For a another view on the CO2 issue, please see also the guest post by Tom Vonk: CO2 heats the atmosphere…a counter view -Anthony
Guest Post by Ferdinand Engelbeen
There have been hundreds of reactions to the previous post by Willis Eschenbach as he is convinced that humans are the cause of the past 150 years increase of CO2 in the atmosphere. For the (C)AGW theory, that is one of the cornerstones. If that fails, the whole theory fails.
This may be the main reason that many skeptics don’t like the idea that humans are the cause of the increase and try to demolish the connection between human emissions and the measured increase in the atmosphere with all means, some more scientific than others.
After several years of discussion on different discussion lists, skeptic and warmist alike, I have made a comprehensive web page where all arguments are put together: indeed near the full increase of CO2 in the atmosphere is caused by the human emissions. Only a small part might have been added by the (ocean) warming since the LIA. That doesn’t mean that the increase has a tremendous effect on the warming of the earth’s surface, as that is a completely different discussion. But of course, if the CO2 increase was mainly/completely natural, the discussion of the “A” in AGW wouldn’t be necessary. But it isn’t natural, as the mass balance proves beyond doubt and all other observations agree with. And all alternative explanations fail one or more observations. In the next parts I will touch other items like the process characteristics, the 13C and 14C/12C ratio, etc. Finally, I will touch some misconceptions about decay time of extra CO2, ice cores, historical CO2 measurements and stomata data.
The mass balance:
As the laws of conservation of mass rules: no carbon can be destroyed or generated. As there are no processes in the atmosphere which convert CO2 to something else, the law also holds for CO2, as long as it stays in the atmosphere. This means that the mass balance should be obeyed for all situations. In this case, the increase/decrease of the CO2 level in the atmosphere after a year (which only shows the end result of all exchanges, including the seasonal exchanges) must be:
dCO2(atm) = CO2(in1 + in2 + in3 +…) + CO2(em) – CO2(out1 + out2 + out3 +…)
The difference in the atmosphere after a year is the sum of all inflows, no matter how large they are, or how they changed over the years, plus the human emissions, minus the sum of all outflows, no matter how large they are, wherever they take place. Some rough indication of the flows involved is here in Figure 1 from NASA:
From all those flows very few are known to any accuracy. What is known with reasonable accuracy are the emissions, which are based on inventories of fossil fuel use by the finance departments (taxes!) of different countries and the very accurate measurements of the increase of CO2 in the atmosphere on a lot of places on earth, including Mauna Loa.
Thus in the above CO2 mass balance, we can replace some of the items with the real amounts (CO2 amounts expressed in gigaton carbon):
4 GtC = CO2(in1 + in2 + in3 +…) + 8 GtC – CO2(out1 + out2 + out3 +…)
Or rearranged:
CO2(in1 + in2 + in3 +…) – CO2(out1 + out2 + out3 +…) = – 4 GtC
Without any knowledge of any natural flow in or out of the atmosphere or changes in such flows, we know that the sum of all natural outflows is 4 GtC larger than the sum of all natural inflows. In other words, the net increase of the atmospheric CO2 content caused by all natural CO2 ins and outs together is negative. There is no net natural contribution to the observed increase, nature as a whole acts as a sink for CO2. Of course, a lot of CO2 is exchanged over the seasons, but at the end of the year, that doesn’t add anything to the total CO2 mass in the atmosphere. That only adds to the exchange rate of individual molecules: some 20% per year of all CO2 in the atmosphere is refreshed by the seasonal exchanges between atmosphere and oceans/vegetation. That can be seen in the above scheme: about 210 GtC CO2 is exchanged, but not all of that reaches the bulk of the atmosphere. Best guess (based on 13C/12C and oxygen exchanges) is that some 60 GtC is exchanged back and forth over the seasons between the atmosphere and vegetation and some 90 GtC is exchanged between the atmosphere and the oceans. These flows are countercurrent: warmer oceans release more CO2 in summer, while vegetation has its largest uptake in summer. In the NH, vegetation wins (more land), in the SH there is hardly any seasonal influence (more ocean). There is more influence near ground than at altitude and there is a NH-SH lag (which points to a NH source). See figure 2:
The net result of all these exchanges is some 4 GtC sink rate of the natural flows, which is variable: the variability of the natural sink capacity is mostly related to (ocean) temperature changes, but that has little influence on the trend itself, as most of the variability averages out over the years. Only a more permanent temperature increase/decrease should show a more permanent change in CO2 level. The Vostok ice core record shows that a temperature change of about 1°C gives a change in CO2 level of about 8 ppmv over very long term. That indicates an about 8 ppmv increase for the warming since the LIA, less than 10% of the observed increase.
As one can see in Fig. 3 below, there is a variability of +/- 1 ppmv (2 GtC) around the trend over the past 50 years, while the trend itself is about 55% of the emissions, currently around 2 ppmv (4 GtC) per year (land use changes not included, as these are far more uncertain, in that case the trend is about 45% of the emissions + land use changes).
We could end the whole discussion here, as humans have added about twice the amount of CO2 to the atmosphere as the observed increase over the past 150 years, the difference is absorbed by the oceans and/or vegetation. That is sufficient proof for the human origin of the increase, but there is more that points to the human cause… as will be shown in the following parts.
Please note that the RULES FOR THE DISCUSSION OF ATTRIBUTION OF THE CO2 RISE still apply!
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Ferdinand Engelbeen says:
August 8, 2010 at 4:58 am
“Group 2 says:
– A lot of natural flows are far larger than the observed increase and can be the cause of the observed increase. Without full knowledge of all flows we can’t be sure that human emissions are the sole cause.”
Without knowledge of all the feedback mechanisms we cannot be sure whether human emissions have had any net effect at all! And even flows that are individually smaller than the observed increase might have caused it in combination.
You still seem quite unable to grasp – or unwilling to accept – that the ability to tell a plausible story is not the same as proving that the story is true.
Paul Birch says:
August 8, 2010 at 3:59 am
In all of these matters you grossly underestimate the range of possible mechanisms by which similar results can arise. We do not understand the mechanisms of the carbon cycle anything like well enough to give any clear-cut answers. We don’t even know the solubility of CO2 in sea water at all depths and pressures (let alone the full equilibria of such important regulating reactions as CaSiO3+CO2=CaCO3+SiO2); many of the experimental observations conflict.
Paul, there are a myriad of possible mechanisms which may (and do) influence the CO2 levels in the atmosphere. But as long as the increase in the atmosphere is less than the human emissions, these play no role in the increase, as any change in anyone of the natural inputs and outputs is visible in the total sum of all natural inputs and outputs together, which is negative over the past 50 years.
Of course, there are a lot of combinations possible, if you mix up some of the natural in/outputs with the human emissions, but as Dikran showed, then you can’t have an answer to the question if humans are responsible for the rise or nature or both, if you lump the human emissions and some parts of the natural carbon cycle together.
Smokey, I’ll take you seriously again when you stop making an attempt to derail the discussion by diverting onto whether CO2 causes warming.
BTW it is well known that ocean temperature affects atmospheric CO2, as discussed earlier in the thread (the effects are even visible in figure 3 – but it doesn’t affect the mass balance argument). Now if you can show that there is a plausible mechanism that means changes in ocean temperatures could have given rise to the observed increases, but which is also consistent with what we know from paleoclimate data (about 8 ppm per degree C, as explained by Ferdinand), then lets hear about it.
Smokey says:
August 8, 2010 at 5:46 am
Dikran,
Don’t be silly. There are alternate conclusions, and they are based on observations rather than opinions. Here, I’ll help you get up to speed on the subject:
This chart clearly refutes the claim that CO2 causes any noticeable global warming. There are certainly other likely causes of the rise in CO2.
Smokey, please no discussion about the effect of the CO2 rise (whatever the cause) on temperature, that is a complete different item. Here we are discussing the cause of the increase, not the effect of the increase…
And the historical data certainly will be discussed in one of the next parts.
Slioch says:
August 8, 2010 at 5:13 am
Paul Birch says: “You wish to argue that some of the rise since the Little Ice Age is natural, which in turn means that the CO2 rise is not entirely man made. But your “slam-dunk” mass balance argument has no room for this.”
“But that is why it is better to say, “the human contribution is more than able to account for the entire increase””
Yes it would have been. But that’s not what the OP said. No one is claiming that the human contribution couldn’t have caused the rise. Only that lots of other things could have too. We could with equal validity say “the natural carbon cycle is more than able to account for the entire increase”. Such rises are far from unprecedented in the history of the planet.
“To then argue about whether Mr Human Emissions “caused” the barrel to fill all by himself, or was helped by the others is, it seems to me, meaningless.”
It is meaningless unless you ask what would have happened without him. And this is just what we don’t know, and just what a proper scientific study should be attempting to discover, by measurement of the actual processes concerned. Not merely the aggregate rates, but the detailed dependences on all the varying conditions, all the sources, sinks and feedbacks. All the non-linearities and irregularities and intransigent unpredictabilities. And even then the answer may turn out to be that we’ve no way of knowing; that the requisite data do not exist and cannot any longer be recovered.
“It is meaningful to enquire whether Mr Warming Oceans and/or Mr Volcanoes and/or Mr Unknown Source could have filled the barrel by themselves, without the help of Mr Human Emissions: but as Ferdinand and others have repeatedly pointed out, the evidence we have is that they were nowhere near capable of so doing.”
Ferdinand and others have claimed this, but the evidence either flatly contradicts this or is quite insufficient to support it. You, for example, claim that volcanos only emit 1% as much as man. This is just not true. The tectonic side of the carbon cycle has to emit on average on the order of a gigatonne of CO2 a year (from the amount of crust subducted annually at the plate margins) , which more like a quarter of the industrial emissions (from the diagram). It may not all be coming out of traditional volcanos, of course. And this doesn’t include any primordial carbon newly arrived from the mantle. But the really important point here is that such emissions are extraordinarily variable and unpredictable from year to year, or decade to decade, or century to century, or periods through to hundreds of millions of years. There have been periods in the planet’s history when volcanos have caused the emission rate, for decades or centuries at a time, to rise to ~10,000 times the average rate. We really have no idea how much CO2 has been emitted by volcanos over the past century. Or even the past year. We don’t even know how many volcanos there are. We do know that the tectonic emission rate can be wildly variable, almost without limit, especially in the deep oceans where we really haven’t a clue what’s going on.
Dikran says:
“Smokey, I’ll take you seriously again when you stop making an attempt to derail the discussion by diverting onto whether CO2 causes warming.”
What?! That is the entire point of the whole CO2=CAGW conjecture!
Get with the program. If CO2 doesn’t cause warming, there is nothing worth discussing.
Ferdinand
I said:”What CO2-compound is included in nDIC besides the carbonates that are in equilibrium with Co2? We are talking about upper ocean layers and thus carbonates sedimenting is not in question.
Ferdinand: “Carbonate sedimentation may be one of the culprits, as mentioned by Julian Flood. ”
but Ferdinand.. (!!) Carbonates sedimenting OUT is removed from the CO2 pool! Thats why pCO2 is a useful indicater of CO2 in oceans.
When for example the biosphere helps sedimenting CO2 out – which was what Julian said (!) – then exactly, the CO2 partly from humans is omitted, and thats my point.
We have a constant pCO2 (which is also the indicator IPCC uses) showing that the CO2 in the pool of available CO2 in oceans is constant even though humans are emitting more and more CO2. Please now reflect over this.
What I say: Humans emit CO2 => CO2 increases => larger biosphere => faster and faster withdrawel of CO2 => human influence is only temporary and since we already now see that we have less and less CO2 increase per year for constant temperature, it appears that the biosphere is already limiting human influence more and more.
Humans cant make rise without nature strongly reacts and soon omits human CO2. However, a bigger CO2 eating biosphere might lead to a stronger decline in CO2 than good is. If humans do damage emitting CO2, this is the damage.
K.R. Frank
Back to the overall mass balance
FSin –FSout = Fa
In which FSin is a standard flux into the atmosphere (concentrated near the equator)
FSout a standard flux out of the atmosphere (near the poles) to the (deep) sea
And Fa the rate of accumulation in the atmosphere
If FSin = FSout than Fa=O
If FSin increases with dFsin and FSout with dFout by a natural change
Then dFsin –dFout = Fa (with FSin still equals FSout, an assumed equilibrium state)
Let’s add an anthropogenic emission Fem=7 GtC/j and a measured accumulation Fa= 3.5 GtC (The situation round the year 2000 with 370 ppmv in the atmosphere)
dFsin + Fem – dFout = Fa
dFout = dFsin + Fem – Fa
Ferdinand’s’ solution of this equation is that there is no change in the natural in flow (dFsin = 0)
3.5 = 7 – 3.5 (The well know figure that half of the amount of the Fem is going out to the (deep) sea.
The assumption is here that the increase of the CO2 concentration in the atmosphere has forced the increase dFout. In the paper mentioned by Richard Courtney in E&E 16(2) 2005 were applied several equations to describe the dFout and constants were chosen in this equations to match the MLO data. See the first line in the table.
1 2 3
dFout dFin dFin-dFout
3.50 0.00 -3.5
5.14 1.64 -3.5
6.75 3.25 -3.5
8.36 4.86 -3.5
9.96 6.46 -3.5
11.57 8.07 -3.5
13.18 9.68 -3.5
14.79 11.29 -3.5
16.39 12.89 -3.5
If however, by a natural cause over some time, (say a century) FSin is changed, thus dFin>0 we can expect that also dFout will further increase and we have in the one equation
dFout = dFin + Fem – Fa
two unkowns, dFout and dFin.
To keep the Fa=3.5 = dFin+Fem-dFout , and have the data still fit with the MLO observations, we just can change the parameterisation of the absorption equations, to choose a particular dFout. And therewith goes a change in dFin to keep the dFin+Fem-dFout = 3.5
dFin = dFout – Fem+ Fa = dFout – 3.5
The results of such exercises are presented in the next lines of the table, with various parameterisations of the absorption equations.
Note that with all parameterisations dFout is always larger than dFin which is due to the raise of the CO2 concentration in the atmosphere.
But we do not know how dFout (and dFin) is changing under the influence of other factors then just CO2 concentration in the atmosphere, e.g. local winds, ocean currents, (to and from the deep sea), and pH. (The influence of temperature changes may be marginal).
Therefore I sustain the view of others in this discussion that the accumulation (Fa=3.5) need not be explained solely by the anthropogenic emission (Fem). A natural variation may be interfering. Ferdinand is, in my opinion, dealing with a too simple algebraic solution for one equation with two unknowns.
By the way, it has been suggested by several people in the past that the E&E paper denies a contribution of anthropogenic emission (Fem) to the accumulation. That is a wrong interpretation. It shows clearly the case if the accumulation is solely due to Fem. But it is concluded that our knowledge of the mechanisms which determine Fin and Fout is still very limited, that current natural circulation models may be wrong, and that a natural cause may have contributed to the current concentration of CO2 in the atmosphere.
Ferdinand sustains his view with the 13C/12C observations. He says the 13C/12C of the ocean water is too high to drop the value in the atmosphere to its observed value. If this is accepted then we have to search for another source which produces a low 13C/12C value of biological origin to explain an alternative. It may be the plankton in the ocean. The amount it holds is however, low (see his scheme, 5 GtC) but the exchange with its environment high, 50 GtC/y which is half the value which is assumed for the up welling CO2 from the deep sea (100 GtC/y) . I think there are still puzzles to be solved around de small drop of 13C/12C.
Arthur Rörsch, The Netherlands
Paul Birch says:
August 8, 2010 at 6:43 am
You, for example, claim that volcanos only emit 1% as much as man. This is just not true. The tectonic side of the carbon cycle has to emit on average on the order of a gigatonne of CO2 a year (from the amount of crust subducted annually at the plate margins) , which more like a quarter of the industrial emissions (from the diagram).
Paul, there is no doubt that many natural fluxes in and out of the atmosphere are a magnitude larger than the human contribution. Even if some of the natural contributions are one-way in, others are one-way out. But that is not relevant at all for the mass balance: Even if the inflow from volcanoes tripled over the past 60 years and now is 10 times larger than the human contribution, that is fully compensated by the increase in one or more natural sinks, as the net contribution of all natural flows together, the whole natural carbon cycle, to the atmosphere was negative in the past 60 years. Thus the human emissions are fully responsible for the increase (here we differ somewhat with Slioch).
What would have happened without human emissions is interesting (although we have a pretty good idea), as good as the difficult search of all ins and outs of the carbon cycle is very interesting, but not relevant for the current situation, as long as the increase in the atmosphere is less than what humans emitted.
Paul Birch says:
August 8, 2010 at 6:43 am
So, you agree that “the human contribution [of CO2 to the atmosphere] is more than able to account for the entire increase” in atmospheric CO2 in recent centuries.
Good.
Since that human contribution DID occur and since the rise in atmospheric CO2 also DID occur, I can’t see that there is a great deal of point enquiring whether other factors could have done so also (other than from a general interest in climatic matters). It’s a bit like finding someone squashed flat by a bus and insisting that a post mortem is carried out to determine if he was about to die of a heart attack, so that you can be sure “what would have happened” if he hadn’t stepped in front of a bus.
It begins to sound as if you have an agenda to exonerate the bus driver, as a member of the bus-driver’s union.
It begins to sound as if you have an agenda to exonerate the role of CO2 in climate, as a member of those who deny its role in global warming.
But let us look at the evidence of other possible sources of CO2 in the atmosphere. Ferdinand has given 8ppmv CO2/degC rise in ocean temperature: that is clearly insufficient to account for the rise, as he has explained.
Your statements concerning tectonic (including volcanic) CO2 are in error: Both the British and US Geological Surveys give a figure of less than 300 Mtons CO2/year from such sources. That is less than 1% of human emissions.
You suggest 1 gigaton CO2 per year to balance tectonic subduction, but provide no reference, and claim wrongly that that must be balanced by tectonic emissions: there is no such need.
Further, estimation of emissions is from actual measurements taken in recent times. Estimates of subduction are made by estimating subduction rates, estimating composition of subducted material and averaging over geological time: that is likely to be less accurate than estimates of emissions.
Further, 1 gigaton is NOT one quarter of human emissions: it is about 3% of emissions from fossil fuel burning (33 Gtons/year) and about 2% of total human emissions, which include land use changes and are closer to 50Gtons/year.
Nor have tectonic CO2 emissions been “extraordinarily variable and unpredictable from year to year, or decade to decade, or century to century” in recent geological times. Just look at the Keeling curve: even Pintubo is scarcely detectable (albeit in the “wrong” direction as (I think) Ferdinand explained earlier. The CO2 curve from ice-core evidence going back 800,000 years shows no evidence of massive changes in CO2 due to volcanic activity. Nor is there any sign in the B/Ca ratios from phytoplankton that go back 20,000,000 years (Triparti et al). There is no evidence of a sudden spikes of tectonic CO2 in all that time that would have been necessary to explain the recent increase in CO2 – and I think we can be pretty sure that IF tectonic CO2 emissions had suddenly increased one hundred fold over the last century or so, we would have noticed.
The man wasn’t about to die from a heart attack – he was squashed flat by the bus.
The atmosphere didn’t suddenly receive a massive dose of CO2 from volcanoes and nor is it necessary to search for such a source – we humans are known to have provided all the CO2 necessary to explain the observed changes.
Arthur Rörsch says:
August 8, 2010 at 8:08 am
Dear Arthur, thanks for your contribution…
Here a few points where we differ in opinion:
dFsin + Fem – dFout = Fa
dFout = dFsin + Fem – Fa
Ferdinand’s’ solution of this equation is that there is no change in the natural in flow (dFsin = 0)
3.5 = 7 – 3.5 (The well know figure that half of the amount of the Fem is going out to the (deep) sea.
First, I never said or implied that the natural inflows are invariant. I always insisted that the exact height of the fluxes or their variability is unimportant. Wat is important is that the sum of all these fluxes is negative in all cases over the past 60 years.
To keep the Fa=3.5 = dFin+Fem-dFout , and have the data still fit with the MLO observations, we just can change the parameterisation of the absorption equations, to choose a particular dFout. And therewith goes a change in dFin to keep the dFin+Fem-dFout = 3.5
dFin = dFout – Fem+ Fa = dFout – 3.5
Exactly, whatever dFin, dFout must be 3.5 GtC higher. It doesn’t matter at all how high dFin is: positive, negative, smaller or 10 times larger than Fem. In all cases Fem makes the difference: an increase, as Fem is about twice the increase.
But it is concluded that our knowledge of the mechanisms which determine Fin and Fout is still very limited, that current natural circulation models may be wrong, and that a natural cause may have contributed to the current concentration of CO2 in the atmosphere.
The knowledge of Fin and Fout is irrelevant for the cause of the increase, as long as the emissions are larger than the increase…
Kind regards,
Ferdinand
Here is an excercise for anyone who thinks the natural environment may have contributed to the observed rise in atmospheric CO2. Fig 1 gives some figures for the fluxes in and out of the principal reservoirs involved in the carbon cycle. The challenge is to produce a new set of figures for these fluxes such that the natural envrionment is a net source (so that all natural emissions exceeds all natural uptake from the atmosphere), but at the same time, the resulting rise in CO2 would be lower than anthropogenic emissions.
If you argue that a natural cause is consistent with a rise less than anthropogenic emissions, you ought to be able to demonstrate that at least there exist values for the natural fluxes for which that is true. You will find it is impossible, go ahead and try.
You can limit it to figures for fluxes into and out of the atmosphere, the internal fluxes of the other reservoirs do not affect the atmosphere other than via the external fluxes. Note also that flux values must be positive, the arrow shows the direction of the flux.
I really have a hard time understanding why this argument continues.
It’s a no-brainer. Man extracts fossil fuels which contain carbon that’s been locked up in sinks for millennium and then pumps it into the atmosphere, resulting in an increased level of carbon in the atmosphere.
It’s like depositing $1000 into your bank account every week and only withdrawing $1000 a month and then denying the increased balance is due to your deposits. Absurd.
Dear Ferdinand,
First of all I agree with you that it is unlikely that the net effect of current annual fluctuations in Fa over the last decennia have been significantly contributing to the observed MLO rise.
The annual fluctuations in Fa just show that in principle fluctuations occur.
But what we are considering is the change of the CO2 cycles over longer periods, parts of centuries. The idea behind the assumption that the human emission is not the sole cause for the current high level of CO2 in the atmosphere , is that over a period of several centuries the major CO2 cycle changed, and probably with some exceptional bursts around 1930-1940 and earlier in the 19the century, as proposed by Ernst Beck from his analyses of the old (chemical) data. I do not appreciate your continued (spastic) neglect of these data as a possibility to explain why CO2 content of the atmosphere increased. I am not saying that Beck provides ‘proof’ . He just provides observations that may make us change our minds how and why CO2 is accumulating at its current rate.
I insist on my conclusion that your simple solution of one equation with two variables is in principle invalid. And it hinders further investigation of other possibilities how CO2 flows may have changed over centuries by a prejudice it has not . Named by Richard Courtney a circular argument.
I have great difficulties to accept your response to ‘my’ possible solutions of the one equation with two unknowns.
Slioch says:
August 8, 2010 at 8:52 am “…”
It would be pointless trying to engage in a discussion about details when you cannot see the fundamental fallacies in your basic arguments. For example, no one can directly measure or observe the total amount of CO2 released by volcanos, so any “estimate”, from whatever august body, is and can be no more than a guess. If any subducted CO2 were not being ultimately re-emitted, this would mean that there was a hole in the carbon cycle, the mass would not be constant, and the mass balance equation would be in error. I would agree with you that industrial emissions amount to ~30Gt/yr (I lazily took the OP diagram figure – which seems rather low – and forgot to convert from C to CO2). However, the extreme variability of vulcanism – up to dinosaur-killing supervolcanos – is well known. Your claims to the contrary are just repetitions of the same fundamental attribution fallacy that you, Dikram and Ferdinand have been promoting all along.
Arthur Rörsch:
If natural long term changes in carbon cycle were causing the rise in atmospheric CO2, that would be revealed by the mass balance argument as the observed rise would then be greater in magnitude than anthropogenic emissions. This is because both man and the natural environment would be contributing to the rise, that is simply an application of conservation of mass. However, observations show that this is not the case (at least for the last fifty years, as shown by the data in figure 3 of the OP). As a result, even though we don’t know what changes have been going on in individual parts of the carbon cycle, we don know that the total environmental flux into the atmosphere must be less than the environmental uptake from the atmosphere.
Dear all,
Ferdinand promises a part two to sustain his conclusion that current rise in CO2 is solely due to anthropogenic emissions. I guess he will in particular explain the observations on 13C/12C ratio changes. I think he is an expert in this field. Therefore I propose we consider his interpretation of the data with an open mind. I am prepared to do so, if he does not bluff his way from the beginning with the prejudice that the burning of fossil fuels is the sole reason for the decline 13C/12C ratio.(The circular argument).
Let’s have a closer look again why other processes may have contributed to the decline and why Ferdinand excludes these other possibilities.
Please note I respect Ferdinand expert knowledge of CO2 cycles but I do doubt his logic reasoning to interpret these.
Paul Birch says:
August 8, 2010 at 10:36 am
However, the extreme variability of vulcanism – up to dinosaur-killing supervolcanos – is well known.
Paul, if the vulcanism increased suddenly up to 300 times the current estimate, that is three times the current human emissions, and everything else remained constant (including sink rates), what would the increase of CO2 in the atmosphere do?
I suppose that you agree that the total increase at the end of the first year would be:
8 GtC (emissions) + 24 GtC (volcanic) – 4 GtC (current sink rate) = 28 GtC increase in the atmosphere.
Simply based on the mass balance, it is made clear that something happened in the natural carbon cycle and that the increase is not solely from the emissions anymore. The increase then is 1/4th from human emissions and 3/4th from the increase in volcanic activity.
The fact that there was no increase larger than the emissions in the last 60 to 100 years shows that there was no change in the net carbon cycle larger than the contribution of human emissions.
Arthur Rörsch wrote:
“Therefore I propose we consider his interpretation of the data with an open mind. I am prepared to do so, if he does not bluff his way from the beginning with the prejudice that the burning of fossil fuels is the sole reason for the decline 13C/12C ratio.”
Seriously chaps, can we do without the rhetoric?
I am willing to accept that there is a natural cause for the observed rise in atmospheric CO2 provided you can explain why if that is so, the observed rise is lower than anthropogenic emissions, and has been for the last fifty years.
Arthur Rörsch says:
August 8, 2010 at 10:35 am
The idea behind the assumption that the human emission is not the sole cause for the current high level of CO2 in the atmosphere , is that over a period of several centuries the major CO2 cycle changed, and probably with some exceptional bursts around 1930-1940 and earlier in the 19the century, as proposed by Ernst Beck from his analyses of the old (chemical) data. I do not appreciate your continued (spastic) neglect of these data as a possibility to explain why CO2 content of the atmosphere increased. I am not saying that Beck provides ‘proof’ . He just provides observations that may make us change our minds how and why CO2 is accumulating at its current rate.
Dear Arthur, you know what I think about the historical data, but that will be for one of the next parts, as that certainly will start a flame war, where this discussion is very civilised… And I need to look at Ernst’s newest additions.
History indeed shows large swings, but in average, over the past few million years (highly smoothed) a rather modest change in CO2 after temperature changes. No extreme events visible (a change of 10 ppmv sustained over 600 years, or 100 ppmv over 60 years, would even be noticed in the Vostok ice core), CO2 follows temperature with an astonishly linear rate…
I insist on my conclusion that your simple solution of one equation with two variables is in principle invalid.
It would be invalid if both variables were near independent of each other, but the two variables are very close to each other:
dFout – dFin < 8 GtC over the past 50+ years.
whatever the real height of dFout or dFsin. Thus the error margin is not higher than the height of the human emissions…
Frank Lansner says:
August 8, 2010 at 7:51 am
Ferdinand
I said:”What CO2-compound is included in nDIC besides the carbonates that are in equilibrium with Co2? We are talking about upper ocean layers and thus carbonates sedimenting is not in question.
Ferdinand: “Carbonate sedimentation may be one of the culprits, as mentioned by Julian Flood. ”
but Ferdinand.. (!!) Carbonates sedimenting OUT is removed from the CO2 pool! Thats why pCO2 is a useful indicater of CO2 in oceans.
Carbonate sedimentation by coccoliths is a reaction with bicarbonates, which forms carbonate (part of which sinks to the ocean floor) and CO2. Thus while bicarbonate is used and carbonate drops out (reducing DIC, total carbon in solution), that also increases pCO2.
Here we see the opposite: pCO2 stagnates and DIC still increases. That may be a result of less biological activity… See further the very nice pages about coccoliths:
http://www.noc.soton.ac.uk/soes/staff/tt/eh/index.html
That also means that the pCO2 – DIC relationship is not linear in this case, but also not linear with increasing CO2 absortion in the oceans: the increase of pCO2(aq) in the oceans more or less follows the increase of pCO2(atm) in the atmosphere with a small lag. But the increase of DIC in general is only 10% of the increase rate of pCO2(aq) (except for the last decade). That is because of the shift in equilibrium between free CO2, bicarbonate and carbonate in solution, due to pH changes as result of the uptake of CO2. In the period 1984-2004, pCO2(atm) increased about 10%, pCO2(aq) increased about 8%, but DIC only increased 0.8% of the range.
Thus one can’t use pCO2(aq) to know the total increase or decrease of carbon in the upper ocean level, without knowledge of any of the other items…
DearDikran.
I am afraid you do not understand the fact that any explanation how CO2 is accumulating in the atmosphere requires parameterisation of the adsorption equation anyway (To match with MLO) . Even if the assumption is that the sole contributor is the human emission. Any supposed contribution of natural interference will just lead to an other parameterisation. Please read the E&E paper and then indicate the possible flaws in it
Yes, let’s consider the case without rhetoric
Sorry if a misread your comment in another way.
Reference for the last remark:
http://www.bios.edu/Labs/co2lab/research/IntDecVar_OCC.html
Arthur Rörsch:
“I am afraid you do not understand the fact that any explanation how CO2 is accumulating in the atmosphere requires parameterisation of the adsorption equation anyway (To match with MLO) .”
No that is not the case, only a simple bit of accountancy is required, if the observed rise is less than anthropogenic emissions then for conservation of mass, the natural environment must take in more CO2 than it emits. That would be true regardless of the mechansims involved. You don’t need to parameterise anything, you just need data and the rest follows from conservation of mass.
“Even if the assumption is that the sole contributor is the human emission.”
No such assumtion is being made by the mass balance argument (just making that clear)
“Any supposed contribution of natural interference will just lead to an other parameterisation. ”
“Please read the E&E paper and then indicate the possible flaws in it”
The flaw (if it questions the anthropogenic origin of the recent increases) is that if the natural environment were a source the observed rise then the rise would be greater than anthropogenic emissions. Of course it is possble for natural mechanisms to give rise to increased atmospheric CO2, the point is that the mass balance argument shows that while this is possible, it isn’t actually taking place.
I gave a challenge earlier in the thread to invent values of the fluxes in Fig 1 that end up with a rise that is lower than anthropogenic emissions, but where the natural environment is a net source. Give it a go, you will find that it is impossible.
Arthur Rörsch:
I have read the abstract of your paper (E&E isn’t open access – so I can’t get the full paper). The aims of that paper are far more general than the aims of the mass balance argument. It is perfectly reasonable to say that the uncertainties are too high to estimate the individual fluxes (e.g. ocean to atmosphere) with an accuracy commensurate to the magnitude of anthropogenic emissions. However, it is not necessary to accurately characterise individual fluxes to know that the natural environment is a net sink. We do not compute the net flux by taking the difference between the sum of all input fluxes and the sum of all output fluxes, because there is a second way to work it out. If you assume conservation of mass, the net flux must be equal to the difference between the observed rise and antropogenic emissions. As the observed rise and anthropogenic emissions are known with good certainty, the net environmental flux is known with high certainty, even though we don’t know any of the component fluxes.