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.
tallbloke says:
July 2, 2013 at 12:36 am
I didn’t get that number from Henry’s law, that’s pure fantasy. It’s the conclusion of two separate lines of investigation.
One is observational, involving measuring thousands of samples, as reported by Takahashi et al. I also get the same answer by analyzing the EPICA ice core data, 16°C temperature rise causes a doubling of CO2 in those records as well.
I note that despite attempting to discount my numbers (by foolishly making incorrect assumptions about their origin), you have followed your usual practice and not provided the numbers that you think are better.
CITATIONS, TALLPERSON, CITATIONS! This is just more vague mud-slinging. What papers? What data?
w.
“Air-sea gas exchange is a physio-chemical process, primarily controlled by the air-sea difference in gas concentrations and the exchange coefficient, which determines how quickly a molecule of gas can move across the ocean-atmosphere boundary. It takes about one year to equilibrate CO2 in the surface ocean with atmospheric CO2…”
One year? I think it’s even shorter.
http://www.pmel.noaa.gov/co2/story/Ocean+Carbon+Uptake
Look at Fig 2 again. Every 10 years the atmosphere loses 1/2 of the CO2 content. Thats mostly biological. Read the frankpwhite comment, and the Buchholz reference.
This fundamental fact has always been known, see Segalstad, Lindzen and even the IPCC has references that confirm the fact that CO2 does NOT accumulate in the atmosphere. The annual global biological carbon fluxes (sinks and sources) are over 30 times larger than fossil fuel fluxes. The IPCC also shows this simple accounting, that anthropogenic CO2 adds about 3 percent to the “natural” carbon cycles. That means the atmosphere CO2 stream exchanges 1/2 of all CO2 in about 10 years. Since anthropogenic CO2 is 3 percent of the stream, then the 390 ppm CO2 of the atmosphere consists of 12 ppm anthropogenic and 378 ppm “natural” levels. Biological sources and sinks may not be “balanced” due to many factors. It’s obvious that “natural sources” have also increased relative the the sinks to account for the remaining change from 290 to 390. The Bern “model” is not data, it’s conjecture that Houghton spun into the foundation of the IPCC’s claims, and swallowed by the mendacious politicians and media.
It’s the seasonal temperature cycle where it’s at. The exchange coefficient is not the same for seasonal warming (outgasing) and cooling (uptake). Atmospheric CO2 doesn’t return to its starting point after one annual cycle is over.
tallbloke says:
July 2, 2013 at 12:46 am
Once again, you engage in argument by assertion, no citations, no references, no math, no logic—just shooting off your mouth and hoping some sucker believes it. I don’t know why I even bother answering.
Steven Mosher and I both say it’s a mistake. I’ve provided references to my own work, and to the work of Jacobson, to show it’s a mistake. Stokes quoted Freeman Dyson making the exact same point, that conflating the two is an error.
So I fear that tallbloke putting his fingers in his ears and saying that “the empirical data indicates, the residence and e-folding times are substantially similar” doesn’t mean a damn thing to me. They’re not “substantially similar”. They’re quite different, as Dyson points out. And I point out. And Jacobson points out.
Now, if you were to cite the “empirical data” and present a logical argument, you might have something. As it is, your strongly held opinion without a scrap of evidence to support it is meaningless.
w.
PS—Even if the residence and e-folding times were “substantially similar”, the author of this piece STILL conflating the two, he thinks they are the same thing—and that’s still a stupid mistake …
According to Joos’ description of the Bern model linked by the OP at
http://www.climate.unibe.ch/~joos/model_description/model_description.html
A coupling constant of 6.3 W/m2 is used for the logarithmic relationship between CO2 and radiative forcing. The fraction covered by land is 0.29 and the heat exchange coefficient between land and continent is set to 7.2 W/(m2 K), corresponding to an atmospheric relaxation time of 8 days. The equilibrium response of the model for a given radiative forcing, say for a doubling of pre-industrial CO2 is not modeled but prescribed according to results of atmosphere general circulation models. The ratio of the climate sensitivities over land and ocean is chosen in order to obtain a 30 percent warmer equilibrium response over land than over the sea. As a standard, the global climate sensitivity is set to 2.5 K for an increase in radiative forcing corresponding to a doubling of preindustrial atmospheric CO2 (Delta-T(2xCO2)=2.5 K).
No wonder the result is such a pile of crap.
Willis Eschenbach says:
July 2, 2013 at 12:59 am
Even if the residence and e-folding times were “substantially similar”, the author of this piece STILL conflating the two, he thinks they are the same thing
On the contrary Willis, the following passage from the OP clearly shows he is fully aware of the difference:
“(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.”
As I pointed out above, the empirical data shows that the e-folding time is substantially similar to the residence time. It’s certainly nowhere near the 100 years or more the skewed Bern model comes up with.
I don’t need to waste my time digging up references to flawed studies to substantiate this point, since this article contains suitable bibliographic references anyway. So quit flannelling and get on with the science.
Willis, I’ll get to you.
Hoser said:
March 30, 2013 at 9:02 am
The half-life of CO2 in the atmosphere is about 10 years. We happened to perform the experiment by injecting 14C into the atmosphere through nuclear testing [1]. A spike of about 2x the natural concentration of 14C in 1963 has been decreasing since then, back toward normal levels. Quick and dirty analysis of the chart (190% in 1963, 145% in 1973, 122% in 1983, 111-115% in 1993) suggests 10 years is about right, and the 100% level may not be as constant as the chart implies. Too bad we can’t see a clear 14C variation that would likely be due to cosmic ray flux changes.
On the paper, if CO2 is taken up at a higher rate and converted to wood, or falls to the bottom of the ocean as sediment, then NPP-> greater sequestration in absolute quantity would be true. However, would ‘excess’ CO2 be taken up with the same efficiency? In other words, if there were 10% more CO2, would there be 10% more wood or diatom skeletons falling to the ocean floor? If this process is the basis of environmental homeostasis, then you would expect the efficiency to decrease if CO2 falls and increase if CO2 levels rise (negative feedback). Obviously, if CO2 levels fall too far, organisms die and CO2 will subsequently rise. So that part of the story seems likely. Eventually, there would be a level of CO2 too high for many organisms to survive, but that level is unlikely ever to be achieved in the atmosphere.
Regarding CO2 in the atmosphere, let it ride, baby.
1) http://en.wikipedia.org/wiki/File:Radiocarbon_bomb_spike.svg
And now for Willis….
We are measuring a process that is not really the atmosphere is working back toward equilibrium. The CO2 levels are not changing the way the 14C levels are. So what are we seeing?
Generally speaking, the CO2 concentration depends on the rates of CO2 leaving and entering the atmosphere. The rates are the rate constant times the concentration of the gas. As the concentration falls, the rate of CO2 leaving slowly decreases as the concentration falls. The rate the gas leaves is not zero when the CO2 level is at equilibrium. It is balanced by the rate of CO2 entering the atmosphere.
Remember, we are not looking at CO2, but 14CO2.
Because 14CO2 enters a very large reservoir of CO2 when it leaves the atmosphere, the rate of 14CO2 returned from the reservoir is effectively ZERO. However, there is a relatively constant low rate of 14C produced from cosmic rays.
We are not measuring equilibria here. When the rate of 14CO2 loss is measured, it starts from a large spike well above the normal level. Thus, that measured rate is approximately the pure rate of CO2 loss from the atmosphere. 14C is a tracer, with effectively no physicochemical properties different from 12CO2.
The 14C spike is therefore a pretty good single turnover experiment, Wills. The spike is sufficiently large that it is very different from equilibrium conditions and measures exactly what we want. There is no significant backward rate of 14C returning from the large reservoir. The only issue is the much lower approximately constant rate of 14C produced by cosmic rays. However, as mentioned, that rate is very low compared to the measured rate of 14C decrease from the initial spike level, and continuing for about 40 years.
Edim says:
July 2, 2013 at 12:55 am
It’s the seasonal temperature cycle where it’s at. The exchange coefficient is not the same for seasonal warming (outgasing) and cooling (uptake). Atmospheric CO2 doesn’t return to its starting point after one annual cycle is over.
Exactly, the temperature driven effect is cumulative, just like the effect of longer sunshine hours is on ocean heat content, which is what raises the temperature in the first place. CO2 is largely along for the ride.
The empirical data suggests the anthropogenic contribution to the increase in airborne CO2 is around 50%. Not that it matters much, since CO2 only theoretically causes around 1C of warming per doubling anyway, and the water vapour feedback is nowhere to be seen, except in the model output of CO2 obsessed climatologits.
Ok, I’m really tired, I’ll try to make sure the point is a bit more clear. The CO2 rate of loss will be proportional to the observed 14CO2 rate of loss. The slope of the curve on a log scale is the rate constant. You can figure out what t1/2 is from there. And if it still doesn’t make sense, I’ll just enjoy my cup of coffee in the morning, and not worry about it.
Willis, sometimes you might try listening instead of defending yourself all the time. It gets silly.
1. Since much of current CO2 is ocean-derived, there is now a measurable positive feedback, i.e. more CO2 leads to even more CO2.
2. Since we have outgassing, there is no IN-gassing: any apparent change in oceanic pH must have some other reason.
3. Biologic activity, i.e. plancton grow, is well documented in the English Channel and the Antarctic waters to be anti-correlated with CO2 as measured above the water surfaces. We could be seeing biological activity changes as well as thermal changes as responsible for CO2 emissions.
4. The Keeling curve shows the final growth of CO2 in the atmosphere. It has been correlated to emissions; although not causitive, its correlation is not in dispute, so we need not ignore the projection per se.
5. Since we are putting in much faster than the planet is taking out, the residence time becomes moot, except to underscore that the science is not settled. If, however, the oceanic component changes, either from thermal reasons (i.e. the sun isn’t warming as before) or biological ones, the emissions:atmospheric increase will change markedly. The warming by IPCC model will also get out of whack, as anthropogenic input is the only variable, the oceans being sinks of CO2 (and which become more “acidic” as a result).
There is much to considerr in this work, some for and some against CAGW – mostly against. It certainly messes up the narrative, the history and asserted predictability of temperatures.
Am I the only one who finds Willis’s emotional and aggressive responses distracting?
CO2 cycle is governed by a high-order system of equations.
There is no “single residence time” as it would be in the case of a first order eq.
The shortest lifetime is indeed about 3 years.
The next one is however 100 years or so.
IPCC finds out 7 (!) lifetimes.
This behaivour is usual for linear systems.
Just take the simplest damped oscillator.
d^2x/dt^2 + 2*g*dx/dt + w^2 x = 0.
It has two decay times
the fastest one is
g + sqrt(g^2 – w^2)
but there is also a much slower one
g – sqrt(g^2-w^2).
Which one works depends on the way you excite the oscillator.
When it is an “explosion” you excite the short living mode.
If you gently push the oscillator, it is the slow decaying mode.
The same is with CO2.
A bomb deposition of carbon decays very fast.
The slow pollution decays very slow.
From Joos description of the Bern model linked by the OP
” results of the Bern model in general agree with results of A/OGCMs.”
This is the usual circular argument which is the hallmark of CO2 obsessed climatologists:
THEY PARAMETERISED THE BERN MODEL WITH THE GCM RESULTS IN THE FIRST PLACE!
“The equilibrium response of the model for a given radiative forcing, say for a doubling of pre-industrial CO2 is not modeled but prescribed according to results of atmosphere general circulation models.”
DOH!
I think we are eventually going to find that the primary driver of changes in atmospheric CO2 is the amount of sunshine entering the oceans with a substantial correlation between solar activity, jet stream meridionality or zonality and global cloudiness and albedo.
The areas of highest CO2 concentration are above the sun warmed oceans under the subtropical high pressure cells and we can even see them drift to and fro latitudinally with the seasons.
Simply put, the Earth is sunnier when the sun is active and the additional sunlight drives CO2 from the oceans. I have explained the mechanism for the necessary cloudiness changes previously.
When the sun is inactive there is less sunlight and less CO2 emanating from the oceans.
That has a large effect on atmospheric CO2 concentrations for a small change in the amount of sunlight and the ice cores are too coarse a proxy for recording such short term variability as Murry Salby points out.
I suspect that the C13/12 issue is dealt with by decomposing organic material in the oceans being a source of low C!3 CO2 just as is decomposing organic material is on land.
Mosher says
QUOTE
There are some good skeptical arguments let me list them
1. C02 warms the planet, but not as much as the consensus thinks.
Opps there is just one.
UNQUOTE
What he missed is
1.] All other things being equal, CO2 warms the planet. But all other things are not equal. Most sceptics state that.
2.] We don’t understand the behaviour of clouds, aerosols and various other factors influencing the climate. The climate models are pitifully inadequate in these respects.
3.] 73 different Climate models supposedly using the ” same basic physics ” arrive at wildly different values. Averaging those values and calling them model ensemble is pure unadulterated nonsense. An average of a collection of crap remains crap. Model runs are not experiments and model outputs are not data. Mosher should repeat these daily till it sinks into his head.
4.] The honest answer is that we still do not have enough knowledge or information to understand how the climate system works and are barely scratching the surface. So based on the knowledge and the crappy output of the models, it is in no way acceptable to proclaim that the science is settled and advise policymakers to take bad decisions involving billions of dollars and negatively affecting millions of lives.
5.] Not a single instance has been shown by empirical evidence or any other evidence [ except scaremongering stories from rabid CAGW adherents ] that a mild amount of warming causes any harm. The benefits of a moderate amount of warming have been totally ignored.
6.] It is ridiculous to expect people to suffer and die today by making energy expensive with the vague promise that the world could be 0.02 degrees cooler in a 100 years, a claim not matched by any empirical evidence and completely untestable by anyone living today. The proponents can never be held responsible for their actions as they would have long gone. But the suffering today happening to people being denied cheap energy is real and lives are being lost.
Anyone with half a brain reading WUWT knows very well that these points have been enunciated again and again by a lot of sceptics, especially prominent people like Anthony, Willis Eschenbach, Dr.Robert Brown, Lord Moncton etc. For Mosher to blithely state the skeptic position in one line as a certainity, is a willful distortion of the truth. It is a false statement. But that is how he has been behaving and trolling off late, with drive by commentary, snark and hate.
@mosher @willis
“Want to destroy your credibility on the one good argument? make a bunch of mistakes on issues like the one in this post”
There are quite a few measures of credibility, including how one responds to criticism. I might add to that, how willing someone is to toss out bald assertions like “destroy” in a comment.
Pettersson’s bio doesn’t strike me as that of a dilettante; maybe he’s aware of the distinction and has a rationale for his treatment of the two effects; maybe he’s wrong.
But certainly it’s worth seeing what the response is.
“But the nett flux is into the sea, not out of it. And not into the land biosphere, where the total mass of C, at about 700 Gt, is not that much more than the 400Gt we’ve burnt. ”
Key points; are they assumed or do you have non-modelled data?
“A bomb deposition of carbon decays very fast.
The slow pollution decays very slow.”
Interesting point Alex; what physical mechanism would do that?
The biological factors shouldn’t be omitted in this debate. There is a strong correlation between fish stocks and the ~60yr oceanic cycles. This is food chain derived. If there are less fish in the warm phases of the ocean cycles then it is because there is less food for the to eat. At the base of the food chain are the plankton.
Less plankton –> less co2 uptake and less ocean bed deposition of carbonaceous shells –> more airborne co2.
Georg Ernst Beck’s data showing the spikes in Airborne CO2 in the 1880’s and 1940’s substantiates the idea that this is an important factor.
If, as my rough calcs indicate, (and given our ignorance of large chunks of the carbon cycle performing detailed ones would be an error of false precision) the human contribution to the rise in CO2 is around 50%, we would expect to see a flatlining of CO2 levels over the next thirty years or so.
bw says:
July 2, 2013 at 12:53 am
It’s obvious that “natural sources” have also increased relative the the sinks to account for the remaining change from 290 to 390.
And some natural sinks have diminished, such as the plankton effect I note above.
No, Stephen.
The author has, as Willis and other have already mentioned, made the error to equal residence time for individual molecules to decay time of the gas. These are very different things and make the whole argument meaningless.
Since obviously so many people mix these things I have made an analogy which I think can be clarifying.
Imagine a leaky bucket standing under an open tap. The water level is an analogy to the CO2 in the atmosphere. The leakage is the natural sinks and the open tap is the natural sources.
The water level is then held constant at 280 mm (280 ppm), and the stream and leakage has a magnitude that renews all the water in the bucket over a period of nine years.
Each water molecule (CO2 molecule) then has an average residence time of 9 years.
What happens then if we put an extra cup of water in the bucket?
The water level increases and the leakage also increase until the water level has again sunk to the equilibrium level. The pulse half-life is the time it takes before the excess water level is a half of what it was after the cup was poured.
The important point is that there are no connection between the residence time for the water molecules and the time it takes for the water to sink. The latter is dependent of how much the leakage changes in response to a change in the water level; the residence time is dependent on the leakage itself.
The Bern model describes the amount of this change in leakage.
The author here talks about the magnitude of the leakage.
“Am I the only one who finds Willis’s emotional and aggressive responses distracting?”
No, it would be much better and more productive to deal with this stuff calmly and in a matter of fact way.
Hoser says:
July 2, 2013 at 1:20 am
Ok, I’m really tired, I’ll try to make sure the point is a bit more clear. The CO2 rate of loss will be proportional to the observed 14CO2 rate of loss.
No, complete different mechanisms at work: the reduction of 14C is mainly a matter of exchange rate with the other reservoirs: part goes into the ocean surface, part goes into vegetation and part goes into the deep oceans. The 14C exchange is fast, but two-sided with ocean surface and seasonal vegetation changes, but slower with deep ocean exchanges and longer term vegetation deposits (peat, roots, browncoal, coal). What goes into the deep oceans is the current composition of the atmosphere (plus the isotope fractionation over the air-water border), what comes out is the composition of the deep oceans, which is poorer in 14C.
The dilution of 14C in the atmosphere is mainly a matter of turnover: mostly over the seasons large amounts of CO2 are exchanged: about 50 GtC with the ocean surface and about 60 GtC with vegetation in and out over one cycle. Together with the continuous about 40 GtC exchange between the equatorial and polar waters, that gives some turnover of 150 GtC / 800 GtC or about 20% of all CO2 residing in the atmosphere per year. Or a residence time of ~5 years. As part of the 14C returns next season from the ocean surface and vegetation, the real residence time of 14C is somewhat longer.
The removal of any extra CO2 (whatever the source) is a different matter: That is a matter of CO2 level (= partial pressure of CO2), compared to the equilibrium CO2 level. That level is currently about 110 ppmv (222 GtC) above the equilibrium level for the current temperature. The net result is a removal of some 4-5 GtC/year as CO2 after a full seasonal cycle. That gives an e-fold decay time of 222/4.5 = 49 years or a half life time of ~35 years. Quite a difference with the residence time… Also much shorter than the Bern model, but that is another discussion…
As said before by Willis and others, the residence time of a CO2 molecule in the atmosphere and the removal of some excess CO2 are two very different things, with hardly any connection between the two.
Just curious as I can find plenty of papers on CO2 and / or atmospheric water vapour but not on the uptake and / or out-gassing of CO2 by atmospheric water vapour if that actually occurs
.
Everybody talks about the out-gassing or absorption of CO2 by the ocean waters as they warm or cool.
But how much CO2 does the atmospheric water vapor bind in the total of all CO2?
The surface reaction area of the clusters of atmospheric water vapour molecules available for CO2 binding is infinitely greater than in an ocean water situation so the amount of CO2 bound up by the atmospheric water vapour might be magnitudes higher per WV volume than in an open ocean with only it’s surface layers exposed to any binding / out-gassing of CO2
Assuming some CO2 is bound to atmospheric water vapour, is this bound CO2 ever actually measured or allowed for?
Does this atmospheric CO2 get released from it’s binding with water vapor molecules as the atmospheric temperatures increase?
As the stratospheric water vapour content has shown a slight apparent decrease over the decades, have the stratosphere’s CO2 levels changed closely in line with the tropospheric CO2 levels or are stratospheric CO2 levels indicating detectable differences between the CO2 uptake mechanisms of the stratosphere and the troposphere?
Are there day / night changes detectable in atmospheric CO2 as the atmosphere warms and cools over every 24 hour cycle?
If so Why?
We know there are seasonal changes in atmospheric CO2 generally attributed to the uptake of CO2 by newly germinated plants and the rapid growth in spring along with the release of CO2 or reduced plant uptake as the season moves into it’s winter phase and plant growth and plant death quite dramatically reduces CO2 uptake.
Or that at least is what we are told.
What if some of those changes were attributable to not only out-gassing of oceans but also due to the release or uptake or the out-gassing of CO2 by the atmospheric water vapour as the atmospheric temperatures change as the season’s change ?