Studies of Carbon 14 in the atmosphere emitted by nuclear tests indicate that the Bern model used by the IPCC is inconsistent with virtually all reported experimental results.
Guest essay by Gösta Pettersson
The Keeling curve establishes that the atmospheric carbon dioxide level has shown a steady long-term increase since 1958. Proponents of the antropogenic global warming (AGW) hypothesis have attributed the increasing carbon dioxide level to human activities such as combustion of fossil fuels and land-use changes. Opponents of the AGW hypothesis have argued that this would require that the turnover time for atmospheric carbon dioxide is about 100 years, which is inconsistent with a multitude of experimental studies indicating that the turnover time is of the order of 10 years.
Since its constitution in 1988, the United Nation’s Intergovernmental Panel on Climate Change (IPCC) has disregarded the empirically determined turnover times, claiming that they lack bearing on the rate at which anthropogenic carbon dioxide emissions are removed from the atmosphere. Instead, the fourth IPCC assessment report argues that the removal of carbon dioxide emissions is adequately described by the ‘Bern model‘, a carbon cycle model designed by prominent climatologists at the Bern University. The Bern model is based on the presumption that the increasing levels of atmospheric carbon dioxide derive exclusively from anthropogenic emissions. Tuned to fit the Keeling curve, the model prescribes that the relaxation of an emission pulse of carbon dioxide is multiphasic with slow components reflecting slow transfer of carbon dioxide from the oceanic surface to the deep-sea regions. The problem is that empirical observations tell us an entirely different story.
The nuclear weapon tests in the early 1960s have initiated a scientifically ideal tracer experiment describing the kinetics of removal of an excess of airborne carbon dioxide. When the atmospheric bomb tests ceased in 1963, they had raised the air level of C14-carbon dioxide to almost twice its original background value. The relaxation of this pulse of excess C14-carbon dioxide has now been monitored for fifty years. Representative results providing direct experimental records of more than 95% of the relaxation process are shown in Fig.1.
Figure 1. Relaxation of the excess of airborne C14-carbon dioxide produced by atmospheric tests of nuclear weapons before the tests ceased in 1963
The IPCC has disregarded the bombtest data in Fig. 1 (which refer to the C14/C12 ratio), arguing that “an atmospheric perturbation in the isotopic ratio disappears much faster than the perturbation in the number of C14 atoms”. That argument cannot be followed and certainly is incorrect. Fig. 2 shows the data in Fig. 1 after rescaling and correction for the minor dilution effects caused by the increased atmospheric concentration of C12-carbon dioxide during the examined period of time.
Figure 2. The bombtest curve. Experimentally observed relaxation of C14-carbon dioxide (black) compared with model descriptions of the process.
The resulting series of experimental points (black data i Fig. 2) describes the disappearance of “the perturbation in the number of C14 atoms”, is almost indistinguishable from the data in Fig. 1, and will be referred to as the ‘bombtest curve’.
To draw attention to the bombtest curve and its important implications, I have made public a trilogy of strict reaction kinetic analyses addressing the controversial views expressed on the interpretation of the Keeling curve by proponents and opponents of the AGW hypothesis.
(Note: links to all three papers are below also)
Paper 1 in the trilogy clarifies that
a. The bombtest curve provides an empirical record of more than 95% of the relaxation of airborne C14-carbon dioxide. Since kinetic carbon isotope effects are small, the bombtest curve can be taken to be representative for the relaxation of emission pulses of carbon dioxide in general.
b. The relaxation process conforms to a monoexponential relationship (red curve in Fig. 2) and hence can be described in terms of a single relaxation time (turnover time). There is no kinetically valid reason to disregard reported experimental estimates (5–14 years) of this relaxation time.
c. The exponential character of the relaxation implies that the rate of removal of C14 has been proportional to the amount of C14. This means that the observed 95% of the relaxation process have been governed by the atmospheric concentration of C14-carbon dioxide according to the law of mass action, without any detectable contributions from slow oceanic events.
d. The Bern model prescriptions (blue curve in Fig. 2) are inconsistent with the observations that have been made, and gravely underestimate both the rate and the extent of removal of anthropogenic carbon dioxide emissions. On basis of the Bern model predictions, the IPCC states that it takes a few hundreds of years before the first 80% of anthropogenic carbon dioxide emissions are removed from the air. The bombtest curve shows that it takes less than 25 years.
Paper 2 in the trilogy uses the kinetic relationships derived from the bombtest curve to calculate how much the atmospheric carbon dioxide level has been affected by emissions of anthropogenic carbon dioxide since 1850. The results show that only half of the Keeling curve’s longterm trend towards increased carbon dioxide levels originates from anthropogenic emissions.
The Bern model and other carbon cycle models tuned to fit the Keeling curve are routinely used by climate modellers to obtain input estimates of future carbon dioxide levels for postulated emissions scenarios. Paper 2 shows that estimates thus obtained exaggerate man-made contributions to future carbon dioxide levels (and consequent global temperatures) by factors of 3–14 for representative emission scenarios and time periods extending to year 2100 or longer. For empirically supported parameter values, the climate model projections actually provide evidence that global warming due to emissions of fossil carbon dioxide will remain within acceptable limits.
Paper 3 in the trilogy draws attention to the fact that hot water holds less dissolved carbon dioxide than cold water. This means that global warming during the 2000th century by necessity has led to a thermal out-gassing of carbon dioxide from the hydrosphere. Using a kinetic air-ocean model, the strength of this thermal effect can be estimated by analysis of the temperature dependence of the multiannual fluctuations of the Keeling curve and be described in terms of the activation energy for the out-gassing process.
For the empirically estimated parameter values obtained according to Paper 1 and Paper 3, the model shows that thermal out-gassing and anthropogenic emissions have provided approximately equal contributions to the increasing carbon dioxide levels over the examined period 1850–2010. During the last two decades, contributions from thermal out-gassing have been almost 40% larger than those from anthropogenic emissions. This is illustrated by the model data in Fig. 3, which also indicate that the Keeling curve can be quantitatively accounted for in terms of the combined effects of thermal out-gassing and anthropogenic emissions.
Figure 3. Variation of the atmospheric carbon dioxide level, as indicated by empirical data (green) and by the model described in Paper 3 (red). Blue and black curves show the contributions provided by thermal out-gassing and emissions, respectively.
The results in Fig. 3 call for a drastic revision of the carbon cycle budget presented by the IPCC. In particular, the extensively discussed ‘missing sink’ (called ‘residual terrestrial sink´ in the fourth IPCC report) can be identified as the hydrosphere; the amount of emissions taken up by the oceans has been gravely underestimated by the IPCC due to neglect of thermal out-gassing. Furthermore, the strength of the thermal out-gassing effect places climate modellers in the delicate situation that they have to know what the future temperatures will be before they can predict them by consideration of the greenhouse effect caused by future carbon dioxide levels.
By supporting the Bern model and similar carbon cycle models, the IPCC and climate modellers have taken the stand that the Keeling curve can be presumed to reflect only anthropogenic carbon dioxide emissions. The results in Paper 1–3 show that this presumption is inconsistent with virtually all reported experimental results that have a direct bearing on the relaxation kinetics of atmospheric carbon dioxide. As long as climate modellers continue to disregard the available empirical information on thermal out-gassing and on the relaxation kinetics of airborne carbon dioxide, their model predictions will remain too biased to provide any inferences of significant scientific or political interest.
References:
Climate Change 2007: IPCC Working Group I: The Physical Science Basis section 10.4 – Changes Associated with Biogeochemical Feedbacks and Ocean Acidification
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-4.html
Climate Change 2007: IPCC Working Group I: The Physical Science Basis section 2.10.2 Direct Global Warming Potentials
http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-10-2.html
GLOBAL BIOGEOCHEMICAL CYCLES, VOL. 15, NO. 4, PAGES 891–907, DECEMBER 2001 Joos et al. Global warming feedbacks on terrestrial carbon uptake under the Intergovernmental Panel on Climate Change (IPCC) emission scenarios
ftp://ftp.elet.polimi.it/users/Giorgio.Guariso/papers/joos01gbc[1]-1.pdf
Click below for a free download of the three papers referenced in the essay as PDF files.
Paper 1 Relaxation kinetics of atmospheric carbon dioxide
Paper 2 Anthropogenic contributions to the atmospheric content of carbon dioxide during the industrial era
Paper 3 Temperature effects on the atmospheric carbon dioxide level
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Gösta Pettersson is a retired professor in biochemistry at the University of Lund (Sweden) and a previous editor of the European Journal of Biochemistry as an expert on reaction kinetics and mathematical modelling. My scientific reasearch has focused on the fixation of carbon dioxide by plants, which has made me familiar with the carbon cycle research carried out by climatologists and others.
However, it would appear that his formulae are based on the assumption of a symmetrical reversible kinetic reaction, where the reservoirs were in equilibrium before the testing pulse. This does not appear to account for the preferential absorption and an asymmetric exchange and the fact that the pretest equilibrium is not one with equal concentrations.
I’m sure the equation he is using could be adapted to account for that but this is not really my field. Wouldn’t the same asymmetry in the reaction simply lead to restoring the deficit ratio. I’m not sure that this makes a fundamental difference.
From his graph it would seem that the pre-test C14 ratio was about 50 per mil. What is C14 deficit in ocean vs air. ? IIRC it is of the order of just a few per mil.
http://www.eng.warwick.ac.uk/staff/gpk/Teaching-undergrad/es427/Exam%200405%20Revision/Ocean-chemistry.pdf
There is one major problem with this treatise as well . It starts by defining the flux as being dependent of several factors, including the wind speed. But by the time they get to the end that dependency has slipped by the wayside and on temp and salinity are still mentioned.
Now, it is precisely agitation by wind enhances mixing and speeds up reactions. There is published evidence that it wind speed squared rather than wind speed.
And when we look at how wind speed varies over time it is not something you can wave aside as just averaging out over a few months or even years !
If that is what the IPCC is now calling the Ravelle factor, I’m not surprised that the results do no match reality.
http://climategrog.wordpress.com/?attachment_id=281
The elephant in the atmosphere that no one seems to mention is RAIN.
This is very pure, cold distilled water that has a massive surface area and, by the time it’s falling, has a considerable speed relative to the air.
Before it falls as rain it is suspended in the form of cloud with a surface area probably larger that that of the worlds oceans.
Rain will be scrubbing the atmosphere of its excess CO2 on a 24/7 basis. That is a context in which Ravelle factor will not apply and there is no reversibility.
A primary factor in the air/ocean interaction may be happening while the ocean is still in the air !
Greg says:
July 6, 2013 at 4:21 am
There is one major problem with this treatise as well . It starts by defining the flux as being dependent of several factors, including the wind speed.
The flux depends of wind speed, the Revelle factor does not depend on it. The Revelle factor only defines the endpoint for which everything is in equilibrium. Wind speed only speeds up (or not) the flux to reach the endpoint. That is because diffusion of CO2 in water is very slow.
Greg says:
July 6, 2013 at 5:03 am
The elephant in the atmosphere that no one seems to mention is RAIN.
Sorry to disappoint you: looks more like a mouse in the room…
The solubility of CO2 in pure water is very low. The solubility depends of the pH, which in seawater is alkaline and forms a buffer which can dissolve far more CO2 than fresh water, where the pH gets slightly acidic.
Solubility of CO2 in fresh water at 1 bar is 3.3 g/l at near freezing, less if warmer. See:
http://www.engineeringtoolbox.com/gases-solubility-water-d_1148.html
For 0.4 mbar (ambient air at sealevel, less if at altitude) that gives 1.32 mg/l.
The 400 ppmv in the atmosphere (sealevel) represents 0.6 mg/m3 of air.
Thus 1 l rain contains roughly all the CO2 of 2 m3 air.
When it falls on land, 1 l rain = 1 mm rain/m2, it may double the CO2 content of the first 2 meters above ground, if everything evaporates. Nothing special, as such levels are frequently measured in forests at night (without rain) for a column up to tens of meters. That is rapidely dispersed by wind and turbulence.
If it falls on seawater, the upper 0.1 mm may be sufficient to neutralize all CO2 content in that 1 mm of fresh water.
The evaporation/clouds side is even less important: water vapour is mostly formed with co-emissions of CO2, thus would be in excess where water vapour condensates, plus that air pressure at altitude is lower, thus even less CO2 is dissolved…
Greg says:
July 6, 2013 at 3:05 am
Again Pettersson explains this and how it related to his derivation in paper 1 . It really appears that you have not read his papers at all.
Wait a minute, I have read his paper cursory, and had looked at his formula:
β = Amount/Flux
Which indeed is the definition of residence time. He calls that turnover time, but for me that has the same meaning. No problem with that.
But as I now look at in detail, his interpetation of that definition is quite different. He interpretates that as “removal” while the general definition is “refreshing” or “througput”. Only if it is an unique component that doesn’t return at the input, then he is right. But I agree, even Wiki mixes both definitions.
In the case of the atmospheric CO2, the turnover or residence time is how much CO2 is exchanged over a year with other reservoirs, but that doesn’t change the total amount of CO2 in the atmosphere, as long as the influxes and outfluxes are equal.
It may change the ratio’s of 13C and 14C to 12C, but then residence time is not the only factor, but also what ratio’s return from the other reservoirs.
No problem with the definition of relaxation time, but a problem where he uses the “relaxation time” of the bomb test (which is the result of mainly the turnover rate and the differences in return ratio’s) to the relaxation time of a pulse injection of extra mass. Two quite different, not directly comparable relaxation times…
“Only if it is an unique component that doesn’t return at the input, then he is right. But I agree, even Wiki mixes both definitions. ”
No, he considers the case where it is a reversible process as well. It’s the same equation which in the case of an irreversible process simplifies to the one you gave, and with which he starts paper one.
It is by examining the data for the presence of a residual that you can tell whether the simplification for an irreversible process is applicable. This is what he does.
What you try to do in words he accounts for in eqn 3 with the inclusion of Keq. His eqn 4 shows the effect of this on the time constant. These are the two time constants you are referring to.
It is that fuller version of the equation, which encompasses the question of reversible flow with a longer time constant, that he fits to the data. The result shows it has a minimal Keq and is thus shown empirically to be effectively irreversible.
There remains your C14 dilution argument. Maybe what this study is detecting is an irreversible process that restores that equilibrium difference in isotope ratios. Though I’m not sure how to go about proving that mathematically.
“even Wiki mixes both definitions.” Yes, EVEN Wikipedia can be wrong . LOL
Greg says:
July 6, 2013 at 9:56 am
There remains your C14 dilution argument. Maybe what this study is detecting is an irreversible process that restores that equilibrium difference in isotope ratios. Though I’m not sure how to go about proving that mathematically.
The difference in relaxation times may be a difference in reaction type.
The bulk of the exchanges that govern the 14C decay are temperature related: the equator-poles fluxes are mainly steered by permanent temperature differences and the seasonal fluxes are steered by short term temperature changes. The fluxes are huge and bidirectional. That is what causes the 14C relaxation.
An extra CO2 mass pulse in the atmosphere does influence the temperature induced equilibria over a year by changing the pressure differences between the atmosphere and other reservoirs. The relaxation in this case is pressure related. That is what causes the CO2 mass relaxation, quite independent of temperature changes.
Thus two different reactions, quasy independent of each other, each having their own decay rates…
The goal of this exercise is to determine to whatever extent we can whether human CO2 is the very same CO2 accumulating in the atmosphere. It would be very nice to know this because if it is not the very same CO2 we produced it could mean our combustion is less important.
The papers suggested we can use the 14CO2 produced by atomic testing which occurred at about the same time human emissions began accelerating to gauge how long human CO2 remains in the atmosphere. Objections were raised that the tiny mass of the 14CO2 could not approximate the 400gt mass of the total human “pulse” over the last century and a half. A corollary objection was raised that the fallout time for an individual molecule with negligible mass is different from the absorption of a massive pulse.
The first objection misses the point that the 14CO2 is a marker, not a mass balance term, and the second objection is simply not true unless there is some reason to believe the individual molecule behaves differently in the system than the rest.
Ferdinand suggested such a reason in that 14CO2 disappears preferentially into the thermohaline sink where it will be isolated from the atmosphere for a very long time.
Rats! We need a marker that doesn’t fall in a hole.
gymnosperm says:
July 6, 2013 at 11:59 am
A corollary objection was raised that the fallout time for an individual molecule with negligible mass is different from the absorption of a massive pulse.
Even if there was no massive pulse, the 14C tracer would go down at appr. the same rate as with the pulse (excluding the mass thinning and the 14C-free effect of the pulse). The tracer is following the massive exchanges as result of seasonal and permanent temperature changes, hardly influenced by the extra pressure pushing the unbalance (about 1.5% of the fluxes).
On the other hand, the only possible decrease of the mass pulse is by the unbalance, which is hardly influenced by temperature changes…
Ferdinand–
I much appreciate your amazing willingness to stick with this discussion. I have some questions:
1. If some appreciable portion of CO2 remains in the atmosphere for hundreds or thousands of years, according to the Bern curve, Susan Solomon, etc., is it not the case that as soon as the bomb curve dipped below that fraction (and it is well below 10% now), the argument is disproved?
2. You have said the Bern curve is wrong and both you and Willis refer to a single curve with a 52-year residence time. Could you apply your model to predict the loss of C-14 due to an initial impulse of about twice the background?
3. If there is some question about the isotopic effect, consider the following: I have a bunch of CO2 molecules that I have painted red. These are all standard C12 and O16 atoms. I insert them into the atmosphere and wait until they are perfectly mixed globally. The total number is of negligible mass compared to the non-colored CO2 molecules. Please apply your best model to predict the decay over time of the red molecules.
Willis Eschenbach says:
“Dang … another person who conflates residence time (the average time that an individual CO2 molecule remains in the atmosphere) and pulse half-life (the time it takes for a pulse of excess gas injected into the atmosphere to decay to half its original value). NOTE THAT THESE MEASURE VERY DIFFERENT THINGS. The author is completely wrong to try to compare these two very different measures of atmospheric CO2.
” Residence time” measures how long an individual CO2 molecule remains in the air. This can be estimated in a variety of ways. It is generally agreed that this value is on the order of five to eight years.
Since what the author is discussing is particular individual carbon atoms, he is talking about residence time.
The pulse half-life (or “e-folding time”), on the other hand, is the time constant for the exponential decay of a single pulse of CO2 injected into the atmosphere. This does not measure how long an individual atom stays in the atmosphere. Instead, it’s measuring changes in the overall concentration of CO2 in the atmosphere”
**********************
Mr Eschenbach; You must have missed the fact that the C-14 bomb spike measurements are measurements of “…changes in the overall concentration of (C-14) CO2 in the atmosphere”, and hence are direct measurements of the “e-folding time” as you define it yourself.
The statement:
“Since what the author is discussing is particular individual carbon atoms, he is talking about residence time.”
is completely absurd.
The author is discussing the bomb spike C-14 measurements which are measurements of C-14 concentration in the atmosphere. There is no possible way of tracking ONLY those C-14 atoms which were injected by nuclear tests and distinguishing them from C-14 atoms entering the atmosphere from other parts of the environment. Nothing whatsoever in this essay could possibly lead logically to such a bizarre conclusion.
***********************
And, just to head off another popular but irrelevant objection: Before 1945 (and the start of atmospheric nuclear weapons testing) C-14 was essentially in equilibrium between the atmosphere and the other parts of the environment. Hence, the flow of C-14 from the atmosphere to the environment essentially equaled the back-flow from the environment to the atmosphere. In addition, the ratio of C-14/C-12 remained essentially the same for the atmosphere and most other parts of the environment. If this were not so, radiocarbon dating would not work.
Hence, the CO2 cycle with C-12 and with C-14 were essentially equivalent (except for absolute concentrations) and measuring the adjustment time for one of them would give the adjustment time for the other.
Lance Wallace says:
July 6, 2013 at 12:53 pm
as soon as the bomb curve dipped below that fraction (and it is well below 10% now), the argument is disproved?
No, that is not (yet) disproved, as the 14C decay seems to be quite independent of the excess mass decay. Not that I think that some 14% of the up to current release of 370 GtC CO2 by humans would remain in the atmosphere forever, as the Bern model says. The 14% probably is based on saturation of the deep oceans in the same way as happens for the ocean surface, due to ocean chemistry. But there are differences: the deep oceans are far from saturated and the cold sinks still have a much lower pCO2 than the atmosphere. Thus until now and into the far future, there is no saturation of the deep oceans in sight, neither in vegetation. Thus at maximum, the extra CO2 up to now would increase the atmospheric CO2 content with 1% after full equilibration with the deep oceans.
You have said the Bern curve is wrong and both you and Willis refer to a single curve with a 52-year residence time. Could you apply your model to predict the loss of C-14 due to an initial impulse of about twice the background?
As said in my message just previous yours, the decay rate of the 14C pulse and of the mass injection are quasi independent of each other, thus the 14C pulse will follow its own course, based on the huge seasonal and permanent CO2 exchange rates. Only corrected for the mass thinning and 14C isotope thinning. That is a decay rate of ~14 years. The decay rate of the mass pulse itself remains ~52 years, as that is based on the small net sink of CO2 in other reservoirs, not the exchange rates. In this case, one shouldn’t call it “residence time”, but that is a matter of definition.
Please apply your best model to predict the decay over time of the red molecules.
The red colored molecules, if they are unique and none of them were previously present in any of the other reservoirs, would show a decay rate of ~7 years, slightly more than the 5.3 years turnover of all CO2 in the atmosphere, because some of it will return after the first year from vegetation (leaves) decay and the ocean surface. Halve the 14 years of the 14C bomb spike, as the latter has a continuous 14C return from the past out of the deep oceans (minus 1000 years radioactive decay) and other reservoirs.
The Bern model uses different e-folding times for different sinks. In the real world a large pulse of CO2 such as from a Volcano must decay with a single “effective” lifetime. So if we take that effective lifetime as being 52 years then we can calculate future CO2 levels in the atmosphere caused by human emissions.
Lets assume that emissions remain at current levels (of 30Gtons/year) for ever. Then the CO2 content of the atmosphere would stabilize at 2325 Gtons or 1250ppm. Of course emissions can’t stay at such levels for ever because fossil fuels will become much too expensive. However this does give a scale of what the worst possible scenario would be if we did nothing to address carbon emissions – 1250ppm. This is about 4 times “natural” levels.
Ferdi: “The difference in relaxation times may be a difference in reaction type.
The bulk of the exchanges that govern the 14C decay are temperature related:…”
The bulk of the exchanges that govern the 14C decay are exactly the same as govern C12.
If you want to suggest the bonb curve is something else, you need specifics.
Ferdinand–
Thanks for your response. To question 2, you are predicting the C-14 from the bomb tests will decay with a half-life of 52 years, which appears to me be disproved by the data (14-15 years). But for the red CO2 molecules, you are predicting a residence time of 7 years. Yet to me, the two situations are almost perfectly the same, at least for all the physical-chemical reactions, which are unaffected by the isotope variation. And for the biological reactions, the isotopic difference seems to be small.
You seem to be considering two situations in your discussion. One is a brief very small spike (the bomb). The other is a very large (high mass) change as might occur over time and continued CO2 injection inthe next century. Granted the latter question is of great importance. But this large change will bring about large adjustments and reactions, so the decay rate is made more complex. But the bomb data is not that at all. It is a (relatively) tiny brief impulse, just like the red C12 molcules. Can we agree that these two questions are separate? The high mass injection has no place in this discussion. Just focus on a tiny brief spike, whether of C-14 or red C-12 molecules, that will not cause any change in the rate constants for ocean, land, etc.
You appear to be saying that some of the C-14 molecules from the bomb test have disappeared from the atmosphere and are being replaced by C-14 molecules from various storage places. And this could be the case, except that we have agreed (I hope) that none of the existing CO2 fluxes other than that from the atmosphere have been affected by the small injection of bomb C-14. So the existing flat background of C-14 concentrations in all reservoirs continues to be flat. Perhaps some C-14 molecules from the bomb have entered these reservoirs, but they have been replaced by an equal number of “older” C-14 molecules. So the excess over background of the C-14 molecules, which is what we are measuring, is unaffected by the fraction of “bomb” C-14 molecules that are entering these reservoirs.
Ferdi says:
This is just taking us back to the beginning of the whole discussion. The whole point is that there are two separate effects: out-gassing and residual of mass-injections that work in a similar sense. The whole question is to identify the proportion of each. The cumulative integral (Keeling curve) is fairly featureless for both and leads to confounding the two effects. The rate of change (annual change in the case of Keeling) does show clear variation that provides a means to separate the different causes. That is what Pettersson goes into.
You seem to have (tacitly) accepted that your earlier logic for two different time constants was in fact taken account of by Pettersson’s eqn 3 as I pointed out. Now you are trying to introduce third one with some very hand-waving arguments.
The out-gassing process can be treated separately as long as the system is assumed to be linear but the relaxation time constant has to be the same. The temperature change is simply moving the equilibrium point. It is air-ocean interface.
You erroneous calculation of 800/15 = 5.33 in fact applies to six months not a year. If that is the annual peak to peak swing it has to go there and back so you need to double your result. It then becomes close to Pettersson’s 9 ppmv/annum change from 1998 El Nino that he discusses in paper 2 and my result of 8ppmv/year/K fitting the whole period.
http://climategrog.wordpress.com/?attachment_id=233
I already said you are incorrectly interpreting the flux term which is the time derivative not a pk-to-pk value and that you need to solve that differential equation. In fact, this is exactly waht Pettersson does and you should (re-)read the discussion in paper 2 which shows how such numbers clearly lead to the conclusion of a long term temperature sensitivity of the order of 100ppmv/K.
Since you, Pettersson and I have all derived a similar figure for that by totally different means perhaps you should comment on that implication.
I can see some grounds in the dilution argument for the C14 curve not being representative but suspect the numbers make it too small. You did not reply to my question about the C14 deficit so perhaps you found it was too small as well.
can you comment on whether there is a credible quantitative difference that needs to be accounted for?
oops, should have read 800/150, but still needs doubling, so 10.7 years. Approximating the rate of change over the annual cycle as one linear change going up and one coming down is pretty crude but should give a ball-park figure. Having said that it is not too far from his 14 year result.
I was confusing this his El Nino 9ppmv/annum, that is something else but well worth reviewing. Especially since I got a similar figure from the whole record.
Greg says:
July 6, 2013 at 4:02 pm
Ferdi: “The difference in relaxation times may be a difference in reaction type.
The bulk of the exchanges that govern the 14C decay are temperature related:…”
The bulk of the exchanges that govern the 14C decay are exactly the same as govern C12.
If you want to suggest the bonb curve is something else, you need specifics.
If I may use the same definition for the 14C decay and the CO2 pulse decay as:
β = Amount/Flux
Then the observed decay rate β is 14 years for 14C, 5-8 years as measured by other observations (of which 800/150 = 5.33 years is the shortest) and the observed decay rate for an extra amount of CO2 is 210/4 = 51.5 years (reservoirs in GtC, fluxes in GtC/year, result in years).
Both the 14C and the extra CO2 decay are observed rates. They are quite different. The only explanation possible is that the 14C decay and the surplus CO2 decay are caused by different mechanisms.
The 14C decline is mainly by exchange rates. An extra addition of CO2 (whatever the source) will decrease the exchange rates, as the bulk of CO2 in the atmosphere increased with 30%, while the fluxes hardly changed (in average, the observations of turnovertime seems to be reduced over time). The exchange of 13C and 12C largely follows the same cycle, but as relative more 13C and less 14C return from the deep oceans, 13C will go less down and 14C will go down compared to 12C.
The decrease of an extra amount of CO2 above equilibrium is only by the difference of fluxes. The difference in fluxes is about 4 GtC on a total of 150 GtC cycling through the atmosphere each year. The driving force for the difference in fluxes is the amount of extra CO2 above equilibrium. For all isotopes combined. That gives an extra output of about 2/150 or 1.5% less input and 1.5% more output. That will hardly have any influence on the 13C or 14C decay rate, but is the only way that all isotopes together as total extra mass can decrease over time.
Thus different processes with different decay rates, hardly connected and hardly influencing each other.
Lance Wallace says:
July 6, 2013 at 4:50 pm
you are predicting the C-14 from the bomb tests will decay with a half-life of 52 years, which appears to me be disproved by the data (14-15 years). But for the red CO2 molecules, you are predicting a residence time of 7 years.
No, I was predicting that the 14C from the bomb tests will decay with 14 years, as the decay rates of an isotope (or a colored) pulse of CO2 is the result of a total different mechanism than the decay of an extra CO2 pulse in mass in the atmosphere.
The difference between the 14C bomb spike and the red CO2 spike is that in first instance no red molecules return, while there is already a 14C base present in all reservoirs, which is about half of the initial bomb spike. That makes that the decay rate of the 14C spike is about double the decay rate of the red CO2 spike for the same fluxes.
The 14C level in the ocean surface and vegetation anway will not remain flat, but increase together with the bomb spike within a few years. Thus part of the increase returns in the following years and reduce the decay rate. The same happens with the red CO2. The deep oceans don’t return the extra 14C/red CO2 for centuries, thus these returns are not affected.
Ferdi says:
Ferdi, you seem well read on the the subject but less good on the maths and physics when you go beyond what you’ve read.
I have pointed out at least twice already that your 800/150 is in error. You have no reply to that but carry on as if it was an established fact. I’ll try again. The “flux” term in this equation is not the peak -to -peak value of an annual oscillation and in noway relates to a specific form of cyclic or non-cyclic variation. It is the time differential .
That means you need to solve the ODE or come up with some estimation of the the rate of change. If you wish to do that crudely by drawing a straight line through 6m of efflux and 6m of influx, you could use 150 Gtn / 0.5 years. You’ll see instantly that the answer is 10.7 not 5.33 years for a crude estimation of the time constant of the decay. Compare this to G.P.’s 14 years.
Willis Eschenbach: “Another person who conflates residence time and pulse half-life”
Nick Stokes: “Another post refusing to understand the difference between residence time and replacement time”
Ferdinand Engelbeen:”The basic point of this paper is completely wrong. The residence time has nothing to do with the decay time of some injected extra amount of CO2.”
The basic point of Paper 1 has nothing to do with the difference between residence time and the relaxation time (which I understand quite well and do my best to explain in the paper). It deals with the bombtest curve, which shows that the relaxation of the excess 14CO2 created by the bomb tests conforms to a monoexponential decay function and hence can be characterized by a single RELAXATION TIME estimated to 14 years. That information (describing the ‘impulse response function’ for CO2) is all one requires to estimate how much emissions contribute to increasing the atmospheric CO2 level. It forms the basis for my conclusion in Paper 2 that only half of the increase indicated by the Keeling curve is of human origin.
I do point out, however, that the bombtest curve tends towards a final value that certainly is lower than 5% and consistent with the expected value 1.5%. This means that the removal of excess CO2 from the air is practically irreversible (Keq <0.05), for which reason the residence time would be expected to be practically equal to the relaxation time. Reported experimental values of the residence time may be expected to provide satisfactory estimates of the relaxation time and have been thus apprehended by experimentalists such as Bolin, Revelle, Suess, etc.
So, the available empirical information on the relaxation of airborn CO2 is fully consistent with what one would expect to find when there is a practically irreversible uptake of atmospheric CO2 by one vastly predominant sink (the hydrosphere): An essentially monoexponential decay with a relaxation time of the same order of magnitude as the reported residence times (5–15 years).
The IPCC disregards this empirical information, claiming that the relaxation kinetics are adequately described by the impulse response function prescribed by the Bern model. Parameter values in that model have been so chosen that they result in an impulse response function consistent with the presumption that emissions account for 100% of the CO2 increase indicated by the Keeling curve. The model designers have started with a prejudiced view on the CO2 increase caused by emissions, and as IPCC authors disqualify all experimental data (relaxation times as well as residence times) that are inconsistent with the model. That is not an acceptable approach in empirical science. Paper 1 shows that the Bern model prescriptions are gravely inconsistent with, and therefore falsified by, the empirical observations made.
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milodonharlani says:
> Pockets of liquid water exist within ice which support life. Maybe it’s a semantic distinction as to what constitutes being “in” ice.
>
Indeed it was. By “ice” I meant stuff frozen solid. We know there’s life in cold brine, and it remains active as long as there there are nutrients in liquid phase.
> But then there are also microbes & even lichens which actually live in ice, with their liquid water worlds within themselves rather than outside.
>
> http://www.astrobio.net/pressrelease/1737/life-in-ice
I find that hard to believe. All claims I have seen about life “in” solid ice are based on the detection of biogenic compounds, or on the findings of trapped cells. If you’re a cell trapped in ice, where do you go for food, or what mechanism can you count on to bring food to you? Note that for anything to be going on at all in your liquid world within, you need to maintain fluxes of stuff (protons and other ions) across the membrane.
I don’t even believe active life can exist in isolated pockets of brine. Whatever life there is initially will eventually reach equilibrium and cease.
The other article you posted, “Bacterial growth at -15 °C; …” suggests that there may be a network of connected brine veins in the permafrost:
http://www.ncbi.nlm.nih.gov/pubmed/23389107
In that case, we’re a go (and that’s a great new study I haven’t heard about — thanks for posting it).
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Richard M says:
> Not according to the links I provided. I assume you didn’t read them. I also got the feeling that this subject has had very little analysis done. The error bars looked to be huge and a lot of maybes in the text.
I did read them, but didn’t find them relevant initially because I thought we were talking about the solid phase that is used in paleoclimate studies. Now I see your point. If there are intrusions of liquid phase in ice, how easy is it to avoid them when sampling for trapped gas?
Once again you throw out numbers without explaining you undeclared assumptions. I’m guessing that “4” is half of 8Gtn recent annual human emissions. Thus your undeclared assumption is that 100% or the rise is due to emissions , which implies a 50% residual.
Once again you assume the answer before you start.
Let’s try this other way around: assume GP’s 40% more thermal that emm. residual ie approx 1/3 is due to residual. emissions. Then we have 210 / 4 / 3 = 17.5years. Not surprisingly, that’s close to 14. Of course the crude straight line calculation is not the correct assessment so it’s not exactly the same.
Oh, only explanation possible . As soon as anyone starts out like that, there’s a fair chance they are wrong. Especially with a system as complicated and poorly understood as climate.
Let me highlight some other “possible explanations”:
1. you got the maths wrong
2. you misinterpreted the terms in the equation
3. the model is wrong or insufficient
4. the data is poor and does not reflect the global process you are assuming it does.
….
Not to labour the point too much, I’ll stop there.There may be mix of several factors. Make your own assessment as to which of those may also be possible before making bold declarations about” the only explanation possible” .
So far your attempts to bring in a “second” time constant to explain why 14 years is an irrelevant result do not seem to be justified.
Ferdi says: “…while there is already a 14C base present in all reservoirs, which is about half of the initial bomb spike.”
Pettersson’s paper show the 1963 “excess” as being 950 per mil. So if we are taking about the same thing, I guess that means the “stable” pre-63 level was about 450 per mil.
What is ocean – air deficit that you are suggesting is diluting the C14 pulse and distorting its apparent decay time ?