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!
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…
Could you please elaborate on how this is done? Is the dollar amount of taxes received for the sales tax on fossil fuel used? Is there some other method?
1) What efforts have been made to determine how constant incoming cosmic rays have been to earth on all timescales? Could a change in C14 production due to fluctuations in cosmic ray intensity be more responsible for any correlation in this regards?
2) My understanding is that C13, being a byproduct of decay of Nitrogen-13 (half-life 10 min), which is itself a product of proton collision with atomic Oxygen, could be a product of cosmic rays entering the atmosphere. So I reiterate question 1 with regards to C13, providing there is no physics reason I am unaware of that would prevent cosmic rays from creating N13 from H+O16 (too low KE, etc..)
Thank you for your time answering these questions.
Tallbloke: I read that as well, but I’m unaware of any other isotopically specific chemical or biological processes, I’ve got a few large grains of salt I’m taking that with. Isotopes have identical orbital structures and would appear chemically identical, no?
Can anyone point to resources indicating isotopically (isotopicly?) specific chemical/biological reactions.
If one could selective chemically react with specific isotopes, the whole centrifugal U235 separation process (and thus our concerns about the numbers of centrifuges certain countries have) would be unnecessary.
Before I begin to discuss why I don’t buy this particular argument, let me just say that I do believe humanity has caused some increase in the overall levels of CO2. I find most of the discussion presented in this post hard to swallow, though because of the following points:
1. “As there are no processes in the atmosphere which convert CO2 to something else” that we know of. Even if that is true (and I’ll readily admit I don’t know), we don’t know, with any certainty, what the natural process’s net effect is. (see my next point).
2. “From all those flows very few are known to any accuracy.” In other words, there’s no way for us to determine what the natural world can actually do with CO2, but our limited amount of knowledge SUGGESTS blah blah blah
3. “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.” If I’m reading this statement correctly, without human emissions, CO2 would eventually disappear from the atmosphere entirely because the net NATURAL increase is negative (meaning an overall decrease year after year).
4. “There is no net natural contribution to the observed increase, nature as a whole acts as a sink for CO2.” See item #2 where it is admitted that we don’t know the natural in and out flows with any accuracy. If we have no accurate measurements, how can this assertion be made?
5. “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.” I seem to remember a previous discussion on this blog about the reliability of ice core records due to diffusion of CO2 from the trapped air bubbles. Hasn’t it been shown that due to diffusion over long periods of time that the levels of various gases in the ice core samples should NOT be considered representative of the atmospheric conditions when the bubble was formed?
All that said, I am not naive enough to state that humanity has not added to the levels of CO2 in the atmosphere. That would require complete disregard for chemistry and common sense. What I am saying is that these bits of “evidence” are not very strong.
Most importantly, though, the ultimate questions remain. Where is there any shred of evidence that this increase in CO2 has done anything to warm the planet? What temperature SHOULD the planet be? Does a global average of temperatures (even if one could be accurately measured) mean anything when none of us are affected by the global mean temperature, but rather by our local weather?
Pamela Gray. I concurr.
Totally unrelated.
Mauna Kea glacier expansion traced to slower North Atlantic current in last ice age.
http://www.staradvertiser.com/news/20100805_Faraway_current_set_off_Mauna_Kea_glacier.html
And note:
“The ancient system also may have stirred up old carbon-rich deep waters, contributing to the increase in atmospheric carbon dioxide, the scientists said.
“This could have catalyzed further warming and accelerated the glacial meltdown,” Menviel said.”
—-
Frankly I am uncertain how calcium carbonate or sediment contributes to atmospheric CO2 in this scenario. The usual vehicle is volcanism. But a good article.
Of course it is MANN-MADE!
Surely this mass balance argument if flawed, since it assumes that CO2 is simply passed around the biosphere and any increase must have come from burning fossil fuels. If that was the case then CO2 would have remained constant throughout geological time. Yet as we know, CO2 can come from inorganic processes, such as volcanoes, calcium compounds in rocks, sea water etc.
So far this seems to be an incomplete analysis: I have the following questions:
1. What is the total reservoir of biologically available carbon in soil, lake and ocean sediment and rock (eg oil in shale and oil sands) for the Earth?
2. What is the rate of conversion of that carbon to CO2 by bacteria/fungi/insects?
3. If the Earth warms, do the bacteria/fungi/insects increase in biomass (change in number of individuals x size of individuals? Do they increase in activity, hence converting carbon reserves to CO2 at a higher rate per unit of biomass?
4. We know that bacteria “eat” oil, presumably creating CO2. Is this process temperature sensitive? Is it limited to oil seeps or does it occur in deep oil collections such as shales and sands?
5. How accurate are the ice core data really?
6. If humans have caused the recent CO2 increases, what caused the previous CO2 increases? Did the CO2 follow the temp up, lead it, or change contemporaneously?
7. I do not doubt that human activity is part, maybe a large part of recent CO2 change, but I am skeptical that the various factors, such as I mention above, are understood with nearly the certainty precisions pretended to in the claims that humans are the cause of almost all of the recent CO2 increases in the atmosphere.
Total biomass of bacteria, fungi, and insects dwarfs humans and human industrial activity, including in overall CO2 production, as I understand it. A small percentage change in non-human biologic production of CO2 could have a large change in gross amounts emitted and ought to be measured and be part of the discussion.
The Engineer has a very valid point. If fossil fuel consumption is the culprit, the percent CO2 increase should be increasing, not remain steady. An interesting correlation should be explored between increased fuel use over time versus CO2 rise. The null hypothesis would be that there is no significant correlation. Or else we would see a CO2 hockey stick instead of the steady ML pump http://cdiac.ornl.gov/trends/co2/graphics/SIOMLOINSITUTHRU2008.JPG. The only explanation for a lack of correlation would be a silly one, that somehow, the isotope for fossil fuel based CO2 is causing less natural CO2 emissions. Given that we have measured the greening of the planet, that explanation would be false.
There was one critical factor left out of the above, that is temperatures.
A certain percentage of CO2 I believe is emitted absorped according to the ocean temps. We know this mechanism does exist simply from ice cores that shows CO2 swinging up and down through the millenia. Could this be happening on shorter timescales. Well it must be, otherwise it wouldn’t happen over longer timescales, the question is then by how much.
Surely it isn’t just coincidence that when the SST is low there is a lower increase than when they’re high.
So are we saying this then?
i.e. in years that CO2 increases are low there are low SST’s is a pure coincidence, that just so happens to have been occuring consistently since CO2 measurements began.
I have always believed that humans have contributed signficantly to the CO2 rise in the atmosphere over the past 150 years or so. I need to be convinced, though, of the accuracy of the ice core measurements. Its hard for me to envision CO2 trapped in a thin layer of ice under enormous overburden ice pressures with no migration of the gas. I envision the CO2 in a snow layer at the surface containing atmospheric air subsequently being covered, pressed with expulsion of most of the “trapped” air into the new overlying layers. Or worse, the CO2 dissolved in the snow as it falls plus the atmospheric air trapped. Heck, we get diffusion of elements through solid rock and crystallized minerals (eg: in pegmatites the lithium aluminum silicate mineral spodumene has been invaded by sodium solutions and replaced by the sodium aluminium silicate mineral albite in part or wholly without destroying the original crystal shape – ice wouldn’t be so formidable a barrier to diffusion. If it is rather a proxy calculation based on isotope ratios, then there is room for significant error in converting this to CO2 in the ancient atmosphere.
Does anyone also measure the nitrogen, oxygen and noble gas concentrations in the ice cores? Such gas ratios may be more indicative of the CO2 content at the time. My thoughts arose on this when I saw the ice core/Mauna Loa CO2 graph of Willis’s – it was just too darn smooth for me.
Models vs measurement again. This is a large planet and lord knows what CO2 might be spewing out in the 67% that is covered by water and I did not see any measurement devices in the plumes when Pinatubo or Mt St Helens went off. I did see a pretty good analysis of ice core data that would lead one to believe that the CO2 increase corresponds nicely with population increase over the last 8000 or so years but I’m not sure who was doing the census back then. Also, still the cause and effect problem. I’ll give you a “possible” but not a “for sure”, by any means. Newton thought he had it pegged pretty well too and then came Einstein and even his results may only be an approximation of reality. Call it the “Jim G uncertainty principle”, kind of like the Heisenberg one of the same name but with less math, just logic.
BillD says:
Anyone who makes unsupported blanket statements of this sort is clearly unable to understand the scientific method, and thus “basic science”.
Just because you want to believe something does not make it so. Asserting your belief in the form of a factual statement or derisive insult does little for advancing knowledge.
Ah, but you are all-knowing, so you have no need to advance your knowledge…
Does anyone know of any sources of CO2 levels before the observatory was established on Mauna Loa? How accurate were these measures?
Also, has someone validated the various sources of CO2? How about sinks?
What is the lifetime of the average CO2 molecule in our atmosphere? Have read where some believe it is hundreds of years to a few years.
I have just assumed mankind is responsible for the rise in CO2; just didn’t think it would ever be an issue.
Good review article.
Ferdinand,
I’m not sure the mass balance is the slam dunk argument that you think it is. For instance, the natural inflows and outflows might somehow be a function of the human emissions.
To take a (silly) example to make my point, imagine if 100% of human emission were from burning wood or, better, grass. This carbon would have been a natural outflow via decay except for the fact that we are burning it. In other words, one of the inflow terms decreased by our human emissions. In that situation, you cannot attribute the CO2 rise to our emissions.
Now, I’m not trying to argue that something so direct is happening or that there is necessarily any link at all. But logically, the mass balance argument cannot, on it’s own, prove causation.
The biggest (potential) problem that I see with this analysis is the assumption that absorption/generation rates (other than human induced) are linear.
Perhaps they are for all practical purposes over the very small changes we are talking about, but in general I would expect these to be non-linear — probably Log(e).
Tom,
Okay, I will go ahead and cede the point. Humans are likely responsible for a significant increase in CO2. And the Earth has warmed by (?) something like 0.8 C degrees (depending on who you ask) in the last 120 years. This if 8ppm equals 1 C, we should be at at least +10C right now. That would seem to cast serious doubt on the AGW hypothesis that CO2 is causing the current warming, wouldn’t it? Tipping points? Right out the window. Feedbacks would necessarily be negative given the data of the last 100 years.
Too simple, but let’s continue on;
No matter what argument you make, it does not follow that the increase in temperature is caused by the increase in CO2. This is an assumption and is refered to as the “post hoc ergo propter hoc” fallacy. The simple bottle experiment with CO2 and a heat lamp doesn’t really apply in a gigantic chaotic system such as the Earth’s atmosphere. This is like stating that a car’s forward motion produces the heat that the car generates. It may seem logical, and the motion may generate a little heat of it’s own, but this is far from the true cause of the heat produced.
Next, a simple review of ideal gas laws and thermodynamics seems to tell us that whatever the situation is, it is far more complicated than just “more CO2 equals higher global surface temp”. All else being equal, the atmosphere would be as likely to simply expand rather than increase in temperature. You’d likely get more clouds, reducing surface T. I will admit to being very much a laymen on the science of all of this, but I do understand enough of it to see that it cannot be as simple as most of the pro-AGW set would have us believe.
But let’s simplify this argument; The only way you can prove CO2 is the cause of the warming is to exclude every other possible cause, and show a direct link between CO2 levels and global surface temp. Right now you cannot even establish the global surface temp to any degree of considered certainty. Right now the uncertainty band of our statistically synthesised surface T proxy is greater than our measured increase over the last 100 years. Just given the number of measurements compared to the total surface area of the Earth tells us we don’t know within a degree with any certainty. Our sample lacks quality control, consistency, longevity, randomness. And every time there is an adjustment made for any quality issue we see that it tends to inflate temps in recent years and decrease them in the more distant past. How certain are we again?
Further, the data that we do have are in such a shambles that it’s doubtful anyone can prove anything. Some of it we cannot be certain what adjustments have been applied, if any. The provenance of all of it is highly suspect and the independence of the several sets is highly dubious. The reason the data are so screwed up? The current powers that be in climate science chose sides about 20 years ago and have co-opted science to their own ends. They’ve literally held the data hostage to their agenda. At the point they don’t share and then collude to violate the law to avoid sharing the data and methodology you can rest assured something is rotten in Denmark. When you start to look at the adjustments they’ve added to the data there can be little doubt as to their agenda. When you hear statements such as “the science is settled” you know you’ve found a problem! Not even gravity is settled. We think we know, and we’ve got pretty good formulas, but then again, so did Newton. So if you hear that climate science is certain about something you should know that the giant Wizard bellowing platitudes and knowledge to frighten everyone who would dare question him is really just a little man behind a curtain with little real knowledge to show.
But nature, as always, has all of the aces. The solar cycle progression and projection has just been updated through July, and if the Sun doesn’t come out of it’s funk pretty soon, the current era will likely come to be know as the “Eddy Minimum” and the whole cadre of prominent climate scientists will come to be regarded as the Charles Dawson’s of their day. Nature is cruel like that. But I don’t know for certain what will happen, I’m just reading the tea leaves. The temp could go up or down, we don’t know. Further, we might know better if our “scientists” weren’t so invested in seeing it increase. So we really ought to drop the whole “settled science” perspective, see if we can piece together a valid data set and really try to understand the inner workings of our climate. As Jack Eddy would say; we need to figure out just how many ends that interface cable has and what they all do. It’ll take time. But if we just assume that there is no interface cable, and that we know everything there is to know about what causes the Earth to heat and cool, we will be caught unprepared for whatever it eventually does. At least Piltdown Man didn’t actually cause any deaths. Mann, Jones, Gore, et. al. will not be able to make that claim.
But I (and I think many others on the skeptical side of the debate) would be glad to cede the point with regard to recent CO2 increases being (largely) anthropogenic.
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.
Hang on a minute! Are we tacitly assuming here that the sum of all the other flows is not affected by human emissions? Why, for instance, would the net outflow from natural sources (which often depend on the process of osmosis) not be slowed down by the CO2 that humanity already puts into the atmosphere?
I suspect that we cannot actually predict what the present-day atmospheric CO2 concentration would be without human-induced emissions. It may end up exactly the same — natural sources making up for the loss of human-induced CO2.
Thanks for the article, and while I believe additional CO2 is human-caused, playing Devil’s advocate I have to point out that your Figure 3 is not “sufficient proof” of the cause of CO2 increase. Even with the graph, it could be possible that 99% of human emissions are absorbed by the ocean, and that an independent natural increase in ocean temperature the last 150 years is thus responsible for 98% of the added CO2. I don’t personally believe this, but nevertheless figure 3 alone does not answer any questions, as it is still possible that ocean release alone is the dominant force — you have made an association/causation error. I am sure that the rest of your article will provide a more scientific basis, and thanks again for your work.
Two things have always bugged me about the ML CO2 data.
1. In figure 3 above, the yearly increase bounces around a lot, from 0.5 to 2.5 ppm/year, over short periods of a few years.
If the human input is increasing all the time, why does the rate of increase vary by a factor of 5?
2. Due the fine economic mess the banksters have given us, I heard the CO2 emissions were down like 7 or 9% for the US, maybe 1% for the world. Has this decrease been observed in the slope of the Keeling curve?
-Jay
Sorry, I should’ve addressed that to Ferdinand.
My mistake.
Peter says: “What I still don’t understand is that if the natural outflow is 4GT greater than the natural inflow, then how come atmospheric CO2 levels didn’t drop to virtually nothing after all the thousands of years before man started burning fossil fuels?”
They did, and they are.
“From all those flows very few are known to any accuracy.”
Precisely – I think you just shot yourself in the foot…
I’m going for a beer… So I can watch the pretty bubbles of plant food rising up and escaping before some moron decides that I have to fit carbon capture device to my beer glass…
Counter point. Review http://www.kidswincom.net/climate.pdf and draw your own conclusions. As to the IR issue, review http://www.kidswincom.net/CO2OLR.pdf.
CodeTech says:
August 5, 2010 at 9:25 am
BillD says:
Anyone who does not understand that the burning of fossil fuels is the main cause of the regular increase in CO2 that is has been documented over the last 50+ years is clearly unable to understand basic science.
Anyone who makes unsupported blanket statements of this sort is clearly unable to understand the scientific method, and thus “basic science”.
Code Tech:
Certain findings are widely and clearly demonstrated in science and do not need support by citation and documentation. In my view, the conclusion that fossil fuel burning accounts for the increase in CO2 in the atmosphere fits into that category. That assumes that one has at least read evidence at the basic textbook level. Another well-accepted finding is that the earth follows an orbit around the sun. At one point these issues may have been cotroversial, but the controvery has long since been settled. Clearly, other aspects of climate science are controversial.
Actually, I am a scientist who publishes on basic science. Although I am not a climate researcher, I have followed the scientific literature on this topic. My peer- reviewed publications have received over 2800 citations, so I do have some credibility as a scientist.