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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Richard – you are right, and they are wrong. But, it is a hopeless task. They do not recognize even obvious logical flaws in their arguments.
CodeTech says:
August 7, 2010 at 1:46 pm
Ferdinand Engelbeen says:
The results, only based on the assumption of the conservation of mass, show that, whatever the underlying mechanisms, nature is a net sink for CO2. That makes that the increase is fully attributable to the emissions. Nothing circular here.
Actually, your insistence on this astounds me.
How do you know that our CO2 emissions are not completely nullified by some natural process, ie. oceanic uptake or increased plant growth, and it’s not SOME OTHER source that is the cause of the increase?
CodeTech, we are comparing the increase in the atmosphere with the human emissions at one side and what nature does at the other side. What you (and Richard and others) are doing is picking one part of the natural cycle which may be large enough to be the cause and assuming that the human emissions are removed by another part of the natural cycle.
Indeed that happens also in reality: any emitted molecule from fossil fuel burning may be captured by the next nearby tree within seconds, or after ten years in the oceans. But in both cases the net effect is the same: the total mass of CO2 in the atmosphere increases due to the human addition. In the first case indirectly, as the captured “anthro” molecule CO2 replaces a “natural” molecule which would have been captured instead, but now remains in the atmosphere.
But that all has nothing to do with the question of the cause of the rise: is the rise natural or anthropogenic or both. To answer that question, one must separate human and natural fluxes and not mix them up. If we bring all natural fluxes together, then it can be shown that total effect of all natural fluxes is negative: nature is a net sink for CO2, whatever the unknown height and unknown variability of all these fluxes individually might be. That is all what the mass balance shows. And that makes that the natural flows are not responsible for the increase.
Honestly, 368 posts are basically all about this question, and you have failed to explain this. Your simple assertion that “it must be so” is the major sticking point here, and to use the word a second time, it is astounding to me that you can’t see it, and that you can’t see how this is circular.
To know what needs to be explained, one need to know what the problem is. I was (and still am) surprised why so many smart people don’t accept, even do not see the simple calculation of a mass balance which shows that the natural fluxes as a whole don’t add anything to the CO2 levels in the atmosphere. I hope the above explanation might have clarified this.
Richard S Courtney says:
August 7, 2010 at 2:58 pm
You still do not get it do you?
The total sysem needs to be considered, and not only the net flux.
Adequately answered by Dikran…
No, no and no!
There is not sufficient data to observe the change in global total carbon in the ocean surface layer with sufficient accuracy for a determination of whether it has increased or decreased over the last 50 years.
Come on Richard. Continuous dataseries indeed are scarce: Hawaii and Bermuda and Gran Canaria are the only stations with a long continuous record, both show the increase in DIC. From:
http://www.bios.edu/Labs/co2lab/research/IntDecVar_OCC.html
From the Hawaii station: nDIC and seawater pCO2 increased at a rate of +1.2 +0.1 µmoles kg-1 year-1, and +2.5 +0.3 µatm year-1, respectively.
From the Bermuda station: nDIC and seawater pCO2 increased at a rate of +1.6 µmoles kg-1 year-1, and +1.4 µatm year-1, respectively.
Of course, one can assume that other places show a decrease in DIC, but as the counterpart in the atmosphere certainly increased everywehere over all oceans, that is extremely unlikely.
The change to isotope fractionation does not match the assumption of an anthropgenic cause (the magnitude of the change differs from that expected from an anthropogenic cause by a factor of at leat 3 x). And the change in the isotope ratio with outgassing from ENSO variations shows that it is not posible to distinguish between ocean outgassing and the anthropogenic emissions. The effect of the pH change would be similar for the postulated pH change or a temperature from ENSO.
Sorry, completely wrong: We are not talking about an anthro effect, but about a huge (200 GtC) ocean outgassing effect. The ENSO effect on d13C/12C is mainly from the influence on vegetation, which can’t be distinguished for that part from fossil fuel. But that is not the case for ocean outgassing.
And the mass balance argument is complete nonsense when applied to a change to the system. All the mass balance would show is that the system has changed to alter the net flux of CO2 between the air and the rest of the carbon cycle WHICH IS WHAT WE SEE.
As we applied the mass balance argument stepwise for the changes over a year, I don’t see any problem, as in all past decades the net natural flux was negative.
As I said, you still do not get it.
The mass balance indicates a change to the system but provides NO indication of any kind as to the cause of the change.
I see, you still don’t get it that a negative net flux, sustained over 50+ years is a very solid indication that nature didn’t add one gram of CO2 to the increase in CO2 mass of the atmosphere.
Sorry to disrupt the friendly feud. Doesn’t the historical record indicate that increases in CO2 lag temperature rises by 800 to 1000 years? Has anyone asked the question, “What was going on 800 to 1000 years prior to 1850?” Could it be the MWP?
As a mere bozo on the bus, I have been observing this thread with fascination. I started out quite prepared to accept that the surplus of CO2 in the atmosphere was anthropogenic, and found Ferdinand’s (and Dikran’s) arguments persuasive.
However, listening to Richard’s (and others) arguments, I think I have come to see that indeed, Ferdinand’s view has been severely challenged.
Put it this way. Imagine we have an observation box, with inputs and outputs, in which the amount of a specified substance, let us call it X, has been observed to increase. We can all agree that X hasn’t come from nowhere, because nothing comes from nothing. We can all agree on conservation of the mass of X.
All sorts of processes put X into the box, and all sorts of processes remove it from the box. Let’s say for argument’s sake that there are 10 inputs of X and 10 outputs of X. Let’s also say that yesterday, and for a number of days previously, the mass of X was 100g, but that today, it’s 105g.
Hitherto, we haven’t been too interested in measuring the inputs and outputs. But now we conceive a desire to select one of the inputs at random and quickly measure its contribution.
Having done that, we discover that its input today has been 7g. Wow! This is very significant, is it not? Does it not prove that all the observed 5g increase can be accounted for solely by that input? The argument seems very compelling.
However, being curious people, we decide to take a close look at the input and output boxes. What we find is a spaghetti junction. They are interconnected by tubes. X isn’t simply coming into/exiting the observation box from isolated sources and sinks, but is circulating between sources and sinks. And the processes occurring in the boxes are quite complicated, with differing dependencies on things like temperature and pressure, as well as different rates leading to different time lags. It is, in fact, an exceedingly complex system when taken as a whole.
Again, being curious, we decide to perform an experiment. We are going to remove the random input box we chose, and block the ends of all its tubes – the one that leads into the observation box, and all the others that lead to both other input boxes and output boxes. The system as whole is now completely devoid of influence by the random input box we chose. Tomorrow, we are resolved to measure the amount of X in the observation box.
What will we find, I wonder? If we find that the observed mass of X is approximately 100g, maybe we will say to ourselves that indeed, all of today’s rise was accounted for by (not the same as saying that all the excess 5g of X comes solely from) the process(es) occurring in the box we’ve removed.
Personally, I wouldn’t stake my life on that occurring, however. And in any case, my bet would be that some other figure would be measured – could be more or less than 100g, but I simply don’t know and couldn’t for the life of me make a confident prediction one way or the other.
Richard is in my view correct. Ferdinand has not *proved* that the sole cause of the rise of CO2 is anthropogenic. He cannot ignore the precise nature of the sources and sinks, or of the processes and interconnections between them.
Unfortunately, we can’t do the analogue of the experiment of removing the box we decided to choose. We can’t wave our hands and simply assert that the mass increase *must* be due to anthropogenic CO2. It’s plausible that anthropogenic CO2 has *some* influence, but I think Ferdinand’s thesis is far from rock solid.
As a postscript, can I say that I have been totally delighted by this thread and wish to express my thanks to and admiration for all contributors, whether for or against the thesis. It is all honest, enlightening and educational debate, of a kind that one struggles to find anywhere else in the climate blogosphere. At the end of the day, we can all thank Anthony for providing this important platform for discussion.
I have a question about the mass balance equation. Could not
dC = E_anthropogenic + E_natural – U_natural
also be written as:
dC = E_everything – U_everything
could it not? Which could then be written as:
dC = E_something + E_everything else – U_everything
So, according to the logic of this post, any “something” emitting more than 4GtC could be the culprit for the CO2 increase. How many “something’s” like this are there? Hmn?
Michael Larkin says: August 7, 2010 at 8:07 pm
quote
Put it this way. Imagine we have an observation box, with inputs and outputs, in which the amount of a specified substance, let us call it X, has been observed to increase. We can all agree that X hasn’t come from nowhere, because nothing comes from nothing. We can all agree on conservation of the mass of X.
unquote
I suspect that the confusion arises because Ferdinand’s definition of the observation box differs from what we are talking about — the atmosphere, where we have knowledge of the variation in CO2 levels, is only a tiny part of the system and as such is not the ‘contains everything therefore changes can only be due to’ box that he imagines.
Ralph Dwyer’s post says it better.
I won’t go through the pipes in, pipes out and widdling little boy again, but it seems so obvious to me that with all the inputs and outputs capable of varying then we have insufficient knowledge to say anything about the increase of the reservoir level and contributions to it by micturition.
My word, aren’t we going to have fun with the isotope changes!
JF
Ralph Dwyer
August 7, 2010 at 8:36 pm
asks, “How many “something’s” [emitting more than 4GtC] are there?”
Plenty (see, Fig. 1 at head of article, for example) but that is not the answer.
The crucial point is not only the size of the flux, but its origin.
If the source of the CO2 flux to the atmosphere is from the short/medium term carbon cycle (ie the atmosphere/oceans/biosphere) , then it MAY cause an increase in [CO2] in the atmosphere, but WILL do so only if it is unbalanced (ie if it is not compensated for by an equal flux from the atmosphere). Examples: warming of the oceans or massive forest fires or extensive thawing of NH permafrost. However, none of those factors has been anywhere near large enough to cause the observed increase, nor has any other similar factor been suggested to account for it that is also large enough.
If the source of the CO2 flux to the atmosphere is NOT from the short/medium term carbon cycle, but from outwith that system, then it MUST cause an increase in [CO2] in the atmosphere, (which will decline towards a new equilibrium point over time). Examples: anthropogenic emissions from burning fossil fuels, volcanoes.
Volcanoes are known to be two orders of magnitude too small to cause the observed effect. The former, human emissions, are known to be more than large enough to cause the observed effect, and they must so do, as illustrated by the mass balance equation. When you have something that you know is large enough to cause an effect and you know that, if it is large enough then it MUST cause the effect, then you know that it HAS caused the effect.
Who would have thought that 45 years after President Lyndon Johnson, in a Special Message to Congress in 1965, stated, “This generation has altered the composition of the atmosphere on a global scale through … a steady increase in carbon dioxide from the burning of fossil fuels*” that there would still be those seeking to maintain otherwise.
* see: http://www.youtube.com/watch?v=2T4UF_Rmlio
at 16:10 minutes.
Ralph Dwyer says:
August 7, 2010 at 7:52 pm
Sorry to disrupt the friendly feud. Doesn’t the historical record indicate that increases in CO2 lag temperature rises by 800 to 1000 years? Has anyone asked the question, “What was going on 800 to 1000 years prior to 1850?” Could it be the MWP?
The historical influence of temperature on ice cores is about 8 ppmv/C (Vostok and Dome C ice cores). This is confirmed for the MWP-LIA cooling: about a 6 ppmv drop for a 0.8 C temperature drop (Law Dome ice core with a 21 years resolution). The lag in this case seems to be around 50 years.
Thus, worst case, the increase in temperature since the LIA (or the return of MWP waters via de deep oceans) would be responsible for 6-8 ppmv CO2 increase, if the temperature increase was 0.8-1 C since the LIA. But we see an increase of over 100 ppmv nowadays…
Further, the temperature-CO2 lag is not fixed: It was about 800 years when the temperatures did rise after the depth of the ice ages, but was many thousands of years when the temperatures were dropping again after a warm period. The MWP-LIA lag seems to be around 50 years and the current lag of the fast response (some 4 ppmv/C) to temperature changes is only a few months…
Ralph Dwyer: Yes, you could partition the fluxes that way if you wanted to, but if you did it may not necessarily answer an interesting or even meaningful question. If you want to know whether man is responsible for the observed rise then you need to separate the anthropogenic from eveything that is non-anthropogenic, and that is what we have done.
Here is an example: A polygamous man (Bob) has two wives (Anne and Jane), with whom he shares a bank account. He puts in $8 a year and withdraws nothing. Anne puts in $90 a year and withdraws $92 a year. Jane puts in $60 a year and withdraws $62 a year.
If we want to know if Bob is the cause of the rise in their bank balance (which very obviously he is) we need to separate the results of his transactions from his wives, giving:
[change of balance] = [Bobs deposits] – [Bobs withdrawals] + [Annes deposits] + [Janes deposits] – [Annes withdrawals] – [Janes withdrawals]
Say Bob knows his own transactions (withdrawals are nill, so we’ll neglect that term for clarity), so if he observes a change of balance, in this case it will be +$4 assuming conservation of money (i.e. no bank charges etc.), he can work out
[Annes deposits] + [Janes deposits] – [Annes withdrawals] – [Janes withdrawals] = [change of balance] – [Bobs deposits]
So although he can work out that between them his wives have spent more than they have saved, but he doesn’t know the volume of the transactions, nor how the transactions were partitioned between his wives. He does know though, that he was responsible for the rise in the balance as he was a net saver and his wives (together) were net spenders.
However, we could have partitioned the mass balance equation as follows:
[change of balance] – [Janes deposits] + [Janes withdrawals] = [bobs deposits] + [annes deposits] – [annes withdrawals]
but the mass balance argument then can’t tell you if bob is responsible for the rise in the bank balance, as his transactions are lumped in with Annes. So it answers a different question.
O.K. So you could argue that Volcanos are only sources of CO2 and have no uptake, so they are partially responsible for the rise, and partition the equation that way. However, that is neglecting the fact that there are other processes that are continually putting carbon back into the lithosphere (for example sedimentation). These processes had been in good balance for thousands of years, which is why CO2 levels had been pretty much stable from the start of the current interglacial. So it is misleading to suggest they are the cause of the rise, unless you have evidence that volcanic output has increased since the start of the observed rise in atmospheric CO2.
As I said, you can partition the equations in many ways, but they don’t tell you anthing interesting. However, if you partition into oceans versus everything else, you will find that oceans are not the source as ocean emissions are less than ocean uptake. The same applies to the terrestrial biosphere.
Ferdinand Engelbeen says:
“I see, you still don’t get it that a negative net flux, sustained over 50+ years is a very solid indication that nature didn’t add one gram of CO2 to the increase in CO2 mass of the atmosphere.”
This attempt to prove that increases in atmospheric CO2 are man-made is false. Changing the subject of the argument to an empirical correlation is not a sufficient response.
Just to add what Ferdinand wrote, while oceans give out more CO2 as they warm, they also take up more CO2 as atmospheric CO2 rises (because the ocean-atmosphere fluxes are determined by both temperature and the difference in partial pressure of CO2). The actual fluxes depend on which of these factors is dominant, so if there is some input of CO2 that is not part of the natural carbon cycle, it is not a given that the oceans will give out more CO2 as temperature rises.
There is often a lot of attention paid to the temperature relation, and often the dependency on the difference in partial pressure is ignored, but both play a role.
Ferdinand, further explanation is not required, you’ve explained your concept quite thoroughly. It’s just that you are wrong.
Forget the other analogies, try this one. Let’s say you have a country. Let’s say that country takes in taxes and pays out benefits and programs. Further, let’s say that country is sloppy in its accounting and all taxes go into “general revenue”, and all expenses come from the same account. Let’s call this imaginary bad accounting country “Canada”.
Now, you have been tasked with finding out why the country is in deficit spending. Unfortunately for you, it’s a country, and their tax records are not available to you. You do, however, have some rough estimates of the bricklayers union. You determine that the bricklayers union members receive more in unemployment and other benefits than they pay in taxes, and the shortfall is approximately equal to the deficit.
Your conclusion is that the bricklayers union are the cause of the deficit. Word of this gets out in the street, and pretty soon everyone is against bricklayers. Heck, Al Gore and Michael Moore make movies denigrating bricklayers, laws are passed banning bricklaying, and most communities ban brick houses in an attempt to fix the problem.
After driving the bricklayers completely out of business, it soon becomes apparent that the deficit remains unchanged. It seems the bricklayers are now all unemployed and therefore receiving even MORE benefits. All of the people that the bricklayers normally do business with like grocery stores, car dealerships, mortar suppliers, brick companies, home builders, etc. are all suffering reduced business, tax revenues are down, and the destruction of the bricklayers hasn’t changed a thing.
So here’s a question: were the bricklayers responsible for the deficit spending?
Ferdinand Engelbeen says:
August 7, 2010 at 2:53 pm
“Definitive answer:
Except for a small increase due to the temperature increase since the LIA, CO2 levels would not have increased if man had not emitted this CO2. Thus near all of the CO2 increase is man-made.”
One more try. 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. You keep insisting that its a matter of logic that the fact that the rise has been less than the sum of human emissions proves that the rise is man made. You keep insisting that only the net balance counts, not the details. So on this basis you have no right to ascribe any of the increase to the temperature rise. If you allow that natural phenomena may have caused some of the rise, then how much is a moot question, dependent upon the complex details of all the workings of the carbon cycle; the natural component could conceivably account for 1% of the rise, or 10%, or 90% or 100%; what the magnitude happens to be does not and cannot alter the logical principles at all.
If you have to bring in other data to justify your theory, it means your mass balance argument is just plain wrong. The mass balance is one constraint upon the theory, but in itself it tells you nothing about which of the many possible causes are operative.
I may say that I agree with you that most probably some of the increase is due to the temperature rise, and some due to human emissions accumulating faster than the natural sinks can presently remove them (and some due to still other things). But your arguments purporting to show that the proportion due to temperature rise is not large are as fallacious as your mass balance argument. 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.
Roger Clague: It isn’t a correllation -it is an observations that one thing is always less than something else. In this case, we know that non-anthropogenic uptake always exceeds non-anthropogenic emissions, that fully supports the assertion that nature has not contributed a single gram to the observed rise (as we know it has been deducting grams from the observed rise instead).
Dikran Marsupial says:
“…nature has not contributed a single gram to the observed rise…”
Planet Earth disagrees.
Ferdinand,
I’ve got to hand it to you, you certainly know how to stir up controversy! 400+ comments so far. Kudos. [BTW, I agree with about 95% of your reasoning. It’s the other 5% that causes heartburn.]
Ferdinand and Dikran are absolutely correct in the framing of their argument and the solution. The mass balance shows that the modern rise in CO2 is a result of anthropogenic emissions.
We can take this further, as I believe Ferdinand will in parts 2 and 3, and then make a prediction as to what will happen to atmospheric O2 levels if the rise in CO2 is a result of fossil fuel burning. Oxidation of the reduced carbon will result in a net loss of O2 in the atmosphere. Careful measurements of atmospheric O2 levels over the past 10-20 years show that the oxygen level has reduced in agreement with the mass balance observations. Moreover, the reduction in oxygen levels and increase in CO2 levels is consistent with the mass balance results and suggests that 50% of the emissions are equipartitioned into 2 sinks: 1) dissolution in the oceans and; 2) photosynthesis and the greening of the terrestrial biosphere.
No other model can account for these observations other than that anthropogenic emissions are causing the rise in CO2 in the atmosphere. Moreover one can consider the observation of a reduction in atmospheric O2 as a test of this hypothesis. I have yet to see any other hypothesis that is proposed by the various debaters on this thread that can account for the observation that atmospheric oxygen is dropping whilst CO2 is rising.
A 3rd test would be the isotope ratios (13C/12C) which I think Ferdinand is also going to discuss.
At some point we have to apply Occam’s razor and seek the simplest model that accounts for the empirical data. This is that man’s output of CO2 through industrial activities is causing the rise in atmospheric CO2 levels.
The debate here is illuminating for both it’s civility, but also for the intransigence of it’s protagonists.
Smokey write:
““…nature has not contributed a single gram to the observed rise…”
Planet Earth disagrees.”
following the link you gave, it gives environment emissions as 770,000 MMt, but it also gives absorption (i.e. environmental uptake) as 781,400 MMt, so your data shows that the environment is a net sink (as Ferdinand and I have pointed out) as it takes more CO2 out of the atmosphere than it puts in, and hence is OPPOSING the observed rise.
Sure it adds CO2 to the ATMOSPHERE, but if it takes even more back in (including about half of anthropogenic emissions), it isn’t adding to the RISE.
Well gentlemen (where are the women here?)
I think several now have nailed down the difference in opinion between the two groups here:
Group 1 says:
– The human emissions are near double the observed increase and the mass balance shows that all natural flows together are negative, that proves that human emissions are the sole cause of the increase.
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.
OK, let’s have a look at opinion 2 in detail:
We are quite certain of only two items in the whole carbon cycle: the human emissions and the increase in the atmosphere. The rest is uncertain, but the sum of all inflows and outflows (natural and human) must obeye the law of conservation of mass. Nevertheless, one of the natural flows, let’s say the oceanic outgassing, increased large enough to be fully responsible for the observed increase. That gives:
dCO2(atm) = sum(in(ocean_old) + in(ocean_extra) + in(human) + in(alle the other natural inflows)) – (out1 + out2 + out3 +…)
That gives with the knowns:
4 GtC = 4 GtC (from ocean_extra) + 8 GtC (from the human emissions) + in(all_others) – (out1 + out2 + out3 + …)
Or rearranged:
in(all_others) – (out1 + out2 + out3 + …) = – 8 GtC
In other words, the increase in one (or more) of the natural inputs must be compensated with an increase of one (or more) of the outputs to fit the mass balance, or you are creating some 4 GtC CO2 from nothing.
The mass balance dictates that, as long as the total increase in mass of the atmosphere is less than the human emissions, any increase must be
Pushed the send button too soon, the end must be:
The mass balance dictates that, as long as the total increase in mass of the atmosphere is less than the human emissions, any increase of one of the natural inflows need to be compensated with an equal increase in natural outflow.
Dikran Marsupial says:
“Smokey write…”
No, no, no: “Smokey right.”☺
And the link is not my data. It is UN/IPCC data. Argue with them if you disagree.
This is the central question: is human emitted CO2 the primary cause of global warming since the end of the LIA? Provide testable, falsifiable, empirical evidence, if you believe that to be the case [models don’t count].
If you can, you will be the first to be able to do so — and you will be on the short list for the [now worthless] Nobel prize.
Paul Birch says:
August 8, 2010 at 3:59 am
said, “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.” etc.
But that is why it is better to say, “the human contribution is more than able to account for the entire increase” as I did at August 5, 2010 at 10:30 am (which seems an awful long time ago … ).
If human emissions from 1850 – 2000 amount to 1620Gts CO2 and the increase in atmospheric CO2 over the same time period was 640Gts (both of which are true) then the fact that other factors may have contributed does not alter the fact that the human contribution is more than able to account for the entire increase.
The situation is analogous to having a barrel labelled “atmosphere” requiring 640 pints to fill it. If Mr Human Emissions comes along and pours in 1620 pints then the barrel will be full (the rest will “spill” into the oceans and terrestrial biosphere). If at the same time Mr Warming Oceans pour in some more and Mr Volcanoes and Mr Unknown Source also adds some then it really doesn’t alter the fact that Mr Human Emissions was more than able to fill the barrel all by himself.
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 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.
LOL Smokey, nice rhetoric, but a bit transparent.
First you evade admitting that the data YOU introduced to make your point actually refutes it and supports the argument Ferdinand has made (and I have supported). It may not be “your” data, but YOU chose to use it to support your position.
Secondly I don’t need to argue with the IPCC as they are in full agreement with me that the rise in atmospheric CO2 is of anthropogenic origin. You can find the mass balance argument in the IPCC reports (only given a very brief mention as it is so blindingly obvious).
Thirdly, it is a classic rhetorical trick to try and change the subject when defeat looms, so I am not going to fall for your attempt to move the discussion onto whether CO2 causes warming, that is for another thread.
Paul Birch says:
August 8, 2010 at 3:59 am
One more try. 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. You keep insisting that its a matter of logic that the fact that the rise has been less than the sum of human emissions proves that the rise is man made. You keep insisting that only the net balance counts, not the details. So on this basis you have no right to ascribe any of the increase to the temperature rise. If you allow that natural phenomena may have caused some of the rise, then how much is a moot question, dependent upon the complex details of all the workings of the carbon cycle; the natural component could conceivably account for 1% of the rise, or 10%, or 90% or 100%; what the magnitude happens to be does not and cannot alter the logical principles at all.
The attribution of the rise of CO2 to humans alone is absolute for the past 50+ years, that is for an increase of some 60 ppmv, measured with very high accuracy. It is less absolute for the first 60 years of the previous century, where the accuracy of both CO2 levels and emissions are less sure, but still show that the increase in the atmosphere (of about 20 ppmv) is less than the emissions (also about halve). And there is room for natural additions in the 19th century as the increase in the atmosphere (20 ppmv) and the emissions were within the margins of natural variability. Thus of the total rise of 100+ ppmv since the start of the indistrial revolution, some 20 ppmv is free for debate, 20 ppmv is highly certain from human additions and 60 ppmv is absolutely certain from human additions.
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.
Ocean temperatures have an observable effect on atmospheric CO2.
The planet disregards the claim of the alarmist crowd that human emitted CO2 is the primary cause of its [recently declining] temperature.
So, what should we believe? The agenda of the warmist contingent? Or planet Earth, and our lying eyes?