Readers may recall claims of 1000 year residence times for CO2. This essay suggests a much shorter interval. -Anthony
Guest essay by Leo Goldstein
Surplus CO2 is removed from the atmosphere by natural sinks at a rate proportional to the surplus CO2 concentration. The half-life of the surplus CO2 concentration is approximately 40 years. This is the conclusion of my research paper, published on defyccc.com today.
I am grateful to Prof. Fred Singer and Prof. William Happer for their help in writing this paper.
The correct (although approximate) formula for CO2 concentration leads to a number of conclusions of public interest:
- CO2 concentration in the atmosphere will increase much slower than has been claimed by the IPCC.
- A relatively small part of the anthropogenic CO2 in the atmosphere has been released by the US; a relatively large part of the anthropogenic CO2 has been released by China.
- If stabilizing or decreasing atmospheric CO2 content becomes desirable at some point in the future, that can be achieved by decreasing anthropogenic CO2 release at that time; no premature action is needed.
- The warming effect of anthropogenic CO2 is less than the warming effect of other gases and aerosols (according to IPCC calculations) in both the short and long term, so what are the motives behind this laser focus on CO2?
The topic of the CO2 removal rate has been discussed a number of times on WUWT (by Christopher Monckton of Brenchley, Docmartyn in comments on Dr. Lindzen’s article, Anthony Watts and others), and various opinions were expressed. Estimates of the half-life varied.
For some time, the subject was surrounded by confusion, created by sloppy definitions and evasive statements in IPCC assessment reports. There was a mix-up between the residence time of a CO2 molecule in the atmosphere and the rate of change of the surplus CO2 concentration. The residence time (~5 years) is of little interest, except as an indication of quick carbon turnaround. The true subject of interest is the rate of change of the surplus carbon concentration in the atmosphere. Another issue was the link between CO2 concentration and temperature. On the geological timescale, the rise in CO2 concentration tends to follow the temperature rise, concurring with a hypothesis that the latter causes the former. Nevertheless, such an effect is not significant on the multi-decadal scale. CO2 concentration in the atmosphere grows mostly because of anthropogenic release of CO2 through fossil fuels combustion and land use changes.
The paper’s full title is Simple Equation of Multi-Decadal Atmospheric Carbon Concentration Change. It is article-length (~5,000 words, not counting references), citable, and discoverable by search engines, including the Climate Sanity and Freedom Search. In a slight departure from a widely-used academic format, the paper contains a Summary (for busy readers). The abstract is as follows.
Surplus CO2 is removed from the atmosphere by natural sinks at rate, proportional to the surplus CO2 concentration. In other words, it undergoes exponential decay with a single decay constant. This conclusion is rigorously proven, using first principles and relatively recent observations of oceans. Historical data for CO2 concentrations and emissions from 1958–2013 are then used to calculate the half-life of the surplus concentration. This theoretically derived formula is found to be an excellent match to the historical CO2 concentrations over the measurement period. Furthermore, the “initial” CO2 concentration in the formula came out to be very close to the likely “pre-industrial” CO2 concentration. Based on the used datasets, the half-life of the surplus concentration of CO2 in the atmosphere is found to be approximately 40 years.
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http://wattsupwiththat.com/2013/03/29/james-hansen-says-coal-is-greening-the-planet/#comment-1261256
and subsequent posts by Hoser.
The 14C bomb spike data make the off-rate of CO2 from the atmosphere crystal clear. It doesn’t matter what the peer reviewed papers say. You can see for yourself, and the truth is undeniable if you understand math.
Here is the math.
http://wattsupwiththat.com/2013/11/21/on-co2-residence-times-the-chicken-or-the-egg/#comment-1481426
The 14C tracer experiment measures very cleanly the rate at which excess 14C leaves the atmosphere. The key point is the CO2 leaving doesn’t come back to any significant degree. The other reservoirs (e.g. ocean, forests, soil) are much larger than the atmosphere.
If you try to use the IPCC estimates of world anthropogenic CO2 production since 1750, assuming ~280 ppmv in 1750, and assuming humans were the only source of excess CO2, you can’t match the Mauna Loa atmospheric CO2 increase curve knowing CO2 has a 5 yr half life. Although CO2 is exponentially increasing in both curves (data and model), a linear fit is a reasonable estimate over 50 years. These linear fit slopes are in no way a close match. There is simply no way human CO2 releases can account for the increase in CO2 measured at Mauna Loa. The only likely alternative is natural variation. A massive positive CO2 feedback acting over about 1 °C has no reasonable physical basis, and therefore is not likely to be a realistic explanation for the observed CO2 increases.
Any 14C coming from a reservoir would be part of the process maintaining the normal 14C balance and not part of the bomb excess. Why? Because the 14C coming from the other reservoirs is no different before, during, or after the bomb spike. The reservoir 14C concentration doesn’t change significantly.
Hoser,
A repeat from above:
There is a confounding factor:
What goes into the deep oceans is the isotopic composition of today. What comes out the oceans is the composition of ~1000 years ago (minus the nuclear decay). That gives at the height of the 14C bomb spike for 100% sink of 12CO2 and 14CO2 (1960) some 97% of 12CO2 returns (as mass) but only 97% x 45% (as mass x concentration) of 14CO2 returns.
That makes that the 14CO2 decay rate is at least 3 times faster than a 12CO2 excess decay rate…
A few years ago, Dr Klaus L E Kaiser proved the Royal Society’s claim – that CO2 remains in the atmosphere for thousands of years – was false.
Dr Kaiser published evidence showing the Royal Society had erred in its calculations, demonstrating that existing peer-reviewed studies found that CO2 only remains in the atmosphere for about 12 years. The studies reported the half-life of CO2 in the atmosphere to be between 5 and 10 years. Dr Kaiser calculated that a half-life of five years meant that more than 98% of a substance would disappear in a time span of 30 years.
Dr Kaiser also came up with a real killer question – If CO2 were to stay in the atmosphere for millennia, then why had its level in the atmosphere not doubled in the previous 15 years, or gone up tenfold-plus over the previous 100 years?
Dr Kaiser proved that the claim of the Royal Society was ‘clearly untenable’ and admonished it for failing to do a few ‘simple order-of-magnitude calculations’ so as to check the veracity of its claim that CO2 remains in the atmosphere for millennia.
Mervyn,
You can return the claim: if the decrease rate of the CO2 injection was that fast, why wouldn’t the increase of CO2 in the atmosphere be much lower than about 50%?
Dr. Kaiser used the wrong decay rate, as good as the IPCC errs in assuming saturation of the main sinks: deep oceans and vegetation…
It is likely CS is about 0.3, much less than even the modest 1.7 used in the article.
The 14C bomb curves are conclusive and obvious. Atmospheric CO2 has a “permanent” sink of 50 percent in 10 years. Eg. 1/2 of the total CO2 in the earths atmosphere in 1965 was removed by 1975. In 10 more years the 1965 CO2 was halved again, leaving 25 percent. Simultaneously, a deep natural source was adding “new” CO2 to the atmosphere at about the same rate. Very small changes in these enormous “permanent” sources and sinks have caused the apparent CO2 increase. Human addition amounts to about 3 or 4 percent of natural fluxes. So .03 of 400ppm is 12ppm. The rapid destruction of old tropical forest biology adds another 1 percent. At most the amount of anthro-CO2 now in the atmosphere is about 20 ppm. The 10 year loss of 1/2 of all CO2 translates directly into a tau of 16 years.
http://euanmearns.com/whats-up-with-the-bomb-model/
CO2 is essential to photosynthsis. Plants have been starving for CO2 for millions of years. So dire is the extreme low levels of atmospheric CO2 that plants have been evolving more efficient extraction mechanisms. Such evolution is very obvious to any botanist. Such evolution would not occur if it were not essential to plant survival.
Anyone who claims that CO2 stays in the atmosphere for a thousand years is just clueless.
“bw
November 24, 2015 at 8:50 pm
So .03 of 400ppm is 12ppm.”
This is exactly what I have been saying for many years here in Australia. I then quote the following; Total human contribution is ~3% of ~400ppm/v, which is ~12ppm/v per year. Australian contribution is estimated to be ~2% of that total. So that equates to ~2% (Australian contribution) of ~3% (Total human contribution) of ~400ppm/v (Total atmospheric concentration) = 0.24ppm/v per year. And Turnbull recons we need a carbon tax?
dadgervais,
What exactly happens in the deep is not accurately known, but what is known is that it takes a lot of time between polar sinks and equatorial – or in between – upwelling. Over 100 years is enough to dilute the 14CO2 bomb spike with waters that contain less than halve the 14CO2 concentrations.
That makes that the 14CO2 bomb spike decay is a lot faster than a 12CO2 spike decay…
bw,
Again, there is a confounding factor:
What goes into the deep oceans is the isotopic composition of today. What comes out the oceans is the composition of ~1000 years ago (minus the nuclear decay). That gives at the height of the 14C bomb spike for 100% sink of 12CO2 and 14CO2 (1960) some 97% of 12CO2 returns (as mass) but only 97% x 45% (as mass x concentration) of 14CO2 returns.
That makes that the 14CO2 decay rate is at least 3 times faster than a 12CO2 excess decay rate…
Here in graph form:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/14co2_distri_1960.jpg
14CO2 has chemical properties identical to 12CO2. That is the basis for all tracer science.
Saying that 14CO2 has a mass dilution much greater than 12CO2 is like saying that CO2 is not the same as CO2.
Release one liter of 14CO2 at say one meter over the ocean surface, Release a liter of 12CO2 nearby as a control. Then observe the diffusion or dilution of those liters of gas into the surroundings. Both will behave exactly the same because both are carbon dioxide. Or, a coal power plant smokestack releases only 14CO2 because only 14Carbon coal were burned. An identical smokestack 100 meters away releases only 12CO2 because the coal is made of only 12C. The observation of the fate of those emissions will show no difference on any time scale.
The observation of the atmospheric 14C atomic bomb curve is exactly the same. See the curve at
http://euanmearns.com/whats-up-with-the-bomb-model/
The 14C peak of 1964 declines by 1/2 in ten years. That is direct observation that 1/2 of ALL atmosphere CO2 is removed into long time period sinks of the global biogeochemical cycle. That mass decay curve is identical to a Tau of 16 years. There are many people who say exactly the same thing. Such as Segalstad, Pettersson, Dietze, etc.
“What comes out the oceans is the composition of ~1000 years ago (minus the nuclear decay)…”
That assertion/assumption is a mere guess with no data to support it. I agree that it probably takes about 1000 years for the descending water to return to the surface half-way across the globe. But, what happens to it during its journey is unknown and, at present unknowable.
The deep ocean is known to have rivers, lakes, seas even, of liquid CO2 that the water floats on top of. Then there are deep ocean vents, undersea volcanoes, etc.; and probably more than we suspect. The condition of the returning water may be significantly different than the water that sank a thousand years ago. We have no way of knowing and no justification for guessing.
As a smart man (my dad) once told me, “A rational person never confuses what they imagine with what they know!”
bw,
Dietze found a half life of 40 years, the same as Ari Halparin:
http://www.john-daly.com/carbon.htm
There is hardly any difference between the uptake of 14CO2 and 12CO2 into the deep oceans: that is just a matter of concentrations (and a small shift due to the difference in mass/uptake speed).
The problem is that not the same composition returns from the deep oceans: that is the composition of ~1000 years ago, long before the bomb spike, which is only 45% of the concentration of the bomb spike that did go into the deep oceans in the same year.
Thus what returns is about 97% in mass for 12CO2, but for 14CO2, that is 97%(mass)*45%(concentration). A lot less that for 12CO2…
The 14CO2 bomb spike decay thus is at least 3 times faster than for an excess 12CO2 decay…
On April 19 2015, Willis Eschenbach posted this excellent article:
http://wattsupwiththat.com/2015/04/19/the-secret-life-of-half-life/
This article shows calculations indicating that CO2 has an atmospheric time constant (“tau”) of 59 years, and a half-life of 41 years, assuming that exponential decay describes its removal from the atmosphere by nature including the oceans. There is cause to consider that exponential decay is an oversimplification, and the actual decay curve for an injection of CO2 into the atmosphere is a Bern model – faster at the beginning, and slower later on.
1,000 years is not what I usually heard. I usually heard from most sources claiming that AGW is a problem that CO2 has an atmospheric lifetime of 100 years.
“1,000 years is not what I usually heard.”
One reads lots of numbers (with zeros) – meaning they have got to be wrong.
Specifficaly, you can find the “thousands” thing Here, via the EPA</strong.
“… but some will remain in the atmosphere for thousands of years, …“
Sorry, poor typing, but the link works.
“1,000 years is not what I usually heard”
Indeed. If you look at the paper cited, it doesn’t give a figure at all. It is establishing, as you have been saying, that there are multiple timescales and, contrary to Mr Halperin’s assumption, it isn’t simple exponential decay. That paper says that one of the slower processes, deep ocean circulation, has a time scale of about 1000 years.
As I think you said elsewhere, it is quite possible that half of a pulse of CO2 would have left the atmosphere in 40 years. Some might say longer. But 40 doesn’t mean the next half will leave in the next 40 years. It isn’t simple exponential. The Bern model tries to express that.
Question, Rainwater is slightly acidic due to dissolved CO2. What percentage of atmospheric CO2 is removed through being dissolved in rainwater and transferred to the oceans on an annual basis?
Robert,
Hardly any: CO2 solubility in fresh water is extremely low: a few mg/l at 0.0004 bar CO2 pressure. Not measurable in the atmosphere where the raindrops are formed and maximum 1 ppmv for 1 mm of rain / m2 if that all evaporates in 1 m3 air.
Most of water evaporates where most of CO2 is released to. Even with a low solubility, still huge quantities of water – and thus CO2 – are moved, but that is largely circulation. Only what drops on land can react with carbonate rocks to form all these beautiful caves, but even that needs millions of years…
Calling Ferdinand Engelbeen….
http://members.casema.nl/errenwijlens/co2/co2afname.gif
Yes. The Bern (IPCC) model says about half gone in 40 years, much as does Ari Halperin. But then it slows.
Nick,
The main difference is in the deep ocean sink rate, where there is no sign of saturation: the cold polar waters still are 250 μatm below atmosphere…
The Bern model is based on 3000 and 5000 GtC emissions, far beyond the current ~400 GtC emissions over the past 165 years. That gives the huge residual increase in the Bern model. The up to current emissions are good for a residual 1% increase in the deep oceans at full equilibrium or about 3 ppmv in the atmosphere…
Ferdinand,
Yes. The Bern model is essentially a curve fit of multiple exponential decays to the data, and it is simple to make any such ‘model’ fit the data, even if the model is not at all able to make accurate projections. There are far too many free parameters for the available data to in any way constrain the model.
The use of absurd assumed levels of total cumulative CO2 emissions (12 times emissions through 2105!) makes the long term projections of the model dubious at best, and perhaps more accurately described as ‘crazy’. Were the model run with more realistic total emissions (say 3 or 4 times cumulative through 2015 as a maximum), then the long term residual in the atmosphere would be much lower. But that is not the scary story some want to tell.
The combination of uncertainties in total emissions, sink capacities (including terrestrial plants), and sink time constants means we need much more atmospheric data to know if the Bern model makes meaningful predictions. My guess: it probably overstates the persistence of CO2 in the atmosphere over all periods.
Hi Hans,
Mentioned your graph already somewhere up…
I recently (accidentally/carelessly) landed on SKS while searching for a factoid and wound up reading the post and comments out of curiosity. The gist of the article was that human CO2 was increasing at a given yearly rate and half of each year’s increase was being added to the atmospheric concentration.
To the SKS author and commenters, this could only mean that the sinks were being overwhelmed and many had reached saturation. Catastrophe sure to follow! Most of the content seemed unhinged, and I won’t be returning any time soon.
How ever, the behavior of the increase in atmospheric content being equal to half the increase in human production on a year-to-year basis seemed quite familiar to me, and nothing to be concerned about.
This behavior is typical of a distribution channel with an average distribution delay (holding time) of 6 months. Since the atmosphere neither produces nor consumes any significant quantity on its own, it certainly functions as a distribution channel: accepting all CO2 produced by the sources, and delivering it (at random) to all sinks to consume.
1. Since the CO2 is a waste product as far as the producers are concerned (if not, they wouldn’t be releasing it), we may assume that producers operate at their capacity to produce.
2. Since the atmosphere has, in the geological past, held much higher concentrations, the distribution channel is certainly not near its holding capacity.
3. Since the majority of sinks evolved in geological periods of much higher concentrations it seems absurd to assume that many (or any) are near their capacity to consume at current levels. Therefore, their consumption rate must be supply-constrained and they must consume all that is delivered. By definition, consumption rate equals delivery rate in any distribution channel.
By way of illustration, consider a distribution channel with a large number of suppliers (all producing to capacity) and a large number of consumers (all consuming everything delivered). If the channel itself is not significantly changing over time and production rate is (more or less) constant, then the steady state will have consumption rate equal to production rate, and channel loading equal to the production rate multiplied by the average holding time (when expressed in the same time units). Take this be be a baseline.
Now, assume that one producer finds a way to continuously increase their capacity to produce by one unit each six months. If we examine just the increase in production, consumption, and channel loading (i.e. totals net baseline), then with an average distribution delay (or channel holding period) of six months we would observe the following.
each 6 month period
prod 1 2 3 4 5 6 7 8
cons 0 1 2 3 4 5 6 7
dist 1 2 3 4 5 6 7 8
We now consider what this would look like on a year-to-year basis.
yearly results
eoy prod 3 7 11 15
eoy cons 1 5 9 13
eoy dist 2 4 6 8
So, after the first year, production increases by 4 units per year, consumption, likewise, increases by 4 units per year, and the quantity in the distribution channel increases by 2 units per year — one half the yearly increase in production. Exactly what any sensible analyst would expect.
Of course, this also suggests the following: At current concentration levels, the total quantity of CO2 in the atmosphere (or, perhaps, the troposphere) should be (approx) equal to the total CO2 produced by all sources in the last six months, and the total CO2 consumed by all sinks in the last six months should be (approx) equal to the total CO2 produced by all sources in the previous six months. This is, of course, not even close to current estimates (WAGs) of either. In any other field, if these ratios did not hold, I would insist that the accountants have significantly mis-counted something. There’s a lot of undetected producin’ and consumin’ goin’ on. Is that possible? Let’s see, we Know there are about 400 billion trees on earth, or maybe that’s 3.1 trillion… duh!
—————
I used a simple discrete case above since some commenters, and many more silent readers, without a lot of math background will see the reasoning more clearly. But, the same conclusion results from considering the continuous case. It takes more than one period to hit the observed ratios, but it asymptotically approaches the above results rather quickly.
The second, continuous (approx) model would be to consider
yearly results as a function of time (y = year)
eoy prod P(y) = 4*y – 1
eoy cons C(y) = 4*y – 3 = P(y – 0.5)
eoy dist D(y) = 2*y
The (indefinite) integral of P(y) is 2y**2 – y + c; and the definite integral from y-0.5 to y is the accumulated quantity in the distribution channel, 2*y.
The third continuous model would consider (perhaps) a geometric growth rate (think compound interest) in production along with an inverse exponential decay rate of existing CO2. This will always be the case if consumers are not saturated and random deliveries are normally distributed about the mean.
The function exp(-t) gives a half-life of -ln(0.5) and a life expectancy (average holding time) of 1.
We would re-scale this function so that life expectancy is 6 months; the half-life is approx 4.25 months.
And, by the magic properties of exp(-t) and the fact that CO2 molecules do not age, both the half-life and life expectancy remain constant no matter how long any individual CO2 molecule actually exists. The resulting model would again quickly approach a two-to-one ratio between increased production and increased channel loading.
I’m sure to hear that I’m out in left-field on this because “climate science”, however, It will be the first time in my life (I’m now retired) that I encounter a distribution channel that does not behave as one.
dadgervais:
Thanks for your good post. I think you may be interested in my post that is here.
I wish more people would emulate your effort to investigate what is happening.
But, sadly, many people are trying to find evidence that supports what they want to claim is happening.
Richard
Mr. Courtney:
Thank you for your reply.
Golly, If that pulse dissipated in three years, that would be about 8 of “my” half-lifes (99.5% gone). Maybe I’m not as far out in left-field as I thought?
My “investigation” is more like a back-of-a-cig-pack guesstimate based on rough rules-of-thumb from fields far removed from “climate science”; I don’t have time to devote to much more than that.
But, the seasonal variation in CO2 being three to five times the year-to-year increase (depending on monitoring site location) and the fact that individuals with personal CO2 measuring devices in rural areas report local concentrations vary greatly from the morning high to the afternoon low on a daily basis (often by 15 to 20 percent) has always suggested to me that life expectancy of CO2 (at current concentrations) must be measured in (at most) years; not decades or centuries.
Thanks again,
–dadgervais
Excellent, thank you.
The pH of rainwater varies from about 4.5 to 6.0 as a result of absorption of atmospheric CO2. The CO2 concentration in rain is only about 350 ppm by weight. One inch of rain over a square mile of ocean will wash about 50,000 pounds of CO2 from the atmosphere.
Usually you only see errors of that magnitude in the unemployment statistics.
Ari Halperin:
Thankyou for your interesting essay. Its conclusions result from the basic assumption you have adopted for your model; viz.
That inherently assumes there is a “surplus carbon concentration in the atmosphere” which sinks for carbon dioxide(CO2) cannot sequester because they are overloaded by the rate of emission of the CO2.
And it leads to your modelling assumptions that
which – in turn – provides your model’s indication that
If the sinks are overloaded then ANY increase to CO2 emission from ANY source would increase the overloading to provide a ‘pulse’ that would be sequestered with a half-life of ~40 years. But that does NOT happen.
This assertion of the sinks being overloaded is presented as the IPCC’s erroneous Bern Mode, by Ferdinand Engelbeen, and by others who now include you.
An alternative understanding of the cause(s) of the rise in atmospheric CO2 concentration was provided in one of our 2005 papers
(ref. Ref. Rorsch A, Courtney RS & Thoenes D, ‘The Interaction of Climate Change and the Carbon Dioxide Cycle’ E&E v16no2 (2005))
and was later independently provided by Salby (as several have noted in this thread).
Basically, the alternative explanation is that something has altered (or is altering) the equilibrium state of the carbon cycle system. Some processes of the system are very slow with rate constants of years and decades. Hence, the system takes decades to fully adjust to a new equilibrium. The human emission may be altering the equilibrium but other factors are more likely; e.g. the temperature rise that has been happening for centuries since the Little Ice Age.
This issue has recently been argued between Ferdinand Engelbeen and me on a thread on Jo Nova’s blog. The argument begins here.
Tom Quirk had analysed a ‘pulse’ of 9Gt of CO2 in the atmosphere and said
He used isotope analysis to determine that the ‘pulse’ derived from increased emission by oceanic plant material; i.e. it was not a result of sink rate variation.
I repeatedly pointed out to Ferdinand (who responded with waffle, evasions and irrelevancies)
In summation, Ari Halperin, your analysis is sound except that its result is a reflection of your basic assumption which is refuted by observations.
Richard
There is a very simple point If the total capacity of the globally available carbon sink is growing year on year (as must be the case since the annual increase in atmospheric CO2 is less than the annual anthropogenic CO2 emissions), the totality of the sinks cannot be overloaded/exhausted.
richard verney:
You make a good point, but I think there is a much more important point that is being ignored by most people posting to this thread.
I repeat the important point using slightly different words in hope that people will consider it.
About half of the pulse of an additional 9Gt in 1989 – 1991 would have remained in the atmosphere for ~40 years if the “half-life of the surplus CO2 concentration is approximately 40 years”. But ALL of that pulse was sequestered in less than 3 years.
That pulse having been sequestered in less than 3 years demonstrates that the sinks are NOT being overloaded. And if the sinks for CO2 are not being overloaded then CO2 from human activities are NOT overloading them to cause the rise in atmospheric CO2.
Richard
Richard Verney,
The sinks do grow in ratio to the extra pressure difference between atmosphere and oceans. Human emissions are twice the current sink capacity, thus they overload the momentary sink rate with a factor 2. That doesn’t imply that the total sink capacity of the deep oceans is exhausted, as that can have much more human CO2. Only the momentary sink rate is overloaded, as the exchange rate between deep oceans and atmosphere is limited…
I think that there are a number of ways at looking at this, and the point you make is important. It is indeed stark, and the explanation for its removal probably lies in the La Nina that followed, which goes to suggest that temperature is the dominant driver, and CO2 is a response.
To some extent the point that Dr Salby was making is relevant when he was talking about not blinking.
In the April article by Willis, he states:
Willis then states:
Man is pumping out a lot of CO2. Despite all the CO2 that we are emitting, it is clear that it is being churned quickly. Have a look at the OCO-2 data from which one cannot even see the emissions from the industrial heartlands which emissions are swamped by natural processes. CO2 is accumulating at a rate that suggests residency is short, especially when it appears that the bulk of the rise in cumulative CO2 levels has been driven by temperature changes.
So far I see no evidence that the sinks are overloaded, nor that they are reaching saturation point.
What appears to be clear is that the total size/capacity of the carbon sinks in 2015 is greater than the total size/capacity of carbon sinks say in 1960 (not surprising given the way in which the biosphere loves and responds to CO2), so that if Man were to stop emitting CO2 immediately, at least in the short term, CO2 would be removed on the basis of the size/capacity of 2015 carbon sinks, Whether as time goes by the available capacity of carbon sinks would subsequently reduce, I do not know but it does not obviously follow that the rate of decrease in the capacity of carbon sinks will inversely follow the rate of the increase in the total capacity of such sinks as from say 1960 to date.
I consider that it is only the satellite data that enables us to properly consider this, and one would have thought that 40 years worth of satellite data would be sufficient, but I suspect that in the course of the next 10 years (or so) we will have a far better handle on the Carbon Cycle, even if large uncertainties persist surrounding some of the estimates. I do not consider that it is shaping up well for the Bern model (but I could be wrong).
>> richard verney
>>November 25, 2015 at 2:37 am
>>
>>There is a very simple point If the total capacity of the globally available carbon sink is growing year on >>year (as must be the case since the annual increase in atmospheric CO2 is less than the annual >>anthropogenic CO2 emissions), the totality of the sinks cannot be overloaded/exhausted.
I agree with this comment if the word “capacity” is replaced with the term “consumption rate”.
If a sink is operating below its capacity-to-consume, then it is, by definition, supply-constrained, and it can/will increase its consumption rate any time the delivery rate increases; that will happen as the atmospheric concentration increases.
The capacity (to consume) may be increasing as well, but the data only reveal the consumption-rate is increasing. The distinction may seem subtle to some, but the implications are not.
Richard Verney,
You need to make a differentiation in the type of sinks: most of the variability you see in the sink rate is from the influence of temperature variability on vegetation: vegetation is very sensitive to short-term temperature variability. Oceans are a lot less, be it the surface more than the deep oceans, which need hundreds of years fro a small change.
Human emissions increase the pressure in the atmosphere, that influences vegetation to a certain extent, but not that much: 0.5 ppmv extra uptake for 110 ppmv extra in the atmosphere. The oceans are more sensitive to pressure: 1.65 ppmv extra uptake for the 110 ppmv above steady state.
That the sink rate is a linear process is easily found out: during the increase over the years, the net sink rate was always in ratio to the increase in the atmosphere above the steady state of the oceans. When going down, it may be assumed that the main sink process (the deep oceans) didn’t change that much…
As usual, Richard doesn’t know – or ignores – that different processes are at work: some are highly temperature dependent (the biosphere), others far more pressure dependent (oceans).
Human emissions increase the CO2 pressure in the atmosphere. The sink rate of any extra CO2 into the oceans (and to a lesser extent in vegetation) is directly proportional to the extra pressure in the atmosphere com pared to the equilibrium pressure in the oceans. For the current average ocean temperature, that is 290 ppmv, or 110 ppmv in the atmosphere above steady state equilibrium. That gives a sink rate of ~2.15 ppmv/year or for a linear process that gives an e-fold decay rate of:
In 2012:
110 ppmv / 2.15 = 51.2 years or a half life time of 38 years.
The figures for 1988 (from Peter Dietze):
60 ppmv, 1.13 ppmv/year, 53 years, half life time 39 years
In 1959:
25 ppmv, 0.5 ppmv/year, 50 years, half life time 37 years
Looks very linear to me, widely within the borders of accuracy of the emission inventories and natural sink capacity variability…
The sink rate shows a lot of natural variability, as can be proven from the 13C/12C ratio mainly the influence of short term temperature changes on vegetation. Over periods longer than 3 years, vegetation is a net, increasing sink. Moreover, the Pinatubo eruption did give extra light scattering and hence extra photosynthesis from leaves normally part of the day in the shadow of other leaves:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/rss_co2_emiss_1985-2001.jpg
The temperature and Pinatubo did give an extra uptake of CO2, but in not one year of the past 57 years the sinks were larger than human emissions. In every year human emissions overloaded the natural sinks.
Thus sorry Richard, you are completely mistaken by not taking into account that different sinks react different on temperature and pressure…
I am well aware that different processes are at play, and that they respond differently to environmental factors. I have not overlooked that, but nonetheless, I consider that temperature is the dominant player in town. Not the sole player, but the dominant one.
All emissions of CO2, whether these be of human origin or natural origin (eg., volcanos, oceanic outgassing) serve to increase the CO2 pressure in the atmosphere.
We are not talking about average temperature of the oceans. The oceans range in temperatures from about 2 degC to over 30degC, and hence the oceanic outgassing and sinking is different in different locations.
You talk as if CO2 has a constant partial pressure, but we know that CO2 is not a well mixed gas at low altitudes, and this again has an impact on the source/sink interchange. After all the interface where this exchange takes place is for the main part at ground level and this is just where CO2 is not at all well mixed.
What is the CO2 atmospheric concentration say at 50 m and below on say a 10 km by 10km grid square for the entire planet? What is the partial pressure of CO2 at surface level for each 10 km by 10 km grid square for the entire planet.
You state:
Whilst I do not disagree that there is a lot of variability (although I question whether we can identify whether the variability, at anyone moment in time, lies in the capacity of the sinks, or in the extent of the source, and/or a combination of the two), why is there such variability?
Explain how the partial pressure of CO2 has varied from year to year, or the average temperature of the oceans has varied from year to year, or how the biosphere has contracted or expanded from year to year such as to explain the variability that you note. Where is the evidence backing it up?
I understand the logic that underpins many of your arguments, but these arguments are based upon assumptions and there is a lack of data supporting the assumptions that you seek to rely upon. Quite frankly we have insufficient data on the Carbon Cycle, there are far too many estimates which estimates have wide ranges/uncertainties and we do not yet sufficient understanding of all processes involved.
All of us are guessing, save that observations from planet Earth seem to be at odds with almost everything that underpins the cAGW hypothesis.
Sorry Richard Verney, too many Richards at play here…
My response was to Richard Courtney, not to you, as we just had a fierce discussion at Jo Nova’s blog…
The area weighted average temperature of the oceans is in equilibrium with the atmosphere at ~290 ppmv per Henry’s law, no matter if that is static (within a sample vessel) or dynamic (between ocean source and sink places). Currently, the average difference from the atmosphere over the ocean surface is about 7 μatm:
http://www.pmel.noaa.gov/pubs/outstand/feel2331/maps.shtml
Thus in average the ocean is more sink than source…
The difference in CO2 levels over the oceans is minimal and not more than 10 ppmv between Barrow and the South Pole, including the seasonal variations. That makes less than 3% in CO2 uptake flux.
For more discussion, my latest work is just published at WUWT (thanks!), need to go there…
Ferdinand:
You laughably assert of me
As usual, you proclaim irrelevance as a red herring to avoid discussion of empirical data that refutes your mistaken narrative.
If there were a “half life” of the CO2 in the air then half that pulse would remain in the air at the end of that “half life”, but ALL the pulse was sequestered in less than 3 years by some process or processes of the sinks.
The fact that the additional pulse of 9.3Gt of additional CO2 emitted to the air was sequestered in less than 3 years demonstrates that the sinks are NOT being overloaded. As I have repeatedly explained to you, the processes of the sinks are not relevant to the fact that IT IS OBSERVED THAT THE SINKS ARE NOT OVERLOADED.
I got fed up with your waffle, irrelevancies and evasions on the Jo Nova blog when I repeatedly pointed this out to you. And I am offended that you have chosen to do it here, too.
Richard
Richard Courtney:
If there were a “half life” of the CO2 in the air then half that pulse would remain in the air at the end of that “half life”, but ALL the pulse was sequestered in less than 3 years by some process or processes of the sinks.
You don’t (want to) see is that the extra uptake was from the Pinatubo, which increased the CO2 uptake independent of temperature or the extra CO2 in the atmosphere.
The Pinatubo aerosols had their own half life of influence on CO2 uptake.
Temperature has its own half life of influence on CO2 release and uptake.
Accumulated human emissions have their own half life of influence on CO2 uptake.
All three (near) completely independent of each other…
Ferdinand:
My having demolished as being irrelevant your excuse that there are several sink mechanisms, you now introduce the irrelevance of Pinatibo.
Clearly, your excuses are becoming more desperate.
I said
That is true.
But you say
No, Ferdinand, what you “don’t (want to) see” is that Pinatubo is a volcano and volcanoes emit CO2.
The half-life of co2
Sorry, for some unknown reason my post in reply to Ferdinand’s daft excuse went before I had finished typing. This is the rest of my post.
The half-life of CO2 in the air is the same for CO2 from human emissions, volcanoes, the oceans or any other source. This is because the sinks have no method to discriminate from where a CO2 molecule entered the air.
If any ‘pulse’ of additional CO2 is emitted to the air then it has THE half-life of CO2.
The pulse of CO2 I am citing was ALL sequestered in less than three years. That fact refutes the narrative you like to promote, but it is a fact.
Richard
Richard Courtney:
The half-life of CO2 in the air is the same for CO2 from human emissions, volcanoes, the oceans or any other source. This is because the sinks have no method to discriminate from where a CO2 molecule entered the air.
I know, it is to no avail to try to convince you, but for the interested readers:
– The half life of CO2 in the atmosphere is the same for each process on its own. But different processes have different half life times for any CO2, whatever its source and different saturations.
The Pinatubo emitted a lot of CO2, but that is not visible in the CO2 increase rate: there was a firm decrease! The cause: light scattering which enhanced photosynthesis and thus more uptake.
That ended after a few years when most of the stratospheric aerosols dropped out of the stratosphere. A drop of ~2.5 GtC in three years or ~0.8 GtC/year during 3 years.
In comparison: human emissions at that time were ~6 GtC/year, increase in the atmosphere ~4.5 GtC/year dropping to ~1.5 GtC/year during the Pinatubo eruption.
Temperature releases and absorbs a lot of CO2 via (tropical) vegetation. That is visible in the huge (El Niño) variations in CO2 rate of change lagging temperature. Sink/source change 8-10 GtC/°C. Maximum 2 GtC/year.
That ends after 1-3 years, as vegetation is a small, increasing net sink for CO2 with increasing temperatures, currently around 1 GtC/year.
The oceans are a continuous sink for CO2 as long as the pressure in the atmosphere is above steady state. For the current average ocean surface temperature that is ~290 ppmv. The current sink rate is ~3.5 GtC/year at a pressure difference of 110 μatm (~= ppmv).
That ends the moment that the CO2 pressure in the atmosphere equals the average CO2 pressure in the oceans.
As one can see, at least 3 different decay rates / half lives are at work, where 2 of the 3 are limited in time and uptake.
Richard uses two of them (Pinatubo + vegetation) over a short period to “prove” that the third one (oceans) is not overloaded by human emissions…
Ferdinand:
You write
NO and NO!
I yet again say, the sink process and/or sink processes are NOT relevant.
And YOU introduced the red herring of Pinatubo, not me.
I wrote
That is true whatever the processes of the sinks are or may be.</b
And if the half-life is not 40 years but is X years then about half of the pulse of an additional 9Gt in 1989 – 1991 would have remained in the atmosphere for ~X/2 years.
The fact that ALL of that pulse was observed to be sequestered in less than 3 years demonstrates that at most the half-life is less than one year and, therefore, it is observed that the sinks are NOT overloaded.
Your waffle, evasions and irrelevancies do not alter that observational fact.
Richard
OK, hugely slap-dash experiment but I got a similar (inside an order of magnitude anyway) figure from my CO2 tester in my grassy lawn.
I simply put the tester under a transparent bucket and watched the CO2 level drop.
Then, making allowance for the length of growing season (say 6 months round here) and how fast the CO2 is coming out of the dirt under an opaque bucket, I worked out (just for a laugh really) how long it would take for the grass on my lawn to reduce the atmospheric CO2 level to zero.
I say = 58 years
I amaze myself sometimes you know I really do. sigh
Salby`s latest research is explained in his lecture this year in Westminster London (March 2015) in which he concludes human influence on climate change is insignificant now on youtube
I like is his slow delivery, which gives the listener time to think about what he is saying.
Presenters often tend to speak too quickly. This is problematic when discussing technical or complex matters since the listener has insufficient time to think upon what has been said, before some new point is being made.
Terri,
I have been in London at his lecture in 2014 in the Parliament buildings and had several remarks, which remained unanswered, partly due to lack of time.
His main error: integrating the temperature: variability + slope means that the attributes all CO2 increase to temperature, which violates Henry’s law for the solubility of CO2 in seawater and has no answer to where human emissions go. Besides that it violates about a lot of other observations…
That could be so IF all other factors remained constant. But there are simply too many variables, and the extent of variability unknown, to conclude that Henry’s law is violated by his views.
Richard Verney,
The observed natural variability is +/- 1.5 ppmv around the trend, hardly visible around the increase of 110 ppmv since 1850, or 80 ppmv since 1958…
Henry’s law was established in 1803 and since then proven by over 3 millions seawater samples measuring the pCO2 of the oceans. It is around 16 ppmv/°C, not over 100 ppmv/°C if Dr. Salby was right…
The biosphere is a proven sink for CO2 (from the oxygen balance), thus can’t be the source either…
Strike-Two for AGW.
I think it is a strike number 10 or 20 to AGW alarmism. It is still going strong.
Did anyone else get warned that the author’s supplemental-information spreadsheet may be dangerous to download?
OK then
We have it on this thread that CO2 residence time is someplace between 10 years and 40 years. We have some who think mankind-generated CO2 is a large contributor and others who think that natural processes swamp mankind’s contribution. I personally am led to believe that CO2 in the atmosphere comes from plant life on the land areas and from the ~70 percent of the planet called … wait for it … oceans. We also know that plant life loves CO2 over 1200 ppm — ask the people who run plant nurseries.
The earth would be a much better place for life if it would warm up another several degrees and if CO2 would triple.
My dear luke-warmer friends, CO2 does not warm the surface of the planet. We need not fear 1200 ppm at all. The James Hansen/IPCC theory of CO2 warming the surface is bogus. This delusion would never have lasted this long if the program for “fixing” the “problem” did not lead to political and monetary gain for the collectivists and all their fellow travelers. (the climate control knob is the sun, oceans, water in all its phases, density of the atmosphere and gravity — it is a weird control knob as it does as it darn well pleases no matter what mankind wants)
.
.
Disclaimer: I have always been an environmentalist. I have always been against government and business fouling the air, land, or waterways. We made great gains towards clean air and water in the 70s.
good link to read: How AGW isn’t happening in the real Earth system … https://okulaer.wordpress.com/2015/11/15/how-agw-isnt-happening-in-the-real-earth-system/
“density of the atmosphere and gravity ”
Agreed, have said so for years, but some here don’t agree.
Unfortunately, I would say many here don’t agree. But someday they will — or their decedents.
CO2 residency time, Climate Sensitivity and the ‘pause’ are all to some extent related and dependent upon one another. Obviously, the longer the ‘pause’ continues (and lengthens) the lower Climate Sensitivity (if any at all) must be.
But likewise the longer the ‘pause’ continues and should the rate of CO2 carry on along its present trajectory, then the more apparent it will become that temperature, and not the rate at which man emits CO2, is the dominant driver of atmospheric CO2 levels. This will lend support to the view that the Bern model is flawed.
Of course, as Climate Sensitivity (if any at all) comes down, the case for drastic action is weakened, and indeed, so too the need to take steps now.
If the residency time of CO2 is also less than the IPCC suggests then again, the need to take action now at this stage to avert disaster is also weakened.
As I see matters, the combined consequence of ever lowering forecasts of Climate sensitivity, coupled to stronger and stronger evidence that CO2 residency time is modest, provides Mankind with the opportunity to step back and do nothing and to allow us to wait and see what is actually happening and to firm up on the data so that we better understand matters.
The case for urgent action to take mitigation action has been grossly undermined since about 2005, and certainly since Copenhagen. As each year passes, the case for targeted adaption grows ever stronger. Any sensible person would know that Paris 2015 is a waste of time and energy. Climate Change is so patently not the most pressing issue facing the world today, and it would be sensible to kick the can down the road and suggest that everyone reconvenes in 2025. In the meantime, to simply firm up on the collection of quality observational data.
I am of the firm view that unless the satellite data shows a long lasting step change in temperature coincident with the strong 2015/16 El Nino as was observed coincident with the 1997/8 Super El Nino, then even by 2019 AR6 will prove almost impossible to write since should the satellite data show that the following La Nina restores temperatures back down to about the 2001 to 2003 anomaly level (with 2015/16 showing as a short term blip but not accompanied by a long lasting step change in temperatures), then many papers will be published suggesting Climate sensitivity at no more than 1.3 (and some suggesting an even lower figure), all the model projections will be more than 2 standard deviations from measured observation. To add to that, if the ‘pause’ is by then more than 21 years in duration, it will almost certainly be clearer that temperature is the major driver of CO2 as is suggested by the various plots set out by Bartemis November 24, 2015 at 4:01 pm, and others.
Try sensitvity less than 0.2….
richard verney
But likewise the longer the ‘pause’ continues and should the rate of CO2 carry on along its present trajectory, then the more apparent it will become that temperature, and not the rate at which man emits CO2, is the dominant driver of atmospheric CO2 levels.
This one doesn’t follow from the observations: temperature is near flat, while increase in the atmosphere is going up unabated, be it more linear nowadays than slightly quadratic it was in the period before…
See further my plots in my comment below Bartemis…
And that is why I said
I am not saying that there is definitely causation, especially as we are dealing with short periods when exponential rises can appear linear, I do not know how the future will unfold, and I am extremely cautious at offering predictions as to the future. I am merely speculating that if the red/green variability and similarity as detailed in the plot set out by Bartemis (November 24, 2015 at 4:01 pm) continues for say another 10 years beyond the current end date of the plot, the stronger the view becomes that temperature is the dominant player in all of this.
Perhaps you might like to comment upon the point I made regarding forest fires (richard verney November 25, 2015 at 2:04 am ), where an existing carbon sink of X capacity (ie., the old forest that is burnt down) is simply being replaced by another carbon sink of about X capacity (ie., the new forest that grows from the ashes) such that every time there is a forest fire it results in an addition burp of CO2 into the atmosphere (equivalent to that released from the burning of the material that comprised the forest), and it is not a carbon neutral event.
Forest fires are not a carbon neutral events since the before and after carbon sink has broadly the same capacity (studies suggest that mature and young forests have substantially the same sink capacity). It would only be a carbon neutral event if the after carbon sink had a larger capacity than the before carbon sink, and that larger capacity of the after carbon sink equalled the immediate outgassing of CO2 released by the fire event.
Ferdinand:
You yet again ignore reality when it refutes your narrative.
You say
Funny how you proclaim “different processes” when it suites your advocacy but not when it refutes the narrative you promote.
If the temperature changes then processes of the carbon cycle will adjust towards altered equilibria. As I said above
It is slightly less than two decades since global temperature stopped rising so not all processes will have completed adjusting to a new equilibrium state yet. Hence, atmospheric CO2 would now still be rising.
The observation that CO2 continues to rise but temperature does not fits with temperature discernibly altering CO2 but does not fit with CO2 discernibly altering temperature.
Richard
Richard Courtney,
Some processes indeed needs centuries to equilibrate, but the very long term equilibrium is about 16 ppmv/°C over the past 800,000 years, where that ratio is within the ratio’s given in the literature for Henry’s law of the solubility of CO2 in seawater.
If you have any indication that the ratio is over 100 ppmv/°C, I like to see where that is based on…
Ferdinand Engelbeen:
You again state your misunderstanding of Henry’s Law and refer me to “the literature for Henry’s law of the solubility of CO2 in seawater”.
I refer you to the excellent explanation of basic ocean chemistry that Michael Hammer recently provided for you on WUWT here. You need to read it and learn from it because it provides a through refutation of your untrue assertions resulting from your misapplications of Henry’s Law.
Richard
In my view the data from cryosphere today especially polar ice can no longer be trusted.
http://www.atmos.illinois.edu/~wlchapma/Forbes.article.response.pdf
There is a definite warmist bias. Even their own graphs show that global ice has been “normal” for the past 4 years
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg
+1
Eliza:
Global sea ice is a terrible metric of ANYTHING. It is worthless, misleading, and un-informative because the reflective heat difference between ice-covered ocean waters is opposite each season:
When the Antarctic excess sea ice is reflecting the sun’s energy, the Arctic Ocean is dark – and the LOSS of sea ice during every period of darkness or twilight INCREASES the ocean’s heat loss to space. Thus, seven months of the year, less Arctic sea ice means a cooler planet overall.
When the edge of the Antarctic sea ice is dark for a few weeks each year, the sun’s top-of-atmosphere radiation levels are LESS than when the Antarctic sea ice are highly illuminated, and the Arctic sea ice (which IS being radiated) has a very low albedo – a sea ice albedo nearly the same as that of open ocean water in the afternoons and evenings. Thus, over the entire year, every extra square meter of Antarctic sea ice reflects about 1.7 times the energy that a square meter of exposed Arctic sea ice could absorb.
Any so-called “scientist” using “global sea ice area” to excuse (or to explain) anything is starting from a position no better than “dead wrong” … and then getting worse.
CO2, Catastrophic AGW, oceans inflation and like, are mere ‘kitten’s cough’ compared to what NASA has just found
?itok=S4fkZkWn
“Earth Might Have Hairy Dark Matter”
This illustration shows Earth surrounded by theoretical filaments of dark matter called “hairs.” NASA’s Jet Propulsion Laboratory, Pasadena, California NASA/JPL-Caltech
Whatever happened at climate change conference in Paris, the Earth is doomed. https://www.nasa.gov/feature/jpl/earth-might-have-hairy-dark-matter
I’m concerned that this discussion seems to ignore the carbonate chemistry of the ocean. For instance described here: https://www.princeton.edu/morel/publications/pdfs/eglestonGlobalBio2010.pdf
My take:
1. The residence time of atmospheric CO2 is much longer than the 40 years suggested in this thread.
2. That’s a blessing. When the CO2 stays in the atmosphere it gives plants a chance to respond and bring the carbon into the organic cycle rather than letting it be wasted in inorganic sinks.
Yes the bomb data shows C14 almost disappear in 40 years after 1966, but that’s to be expected for a trace amount. It would happen even if the ocean was saturated with CO2.
reference to bomb data on page 55 in this article:
http://www.ams.org/journals/bull/2015-52-01/S0273-0979-2014-01471-5/S0273-0979-2014-01471-5.pdf
Look at the actual data on the amount released, the amount of ppm increase each year, then tell me how 1998 is still the highest year with 2.93 ppm increase?
I guess that’s because of El Nino and high SST in 1998. Same reason as Co2 increase some hundred years after ice age. Warmer water first then outgassing. I just think this ocean-sink question involves many complex processes and the discussion doesn’t reflect that. After reading the Halperin paper I must admit I have no strong objections. Maybe he’s right that the “half-time” is 40 years. That’s still longer than the 10 years half-time for C14 in the bomb-curve.
I can’t tell how much the ice core samples have been manipulated. I suspect that co2 has a half life of 20 years under current conditions. I also suspect that it is a sliding scale. One of which is the direct conversion of co2 into c and o2, about 5%, about 20 ppm currently. That’s what’s wrong with the current state of climate science. There are so many things. It’s complex and none of it is easy.
I would have thought there would be more data showing a difference between NH and SH concenrations of CO2 in atms, esp. Since vast majority of man-CO2 is generated in NH.?? But no such luck. Me thinks with 70% earths surface being ocean, and CO2 being hundreds times more soluble in it than in air, its a natural water: temperature partial pressure function at play. Hubris of man is overcooked… Just sayin.
macha,
See:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/co2_trends_1995_2004.jpg
(needs some update…)
The same for the 13C /12C ratio: drops first in the NH at ground level…
Data downloadable from:
http://www.esrl.noaa.gov/gmd/ccgg/iadv/
And why are the lines parallel.
Macha,
That is because most of human emissions are at ground level in the NH. While there is a relative fast mixing in the atmosphere, a continuous increase needs time to reach higher altitudes and the other hemisphere. In the latter case, the ITCZ (upwelling air around the equator) only passes 10% air exchange between the hemispheres.
Thus a full exchange needs time to reach the whole earth. As you can see: some 2 years between Barrow (near sea level) in the High North and the South Pole at ~3000 m height.
Article quotes:
It is a provable fact that on a non-geological time scale (bi-yearly & yearly) the “latter” (land & ocean temperature) increases also causes the “former” (atmospheric CO2 quantity) increases.
But the above begs the question of, ….. ”If the surplus CO2 concentrations have a “half-life” residency time of 40 years in the near-surface atmosphere …… does the temperature increase also have the same 40 years “half-life” residency time in the near-surface atmosphere?”
Of course the answer to the above question is “NO” …… because everyone knows that any near-surface temperature increase attributed to atmospheric CO2 is only here today ….. but gone tonight …… and is neither additive or cumulative from one (1) day to the next or one (1) year to the next.
This issue, above all others, lends itself to sophistry and obfuscation. And both sides in the debate use the same facts to promote their argument.
The headline is is very disingenuous.
50% remaining after 40 years matches the low BERN model.
So after 80 years 25% remains. After 120 years 12.5% remains etc. etc.
So in 1000 years, some CO2 will remain. Until quantum physics takes over.
Once again we have the problem of unreliable data.
New satellite data show that the MAGICC molecule is not well mixed.
Freeman Dyson pointed out a long time ago that the natural production and absorption of CO2 varied from region to region and was not well understood.
We really do not have the ability to distinguish what molecules of CO2 arrived there naturally, and what ones arrived there by burning fossil fuels.
I seem to recall that someone did look at a different isotope and determined that its half life in the atmosphere was of the order of 10 years.