to pay.
Given that most readings of CO2 are land based you quibbles with me about “well mixed” do not hold. Not only do land plants absorb CO2, the ocean water absorbs CO2 as does the plant life it contains you can not ignore that as you do in your explanation. You also have volcanoes, factories, and other point sources of CO2 like the soil. The whole blasted planet with the possible exception of the glaciers is CO2 “active”
@Ferdinand,
You can’t recover higher frequencies than you put into the ground. The Nyquist frequency is equivalent to two-times the bubble enclosure period.
David Middleton says:
September 30, 2011 at 6:59 pm
You can’t recover higher frequencies than you put into the ground. The Nyquist frequency is equivalent to two-times the bubble enclosure period.
Agreed, but the bubble enclosure period in the high accumulation Law Dome cores is only 8 years starting at 72 m depth. Thus any continuous change of 16 years above the accuracy limits (1.2 ppmv, 1 sigma) can be detected in the ice core. For the lower accumulation third Law Dome core, the closure period is 21 years, thus any frequency of longer than 40 years would be detected. In the case of the MWP-LIA change, the frequency is ~1000 years, thus no problem to detect the change in CO2 between the MWP and LIA, which was about 6 ppmv. That means that it is highly unlikely that the variability seen in stomata data is real, anyway the higher average CO2 levels are impossible, as the ice core data are filtering out the higher frequencies, but filtering doesn’t change the average…
The confusion, I suppose, is in the ice-gas age distribution, but the diffusion of air/CO2 through the firn until closing depth is independent of the ice age, only depends of temperature and pore diameter/ice density. The closing period also is temperature dependent and accumulation dependent. For the high accumulation, “warm” (-19°C) Law Dome ice cores the closing period is 8 years, but for the very cold (-40°C) low accumulation Vostok and Dome C ice cores, that is 600 and 560 years resp (worse in glacial periods). But even these two would detect the current (one-sided!) increase of 110 ppmv over 1.5 century…
I remember learning this in school like 20+ years ago. First in biology, then in chemistry, where we actually did the photosynthesis calculation. We learned that CO2 is good for plants. Plants love CO2. It’s nom-tastic for them.
How much has changed in 20+ years. It’s actually creepy.
Maybe this helps explain how my bare-root, mail-order tuliptree planted in spring 2004 is now 40′ (>13m) tall! Even w/only 6 hrs direct sun a day. At that rate it could be 100′ in a mere 20 yrs. Chinese elm and honeylocust planted at the same time are only slightly behind in height — over 35′ tall.
Gail Combs says:
September 30, 2011 at 6:28 pm
1. The graphs show CO2 at or below 180-200ppm. An old paper since removed from the internet stated trees stop growing at 220ppm. Other sources indicate plants run into trouble at 180 to 200 ppm.
Land plants have the advantage to grow on… land. CO2 levels in the first few hundred meters in average are elevated (some 30-40 ppmv) compared to “background” CO2 levels. At ground level even up to 1000 ppmv. The “background” represents 95% of the atmosphere, including all heights over the oceans and over barren land like Antarctica. Thus the real CO2 levels over land might have been 210-240 ppmv while the ice cores show 180-200 ppmv.
2. The diffusion of CO2 through the ice.
The investigation of CO2 diffusion is quite difficult, because it is so small. In the case of the Siple Dome, they used CO2 levels in the neighbourhood of impermiable (remelt) layers to estimate the diffusion over longer time. The result for this “warm” (-21°C) ice core is that the resolution at medium depth is broadened from 20 to 22 years and at full depth (70 kyr in the past) from 20 to 40 years. Not really a problem, as there is more averaging, but that doesn’t change the average, only reduces the ability to detect fast changes.
For “cold” (-40°C) ice cores like Vostok and Dome C, the diffusion is unmeasurable small. That is proven by the CO2/temperature ratio which remains the same over 800,000 years, with a warmer period every 100,000 years back in time. If there was the slightest migration, the highest CO2 levels (at 10% of the time) would fade away for each period further back in time.
I am aware of the objections from Jaworowski/Segalstad against the reliability of ice cores. Most of the objections are from 1992 and before and most were answered in 1996 by the work of Etheridge e.a. on the Law Dome ice cores.
Further, Jaworowski claims points which are physically impossible, like migration of CO2 out of the ice core via cracks, while the outside CO2 levels are 100 ppmv higher… See further:
http://www.ferdinand-engelbeen.be/klimaat/jaworowski.html
Even if some ice core specialists would be economical with the truth, it seems very unlikely to me that really nobody of all (tens of) people from different labs and different countries working at different cores in different time periods would protest against such a practice, even not after retirement…
Ferdinand Engelbeen
So average atmospheric CO2 is slighly lower than at ground level? Is this a fig leaf to jusify the suicidally irresponsible policy of reducing CO2 when current atmospheric levels are dangerously near the low, not the high, end of the safe range of 300 – 10,000 ppm evident from palaeo history?
That the biosphere is stressed by current low CO2 is evidenced by the recent evolution 24 MYa of monocotyledonous plants (e.g. grasses) with their more efficient C4 photosynthesis.
BTW grasslands have higher albedo than forests, this could be a factor in the current glaciation as much as any direct physical effect of CO2 on temperature.
Has the movement for voluntary human extinction become influential at government and UN level?
In the paper by Franck et al. on the timeline of biosphere extinctions, he points out that it will be CO2 starvation, not temperature, that will finally kill off all life on this planet within the next billion years.
phlogiston says:
October 1, 2011 at 9:28 pm
Has the movement for voluntary human extinction become influential at government and UN level?
Probably, but I am not very interested in the policy of the UN, except that what they do in the case of CO2 costs a lot of money for little effect.
I am more interested in what the observations show: CO2 levels over land and especially near ground are (much) higher than in the rest of the atmosphere, so that may help the survival of plants when most of the atmosphere is at the 180-200 ppmv level during glacial times. Thus the survival of plants is not an argument against the low levels found in ice cores during such periods.
For plants anyway higher levels are better. And for climate, I would like to have the Mediterranian climate here in my (in general) cool and wet country…
I’m sorry, Ferdinand, but you are totally wrong…
Aa = Ai + δa = Ai + Ts – Td
δa = Ts – Td
Aa = Mean air age
Ai = Ice age at extraction depth
Ts = Time for ice to reach sealing depth
Td = Time for air to mix down to sealing depth
DE08 205
Ai= 1939
Aa= 1969
δa= 30
Ts= 40
Td= 10
d= 72
The bubble enclosure time is 4 times the time for the air to mix down to the sealing depth. Every point in the DE08, DE08-2 and DSS cores is approximately a 30-yr moving average of annual CO2 concentrations. The highest frequency recoverable is equivalent to a 30-yr period. The Nyquist frequency at Law Dome is equivalent to a period of 60-yr.
Law Dome cannot resolve CO2 shifts that occur over periods of less than 60 years. That is an absolute immutable fact.
The deepest Law Dome core, DSS, has a δa=58. Its resolution is 116 years.
It can’t resolve any sub-centennial CO2 shifts.
Ferdinand Engelbeen
Thanks for the reply. Its a good thing for plants that local CO2 is significantly elevated over the atmospheric mean.
Out of interest would the presence of these 2 compartments – ground level (say over a tropical rain forest) and the higher mixed compartment – combined with any measured differences in C isotope ratios in the 2 compartments, provide any handle on CO2 kinetics, e.g. residence time
/ half life? Or is this wishful thinking.
Dave Middleton
If imaging technology is anything to go by, the oft-cited Nyquist frequency is more of a guideline than an immutable law – in the real world higher spatial resolutions are attainable, but only if you get everything right in terms of stability, alignment etc.
For instance resolution as measured by 10% MTF (Fourier modulatuon transfer frequency) often comes in at around
1.5 times, not 2x, the pixel size.
@phlogiston
There are “tricks” to infer better resolution than Nyquist. We can use amplitude and other attributes to infer stratigraphic variability below minimum resolution thickness in reflection seismic profiling for oil exploration; but we don’t have the academic liberty to ignore Nyquist.
David Middleton says:
October 2, 2011 at 6:53 am
David you are confusing between mean gas age of the air enclosed in the ice and gas age distribution within that enclosed air.
At sealing depth of 72 meter, the air is starting to be sealed from the atmosphere. At that moment the average gas age is only 10 years older than in the atmosphere, while the ice age is already 40 years. The gas age distribution at that moment is mainly +/- 3 years, be it with a relative long tail of older gas ages. Then it takes about 8 years to close all bubbles. That means that the average gas age now goes up at the same pace as the ice age, thus the mean gas age now is 18 years and because of less and less sealing bubbles left, the gas age distibution then is less than 8 years + the gas age distribution at sealing start depth, that makes about 11 years for the main age distibution, with relative smaller leads and longer tails of younger and older air, see Fig 11 in:
http://courses.washington.edu/proxies/GHG.pdf
The bubble enclosure time is 4 times the time for the air to mix down to the sealing depth.
Here you are mistaken: there is no bubble enclosure until 72 m depth and all air is fully enclosed at 83 m depth, that is about 8 years (with 1.2 m ice equivalent precipitation at Law Dome). Thus the bubble enclosure time is less than the mix down time of the air in the firn.
The bubble enclosure time and gas age distribution in the bubbles have nothing to do with the mean gas age or ice age or ice age – gas age difference, only with temperature and the static pressure caused by precipitation.
How come that “seeing is believing” video doesn’t take into account nutrient concentration? If there aren’t enough nutrients available (primarily the most limited one, phosphorus) then you won’t see that growth no matter the CO2 concentration.
fsu1jreed says:
October 3, 2011 at 9:44 am
How come that “seeing is believing” video doesn’t take into account nutrient concentration? If there aren’t enough nutrients available (primarily the most limited one, phosphorus) then you won’t see that growth no matter the CO2 concentration.
The experiment was done in optimal conditions, that is with sufficient water, nutritients, fertilizers and the adequate temperature. That gives a huge difference in plant growth with increased CO2 for many plants, but not for all. In average a 50% increase in carbon mass for a CO2 doubling. In the real world, conditions are not always optimal, as there may be insufficient nutritients, sub-optimal temperatures, lack of water, etc…
That makes that the “greening earth” at this moment gives an increase of about 1 GtC more uptake than release (on an estimated 550 GtC living biomass) for a 30% increase in atmospheric CO2 level. Not that much, but anyway positive.
Ferdinand,
You are totally 100% wrong.
The sealing interval is below the bubble enclosure interval. Sintering begins when the snow is buried to a depth sufficient to compact its density to 0.55 kg/l (~9 m at DE08). The bubbles begin to close off at ~.70 kg/l (~60 m at DE08) and are completely sealed off at a density of ~0.84 kg/l (72 m at DE08). At the time the core was drilled (1987), the relatively open mixing interval was from the surface down to ~60 m (“1954” ice layer). The sealing interval was from 60-72 m (1954 down to 1946). Even though the sealing interval only spanned 8 ice years, it contained a 30-yr blend of gases because it took that interval ~30 years to be buried to a depth sufficient to achieve sealing density.
At the time of deposition of the “1969” ice layer in the DE-08 core, the top of sealed ice was at an approximate depth of 72 m at the “1929” layer. The sealing interval in 1969 was from the “1937” layer down to the “1929” layer. From the 1969 surface down to the “1937” layer the firn was permeable. During the 10 years that the 1969 air mixed down to the “1939” layer, the 1929-1937 interval sealed completely off.
The air trapped at the “1939” ice layer was a mixture of 1939-1969 air. The mean age of that air was not 1969, as asserted by Etheridge et al.; the mean air age was no younger than 1954. It was actually older than 1954 because the firn/ice becomes less permeable with depth.
Once again, it is physically impossible for the DE08 or DE08-2 cores to resolve CO2 shifts that occur over periods of less than 60 years; and it is impossible for the DSS core to resolve CO2 shifts of shorter duration than 116 years. Below 120 m in the DSS core, the resolution may actually even be much worse than 116 years. There is a pronounce decline in the sampling rate below 120 m. There is a linear decline from 0.74 m/yr to 0.27 m/yr from 116.9 m down to 523.6 m.
The linear nature of the trend means that this is most likely due to compaction, rather than accumulation rate. If the sampling rate decline is due to compaction, it would only have a minimal effect on resolution. If it’s due to accumulation rate, then the resolution below 120 m could be as poor as ~500 years.
David Middleton says:
October 5, 2011 at 6:58 am
David,
Sorry for the late reply, didn’t check this discussion again until know…
Again you are mixing the average gas age and the distribution of the age in the bubbles. Indeed it takes 40 years until closing depth, but because the still open connection with the atmosphere, the average age of the air at that moment is 10 years older than in the atmosphere, not 20 years. Even if for slower accumulating ice cores, the ice age was already 500 years at closing depth, that wouldn’t change the average gas age much from the 10 years, as mean gas age and ice age are independent of each other (only temperature plays some role for both). 80% of the gas mixture is 5-15 years old in both cases, 10% is younger and 10% is older, where the older part has a very long tail up to 40 years (or 500 years for other cores).
The mean air age of the DE08 core was calculated from a firn densification model and confirmed by direct measurements of CO2 levels in the firn: because there is an overlap of 20 years between direct measurements at the South Pole and in the firn and there is a trend in the atmospheric CO2 levels, we know the average age of the gas mixture in the firn. Other items (CH4, bomb 14CO2, CFC’s) did confirm that. Thus the average gas age at the “1939″ ice layer was a mixture of 1939-1979 (not 1969) air and the mean age of that air was certainly at 1969, because that is what was measured. The mixture of gas ages is not a normal Gaussian distribution, it is quite assymetric, as fig. 11 in http://courses.washington.edu/proxies/GHG.pdf shows.
So you are right that the DE08 mixture has a distribution of air over a period of 40 years, but most of the air is in the +/- 5 years range around the mean gas age. The total distribution is not relevant to detect any peak in CO2 levels for a short or longer period, because the values around the average gas age have enough amplitude to detect any change of 20 ppmv over one year or 2 ppmv sustained over 20 years. That is much sharper than what you expect from a Gaussian distribution.
Even a sinusoidal CO2 level variation with a wavelength of 20 years and an amplitude of 20 ppmv would be detected in the DE08 core of Law Dome. That is by far sharp enough to reject the high(er) amplitudes seen in stomata data or the 1942 “peak” from historical CO2 measurements by wet chemical methods. And sharp enough to know from the DSS core that the LIA had CO2 levels at some 6 ppmv lower than during the MWP. Or sharp enough to detect a 100 ppmv increase over 100 years, like we have nowadays, in the Vostok or Dome C ice cores in the 800 kyr past.