Guest essay by Clive Best
Summary
The currently held belief that we must decarbonise the world’s economy in order to to stop climate change is a dangerous illusion. It is a ‘hiding to nothing’. I have come to the conclusion that if emissions were held constant for 30 years then the airborne fraction of CO2 emissions would reduce to zero. In other words if the world can hold emissions constant at say 30GT CO2/y then sinks will increase to balance all annual emissions. Thereafter CO2 levels would remain at below 440ppm indefinitely, so long as emissions remain constant.
Introduction
I will argue below that in order to stop global warming all we really have to do is simply stabilise CO2 emissions, not reduce them to zero! This alone will stabilise CO2 levels within less than 30 years. The origin of the ‘myth’ as promoted by nearly all IPCC climate scientists is that we have to stop burning all fossil fuels i.e. we must ‘keep it in the ground’. This is a fallacy and I will try to explain why in this post.
The origin of this belief that we must stop burning any fossil fuels by ~2050 can be traced back to Figure 10 which appeared in the AR5 ‘Summary for Policy Makers’. Here it is again.
Figure 10 from SPM AR5
Figure 10 was intended to send a simple message to the world’s political leaders. Namely that there is a finite total amount of fossil fuel that mankind can ever safely burn, and that we have already burned half of it. Therefore unless all major industrialised countries stop burning fossil fuels altogether by 2050, the world will warm far above 2C (the red curve) causing a global disaster. This message worked, but I find that there is so much wrong with the hidden assumptions and even subterfuge used to produce Figure 10 that I wrote a post about it at the time.
The principal hidden assumptions, as I see it, in Fig 10. are as follows:
1. Carbon sinks are saturating (they are not)
2. ECS (Equilibrium Climate Sensitivity) is 3.5C (Very uncertain – and could even be as low as 1.5C)
3. The subtle replacement of logarithmic forcing of CO2 with a linear forcing.
4. The assumption that past emissions stay in the atmosphere essentially forever.
As a direct consequence of IPCC successful lobbying based essentially around Figure 10, the Paris treaty now proudly “sets the world on an irreversible trajectory on which all investment, all regulation and all industrial strategy must start to align with a zero carbon global economy“. Does anyone really believe that this is even feasible, let alone realistic? It simply is not going to happen because well before then, their citizens will revolt and kick them out. The best we can hope for in the short term is a stabilisation of global CO2 emissions. The minimum condition needed is that annual growth in emissions needs to be brought to zero.
Carbon Cycle
To understand the carbon cycle means understanding the difference between CO2 decay time and CO2 residence time. The decay time for an individual CO2 molecule emitted by man is only about 5-10 years (based on C14 measurements in both bomb tests and those produced by cosmic rays). Every CO2 molecule in the atmosphere is rather quickly absorbed either by photosynthesis or by the ocean. However on average most of them are simply replaced by another CO2 molecule entering the atmosphere through evaporation from the ocean surface or by biological respiration. The residence time however, is the e-folding time needed for a sudden net increase in CO2 to decay back to normal as the carbon cycle reacts. At equilibrium the total CO2 content of the atmosphere remains constant over centennial time scales. Currently though, as a result of our emissions, slightly more net CO2 molecules are being absorbed than are being returned to the atmosphere each year. As a consequence the atmosphere is not quite in equilibrium with the rest of ‘natural’ life and the oceans. We have given the carbon cycle a kick, and as a result it is reacting to return back into balance. The problem is that we have continued to kick a little harder each year so that balance is never reached.
If you sum up all the sources and sinks since 1960 then you find a remarkable fact, which was unexpected by climate scientists. About half of man-made emissions are being absorbed each year. This means that just one half of the net CO2 emitted by humans remains in the atmosphere each year. This is called the airborne fraction. The strange thing is that this airborne fraction hasn’t changed at all in 60 years, despite exponentially increasing human emissions.
AR4 plot: The fraction of Anthropogenic CO2 retained in the atmosphere (b) is unchanged in 50 years, despite increasing emissions (a). Note how the annual change stalled after the 70s oil crisis
Plot of Carbon content of air versus Cumulative Carbon emissions produced by Nick Stokes.
This means that today we are emitting about twice as much carbon dioxide as we did 30 years ago, yet still only half of it survives a full year. Or putting that another way, the equivalent of 100% of 1990 emissions are now absorbed each year. This ratio of 50% airborne fraction has been true for over 100 years while emissions have been forever increasing.
Comparison of Carbon emissions and that retained in the atmosphere. Increases in Emissions consistently remain about twice the levels of increases in CO2. Flat periods occur when growth stalls.
Natural carbon sinks are increasing dynamically to offset our emissions. The problem is that they don’t have enough time to catch up with the ever increasing rate of emission. The best they can do in a single year is offset half of them. Why is that the case and what does it really mean?
There is a ‘concentration effect’ acting on ocean sinks due to the increasing partial pressure of CO2 in the atmosphere. Similarly land biota (plants and soil) react to increased partial pressure by absorbing more CO2. While we are still increasing emissions then CO2 levels in the atmosphere will always continue to rise. If instead we can stabilise emissions at some fixed number of Gtons/year then CO2 levels would also stabilise, albeit at a slightly higher level than now and in the future. This is because the sinks will finally be able to catch up to balance our CO2 source. The atmospheric faction will decay to zero.
Dissolution/Absorption of CO2 at Ocean surfaces.
In stability there is a balance of CO2 Partial Pressures between the surface of the ocean and the atmosphere. At any given temperature the exchange of carbon dioxide molecules between the atmosphere and the ocean surface always reaches an equilibrium. This equilibrium is controlled by the partial pressure of CO2 in the atmosphere equalising to the partial pressure of CO2 in the surface of the ocean. Then the number of carbon dioxide molecules that escape from the sea surface is balanced by the number that enter the sea from the atmosphere.
If the temperature of the ocean rises then the kinetic energy of the carbon dioxide molecules in the seawater increases and more carbon dioxide molecules will leave the ocean than would enter the ocean. This continues until the partial pressure of carbon dioxide in the atmosphere increases to balance the new pressure at the sea surface.
If instead the ocean were to cool then the reverse of the above would happen, and CO2 levels would fall. Consequently carbon dioxide is more soluble in cold water than in warm water. This is Henry’s law. One consequence of this effect is that the oceans “inhale” carbon dioxide from the atmosphere into cold sea surfaces at high latitudes and “exhale” it from warm sea surfaces at low latitudes.
Increasing the carbon dioxide concentration of the atmosphere therefore causes the oceans to take up (inhale) more carbon dioxide. Because the oceans surface layer mixes slowly with the deep ocean (hundreds of years) the increased carbon dioxide content of the surface ocean will be mixed very slowly into much larger carbon reservoir of the deep ocean. The rate of our adding carbon dioxide to the atmosphere has been too fast for the deep ocean yet to be a significant reservoir. So as the carbon dioxide content of the atmosphere rises, so too does the concentration in the ocean surface, causing short term acidification of surface waters. If atmospheric carbon dioxide remains constant then a ph balance throughout the ocean volume can be reached.
I argue that by simply stabilising emissions, we can halt global warming because CO2 levels will stabilise as the sinks will then be able reach equilibrium with emissions. Clearly the lower total ‘stable’ emissions become then the cooler the planet will be, but even if we only managed to stabilise emissions at current values, then the net warming will still be <2C and CO2 levels will soon stop rising and stabilise at <440 ppm.
Atmospheric CO2 levels must always reach an equilibrium as the natural carbon sinks catch up to balance emissions. For the last 40 years about half of man-made emissions have been absorbed mainly into the oceans, but also into soils and biota. The reason why CO2 levels have been continuously increasing since 1970 is that we have been increasingemissions each year, so the sinks never get a chance to catch up. Sinks will rather quickly balance emissions and CO2 levels will stop rising once emissions stop increasing. This fact is obvious because run-away CO2 levels have never happened before in the earth’s long history. Such a balancing mechanism has always stabilised atmospheric CO2 over billions of years during intense periods of extreme volcanic activity, ocean spreading and periodic tectonic mountain building. Fossil fuels in this context are an insignificant fraction when compared to the buried carbon contained in sedimentary rocks.
Simple Model
CO2 levels rise when the rate of change of the sources – S exceeds the rate of change of sinks – K. Without human emissions then S = K, averaged over one year. However with ever increasing human emissions the situation becomes dynamic
If C is the yearly value of CO2, S the net sources of CO2 and K the net sinks, then at time t.
However it has been measured for at least the last 60 years that
If 
then 
Now let’s assume that the world manages to stabilise annual emissions at current rates of 34 Gtons CO2/year indefinitely. CO2 sinks currently absorb roughly half of that figure – 17 Gtons and have been increasing proportional to the increase in partial pressure of CO2 in the atmosphere – currently that of 400ppm. Stabilising emissions now results in a decreasing fractional uptake by carbon sinks as the partial pressure imbalance between the surface and atmosphere begins to fall. The simplest assumption is that the sink increase depends only on the partial pressure difference for a given year. Therefore if this pressure difference is reduced by half in one year then the next year it will be reduced by one quarter, then one eighth and so on. The same argument applies for the case that it takes longer to reduce pressure difference by a half.
Year 1: 50% Year 2: 25% Year 3: 12.5% Year 4: 6.25% etc. which is simply equal to the infinite sum
So in this simplest of models, CO2 levels in the atmosphere will taper off after just ~10 years to reach a new long term value equivalent to adding an additional one year of emissions 34 Gtons of CO2 to the atmosphere. The atmosphere currently contains 3.13 x 10^12 tons of CO2 so the net increase at equilibrium would in this simple model be just 1%. Therefore for the years following 2016 the resultant CO2 curve would look like the red curve below. If instead it takes say 4 years for the sinks to increase by 
then we get the blue curve. In this case it would take 30 years for CO2 levels to to stabilise and the increase would be 5 times larger.
CO2 stabilisation curves for different time constants. The red curve assumes sinks match half the imbalance in 1 year while the blue matches it in 4 years.
Currently there is also a good chance that the world will achieve a fixed level of annual emissions, but there is no chance that it will meet an impossible target of zero emissions this century. This does mean that CO2 levels will remain at ~410 ppm indefinitely, which is far higher than a planet without human beings, but it buys us time to replace fossil fuels with say new nuclear energy. If I am right then CO2 levels will begin to level off within the next 10-20 years. This would also save trillions of dollars by trying too soon now to replace all fossil fuels, and then probably failing.
Reducing emissions in the future will slowly cause such ‘stable’ CO2 levels to fall. In the long term we will have to develop non-carbon energy sources anyway, most likely nuclear, since fossil fuels must run short. However using remaining fossil fuels to control CO2 levels may one day have another advantage. It could mean that we can eventually use ‘enhanced global warming’ as a thermostat, thereby avoiding another devastating ice age otherwise due to begin within the next 5000 years.
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Clive..it’s late here…I want to read this again with coffee 🙂
..thank you!
I have always wondered about this…when did the sinks stop working?
Leaving aside the error of fact (“Reducing emissions in the future will slowly cause” — no causation has ever been proven), that is, there is no evidence proving that any meaningful effect on climate of human CO2 emissions is not completely superceded by/overwhelmed by natural CO2 emissions…..
For all those who (like I) did not know what the British phrase “a hiding to nothing” meant:
To be faced with a situation which is pointless, as a successful outcome is impossible. … One scenario would be that of a team which is expected to win easily but has the betting odds so strongly in its favour that no kudos or reward, that is, ‘nothing’ , would be gained from victory. The other is that of a weak contestant who is expected to be beaten, that is, get ‘a hiding’.
Origin
The phrase is known from the early 20th century and originated as horse racing parlance. …
(Source: http://www.phrases.org.uk/meanings/on-a-hiding-to-nothing.html )
Edit: “no evidence proving … OR that human CO2 emissions are any significant % of the current level of CO2 in the atmosphere — that is only a guess, an assumption, for natural sinks, two orders of magnitude greater than human CO2, could be absorbing ALL of the human CO2, making the net CO2 level all natural.
So far, I have seen no credible evidence that anthropegenic Carbon, in any chemical form, has any detectable effect on climate change – either warming or cooling. Lots of theories, lots of ‘models’ and ‘studies’ but no evidence of any causal relationship. Why there is any effort study the AMOUNT required to influence a change is certainly premature at best.
Janice – I hasd a fairly comprehensiveanswer but the dog ate the first partb of vmy answer. What remained was this:
“The worst predictions are for the twenty-first century. What they have done is to aim the predicted temperatures (which they derive by averaging individual predictions by the hundreds) along the same trajectory that warming took place before 1980. Of course they did not know that nature would fool them and cause a slowdown of warming in the twenty-first century. They just produced a linear extension of trends before 1980 and ended up with a complete separation of model predictions and reality. Looking at a display of CMIPS-5 model predictions released this year it is obvious to even to a child that the predicted curve is way off reality, just floats up there. These data have even been shown at congressional hearings but I do not hear anyone stating publicly that climate modeling enterprise has completely failed in trying to forecast future warming and must be shut down.”
iI will have to follow up with an article. Arno
Janice,
As usual: you forget that human emissions are one-way additional and the natural emissions are only half of the natural cycle, the other half are natural sinks. With extra CO2 from humans, the natural sources, mainly from the oceans, are reduced and the natural sinks, both oceans and vegetation, expand. Without human emissions, there wouldn’t be an increase in the atmosphere, besides a small one due to temperature (~16 ppmv/K).
90% of the current increase over pre-industrial is from human emissions, 10% from the temperature increase since the LIA. As there are huge exchanges with other reservoirs, not all human emissions (as original molecules) remain in the atmosphere but are distributed over all reservoirs. Currently about 9% of the atmosphere still are from human emissions, as can be deduced from the 13C/12C ratio.
More detailed information:
http://www.ferdinand-engelbeen.be/klimaat/co2_origin.html
Without human emissions, there wouldn’t be an increase in the atmosphere
====================
nonsense. temperatures have been increasing since the bottom of the LIA 250 years ago. It is well established from the ice cores that temperatures rise, CO2 increases.
As to the magnitude of change, there is no historical proxy with the resolution of current measurements, so there is no way to gauge if current levels are exceptional. There is conjecture, to be sure, but humans have an infinite ability to rationalize anything, so good science requires conjecture be treated with a large dose of salt.
ferdberple,
I have mentioned the effect of temperature on CO2 levels: 16 ppmv/K that is all. If we may assume that the MWP was at least as warm as today, the levels were 285 ppmv, 400 ppmv today.
If you agree that ice core CO2 levels (directly measured) follow temperature levels (proxy), then the recent ice core CO2 levels (1850-1980) by far lead temperature changes:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_1000yr.jpg
Different ice cores have different resolution, but over the past 1,000 years the resolution of the Law Dome DSS core is better than 20 years, with a repeatability of the samples at the same depth of better than 1.2 ppmv. Good enough to detect any one-year 40 ppmv spike or a sustained 2 ppmv increase over a period of 20 years.
Even the worst resolution ice cores (Vostok, Dome C) would detect the current 110 ppmv increase over 160 years, over the full period of 800,000 years, be it with a lower amplitude…
Ferdinand Engelbeen @ur momisugly December 16, 2016 at 1:12 am
“…you forget that human emissions are one-way additional…”
No. They are not. They induce sink activity. That induced sink activity is anthropogenic sink activity. It is two-way.
Bart,
The sink activity is in ratio to the total pressure of CO2 in the atmosphere above steady state, not from human emissions of one year. If humans had emitted 4.5 ppmv/year CO2 in 1850, almost all of that would have remained in the atmosphere, as the CO2 pressure in the atmosphere increased from ~280 ppmv to 284.5 ppmv, 4.5 ppmv above equilibrium. That gives a linear net sink rate of ~0.09 ppmv, about 4.4 ppmv of human emissions remaining in the atmosphere…
In the current circumstances only half the human emissions as mass (not the original molecules) are removed and half the mass remains in the atmosphere. That is the case for at least the past 57 years. Thus all increase (except a small part by temperature) is from human emissions and indeed most of the unbalance between source and sink rate is caused by the accumulation of the difference between human emissions and increasing sink rate…
Compared to the (mainly temperature induced) natural fluxes still small: some 3% extra sink rate after 165 years for currently 6% of the influx… Still most of the incease is from human emissions…
Clive Best:
I have followed your blog on the atmospheric carbon balance. Her is what I know, and if I can e-mail you, I can go into more detail?
1. The capacity of the ocean to hold CO2 in a physical-chemical-inorganic form is vast. The ocean holds 50 times as much CO2 this way as the atmosphere. To the extent that the atmosphere and ocean are presumed to have at least started the 20th century in near equilibrium, the amount of CO2 in a reservoir is in proportion to the size of that reservoir.
2. The bulk of the CO2 “dissolved” in ocean water is not in the aqueous fraction subject to Henry’s law. The aqueous fraction is in a Henry’s law relationship with CO2 in the air, but the aqueous fraction is also in chemical equilibrium with the “soluble carbonates” through a chain of fast-acting chemical reactions. This is on account of ocean water not being pure water but rather a “chemical soup.”
3. The equilibrium of concentrations of a chemical, CO2 in this case, between different chemical species in the carbonate reaction does not follow a linear Henry’s law relation. Instead, it follows a power law relation owing to the number of molecules of different types that have to come in contact to make the reaction happen. Owing to the complicated chain of chemical reactions in the carbonate system, this follows a 10th power relationship, where this exponent of 10 is the value of the “Revelle factor”, named after ocean scientist Roger Revelle. The way the chemicals in ocean water interact in reactions to give this factor is the “Revelle buffer.”
4. The consequence of the Revelle buffer and the Revelle factor exponent is that a 1 percent increase in the atmospheric CO2 concentration, same as partial pressure that drives the exchange, results in only about a 1/10 or .1 percent increase in concentration in ocean water. But the ocean reservoir is 50 times the size of the atmospheric one. Taking the Revelle factor of 10 into account, adding 6 measures of CO2 to the atmosphere will result in only 1 measure retained in the atmosphere and 50/10 = 5 measures of CO2 ending up in the ocean. This was the conclusion of Revelle and Suess (1957) Tellus IX Vol 1 pp 18-27.
5. Since that paper, it is regarded that the ocean is not well-mixed but rather divided into a surface layer that exchanges CO2 rapidly with the atmosphere and of similar CO2 capacity as the atmosphere, and a deep ocean layer with an “exchange time” of 500 to 1000 years. Assuming that the anthropogenic part is the sole perturbation of the carbon cycle out of equilibrium, as you say, half the emitted CO2 stays in the atmosphere and half is absorbed by “sinks.” Recent, accurate measures of the atmospheric oxygen content indicate that of the net flow into sinks (does not account for large back-and-forth exchanges), half of the sink is in an inorganic form, such as the ocean soluble carbonates, and the other half is in organic form, such as land plants.
6. My own modeling suggests that in a quasi-static model (no natural disturbances from equilibrium), the rate coefficient for CO2 between the atmosphere and the surface ocean is about the same for exchange between the surface and deep ocean. The “500 to 1000 year deep ocean turnover” comes from the deep ocean being so vast that it would take 500 to 1000 years to fill it up to the level by which the atmospheric CO2 has increased, not that the deep ocean acts on a time scale too long to sequester CO2 from the atmosphere during a human lifetime.
7. Taking into account the Revelle buffer mechanism that prevents increased CO2 in the air from being swallowed up in the ocean, setting the rate coefficient for exchange between surface and deep ocean to a value that matches the ocean/land sink split from the oxygen concentration data, setting the absorption of CO2 by land plants proportional to CO2 concentration, and setting a constant release of CO2 from decaying vegetation, my model can match the 20th century rise in atmospheric CO2 from 290 PPM to short of 400 PPM, but it also matches the measured curves for C13 concentration over time, C14 radiocarbon ages for surface and deep ocean, and the “bomb test” extinction curves for C14 in the atmosphere. I also come up with an “e-folding time” for extinction of bulk CO2 added to the atmosphere somewhere in the 40-50 year range, considerably less than the IPCC Bern Model based on curve fitting, and close to what our esteemed friend Ferdinand Englebeen in claiming?
8. There is strong evidence that the apart from the human CO2 contribution, the carbon cycle is not quasi-static. The “net emission of CO2 into the atmosphere”, by mass conservation, is simply proportional to the slope of the Keeling curve of atmospheric CO2. Not only does net emission have a strong seasonal variation, it has a year-by-year variation that is of comparable in magnitude to the anthropogenic contribution. This variable portion of net emission is highly correlated with global temperature — the Wood for Trees web site allows displaying the time series showing this.
9. Changing my model to make the emission of CO2 from dead plants sensitive enough to temperature to match the variation in net emission, and increasing the sensitivity of plant uptake of CO2 to CO2 concentration to match the long-term Keeling curve trend from 290 to about 400 PPM, I find that only half of the increase in atmospheric CO2 is from human activity with the other half being from this temperature-stimulated emission from this natural source, which has emitted more CO2 as global temperature has increased in the 20th century. This change also reduces the e-folding extinction time for anthropogenic CO2 to about 20 years.
10. The temperature sensitivity for natural CO2 emission required to match the model to known data is comparable to the temperature-driven emission from soils recently claimed by Bond-Lamberty and Thomson, Nature, 2010.
11. The modified model to account for temperature-stimulated CO2 emissions from soils gives a somewhat better fit to the C13 curves, but I am still working on plausible turnover times and reservoir capacity of soil carbon to properly treat its carbon isotope fractionation and hence modification of the atmospheric values.
12. Fellow commenter “Bartemis” has critiqued this effort for not taking into account ocean-current driven turnover of deep ocean waters along with current-induced temperature changes affecting CO2 absorption or emission.
In challenging the consensus view of the carbon cycle, we need to take the known ocean chemistry into account, and we need to not only explain the change in atmospheric CO2 on the different time scales, we need to predict the isotope ratios too. I believe I am making progress in that direction, and I am interested in sharing more of what I have found out with interested parties.
Paul –
You say: “This variable portion of net emission is highly correlated with global temperature…”
But, it isn’t just the variability of the rate of net emission that matches temperature. The long term trend matches as well, when the data are scaled such that the variability matches:
http://woodfortrees.org/plot/esrl-co2/derivative/mean:24/plot/hadcrut4sh/offset:0.45/scale:0.22/from:1958
This is too much of a coincidence to be mere happenstance. It shows beyond any reasonable doubt that temperature anomaly is the overwhelming driver of the rate of change of atmospheric CO2, and hence the overall change in concentration. The match with the more accurate (but shorter term) satellite data is nothing short of spectacular:
http://woodfortrees.org/plot/esrl-co2/derivative/mean:12/from:1979/plot/rss/offset:0.6/scale:0.22
There is a lot of excellent information in what you write. But, in the end, the theory must follow the data.
It seems, especially to people living in big cities, that we just must be having an impact on CO2 levels. But, the sum total proportion of urban area on the globe’s land mass is at most a mere 2.7%. We’re just not as big a deal to the globe as we imagine we are.
Paul Milenkovic,
We largely agree with what you wrote, with a few exceptions:
4. The Revelle factor is only important for the mixed layer, it hardly plays a role in the deep ocean mix. What goes down with the THC is far from saturated and once in the deep, it doesn’t matter how much it gets C enriched by the drop out of organics and inorganics from dead plankton (coccoliths) and other debris from the surface layer. The pCO2 difference at the main sink place (N.E. Atlantic) is ~150 μatm, where the ~250 μatm of the ocean surface remains about the same over time, as that is only temperature (and biolife) dependent and is continuously refreshed with new incoming waters from the upwelling near the equator.
That makes that the exchange with the deep oceans gets a mass distribution of 1:50 at equilibrium, largely independent of the Revelle factor. After a few centuries all the CO2 released by humans would be distributed over (deep) oceans and atmosphere and the 400 GtC extra gives about 1% increase in C content of both atmosphere and deep oceans.
9. The problem with the CO2 releases from the soils is that it has a huge initial response to an increase in temperature, but a limited capacity over time: maintaining the same temperature gives a rapid decline in extra release, due to a lack of “fuel” from fallen leaves and debris. That is mainly in the tropical forests. See Pieter Tans from slide 11 on:
https://esrl.noaa.gov/gmd/co2conference/pdfs/tans.pdf
Once the temperature drops, photosynthesis takes over and during a La Niña (and Pinatubo) we see minimum increase rates of CO2. The net result is that the fast variations zero out after 1-3 years and that over longer time spans the biopshere is a net sink, thus not the cause of the CO2 increase. That biolife is dominant can be seen in the opposite CO2 and δ13C changes.
The main cause of the δ13C drop is human emissions at average -24 per mil. As vegetation is a small net sink (thus including soil releases!) for CO2 and preferentially 12CO2, that increases the per mil of the atmosphere. The same for the ocean continuous CO2 flux between upwelling and THC sink.
The upwelling waters show a shift of about -10 per mil in δ13C at the water-air border, while the sinks give a shift of +2 per mil, average -8 per mil over ocean δ13C. While most is from deep ocean upwelling at 0 to +1 per mil, biolife gives 1-5 per mil in the surface waters.
The long term equilibrium over the whole Holocene was -6.4 +/- 0.2 per mil, probably largely caused by the ocean exchanges…
Based both on the 14C bomb spike decay and the “dilution” of the human δ13C “fingerprint”, the continuous CO2 flux from the equator to the poles is estimated around 40 GtC/year…
Bart,
As said before, near all variability in CO2 rate of change is mainly the effect of temperature on tropical vegetation. That effect levels of to below zero after 1-3 years: all biolife together is a small, but increasing sink for CO2. Thus the variability has a negative effect on the slope and is certainly not the cause of the increase of CO2 in the atmosphere.
Then we have two possibilities left: human emissions which have double the slope of the measured increase rate slope or the temperature effect on the oceans surface (including upwelling and downwelling). which also has a limited effect. The latter not more than 16 ppmv/K for a constant upwelling. The former more than enough to explain the full increase for every year in the past 57 years and over the full period since 1850.
There is zero evidence that temperature is the cause of the slope in the CO2 rate of change, all observations point to human emissions…
“A hiding to nothing”
A ‘hiding” means “a beating”. (Students need a good “hiding” now and then to sustain their character.) In horse racing it meant whipping your horse to make him run faster. (Which came first, beating the horse or beating the student, I don’t know.) Carpets, once a year, were hung on a line and given a good hiding to knock the dust out.
(For comparison the term “boxing his ears” [giving someone a good “boxing”] is another old time term.)
In the past “a hiding to nothing” basically meant “frantic actions having no effect on outcome”. An example would be a last place horse being beaten by its rider.
In our more modern times, In the few times I have seen it used, it has been used “post facto”. For instance in its generalized usage the Clinton campaign spending well over 600 million dollars could be called “a hiding to nothing” — though during the campaign it was thought that level of spending would guarantee a Clinton win. (The same certainly could be said for Jeb Bush’s spending well over 100 million dollars to win just four electors during the nomination process. The Clinton campaign saw Jeb’s absolute failure and they DIDN’T GET THE MESSAGE!! Trump did.).
A “hiding” once had common usage but the meaning of the word has faded from our minds.
That the English now use the phrase to mean “a frantic effort put forth when no gain can be expected” must have come about from their experiences with the fanaticism of Socialists. In that sense such fanaticism is certainly “a hiding to nothing”.
Eugene WR Gallun
In South Africa ‘a hiding’ is a beating. To get or be on a ‘hiding for nothing’ (similar words) means to take or get punishment for no gain or effect, i.e. pointless pain.
I always felt it meant get a beating or a whipping – and still end up nowhere like a bad horse in a race.
I.e the worst of all possible worlds. All pain and no gain.
‘On a hiding to nothing’ means betting all the family savings on a horse that has no chance of ever winning. 😉
Oh, I thought it was Mickey Mann’s latest excuse for truncating Briffa’s tree-ring proxy: you’re on a hiding to nothing because there’s nothing to hide.
Nice word play.
You have to remember that Trenberth et. clique. allows heat to be suddenly mixed into the deep ocean much faster than the models previously allowed for, but that carbon dioxide, for some strange reason, apparently doesn’t have to follow the same laws of mass action.
They are all at sea.
“originated as horse racing parlance”
I always thought that it was from either cricket or rugby.
Bart:
I am not saying I’m right and you are wrong. I am advancing my “temperature-stimulated natural CO2 emission on land, only” model as an alternative scenario to the “CO2 consensus” where there is no natural source and the large fluctuations in net emission are unexplained.
In analogy to being a “luke Warmer”, my “luke CO2 increase” model has the effect that the correlation between global temperature change and net CO2 emission is a physical effect at short times, and yes, it would be a remarkable coincidence at longer times, based on the 20th century ramp-up in industrial activity just happening to be coinciding in a time when it was naturally getting warmer.
Yes, I need to learn more about the thermohaline ocean circulation and ocean temperature effects on CO2 emission, but I haven’t gotten that far. Think of my model, “let’s not invoke ocean effects because of uncertainty in modeling them, as of right now, let’s see how far we get with a land source for the temperature-correlated emission.”
Ferdinand:
4. There are two effects — one is a rate coefficient for CO2 exchange in response to concentration difference between reservoirs, the other is the non-linear Revelle buffer effect giving a non-linear rate coefficient. I have rate coefficients both at the air-surface ocean and surface-ocean deep ocean interfaces, but I only have the non-linear Revelle buffer effect between air and surface ocean.
Yes, I have rate coefficient segregating surface from deep ocean (this has nothing to do with the fall of organic detritus from surface ocean through deep ocean to the bottom — this detritus in organic matter, and if it doesn’t rot in the cold, deep ocean water, it is an additional source of CO2 sequestration that I can add to my model, but it isn’t the carbonate system that I treating differently from organic uptake, whether on land or sea). This rate coefficient is a “knob” to get the known partition between CO2 uptake from inorganic (ocean carbonates) and organic(plant life, wherever it happens). This partition is known from the recent chemical analytical techniques to get a “Keeling curve” for atmospheric oxygen.
9. A reservoir and a rate coefficient — an electric capacitor fed by a resistor — and result in a broadening of an effect (increased CO2 emission from decay) from a cause (increased temperature). The smaller the reservoir (you are claiming a small reservoir), the less broadening. But I don’t see a way to switch the resistor and the capacitor to get a sharpening of the response — this would require stimulation of CO2 emission by the rate of temperature change, and there is no plausible physical mechanisms for it in this system.
Something of a “lukewarmer” article, as the author buys into many warmist assumptions. It does probably describe the real-world worst defensible case for CO2 and climate, as many of his premises, like the sensitivity number for CO2 doubling, are probably too high.
Agreed. I think with proper water based negative feedback, the climate sensitivity is probably under 0.5C.
Which makes CO2 levels of only academic interest, temperature wise.
The effects on plant growth especially in marginal rainfall regions is far more interesting, and that my in the end suck out CO2 anyway.
“this does mean that CO2 levels will remain at ~410 ppm indefinitely, which is far higher than a planet without human beings” excuse me ? we have had CO2 levels well above 410 ppm when human beings didn’t exist on THIS planet … very odd claim …
It means that he thinks the climate during last couple of hundred years is the normal climate of the Earth. I.e. he has no knowledge of Earth history. Many people have similar difficulty visualizing time scales longer than a few human generations. Climate scientists all have this failing (and if they did, e.g. Mike Mann, get an education in geology, they have deliberately set out to forget it). How many people you know understand that we are in (an interglacial period within) an ice age? Most of them probably think that there was an ice age in the distant past and that it’s over and done with.
And Naomi Oreskes too. She actually did some decent research on the Olympic Dam iron-copper-gold-uranium-lanthanum mine in South Australia before getting the alarmist virus.
Yup. And if sensitivity is around 1.5 we’ve got even longer to not worry. Perhaps a little time to enjoy the minimal warming and miraculous fertilizing we’re doing.
=================
Why 440ppm why not 800 ppm. Plants would love it. If, sometime in the future,, we go into another ice age or cold period more types of plant may survive longer.
Greenhouses that use propane to heat, can by a kit to capture fuel emissions to raise the CO2 rate to 1000ppm within the greenhouse. The plants love it and grow faster. Only people who never have farmed want to de-carbonize the world.
“The strange thing is that this airborne fraction hasn’t changed at all in 60 years, despite exponentially increasing human emissions.”
I don’t think it’s strange. Here I show why I think it is a mathematical consequence of exponential growth. And would diminish with slower growth, but not, I think, to zero.
The planet is greening.
Do you think the extra sink due to greening would be enough to get to zero?
Bob,
“Do you think the extra sink due to greening would be enough to get to zero?”
Nt enough capacity. Above ground biomass is about 500 Gtons C. We have dug up and burnt about 400 Gtons C already. Biomass (mainly trees) is limited by availability of water and sunlight, usually not CO2. So it is a limited sink.
Commiebob,
The main long-term sinks are the deep oceans, but these have a limited exchange with the atmosphere (~40 GtC/year) and a limited unbalance due to the increased CO2 pressure in the atmosphere (~3 GtC/year more sink than source). Over long time spans deep oceans and atmosphere would get in equilibrium (half life time ~35 years). If we stop all emissions today, that would mean that the 400 GtC emitted up to now, would be redistributed into the ~36,000 GtC in the deep oceans, leaving just over 1% or ~3 ppmv extra in the atmosphere.
With constant emissions, there still would be an increase until sinks and emissions are in equilibrium, while the acceptance of extra CO2 in the deep oceans still is near unlimited and only increases with a few % over centuries…
The uptake by vegetation is huge, but mainly bidirectional (leaves, small stens). The more permanent uptake in peat, (brown)coal,… is near unlimited, but much slower over longer periods compared to the deep oceans.
The rate of greening can actually increase. Higher CO2 concentration means plants do not need to keep stomata open for as long to get the CO2 they need to grow. Therefore plants can respire less, so lose less water to the atmosphere. So plants in arid areas can grow using less water. Making plant growth in arid regions better than a linear projection.
Ocean phytoplankton are already responding to increased pCO2. The limiting factor for their growth is mostly iron and phosphate. They sequester CO2 into their carbonate skeletons that sink to the ocean floor.
Ferdinand,
You said, “Over long time spans deep oceans and atmosphere would get in equilibrium (half life time ~35 years).” I think that you are overlooking the role of biology in adding to the CO2 of the deep oceans. Also, the warmer, low-pressure surface waters would potentially saturate with CO2 long before they reached the concentration of CO2 in the deep, cold waters.
Nick Stokes (at 10:51pm),
“Biomass (mainly trees) is limited by availability of water and sunlight, usually not CO2. So it is a limited sink.”
This is an incorrect statement. At a given CO2 level biomass production may be limited by water and sunlight, but the biomass production at a given water and sunlight level increases with increase of CO2. In addition an increase in CO2 reduces the water requirement while at the same time increases biomass production.
Nick says, “Biomass (mainly trees) is limited by availability of water and sunlight, usually not CO2.”
I don’t think that this is true. The main limit on plant growth is availability of CO2. Until the industrial revolution released large amounts of CO2 that had been, until then, captured in coal deposits, the plants were starving for lack of CO2.
“The main limit on plant growth is availability of CO2.”
You can see that can’t be true if you just look at an area like Congo. Some of it gets plentiful water, and has dense forest. All on 400 ppm CO2, but was still true with 280 ppm. Then as you go north, the rainfall diminishes, and so does the forest. Same CO2. Water is the limit. Then Sahel, then desert.
Plants with adequate water have as much CO2 as they want, by opening stomata. Under water stress, they have to part close them to conserve water, which then limits CO2. Higher ppm can help there, but it is a restricted regime. With further stress, the stomata close completely, and the plant struggles, with or without CO2.
And CO2 does nothing to help with lack of sunlight.
Not usually, but there are vast stretches of area that might benefit.
https://www.sciencedaily.com/releases/2013/07/130708103521.htm
And yet, you’ve been told that one of the effect of CO2 is warming, which will ultimately put more water vapor in the air. More water vapor = more opportunity for water for plants. Example: greening of the deserts.
http://news.nationalgeographic.com/news/2009/07/090731-green-sahara.html?source=email_wn_20090807
More plants = more CO2 sinks, which could very well be a natural break on the run-away warming scenario that the models show, as they assume the sinks are static.
Nick,
You explain why the exponential growth of annual emission has forced the airborne fraction to be stable, but you don’t explain why it is 0.5. This is one of two mysteries which no-one as far as I am aware has ever explained. The other one is
Why is the natural CO2 atmospheric concentration 280ppm (why not 600ppm or 200ppm) ?
(I have a theory as to why it is exactly 280ppm)
No theory is needed. Start with the ‘observation’ of ~ constant 280ppm preindustrial. Now that must be a rough equilibrium value. There are two sinks and one source. The first sink is biological (some biomass, but long term mostly marine calcification (limestone is a massive carbon sink). That has some sink ‘productivity’ in equilibrium with 280ppm. (For example we know that calcifying coccolithphores have increased 10 fold in the North Atlanric over the past 30 years as CO2 ppm has increased.) The second sink is the physical chemistry of Henry’s Law acting on the oceans via the mixed layer. Thatnis proven bynthe ~800 year lag of CO2 behind temp seen in the ice cores, the lag nicely matching one overturning of the thermohaline circulation. Neither the area of the mixed layer nor its global temperature has changed very much in the Holocene, ego ocean dissolved CO2 equilibrium at 280ppm. The primary souce of CO2 is subduction zone decomposition of carbonates with associated volcanic venting of regenerated CO2. Plate techtonics changes very slowly, and we know volcanism is roughly constant (about 60 eruptions per year, and over the past hundred years a roughly constant distribution of VEI). So 280ppm is simply the number at which the marine calcification ‘permanent’ sink happens to equal the volcanism ‘permanent’ source during a blink of geological time like the Holocene.
Of course, none of this holds on geological time scales.
Clive Best @ur momisugly December 16, 2016 at 2:48 am
“I have a theory as to why it is exactly 280ppm”
It isn’t.
B, different time scale. That is geologic time, not the Holocene.
The natural carbon dioxide varies a lot, and the current levels are uncommonly low.
http://www.geocraft.com/WVFossils/PageMill_Images/image277.gif
CO2 after R.A. Berner, 2001 (GEOCARB III) http://www.geocraft.com/WVFossils/Reference_Docs/Geocarb_III-Berner.pdf
Nick : “I don’t think it’s strange. Here I show why ”
Very nice derivation of the constancy of AF under a constant exp growth. Simple and elegant.
Panel b) in the second IPCC graph does seem to back up this relationship in that AF is less during the temporary reductions in emissiosn, although the rather clunky 5y averages makes it a little less easy to see.
Sorry, Clive. Your math is likely wrong. I might get up the energy to prove mathematicaly why tomorrow. You can figure it out from your comment simple model.
Clive and Ristvan,
Too long ago for me to make the right calculation…
My rough estimate is that with the current emissions twice the current sink rate at ~110 ppmv above steady state, one need ~220 ppmv above steady state to get rid of the full ~4.3 ppmv/year human emissions. That is a level of 510 ppmv, far above the 440 ppmv of Clive…
The observed e-fold decay rate of the extra CO2 in the atmosphere is around 51 years, surprisingly linear over the past 57 years. No reduction in sink rate to see…
Thanks Ferdinand,
I am sure my model is far too simplistic, but what is more important is that you also agree that CO2 levels will stabilise once emissions are held constant. This is the key message that needs to be got out there !
The natural absorption rate has been 1.8% of the “excess” CO2 in the atmosphere since about 1950.
If CO2 levels keep rising, the natural absorption rate will continue increasing at 1.8% of the excess above 280 ppm.
If we can limit our emission, eventually the natural absorption rate will catch up.
But when you run the numbers, this won’t happen for many decades out.
The point is you need to model the natural absorption rate and how that varies with the levels of CO2 in the atmosphere.
Some have asked when the natural absorbers of oceans, vegetation and soils will run out of capacity? In the history of Earth, the natural absorbers have shown unlimited ability to bury Carbon. During the Carboniferous, vegetation buried 10,000 billion tons of Carbon over 60 million years. At.24 million years ago, the newly evolved C4 grasses dropped the equilibrium CO2 level from 1,200 ppm to 280 ppm. That is a lot of capacity and will dwarf any number we can add.
The only real limit is now 280 ppm in an interglacial and 185 ppm in a deep ice age. Oceans and plants will go on being a net absorber until CO2 gets down to these levels. This appears to be net natural equilibrium level in today’s vegetation biome and ocean arrangement.
Clive, I was wrong. My more complex model roughly reduced to yours when I worked it over today. The more complex model was created to check Salby, who is way off base in several ways. Your 0.5 is a good enough approximation; last night I suspected it wasn’t over sufficiently large delta PPM. My intuition last night was just off. And, as you point out, constant emissions must eventully equilibrate S to K so long as K doesn’t saturate. All the available evidence says it doesn’t, rather ocean calcification just increases. Theoretically this eventually could become micronutrient limited (iron) as in ‘barren oceans’. But that appears experimentally overcome by species substitution.
I think this is a good study to understand the carbon sinks and how to obtain an equilibrium. This is good knowledge to have to add to the understanding of how our world works.
Is it even possible to get to a 700-800 ppm doubling given that the cost of recoverable carbon will eventually rise and we might even come to our senses and discover thorium reactors.
David T
No, it is impossible with the known reserves and the time it would take to extract and burn them, plus 100% more. 800 ppm is not achievable by 2200.
“I will argue below that in order to stop global warming …”
Perhaps you should include a nod to CO₂ in this.
Insofar as Earth appears to be capable of warming or cooling without help from humans it is astonishing to think of stopping either. Whatever warming human-added CO₂ is causing may be slowed or stopped. I think that is what you intended to mean.
If we only knew the optimal CO2 atm concentration, we would have a target to maintain. I have never heard scientific evidence as to the ideal ppm level. Without a target, there cannot be a plan. I can only suggest 600 – 800 ppm will be closer to optimum then the near starvation current levels, but that has yet to be studied. I really don’t understand the conversation until we know. GK
This sounds like the radical idea that the federal budget could be balanced by increasing natural growth in the economy if the federal spending were simply held constant.
First I’d like to see proof that CO2 from burning fossil fuels is actually causing global temperature to rise before doing anything to mitigate it. If we can prove CO2 causes temperature to increase then we’d know by how much and whether or not stopping it is worthwhile. Forget the defense of AGW. Concentrate on the proof. If any.
Seconded
The problem is even less than he says. As the IR from CO2 sent downward is from -17 deg C air and the land surface is 15 deg C, there is no way that the former can warm the latter. Simple thermodynamics indicates that a cold tropical upper troposphere cannot warm the Earth’s surface. They also ignore that most of this region’s downwelling IR would be into the oceans and have little effect.
The bottom line is that a trace gas of any kind cannot drive Earth’s climate. Water vapor vastly overwhelms CO2 and CO2 is not a slave master of water vapor. To think that a trace gas drives the water vapor levels is sheer stupidity. Water vapor rules and humans are not altering water vapor. CO2 is a minuscule actor at most and undetectable in effect. Methane and Nix are much too short-lived like CO2 to have any lasting effect.
The author started out dissing the idea of decarbonizing and then said we should stabilize our carbonizing. Darn, he missed the target. We should completely ignore our carbon usage as all it does if green the planet and increase the food supply. It is true that the globalists do not want a burgeoning food supply as their goals include a 95% decrease in the human population. That’s another reason that they push the decarbonizing meme.
The surface will be warmer facing a -17 C layer of greenhouse gases than if it faces -270 K deep space. Thermodynamics only says that net flow of thermal radiation be from warmer to colder.
yes. we don’t radiate as MUCH towards cold clouds as sub zero space.
Desert nights are chillier than tropical nights…
Donald L. Klipstein December 15, 2016 at 8:29 pm
You wrote:
“The surface will be warmer facing a -17 C layer of greenhouse gases than if it faces -270 K deep space. Thermodynamics only says that net flow of thermal radiation be from warmer to colder.”
Thank you for this concise and exact statement for refuting the assumption that downweliig radiation from GHGs have no effect on earths temperature.
GHGs actually are slowing down the cooling, that’s all.
Herbst,
You said, “GHGs actually are slowing down the cooling, that’s all.”
I don’t think that anyone other than a few extremists have claimed otherwise.
Desert nights are chillier than tropical nights…Bingo we have a winner. Likewise Desert have a higher daytime temp than “tropical” type areas along the same longitude. REF: Tucson, Arizona compared to Shreveport, Louisiana
Higley7,
If the globalists want to decrease population, why are they bringing people that breed like flies into the rich economies, where they can breed even faster and in more places?
because the natives are getting restless.
“Water vapor rules and humans are not altering water vapor.”
With increasing urban lawn watering and rural agricultural irrigation, humans certainly are not decreasing water vapor in the atmosphere.
NOAA,
You left out golf courses, especially in Phoenix and Las Vegas. But numerous reservoirs also provide for more evaporation than what would take place without the rivers being dammed. Also, one of the byproducts of combustion is water, even pure hydrogen.
“I argue that by simply stabilising emissions, we can halt global warming because CO2 levels will stabilise as the sinks will then be able reach equilibrium with emissions”
As a matter of maths, this just isn’t true. Suppose the sea was infinitely deep, and CO2 diffuses in subject to the ordinary diffusion equation. Initial concentration uniform, and constant influx of CO2 commence at time zero. Boundary (sea surface) pCO2 rises as sqrt(t). (For proof see case 2(d) here and set z=0). It never reaches a stable level. Yet the sea is an infinite sink.
That is s simplification, of course, but there is no reason to suppose the real situation is more favorable. If CO2 in air is to be stable, with constant emissions, the flux will have to match the emissions.
Don’t see relevance there, your reference would be true if the ocean were the only sink and unbuffered. The article deals with the observation that half the extra CO2 is taken up in the first year and proposes that this is adaptation of carbon sinks to the CO2 partial pressure that the CO2 is fixed into carbohydrates or calcium carbonate. In the second year Half the remaining half is taken up, so the Biosphere would grow to be capable of consuming 3/4 of the human emission each year, then 87.5 in the 3rd year. By Year 5 if emissions were held stable the Biosphere would adapt to take up over 95% of emissions. I contend however that in this process, the biosphere will overshoot the equilibrium level and would in fact draw down sufficient CO2 to reduce the CO2 partial pressure if emissions were held constant.
“if the ocean were the only sink and unbuffered”
The ocean is the only plausible near-infinite sink. The amount of carbon we have already burnt is comparable to biomass; that can’t keep doubling.
Buffering only acts to change the diffusivity, but not the euation.
There is ageneral principle that as sinks fill up, the next lot are less accessible. That is what is really behind the sqrt(t) dependence.
Nick, the ocean is governed by Henry’s law while the biological processes are not. Biological processes drew down CO2 from very high levels to fractional percentages over the history of the earth.
The amount of carbon we have already burnt is comparable to biomass;
It doesn’t work like that because you have ignored TIME, how does emission compare with all growth produced over the time we have emitted CO2? Most of that biomass cycles carbon in it’s growth processes. Particularly remembering the bulk of the weight 32/44 ths of the related CO2 is released as Oxygen back into the atmosphere. The Carbon component of consumption is well less than total biomass.
Nick, is eddy diffusion a sufficient model?
CO2 is absorbed by warmer water cooling. This means we need to be looking at the thermo-haline circulation and the absorbed CO2 being taken down to depths in the Arctic Ocean by ocean currents , not diffusive processes.
Once in the abyssal depths some of it will form calthrates and not resurface.
Greg,
Calthrates are formed from methane, not CO2.
That’s correct Nick. One of the problems with the language here is that we are dealing with differentials. When we talk about emissions we are really mean emissions/year or DE/DT. When we refer to sinks here we mean the net flow rate out of the atmosphere per year DS/DT
If DS/DT = DE/DT then annual CO2 levels in the atmosphere would be constant. However mankind has been constantly accelerating emissions. During this entire period of exponentially increasing emissions i.e DE^2/DT^2 > 0 the airborne fraction has been ~0.5 so DS/DT = 0.5 DE/DT. If we now continue indefinitely with DE^2/DT^2 = 0 then will slowly increase i.e DS/DT = 0.7 DE/DT…..DS/DT = 0.8 DE/DT and reach unity.
“If DS/DT = DE/DT then annual CO2 levels in the atmosphere would be constant. “
Yes, I’m talking about flow rates. And you’re talking about DE/Dt constant. And I’m saying that the diffusion solution to that has surface pCO2 (and so air pCo2) rising with sqrt(t). No limit.
Here is a comparison between your sqrt(t) rise and my fast equalisation out over next 300 years. Your solution is not too bad either. We could live with that perfectly well for the next 100 years !
http://clivebest.com/blog/wp-content/uploads/2016/12/Nick-1.png
reiterating my point made above, the transport to deep ocean is not really diffusive, that is unrealistically slow when it is short-circuited by the themo-haline circulation which goes straight into the abyssal depths.
Nick,
Your formula is right for the ocean surface, but fails for the deep oceans, the same problem as in the Bern model…
The main exchange between atmosphere and deep oceans is via the THC and other ocean currents. These take lots of CO2 out of the atmosphere due to colder temperatures near the poles and release lots of CO2 at the upwelling places. The net sink rate is directly proportional to the extra CO2 pressure difference between the atmosphere and the ocean surface, mainly at the sink place, which is temperature (and bio-life) dependent, hardly influenced by saturation from previous years: what is upwelling is deep ocean water, hardly influenced by humans, what is downwelling has taken all CO2 possible for the moving temperature over its trajectory on the surface.
The long term equilibrium (half life time ~35 years) between deep oceans and atmosphere for all CO2 released in the past 166 years is just over 1% of the total CO2 in atmosphere + deep oceans.
The observed pCO2 difference at the main sink place (N.E. Atlantic) is ~150 μatm, hardly influenced by temperature or saturation over time…
Ferdinand,
Yes, assuming uniform diffusivity is obviously wrong. But the problem is, the deviation goes the wrong way. Diffusivity decreases with depth. So new CO2 entering the sea not only has less concentration gradient to help it along, but resistance to flow gets worse.
Ferdinand,
I didn’t really engage with the advective aspect of these currents. It depends on their capacity. But I don’t think they fit with the simple half-life model any better than with diffusion.
Nick,
Indeed it is difficult to know how well mixed the deep oceans are over time, but looking at the distribution of oxygen, which is only coming from mixing with the surface and looking at the disribution of traces of recently introduced chemicals (14C, CFC’s,…) there is more mixing than was expected.
Until now it is not possible to make a differentiation between the linear model and the IPCC’s Bern model (which expects saturation of the deep oceans and vegetation), because there still is little difference between the two results. Time will tell us…
I have been arguing this for a while, and also that the fact that only half the CO2 rise survives a year, trivially means the half-life is 1 year!
I think you are wrong though, when you have a perturbation in a system the rate rises in the system dependent on the difference between the driving force and the no-growth equilibrium level. As CO2 partial pressure grows the biosphere grows to meet it but the acceleration in the rate of emission means that the CO2 level must BE ABOVE the equilibrium. If we were to immediately stop increasing CO2, the CO2 Level WOULD FALL to the equilibrium level as the biosphere adapts, and takes up the difference between current CO2 and the equilibrium.
You only need to know that the biosphere is EXPANDING to know that CO2 is above equilibrium level.
That is another possibility. The sinks could well overshoot unity for a short while before the system relaxes to a slightly lower CO2 level. It would be far higher though than zero emissions. However a stable atmosphere is the priority.
“A stable atmosphere is the priority”
So your solution is to make emissions stable, because your assumptions is that optimal CO2 levels are 280 ppm. You are wrong, Clive. And you seem to be under the warmist assumption that CO2 regulates temperature.
Aside from the brouhaha, your solutions really don’t strike me as any different from James Hansen’s.
Bobl,
Your half life time is a little too short…
The sink rate doesn’t depend of the emissions of one year, it depends of the total CO2 pressure above the long time dynamic equilibrium, which for the current (area weighted) average ocean temperature is ~290 ppmv over the past at least 800,000 years. It is the 110 ppmv (~μatm) above steady state which gives enough extra pressure to push ~2.15 ppmv CO2 of the 4.3 ppmv CO2 emissions into the (deep) oceans and vegetation.
That gives an e-fold decay rate of 110 / 2.15 = 51.2 years, the same as it was 55 years ago. The slightly quadratic increase in human emissions over the years compensated for the increasing sink rate caused by the increasing CO2 pressure in the atmosphere above equilibrium, thereby maintaining the ~50% residual increase in the atmosphere. But that is just coincidence caused by the increase in emissions.
Halving human emissions from the current rate would give a flat CO2 level. Maintaining the same emissions level would give a slowing increase until emissions and sink rate are equal.
“It is the 110 ppmv (~μatm) above steady state which gives enough extra pressure to push ~2.15 ppmv CO2 of the 4.3 ppmv CO2 emissions into the (deep) oceans and vegetation.”
Correct. The 2016 paper on “Recent Paul in the growht ratoe of atmospheric CO2” has this equation:
.Fsink = B(M – M0) where M is mass in atmosphere, and M0 is background mass.
Growth(CO2) = F_anthro – B(M-M0). So B, a constant, is about 2.15 ppmv per 110 or about 2% of the delta.
Fsink = 4.3 ppmv when (M-M0) is double of corrent levels when we get another 110 ppmv, or around 510ppm CO2.
.
As I understand it the oceans at most locations are not at CO2 equilibrium ever.
Remember CO2 is a well mixed gas. Per Henry’s law the cold polar waters can’t be at equilibrium at the same time the warm tropic waters are.
When the overall ocean/atmosphere CO2 levels are stable for 10’s of thousands of years, it is because the tropics are sourcing the appropriate amount of CO2 to match the polar oceans CO2 sink.
After absorbing CO2, the cold polar surface water in turn sink to the ocean floor to emerge centuries or millennia later in a warmer climate. When those waters surface they outgas the sequestered CO2. Over centuries/millenia those surface waters make their way to polar regions and during the trip they cool down and absorb CO2.
I suspect you can incorporate that dynamic in your description, but for now you’re not describing earth’s oceans.
That is of course correct. Warm surfaces in the tropics are net emitters of CO2 and it is absorbed in high latitude oceans. I am simplifying things too much but it is really about the net annual change.
I am not sure if I missed it, but isn’t it the case that CO2 is stored in the ocean ground as Limestone (CaCO3 / Calcium Carbonate)? So not all of it can be emitted again.
and all the coal and oil was once CO2 in the atmosphere.
until something sank it.
what could that have been?
The storage of CO2 as limestone from rock weathering and ocean sedimentation has pumped out vast quantities of CO2 over billions of years. The buried organic carbon in rocks is equal to the oxygen content of the atmosphere. Eventually some of this CO2 gets recycled back to the atmosphere by plate tectonics which is a good thing too since otherwise life would run out of phosphorous.
Clive,
As I said, I think the basic argument can address the dynamics of non-uniform ocean surface temps, but I didn’t even see a cursory statement that you were modelling the ocean as having a uniform global temp.
Even more importantly, you aren’t discussing the long term sequester of CO2 caused by the ocean currents. When those cold waters sink they take CO2 with them and that CO2 doesn’t get a chance to interact with the atmosphere for centuries/millenia.
I would think that long term sequester would bolster the argument that once CO2 emissions level off a global CO2 equilibrium will kick in.
gregfreemyer,
It doesn’t make any difference for the equations: indeed there is a continuous flow of CO2 from the upwelling zones near the equator (mainly the East Pacific) and the polar sink places (mainly the N.E. Atlantic). At dynamic equilibrium (“steady state”) the upwelling amounts of CO2 equal the absorption of CO2 at the sink places. Calculated on the base of the 14C bomb spike decay and the “dilution” of the 13C/12C ratio from human emissions by the CO2 release from the deep ocean upwelling (not influenced by humans), some 40 GtC/year as CO2 is passing from warm upwelling to cold uptake. That doesn’t influence the total amount of CO2 in the atmosphere at equilibrium, which is ~290 ppmv for the current ocean surface temperature.
If the average ocean temperature increases, that gives an increase of 16 ppmv/K to reach a new steady state, the same as for a single sample in a laboratory, per Henry’s law.
If the CO2 pressure in the atmosphere increases, that decreases the release at the upwelling side and pushes more CO2 in the sinking waters at the other side. The difference is currently ~2.15 ppmv for 110 ppmv extra CO2 pressure above steady state in the atmosphere (inluding the uptake by the ocean surface and vegetation).
Thanks Ferdinand,
My mind tells me that fact that the polar CO2 absorbed is removed (sequestered) from the equilibrium process as an impact on the dynamics of how long the equilibrium takes to reestablish itself.
The main post argues for 30 years. I would think the long term sequester would accelerate that process and reduce the number of years required to reach equilibrium?
But I’ve done no calculations to confirm my gut feel.
Incorrect, Ferdinand. You are only looking at equlibration with the surface oceans. But, the equlibration period with the entire oceans is long. This begets an integrating dynamic in the short term in which sensitivity is in ppmv/degC/unit-of-time.
There is no doubt about it. None at all. Just look at the graph.
http://woodfortrees.org/plot/esrl-co2/derivative/mean:24/plot/hadcrut4sh/offset:0.45/scale:0.22/from:1958
My issue is that the main co2 sink is not the ocean via Henry’s law. It is biological sequestration via marine calcification via calcarious phytoplankton such as coccoliths (White Cliffs of Dover).
gregfreemyer,
Over the long term indeed the deep oceans will remove most of the extra CO2 in the atmosphere. The main problem is the relative small exchange between the two and the relative long decay rates that gives for the extra CO2…
Bart,
Incorrect, Ferdinand. You are only looking at equlibration with the surface oceans. But, the equlibration period with the entire oceans is long.
I am looking at both: the ocean surface has an equilibrium rate with the atmosphere of less than a year, but can’t take more than 10% of the change in the atmosphere.
The deep oceans are near unlimited in capacity, but the exchange is much smaller, which gives a decay rate of ~51 years (including a small, but growing contribution from vegetation).
Your graph shows mainly the variability caused by the influence of temperature on (tropical) vegetation, which zeroes out over periods longer than 1-3 years. For longer periods, vegetation is a small, but growing sink for CO2. The integral of the effect of the temperature variability on biological CO2 levels is below zero… Thus not the cause of the increase, neither are the oceans, as the effect of temperature on ocean-atmosphere equilibrium is rather small: ~16 ppmv/K…
ristvan,
You need to take the time period into consideration: the white cliffs of Dover needed some 0.1 mm/year of sediments to form over tens of million years… Sedimentation may play a role, if that depends of the increase of CO2 in the atmosphere which is followed by an increase in the ocean surface.
On the other hand, oceanic CO2 releases from upwarming upwelling waters near the equator are suppressed by higher CO2 pressure in the atmosphere and the uptake near the poles get increased. These two are linear in ratio to the pressure differences between ocean surface and atmosphere. That is what is observed over the past 57 years: a linear increase in net uptake in ratio to the pCO2 difference between ocean surface and atmosphere… I am not sure if a bio-life reaction in the ocean surface is that linear…
“On the other hand, oceanic CO2 releases from upwarming upwelling waters near the equator are suppressed by higher CO2 pressure in the atmosphere and the uptake near the poles get increased.”
Not even close. Higher pressure in the atmosphere does not increase uptake near the poles, because it is merely a splitting of the flow that otherwise would be confined to the ocean currents. What gets transferred via atmospheric currents is reduced in the ocean currents. It does not suppress what is upwelling in the ocean waters because that flow is driven by centuries of inertia, and cannot be stopped over any timeline short relative to the turnover interval.
Bartenis:
Not even close. Higher pressure in the atmosphere does not increase uptake near the poles, because it is merely a splitting of the flow that otherwise would be confined to the ocean currents. What gets transferred via atmospheric currents is reduced in the ocean currents. It does not suppress what is upwelling in the ocean waters because that flow is driven by centuries of inertia, and cannot be stopped over any timeline short relative to the turnover interval.
Bart, I was talking about the release of CO2 from the upwelling waters into the atmosphere. At a constant CO2 concentration in the upwelling water and an increased CO2 pressure in the atmosphere, less CO2 is released into the atmosphere in the warm zones and more remains in the transported water. Near the poles, more CO2 is pressed into the already CO2 richer water, thus a part of the extra CO2 in the atmosphere sinks with the waters into the deep oceans.
Currently that gives an unbalance of ~3 GtC more sink than source, no matter how much CO2 is transported by the total THC circulation.
In all cases, an increase in CO2 pressure in the atmosphere gives an extra uptake by the deep oceans, as release and uptake are directly proportional to the pCO2 difference between ocean surface and atmosphere.
Ferdinand,
It is my impression that much, if not most, of the CO2 (and derivative carbonate species) in up-welling waters is biogenic, derived from detrital material in the water column that oxidizes as it drifts downward. That is why the pH is so much lower than surface waters at any latitude. The CO2 levels are therefore, primarily related to the biological productivity of surface waters in years past. I think that your characterization is assuming the up-welling waters are saturated with CO2 and previously (years past) gave up excess CO2 as it reached lower pressures and higher temperatures. We now have a situation where the CO2 partial pressure in the atmosphere is higher, suppressing effervescence, but at the same time, the surface waters are warmed by a warmer atmosphere, increasing effervescence. How does that balance?
After giving up the excess CO2, the water is transported laterally. It doesn’t always move poleward, at least not immediately. In California, the long-shore transport current moves water and sand southward. I’m not personally acquainted with what happens off the coast of South America. However, a quick check indicates that the Humboldt (Peru) current flows northward towards the equator. So, for true up-welling, it appears that the movement is NOT poleward (at least initially).
In any event, for something like the Gulf Current, which does flow northward, and cools as it does so, I expect it to stay in equilibrium with the solubility of CO2 for its ambient temperature. When it does sink, it will have a CO2 content determined by temperature and CO2 partial pressure. Again, the question is, how does the interplay between temperature and partial pressure play out?
You said, “In all cases, an increase in CO2 pressure in the atmosphere gives an extra uptake by the deep oceans, as release and uptake are directly proportional to the pCO2 difference between ocean surface and atmosphere.” This seems simplistic and dogmatic. The down-welling water will always be saturated for the given temperature and pressure. However, something to consider is the role of coccolith blooms in northern waters depleting the CO2 and having the water sink before it can re-establish equilibrium. In any event, as I stated at the beginning, the atmospheric CO2 going into solution is probably only a fraction of what comes back up in the future.
The outgassing depicted by the OCO-2 satellite along the tropics is clearly the result of warming, and I suspect that the origin of the water is from shallower water than what rides up the continental shelves from submarine canyons. I think that there is a great deal more complexity to the situation than what you are explaining to Bartemis.
If it was not that the World Temperature controls CO2 levels and not the other way around, there would be something interesting in this article.
Ntesdorf, what you say is true in the ice cores via Henry’s law for long time scales (millennia, ice ages) in the absence of anthropogenic CO2. It is not necessarily true on shorter time scales (centuries) for ‘extra’ anthropogenic emissions. CO2 is a GHG. We know that in the absence of feedbacks doubling increases GAST ~1.1-1.2C (Monkton’s third post in his recent ‘error’ series enables the calculation of 1.16C). What we don’t know for sure are the feedbacks. Observational evidence says they are weakly positive, resulting in observational ECS about 1.5-1,7 rather than 3-3.2. In other words, no C in CAGW.
Moderator —
Yet again my post has not appeared. Has Santa’s “Naughty or Nice List” been hacked and the information contained therein being used against me?
Eugene WR Gallun
[Nope . . . mod]
The rate of ice formation is the highest it has been in a very long time. It comes later by a matter of hours later than typical, but it is raging steep. If global warming were a thing this would be impossible and yet it has been happening for several years. Earth is retaining its ability to refreeze the arctic despite the increase in CO2 ppm. Something we’re sure of is very wrong.
The article explains the reasons why the rise in CO2 follows temperature. However there are numerous mistakes in the arguments, too many to itemize.
The conceptual errors I see as most important are 1) the idea that CO2 is largely responsible for the whole GHG effect and 2) the implication by omission that there are no external influences altering the temperature of the atmosphere.
Water vapour is a far greater contributor to raised temperatures and there is no need for any CO2 at all to accomplish, contrary to what Tonyb persists in trying to sell. Even snowball Earth had water vapour subliminating off the ice.
The article previous to this one shows that CME’s can heat the upper atmosphere 750 degrees C, followed by net cooling from the NO produced. GCR seed clouds, and the oceans can themselves create large swings in the temperature of the air above them. This cannot be reduced to simplistic explanations, as evidenced by the temperature record.
However, all things considered, the calculation is sound: the CO2 would indeed stabilise because of the presence of such a huge amount of water and the vastness of the plant population which I think hardly gets a mention.
What is not at all clear is what would happen to the air temperature given a stable CO2 level. In the past there have been huge and rapid changes in temperature, the most recent being the late 1700’s when it rose at a rate of 4 C per century with, apparently, no change in the CO2 concentration. So obviously there is more to it.
We can expect that the heating and cooling cycles will continue, as will ice ages and passably warm interregna. The reason for this is straightforward: CO2 only has a weak influence on global temperatures. As Anthony and Willis’ presentation shows clearly, water vapour is by far the main GHG forcing and even that is being neutered by other more powerful influences.
So, yeah, the CO2 will stabilise and life will carry on, a bit more productively when it comes to farming.
The aim is to prove that rise in CO2 levels can halted by halting the increase in emissions. The activists say we must stop ALL emissions, but we know this is economic suicide. How sensitive the climate is to CO2 levels is another question. The governments of the world are being told that all emissions must stop now. This is not true.
Regarding “The subtle replacement of logarithmic forcing of CO2 with a linear forcing”: IPCC is not doing that – their favored figure for direct effect of CO2 change is 3.7 W/m^2 per 2x change of CO2 – obviously indicating the effect is logarithmic. Also, the climate sensitivity figures in or near the range of 1.5-3.5 degrees C are degrees C per 2x change of CO2 – which indicates the effect being logarithmic.
Here is Fig 10 again with a logarithmic forcing. I asked Prof. Gregory at the Royal Society meeting on AR5 why the different emission lines were linear. He admitted that they all Earth System Models assumed that sinks slowly saturated and that other ‘feedback’ forcings like methane etc. etc. kicked in at exaclt the rate to give a linear line. That was the picture that was storyline needed.
http://clivebest.com/blog/wp-content/uploads/2013/10/Walport-Comparison.png
This chart is as horrendously misleading as the TAR hockeystick.
Let’s review:
1) The land and ocean sinks are rising not falling and NOT saturating.
2) if we stabilize emissions at any level, we will EVENTUALLY stablilize at a CO2 level.
3) Because of #2, there is no fixed amount of carbon to be limited to, there is emissions PER YEAR limits if you want to stop CO2 rises. The “carbon budget” is a bogus and incorrect approach! There is no ‘carbon budget’ and it does matter if you emit that carbon in 2 decades (see a sharp rise in CO2) or 10 decades (and see most of it abosorbed. If we reduce emissions by merely 50%, we effectively end any significant rise or impact of CO2, as the remainder is tiny rise in CO2. Thus, the Paris efforts to reduce by 80% are an insanely counterproductive effort.
Clive,
Very interesting finding!
That means that the difference between the linear model (no saturation: sinks remain in ratio with the extra pressure) and the Bern model (saturation of the different sinks) would be obvious between now and 2020…
Regarding “The decay time for an individual CO2 molecule emitted by man is only about 5-10 years (based on C14 measurements in both bomb tests and those produced by cosmic rays). Every CO2 molecule in the atmosphere is rather quickly absorbed either by photosynthesis or by the ocean. However on average most of them are simply replaced by another CO2 molecule entering the atmosphere through evaporation from the ocean surface or by biological respiration. The residence time however, is the e-folding time needed for a sudden net increase in CO2 to decay back to normal as the carbon cycle reacts.”:
Not quite stated here is that the e-folding time for decay of a “sudden net increase” (AKA a pulse of CO2 injected into the atmosphere) is longer than the atmospheric residence time of individual CO2 molecules. Willis Eschenbach explained this well in https://wattsupwiththat.com/2015/04/19/the-secret-life-of-half-life/
There, he said that for individual CO2 molecules, the e-fold time (time constant referred as tau) is 10 years and the half life of that is 6.9 years. And for e-fold time (time constant mentioned as tau) of a pulse of CO2 – Willis E. comes up with 59 years, which means half-life of 41 years. Have a look at Figure 3 and its caption in the above-mentioned https://wattsupwiththat.com/2015/04/19/the-secret-life-of-half-life/
I also looked into this. I get about the same e-folding time as Willis.
http://clivebest.com/blog/?p=7393
A correlary here, in consideration of Figure 3 and its caption in https://wattsupwiththat.com/2015/04/19/the-secret-life-of-half-life/: The rate at which nature does net removal of CO2 from the atmosphere year-by-year is proportional to how much atmospheric CO2 exceeds 283 PPMV. If during any short period of time (per month year-round average, a year, or 4 years) nature removes an amount equal to half of what mankind adds, then if CO2 emissions stabilize and get sustained at current levels – atmospheric concentration of CO2 will stabilize at a level twice as much above 283 PPMV as it is now. Using 405 PPMV for current, I figure that is 527 PPMV. The half-life of the difference between 527 and 405 PPMV would be 41 years.
This 527 PPMV figure would increase by 10 PPMV per degree C of warming of the ocean surface (less because ocean surface warming reducing ocean absorption of CO2 caused the half-life to be 41 years instead of mid-upper 30s that would be the case if the oceans weren’t warming). Also, as the deeper oceans gain CO2, the long term equilibrium figure for atmospheric CO2 increases a little for a given global ocean surface temperature. Overall, I think this means atmospheric CO2 stabilizing around 550-580 PPMV if we maintain CO2 emissions at the current rate (2014-2016 average) for a few centuries – if our fossil fuels last that long.
A very interesting article, clearly and well written, Mr. Best. The implication of the constancy of the airborne absorbed fraction of CO2 had never struck me before in this light. The argument seems quite convincing at a first read; however, Nick Stoke’s point that the uptake by biological sources will reach saturation at some point needs further attention, and the relative importance of ocean and biota in the CO2 uptake. I need to look at Nick’s other points and look at the maths some more, but at first glance there’s some original ideas here. I rate as a lukewarmist and wonder – has Dr Roy Spencer seen this?