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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Jim McK says:
August 17, 2010 at 2:54 pm
Thanks for your comment.
The analyses is already done for the past near 50 years: Fig. 3 in the introduction shows the yearly balance for 1960-2006, the latest figures for the emissions not yet included.
As we don’t know what happens in the detailed transactions during a year, we can’t make a detailed cash flow chart without huge margins of error. Fig. 1 is such an attempt, but errors in fluxes may be from +/- 30% to +/- 60% of the estimated flows.
But we do know with reasonable accuracy the contribution of the human emissions (based on fossil fuel sales) and we know with good accuracy the increase in the atmosphere. Thus we know only the yearly balance with reasonable accuracy, whatever the height or variability of the fluxes within that year.
Our view is that, looking at the mass balance over the past 46 years, the human emissions are the only contribution to the gain, as all the other (natural) items together show a net loss, variable but continuous over the past (meanwhile) 50 years.
In company terms: If I buy every year some shares of a company and at the end of the year I only look at the one-line company balance, even if I don’t know anything about any cash flow of that bussiness (which is quite naieve), that will tell me that without my money the company would show a year by year loss, and that I better look for another investment…
Agreed?
Dear Ferninand
I certain don’t agree with or even understand the last comment.
Sorry I had not realised quite how limited the mass/balance equation was. I imagined it applied to all inputs and outs of the carbon cycle not just the bits that were easy to calculate.
If errors need to applied to the uncertainies so be it . At least that gives a more resonable representation of the state of knowledge.
Thank you for the references I will go any for a while and continue my research.
Regards
Jim
Jim McK wrote:
“Sorry I had not realised quite how limited the mass/balance equation was. I imagined it applied to all inputs and outs of the carbon cycle not just the bits that were easy to calculate.”
That is the really neat thing about the mass balance argument, we can determine that the natural environment (treated as a whole) is a net sink using only a couple of bits of data that are measured with good accuracy and the assumption of conservation of mass. It may be that its very simplicity makes it look too good to be true, but in this case, it actualy is!
“If errors need to applied to the uncertainies so be it . At least that gives a more resonable representation of the state of knowledge.”
Yes, that the conclusions of the mass balance argument are quite solid, even considering the uncertainties. We can be very confident that the natural environment is a net sink, even if we can’t do detailed accounting of the indivudual fluxes.
Hi Ferndinand,
If I could bother you a bit more. In building up my Balance Sheets and C Flow statements the fossil fuel numbers don’t seem to tie up with known reserves and expected life of those reserves as I would expect.
Could you tell me whether the data series at the global info centre represents the C component of fuel being burned/processed or the C component of that burned/processed fuel that makes its way to the atmosphere as CO2 (eg 3087GtC liquids 2007).
Thanks Jim
Jim McK says:
August 19, 2010 at 12:27 am
As far as I know, the numbers of EIA are the real CO2 emissions directly to the atmosphere, as these should be calculated by the different countries with the burning efficiency of the different fuels, thus not the total processed fuels, of which part is used in asphalt and other more permanent commodities.
I didn’t include cement use in my graphs, as that releases CO2 during manufacturing, but absorbs a large part back when hardening. Neither land use changes, as these are highly uncertain, but may add some 20% to the overall emissions.
Hi Ferninand,
Yes I would have thought the same thing but I can’t find a methodology on EIA sites.
Wikipedia has the total crude oil production at 10,100,000 m3 per day for 2008 for the top 17 producing countries
Using specific gravity of crude 85% and percentage of C 85% that comes to a total C component in production of 2.663GtC for 2008. Allowing for all other countries say 3.0GtC. This compares with the EIA number of 3.087GtC for 2007.
I haven’t looked at coal and gas in detail but I suspect the same applies. For my model I have been using 50% of C making it to atmospheric CO2, do you have a better number?
Jim
Dear Ferdinand,
Thanks again for pointing out to me that the net sink is a (small) fraction of the total volume of CO2 in the atmosphere. But it is the refreshment rate that counts: 150 natural (nC) going in and 150 GtC going out.
You say “I fear that you are confusing the origin of the molecules and the origin of the increase in mass”
I fear that my explanation was not clear.
When I write: from human emission 7 GtC/y goes out 1.22 GtC/y only, I of course want to say: out of the atmosphere And that 5.78 GtC/y remains in the atmosphere.
I shall try to explain again. (And send you the calculation separately)
With 7 GtC/y antropogenic (aC) injection with 150 GtC/y natural inflow the ratio is 7/150=0.047 in the inflow. (4.7 % of the inflow is anthropogenic)
In a ‘clean’ atmosphere of 700 GtC the first 7 GtC/y is strongly diluted to 0.008 in 700+150 GtC. Outflow is only 0.008*150. Since we assume that half of the 7 aC remains in the atmosphere, the outflow is 3.5+150. Out goes 0.008*153 = 1.25 aC. Remains in the atmosphere 5.75. The ratio aC accumulating over inflow x=0.82
With the second injection the aC concentration in the atmosphere increases further, with the result that also the fraction aC going out increase.
After 5 injection the ratio accumulating x=0.38. After 20 injection x=0.04. Thus almost all injected aC flows out. That is the reason that people dare say that the amount of aCin is only a rumple on the natural flow.
This calculation is not fully correct, because we assume that the accumulating total C is from the beginning Fa=3.5 GtC/y. But it gives an impression of the effect of the refreshment rate on the accumulation.
Therefore I agree with your statement:” The second year is more problematic to calculate for attribution of the origin of the molecules, as part of the absorbed CO2 in the ocean’s mixed layer and vegetation simply returns in the next year (even already in the next season!). Only the deep oceans are still aCO2 free in the upwelling zone. If we use that to calculate the deep ocean – atmosphere refresh rate, we come to some 40 GtC exchange between the deep oceans and the atmosphere (based on d13C reduction).”
But I do not know about your figure of 40 GtC from the deep sea. Your fig3 indicates 100 GtC/y. The effect of a lower throughput is that the decrease of x is slower with increasing aC.
Next, if most of the 100 GtC/y disappears first in the mixing layer, which was named previously the water box (exchanging with the atmosphere), then we can revise the size of the reservoir in which the throughput takes place (air + waterbox) to 1400. Again the ‘dilution’ of aCin is slowed down and therewith the decrease of x.
Nevertheless the principle remains that by the increase of aC in the reservoir, its outflow fraction increases and can rise above its absorption fraction x=0.5
I think my former equation is still valid:
Fa = (FemIN + dFin)*(1-x)
Fa is accumulation rate in atmosphere, FemIN the human contribution, dFin the natural contribution and x the fraction which is absorbed of the extra inflows.
1. If x=0.5 than then Fa=0.5*FemIN if dFin =0
2. If x is lower than 0.5 (strong constraint on absorption of extra inflows) then the dFin must be negative.
3. If x is greater than 0.5 then dFin must be positive.
Case 1 is a rather arbitrary assumption
Case 2 needs proof that there is a strong constraint on the extra inflows and that dFin is negative
Case 3 needs proof that there is little constraint and that dFin is positive.
Jim McK says:
August 19, 2010 at 6:20 pm
I haven’t looked at coal and gas in detail but I suspect the same applies. For my model I have been using 50% of C making it to atmospheric CO2, do you have a better number?
Jim
My calculation finds some 53% accumulating in the atmosphere, see:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2_1900_2004.jpg
Indeed about 50%, others find somewhat higher figures for the last period (57% if I remember well), because of “saturation” of the oceans, but that was recently rebutted by others who didn’t find a reduction (that investigation found 45%, but included land use changes)…
Anyway, the increase in the atmosphere is remarkably linear compared to the emissions. I don’t know of any natural process that can follow the emissions at such constant ratio…
Arthur Rörsch says:
August 20, 2010 at 4:26 am
Dear Ferdinand,
Thanks again for pointing out to me that the net sink is a (small) fraction of the total volume of CO2 in the atmosphere. But it is the refreshment rate that counts: 150 natural (nC) going in and 150 GtC going out.
You say “I fear that you are confusing the origin of the molecules and the origin of the increase in mass”
I fear that you still are confused, the refreshment rate has nothing to do with the increase rate or the removal rate… But see further.
I fear that the rest of his discussion is rather technical, and many don’t know the background discussion we had in the past years, where this is partly based on. In summary (that makes my thoughts also more systematic), with my comment included:
– In first instance, the human emissions (aCO2) add to the natural inflows (nCO2). With the year 2000 figures that is 7 GtC plus a natural inflow of 150 GtC (largely oceans and vegetation, which adds to the amount already in the atmosphere of 700 GtC, that gives 857 GtC of which 7 GtC is of anthropogenic origin. or a fraction of 0.008.
(this is not completely right, as most of the in- and outflows are simultaneous and vegetation and ocean flows are countercurrent, the real variability is not more than +/- 6 GtC over the seasons, but for the sake of argument not important here).
– In second instance, the natural outputs remove 153.5 GtC from the atmosphere into other reservoirs (largely oceans and vegetation). A fraction of 0.008 is from anthropogenic origin, that is about 1.25 GtC of aCO2 is removed, thus about 20% is removed and 80% stays in the atmosphere, that is 5.75 GtC, or a fraction of 0.0064.
– Not mentioned by Arthur, but important in our view, is that while 80% of aCO2 remains in the atmosphere or 0.008 in fraction, the real increase in total CO2 mass is 3.5 GtC, that is only 50% of the input of aCO2, but 100% caused by that input of anthropogenic emissions, as these were double the increase and the net result of the natural flows was 150 – 153.5 = -3.5 GtC, thus a net sink, not contributing to the increase in CO2 mass. The new total mass of CO2 in the atmosphere then is 703.5 GtC.
– In year two, the same scenario: 7 + 150 input, aCO2 fraction in 810.5 GtC is (5.75 + 7)/810.5 = 0.015. Then we have again 153.5 GtC output with now 0.015 aCO2 fraction, or 2.3 GtC of the now 12.75 GtC aCO2 is removed with the outputs, or again about 20%, 80% of old and new aCO2 or 10.45 GtC remaining in the atmosphere. But, says Arthur, compared to the new addition of 7 GtC aCO2, the removal increases to 35% of the newly added aCO2. Which is true.
(this is not completely right, as the increase in the atmosphere suppresses the natural input flows and increase the natural output flows, but for the sake of argument not important here).
– Again in our opinion, while only 65% of the newly added aCO2 remains in the atmosphere, with a fraction of 0.015 (new and old), the real increase in total CO2 mass is 3.5 GtC, that is only 50% of the input of aCO2, but 100% caused by that input of anthropogenic emissions, as these were double the increase and the net result of the natural flows was 150 – 153.5 = -3.5 GtC, thus a net sink, not contributing to the increase in mass. The new CO2 total mass in the atmosphere then is 707 GtC.
And so on for all following years.
Thus at a certain moment, the increase in fraction of aCO2 is near zero, as about as much aCO2 leaves the atmosphere with the outflows as there is new input of aCO2. That is right.
Now Arthur shows a formula that once that more that 50% of all new yearly aCO2 is removed in the same year (that is already in the third or fourth year), then the increase in the atmosphere is at least in part from the natural flows.
But in our view, that can’t be, as also in the third and fourth year and all following years the real increase in total CO2 mass is 3.5 GtC per year, that is in every year only 50% of the input of aCO2, but 100% caused by the input of anthropogenic emissions, as these always were double the increase and the net result of the natural flows was 150 – 153.5 = -3.5 GtC each year, thus a net sink, not contributing to the increase in mass. The new CO2 total mass in the atmosphere then is 700 GtC + n*3.5 GtC, where n is the number of years (in reality about 55% of the accumulated emissions over the years).
Where is the difference? Arthur looks at fractions of remaining aCO2 in the atmosphere. But fractions haven’t anything to do with the total mass of CO2 in the atmosphere. Even if the refresh rate (150 GtC in, 150 GtC out) doubled (to 300 GtC in, 300 GtC out), that would double the removal speed of aCO2 from an average 5 years half life time (for 20% removal per year) to 2.5 years half life and that would halve the maximum fraction of aCO2 in the atmosphere with a constant aCO2 supply. But that wouldn’t change one gram in the increase rate of total CO2, which still remains 3.5 GtC (in reality that is what was measured, the throughputs are far more difficult to establish). In all cases, the increase is fully attributable to the emissions as we have shown in the year to year increases, where in all cases the net natural flows were negative, thus removed more CO2 than they added. That is true for 49 of the past years, and one borderline year.
I have worked out what happens when one should add 100 GtC anthro CO2 at once to the pre-industrial atmosphere of about 580 GtC: The fraction of aCO2 increases from zero to over 14%, a does the total mass of CO2 which increases to 680 GtC. The years following that event are interesting: the fraction of aCO2 decreases rapidely with 20% per year (always of the remaining fraction), thus an about 5 years half life time. That is based on the refresh rate of 150 GtC/year. Thus after some 50 years, near all aCO2 is replaced by nCO2. But what happens with the mass of the pulse of 100 GtC extra aCO2 in the atmosphere? Well that depends of the removal rate, and that is (2000 figure) only 3.5 GtC/year, quite a difference with the refresh rate of 150 GtC/year. That results in a much slower change in total CO2 mass (whatever the origin) than the change in aCO2 fraction. How fast or slow, that still is a matter of debate, but I used the half life time of 38 years by Peter Dietze at http://www.john-daly.com/carbon.htm (the IPCC uses a complete set of different removal rates, including 10% that never disappears, but let’s use more realistic rates). This gives following figure:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/fract_level_pulse.jpg
Where FA is the fraction of aCO2 in the atmosphere, FL in the mixed ocean layer (not relevant here), tCA total carbon in the atmosphere and nCA total natural carbon in the atmosphere, where aCA is the difference between the two (not shown).
Thus while both fraction and total CO2 increased with over 14% by the 100 GtC aCO2 pulse, the fraction aCO2 disappears rapidely and is near completely gone in some 50 years. But the increase in mass still is for 50% present in the atmosphere after 40 years. Even when near all aCO2 molecules are replaced by nCO2 molecules, that doesn’t change the fact that the original pulse and the difference with the original level in all following years is 100% caused by the original aCO2 contribution…
That is also the case for the current emissions: while the fraction aCO2 is less than 10% in the atmosphere, the anthro emissions are fully responsible for the total increase of some 30% in total CO2 mass…
Ferdinand
I just realized that I made a mistake in the calculations of the fractions, as in the paragraph “in second instance”, the fraction remains 0.008 after removal of part of aCO2 via the outputs: the fraction remains the same, while the total mass is reduced with the outflows.
That makes no difference for the rest of the logic, which compares fractions with the increase in mass…
Hi Ferdinand,
No we are talking at cross purposes. I am still working on imputs to my model. What it seems to me is that the EIA numbers are overstated.
You said
“As far as I know, the numbers of EIA are the real CO2 emissions directly to the atmosphere, as these should be calculated by the different countries with the burning efficiency of the different fuels, thus not the total processed fuels, of which part is used in asphalt and other more permanent commodities.”
What I showed above is the C component of world gross crude oil production is identical to the EIA number for 2007 ie assumes 100% conversion of C to ACO2.
Using production figures rather than EIA and oxidation rates of 60% for natural gas and 50% for coal and oil the ACO2 averaged 5GtC for the decade 1998 to 2007 with 2007 being 5.7GtC.
What is your view on the EIA numbers?
Jim McK says:
August 21, 2010 at 1:36 am
Sorry for the delay, it was very busy at part 2…
Using production figures rather than EIA and oxidation rates of 60% for natural gas and 50% for coal and oil the ACO2 averaged 5GtC for the decade 1998 to 2007 with 2007 being 5.7GtC.
Their definition of energy consumption is rather broad:
“Energy Consumption: The use of energy as a source of heat or power or as a raw material input to a manufacturing process.”
The latter is rather ambiguous, not clear if that e.g. includes asphalt use…
60% for natural gas seems rather underestimated to me: a small part may be used for chemical processes, but the bulk is used for heating and/or power production. Even flaring (20 years ago still 9% for Shell worldwide) is all CO2. Likewise line losses (estimated 4% in The Netherlands) indirectly forms CO2 (half life about 10 years in the atmosphere). Incomplete burning to CO also sooner or later converts to CO2, in the presence of ozone or OH radicals…
For oil and coal, some more is used for e.g. plastics manufacturing (4% worldwide), but other products (greases, lubrucating oils, solvents), all have their share and not all give a direct or indirect contribution to CO2 releases. Asphalt is the residue, that is the only one of which one can be sure that it doesn’t contribute, but how much is that from the total crude? Here too, 50% conversion to CO2 seems rather underestimated to me.
Hi Ferdinand,
I still think the oil number is overstated and like you that cement production is too. But when I bring in gas and coal the total EIA fossil fuels emmissions now only look modestly overstated.
On to other things. I will send you my big picture model when it is worked over a bit more.
Regards,
Jim