Guest Post by David Middleton
Fingerprints are admissible evidence in criminal trials because of their uniqueness. The probability of two human beings having identical fingerprints is very low.
Measurements of δ13C depletion have often been cited as anthropogenic “fingerprints,” proving human culpability for the rise in atmospheric CO2 over the last 200 years or so…
While δ13C depletion certainly could be evidence of the Suess Effect, it is not a unique solution; therefore, not a “fingerprint.”
Examples of geologically recent δ13C depletion not of anthropogenic origin…
δ13C depletions were associated with warming events ~5,000 years ago in India, ~9,100 years ago in Poland and ~150,000 years ago in the Indian Ocean. It appears to me that δ13C depletion has been a fairly common occurrence during periods of “global warming.” It also appears that δ13C increases have occurred during periods of global cooling…
The red curve in Figure 5 is the Flinders Reef δ13C that was cited as “Human Fingerprint #1” in Skeptical Science’s The Scientific Guide to Global Warming Skepticism. The rate of δ13C depletion is quite similar to that of the lacustrine deposit on the Yucatan. The Flinders Reef data do not extend back before the Little Ice Age; so there is no way to tell if the modern depletion is an anomaly, if the δ13C was anomalously elevated during the 18th and 19th centuries and the depletion is simply a return to the norm or if δ13C is cyclical.
Is it possible that Skeptical Science’s “Human Fingerprint #1” is not due to the Suess Effect? Could it be related to the warm-up from the Little Ice Age?
References
Cook, J. et al., 2010. The Scientific Guide to Global Warming Skepticism. Skeptical Science.
Banakar V., 2005. δ13C Depleted Oceans Before the Termination 2: More Nutrient-Rich Deep-Water Formation or Light-Carbon Transfer? Indian Journal of Marine Sciences. Vol. 34(3). September 2005. pp. 249-258.
Enzel, Y. et al. High-Resolution Holocene Environmental Changes in the Thar Desert, Northwestern India. Science 284, 125 (1999); DOI: 10.1126/science.284.5411.125.
Apolinarska, K. δ18O and δ13C Isotope Investigation of the Late Glacial and Early Holocene Biogenic Carbonates from the Lake Lednica Sediments, Western Poland. Acta Geologica Polonica, Vol. 59 (2009), No. 1, pp. 111–121.
Hodell, D.A., et al., 2005. Climate change on the Yucatan Peninsula during the Little Ice Age. Quaternary Research, Vol. 63, pp. 109-121. doi:10.1016/j.yqres.2004.11.004
Pelejero, C., et al. 2005. Flinders Reef Coral Boron Isotope Data and pH Reconstruction. IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2005-069. NOAA/NCDC Paleoclimatology Program, Boulder CO, USA.
gavincawley says:
April 3, 2012 at 2:41 am
“No bart, i you did that your model would violate the principle of conservation of mass.”
Not when you include what the oceans took up. This is a very basic model of the carbon cycle. If you do not understand it, you do not understand what you are doing. But, that has been rather evident all along.
“In a scientific discussion however, both parties are seeking the truth and trying to identify errors in both their opponents reasoning and their own. “
I am not in error, Gavin. You do not know what you are doing. And, I am tired of trying to enlighten your invincible ignorance.
FerdiEgb says:
April 3, 2012 at 3:03 am
“…it doesn’t make any difference for the sinks if an increase in the atmospheric mass above setpoint is from N or U. It only matters that there is an increase in mass.”
Hopelessly, painfully, irredeemably WRONG. I give up.
“The equation is:
dM/dt = A + N – kM”
[SNIP: Can we avoid this? -REP]
FerdiEgb says:
April 3, 2012 at 3:41 am
“The mass balance itself is sufficient to prove that the human emissions are the sole cause of the increase in the atmosphere, as long as the increase is less than the emissions. It is as simple as that.”
[SNIP: And this? -REP].
I cannot be kind to you guys anymore, and there is nothing more to be gained. Jut when I think I have it all explained that even a child could understand it, you all surprise me again with your level of scientific illiteracy. Let’s just go our separate ways. You will learn the errors in yours someday, and it will not be a happy occasion for you, I am afraid.
gavincawley says:
April 3, 2012 at 2:41 am
“The original equation
dM/dt = A + N – U
was a restatement of conservation of mass, so if you arbitrarily halve A and N then obviously that principle no longer holds.”
Why can you not see this? What is this mental block? If you want to treat this problem rigorously, you have to include state variables for all three reservoirs, oceans, land, and atmosphere. If you choose to focus just on the atmosphere alone, then you have to make approximations, and conservation of mass DOES NOT HOLD FOR THE ATMOSPHERE ALONE.
Sheesh.
[SNIP: Can we avoid this? -REP]
No, “we” cannot. Not anymore. This has gone beyond the bounds of the ridiculous to the sublime. I cannot dignify these two guys’ mind-numbingly blinkered opinions with even a bare modicum of courtesy anymore. So, I must needs bow out of the conversation.
There is absolutely nothing wrong with doing a mass balance for the atmosphere alone.
The equation I wrote was that the rate of change in the atmosphere equals the sum of the sources and sinks, that conservation of mass must apply. The change that you made to the equation made no sense at all and didn’t balance, you subtracted part of the sources but didn’t add that part to the sink term, that’s not a balance equation!
I guess it’s all summed up in your last statement: “conservation of mass DOES NOT HOLD FOR THE ATMOSPHERE ALONE”, you really believe that it’s not possible to write a conservation equation for a reservoir, in which case there’s no hope for you.
Bart wrote: “Not when you include what the oceans took up.”
No you earlier wrote “c is a factor of perhaps roughly 1/2, which models the relatively rapid dissolution of a portion of the atmospheric CO2 into the oceans.” The dissolution of atmospheric CO2 into the oceans is already modelled by the natural uptake U. Multiplying A+N by C is merely counting this uptake twice, which as I said would contravene the principle of conservation of mass.
Bart also wrote: This is a very basic model of the carbon cycle. If you do not understand it, you do not understand what you are doing. But, that has been rather evident all along.
I mentioned earlier that refusing to answer direct questions, and refusing to engage in a step by step analysis of the argument were both hall marks of a rhetorical rather than a scientific debate. Trying to belittle your opponent as you have done here is another hall mark of rhetoric. Please can we stick to rational scientific discussion?
Bart wrote “If you want to treat this problem rigorously, you have to include state variables for all three reservoirs, oceans, land, and atmosphere.
Yes, and indeed that is what e.g. GEOCarb does (and more). If you adopt such a model you will still find that if the rise in atmospheric CO2 is less than anthropogenic emissions, then the total natural uptake is greater than the total natural emissions. The scientists who study the carbon cycle have been working on this for decades. I am using a greatly simplified model here because it is sufficient to make the basic point.
“If you choose to focus just on the atmosphere alone, then you have to make approximations, and conservation of mass DOES NOT HOLD FOR THE ATMOSPHERE ALONE.”
The simple model I gave earlier obeys conservation of mass for the whole carbon cycle, not just the atmosphere. I could have included a variable to record the mass of the non-atmospheric reservoirs, but they are irrelevant to the central point.
Do you agree that total natural uptake (ocean+land) has exceeded total natural emissions (ocean+land) for each of the last fifty years, yes or no?
Bart: you are banging your head against one of the tablets of stone here.
Use a jackhammer and a dust mask.
tallbloke, If you think Ferdinand and I are wrong, the I would invite you to try proving it. The argument involves half a dozen steps, are you willing to go through them with me, so you can point out where the error lies? I am making it as easy as I can for you to prove me wrong, so if you are condfident I am wrong, why not give it a go?
Step #1 Do you agree that the carbon cycle obeys conservation of mass, such that the annual increase in atmospheric CO2 is the difference between total emissions from all sources minus total uptake by all sinks? Yes or no, if “no” then please justify your objection.
tallbloke says:
April 3, 2012 at 8:56 am
Rog – I cringe at almost every word from these guys. No matter how much I shout that 2 + 2 = 4, they insist it is 3. And, they are absolutely certain they are right. It is pretty pointless.
The kicker is, there is a valid debate to be had here. But, these guys aren’t even stepping up to the plate. They’re hanging out at the dugout, holding their bats upside down, and insisting that the pitcher already walked them (hope you know enough about American baseball to appreciate the metaphor).
Bart, if you want to be understood, then giving direct answers to direct questions that are designed to clarify your position would be a great help. You could start by giving a direct answer to my previous question “Do you agree that total natural uptake (ocean+land) has exceeded total natural emissions (ocean+land) for each of the last fifty years, yes or no?”
Bart: I’ll see if I can help, take a breather.
Gav: We can’t assume a priori that it will rise, so we can refer only to change, not increase. With that caveat, proceed to #2.
Bart says:
April 3, 2012 at 9:37 am
Rog – I cringe at almost every word from these guys. No matter how much I shout that 2 + 2 = 4, they insist it is 3. And, they are absolutely certain they are right. It is pretty pointless.
Bart, you are a master in using words to accuse others of what you are doing yourself.
The basic equation is:
increase in the atmosphere = human emissions + net natural addition
where increase and human emissions are known over the past 50+ years.
In graph form:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/dco2_em.jpg
That gives for the past 50+ years:
net natural addition = 1 GtC/yr +/- 1 GtC – 2.5 GtC/yr (1960)
increasing to
net natural addition = 4 GtC/yr +/- 2 GtC – 8 GtC/yr (2006)
that gives:
net natural addition = -1.5 GtC/yr +/- 1 GtC (1960)
increasing to
net natural addition = – 4 GtC/yr +/- 2 GtC (2006)
But no matter how that proves that there was no net natural addition, only a net natural sink in the past 50 years, you insist that a negative figure can be positive…
Tallbloke, yes change would be a more general term and I am happy to go with that as well.
Step #2 The carbon cycle is a closed system, i.e. carbon isn’t spontaneously created or destroyed (except for the insignificant amounts of 14C of course) but is exchanged between reservoirs (atmospheric, oceanic and terrestrial) and there are natural sources of CO2 into the atmopsher, anthropogenic sources and natural sinks that take CO2 out of the atmosphere and no other sources or sinks into or out of the atmosphere.
Do you agree with that. yes or no, if no, please explain.
It must be possible to write down a maximum of 3 differential equations governing CO2 concentrations in the atmosphere. Then we can all argue about these 3 equations !
clivebest: Indeed, see my paper in Energy and Fuels http://pubs.acs.org/doi/abs/10.1021/ef200914u . However you don’t actually need differential equations to prove that the rise is anthropogenic. Ferdinand Engelbeen also has a very good website on this issue, see http://www.ferdinand-engelbeen.be/klimaat/co2_measurements.html .
Woody biomass has increased by a substantial percentage over the last 50 years. Those plants and trees are lovin’ it up. That means a big increase in sink capability, plus a lot more natural output as more dying biomass rots.
So how do we gauge the overall effect of an accelerating natural biosphere reaction to a warming world which increases its co2 airborne fraction?
Seems to me that’s where the uncertainty in all this arises.
@tallbloke – is that a response to step #2? Note that increase in woody biomass would be a component of the natural sink.
Do you agree with step #2, yes or no?
Gavin, no, I wrote my comment before I saw your response and your #2 question. I must be prescient,or transcendent, or something.
Anyway, my reply is a don’t know, because increased biomass means more natural addition to airborne co2 as well as an increased natural sink for it. A bigger mass is rotting as well as growing.
@tallbloke increased biomass would be both a natural sink (gross primary production) and a natural source (respration), this is no big deal, the ocean is both a source and a sink as well. Soil respiration (i.e. rotting) is also a natural source.
None of that affects whether the carbon cycle is a closed system or not. Perhpas I could rephrase it, do you agree that no carbon dioxide enters or leaves the atmosphere other than due to anthropogenic emissions, or uptake by natural sources (which take carbon out of another natural reservoir and put it into the atmosphere) or natural sinks (which take carbon out of the atmosphere and put it into a natural reservoir)?
I am not specifying what these natural reservoirs actually are, apart from that they are part of the planet (i.e. e.g. we don’t have aliens stealing CO2 for some nefarious purpose). Neither am I specifying what these natural sources actually are, or how they operate, just that they exist.
Do you agree with this, yes or no?
gavincawley says:
April 3, 2012 at 9:56 am
‘You could start by giving a direct answer to my previous question “Do you agree that total natural uptake (ocean+land) has exceeded total natural emissions (ocean+land) for each of the last fifty years, yes or no?”’
I do not agree that total natural uptake (ocean+land) of natural emissions has exceeded total natural emissions (ocean+land) for each of the last fifty years. There is no way to tell with the information we have available. Read my 10:03 am post. Understand it.
clivebest says:
April 3, 2012 at 11:17 am
“It must be possible to write down a maximum of 3 differential equations governing CO2 concentrations in the atmosphere. Then we can all argue about these 3 equations !”
And, if you do that, and assume dissolution into the oceans is “fast” relative to other dynamics, and assume a single dominant time constant, then you can simplify the equation into the single one I gave:
dM/dt = c*(A + N) – kM
Neglect land for a moment and assume, for example, the following:
O = oceanic concentration
M = atmospheric concentration
A = anthropogenic input
N = natural input
Mdot = N + A + a*(O – M)
Odot = a*(M – O) – 2*k*O
“a” is a coupling constant between oceans and atmosphere, and the term involving “k” represents ultimate sequestration in the ocean. The transfer function between N + A and M is
H(s) = (s + a + 2*k) / (s^2 + 2*(a+k)*s + 2*a*k)
Under the assumption that “a” is much greater than “k”, then this transfer function is approximately
H(s) := a/( (s+2*a) * (s+k) )
The term a/(s + 2*a) is a wide bandwidth process with dc gain of 1/2. Thus, we can further approximate
H(s) := 0.5 / (s + k)
Which is to say that the differential equation is approximately
Mdot := 0.5*(N + A) – k*M
WHICH IS WHAT I EFFING SAID SEVERAL POSTS AGO!!!!! But, apparently, I have to spoonfeed it to these youngsters.
Note that Mdot + Odot, in this model, is N + A – 2*k*O, i.e., is what is coming in, minus what is ultimately sequestered. So, Gavin can have no frivilous objections to violation of conservation of mass.
Bart wrote: “Write down the equations. Carefully label what is known and what is unknown. In the end, you will come up with the difference between natural inflow and outflow as being the only fundamental quantity known, but with nothing more than handwaving to assert how much of each there is individually.”
You agreed that the mass balance argument means that we can infer the difference between total natural emissions and total natural uptake as it is equal to the difference between the annual change in atmospheric CO2 and anthropogenic emissions. Have you changed your mind now?
OK, the teabreak obviously did Bart a power of good, so I’m gracefully heading back to look after my blog at this point…
🙂
Note that the model I gave is arbitrary. AGW advocates like it because it gives them a factor of 1/2 that, when N and k are set to zero, gives an atmospheric rise of approximately half the accumulated emissions, and they think this is some way-out, weird coincidence that proves their bias.
But, we can as easily introduce another coupling constant “c” such that
Mdot = N + A + a*(O – 0.5*M/c)
Odot = a*(0.5*M/c – O) – 2*k*O
It is left as an exercise to the reader that this can produce an approximate first order differential equation for the atmospheric concentration of
dM/dt = c*(A + N) – kM
Thus, “c” can be anything, and assuming it is near 1/2 is just cherry picking to confirm one’s bias.
“You agreed that the mass balance argument means that we can infer the difference between total natural emissions and total natural uptake as it is equal to the difference between the annual change in atmospheric CO2 and anthropogenic emissions. Have you changed your mind now?”
I’m put out enough having to teach you math. I’m not going to teach English as well. Read what I wrote. If you can’t figure it out, that’s your problem.