Dusting for Fingerprints in the Holocene

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…

Fig 1) The so-called Suess Effect from John Cook's "The Scientific Guide to Global Warming Skepticism"

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…

Fig 2) δ13C depletion during Holocene Climatic Optimum in the Thar Desert of Northwest India (Enzel et al., 1999).

Fig 3) δ13C depletion during Preboreal to Boreal in western Poland (Apolinarska, 2009).

Fig 4) δ13C depletion during last interglacial in the Indian Ocean (Banakar, 2005).

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…

Fig 5) δ13C rise and depletion across the Little Ice Age in the Yucatan compared to recent δ13C depletion in the Coral Sea.

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.

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About David Middleton

I have been a geoscientist in the evil oil and gas industry for almost 30 years. My favorite hobby is debunking the junk science of the radical environmentalists...Particularly the junk science of anthropogenic global warming.
This entry was posted in Alarmism, Carbon dioxide, Paleoclimatology and tagged , , , , , , , . Bookmark the permalink.

247 Responses to Dusting for Fingerprints in the Holocene

  1. Gail Combs says:

    Oh, this is great information. Thank you David. It is one of the key points that is always brought up when CO2 is discussed.

  2. Philip Finck says:

    So it is elevated in association with the Little Ice Age……. and it is still elevated compared to 0 – 1400 AD. Note the many precipitous drops far greater that what is seen in the 20th century. There is obviously another mechanism controlling c13/C12 ratio.

  3. Philip Finck says:

    Hold it now … I just realized that the scales are different.Flinders reef was 0 around 1700 and is now <-1 in 2000. Yucatan makes an arch between -2.5 and -4.5 with extreme variability between 1500 and 2000. The Flanders Reef series isn't long enough to say anything meaningful when it is compared to the Yucatan record. Variability of 2 full units in the ratio is very common. If the ratio goes negative due to fossil fuel input then why has the Flinders reef dropped from 0 to -1 while in the Yucatan it was in the -5 range for 1400 years ……. must have been a lot of Aztecks (sp?) burning a lot of coal. Mind you the Yucatan area is full of gypsum …wonder what the C ratio is in gypsum, ie does C12 – C13 speciate when gypsum crystallizes in the evaporite forming process or alternatively what was the C13 – C12 ratio when the gypsum formed in ocean water?

    Is the ratio a regional thing versus a global proxy?

  4. Philip Finck says:

    Hold it again. The Flinders Reef (Great Barrier Reef) in the SKS post has the ratio from -1.2 to -3.6. That doesn’t agree with the right hand scale where the curve is placed in Figure 5?

  5. James Sexton says:

    Ditto the thanks David…… I had no idea there were so many examples of the ratio change…. minus human influence. More stuff well within natural variability. I’ve always argued that the isotope doesn’t matter. I think we assume we know more than what we really know.

    The Yucatan graph is a bit off if anyone is trying to argue the isotope ratio, at least for that place, is indicative of warming or cooling. And, it is problematic. Not only is the vertical divergence off, so is the frequency.

    Just from experience, looking at the graph, I’d say a methodology of some sort, or sampling size changed for gathering information prior to about 1200-1400 as opposed to after. It doesn’t invalidate much of anything…. other than going back beyond 1200.

    For those that can’t see, what I’m on about, the intersession between the RWP and MWP is missing, but if you look, @ about 1200-1400….. the graph changes its characteristics.

    I hate graphs that look like that…..

  6. R Taylor says:

    To worry about the origin of CO2 is to imply that present (or forecast) concentrations are a cause for concern. Elevated CO2 is an issue only for those who insist on misinterpreting temperature-CO2 cause-and-effect, and those who hate food.

  7. michael hart says:

    This is something I’ve been considering spending more time on. But if I start, I may never finish. ‘Cold’ isotope-labels are frequently used as probes and internal standards in Chemistry, but the number of processes that can cause isotope fractionation is more than you can shake a stick at.
    Deuterated hydrocarbons can be separated by liquid chromatography. For many enzymes/biological-catalysts I would expect fluctuating isotope effects to be the norm, not the exception. It’s a minefield.

  8. Hoser says:

    It’s pretty annoying there is no actual calendar year 0; we jump to 1 BC, skipping 0.

    Get out of the weeds. What is the point of criticizing the Yucatan v Flinders chart? It’s not published peer reviewed work. It’s an interesting comparison just to get people thinking. Isn’t it interesting the curves can be placed on top of each other relatively easily? What the overlay really means, if anything, hasn’t been determined. It serves to help people view the red curve in a larger context. The overlay makes the point the red curve doesn’t necessarily indicate the δ13C decline is due to human influence. Isn’t that the point of the story?

  9. I think the isotope ratio is interesting and worth thinking about. It does possibly reflect human origin, and should be taken seriously as an argument. However . . .

    We do not know enough about total CO2 sources and sinks to determine whether the increase in overall CO2 *would not have happened* but for human fossil fuel use. Further we do know that CO2 has risen at a remarkably steady pace in recent decades, despite ups and downs in fossil fuel use. Both of these facts should give us pause.

    Finally, many argue that the amount of human emissions is greater than the total increase and, therefore, humans are responsible for the increase (meaning, the biosphere is able to handle part of the human emissions, but not all). However, even if the isotope ratio changes (more CO2-12), consider this analogy:

    I run a small business on a cash basis. At the beginning of the year I have $1000, 3 of which are marked with a red dot. Throughout the course of the year I exchange thousands of dollars with many vendors and customers, including occasional transactions with one tiny customer who marks red dots on all his bills. At the end of the year, after thousands of transactions of cash flowing in and out, I count my cash, and it turns out I have $1001, 4 of which are marked with a red dot. According to AGW advocates, the tiny customer who pays only with bills marked with a red dot (i) *must* be the sole source of my $1 profit, and (ii) but for that tiny customer, I would not have made my $1 in profit. It should be easy to see that this is not a valid conclusion. The conclusion is even more shaky if David Middleton’s post is correct, because then we would have to say that there might even be another customer (we’re not quite sure) who sometimes also pays with bills marked with a red dot.

  10. R. Shearer says:

    Finger prints may be on the gun, but the alleged murder victim is happily moving about as if nothing has happened.

  11. Steve R says:

    It seems obvious that the Seuss effect is not just an anthropogenic fingerprint; instead it is the fingerprint of Life. Most plants and virtually all animals consist almost entirely of C12 and are depleted of C13 and C14. Hence when the global biomass increases, the proportion of total atmospheric carbon that is C12 increases, and the proportion that is C14 declines accordingly. The Seuss effect provides conclusive proof that a warm Earth enables life to thrive.

  12. chuck in st paul says:

    I get so worn out reading BS from the Gaia worshippers and rent seekers on the subject of CAGW. This article is just one more reason to be skeptical of the ‘man made’ part. I know we do have some effects such as Urban Heat Island Effect (UHIE) and I am sure our contribution to the Satanic Gases must have some effect, but I am skeptical that it rises above signal to noise ratio of the data itself.

  13. Gail Combs says:

    Since Coal is from dead plants so that is not the origin, I was wonder where the C-13 actually came from and ran into this little gem…

    Many thanks to Geophysical Institute, University of Alaska Fairbanks for permission to use the following extract…

    … The very rare carbon 14 is another matter, though, because it is radioactive. By losing an electron, every atom of C-14 eventually will decay into an atom of N-14; that is, it will turn into ordinary nitrogen….

    1998 by Macquarie University
    http://dwb4.unl.edu/Chem/CHEM869Z/CHEM869ZLinks/www.all.mq.edu.au/online/edu/egypt/carbdate.htm

    That mess brings to mind this article:

    …..“Publishers now employ more people to censor books for content that might offend any organized lobbying group, than they do to check the correctness of facts.” Unchecked errors spread: in 1999 the Boston Globe reported, “Some educators have traced the transmission of errors from one textbook to another and compare the process to the spread of a virus through a population.”

    An exasperated William Bennetta explained why so many teachers accept inferior textbooks from these publishers, “[T]he major schoolbook companies… have long recognized that the teacher corps in America includes some desperate dumbbells, and the companies have learned to produce books that the dumbbells will like.” Alistair B. Fraser…, concluded bleakly, “Apparently, most teachers believe everything they teach.” … Cornell professor Donald Hayes, …. reported on results of sampling 788 textbooks used between 1860 and 1992: “Honors high school texts are no more difficult than an eighth grade reader was before World War II.” (And in an essay written over half a century ago Randall Jarrell complained that 1930′s textbooks were much easier than the ones from the 19th century!) So by now our teachers, and their teachers, and their teachers, have been dragged through the same swamp of bad textbooks. They know not what they do, and they know not that they know not….

    No wonder CAGW has spread so easily.

  14. Peder Larsen says:

    Gail combs quotes that bit about “every C-14 atom losing an electron” and seems to suggest it’s not correct. She’s right that it makes the naive reader think the atom is losing a shell electron, but of course what is actually going on is nuclear decay, as a neutron becomes a proton by beta decay, emitting an electron and an electron anti-neutrino. Textbooks have a lot of sins for which they should answer, such as watering down the facts to make them” easier.”

  15. SteveSadlov says:

    I am gravely concerned that the concentration of CO2 is below 500ppm. To me, this means we are in a highly vulnerable state. This concentration (or lack of) has been fine during this fairly benign period of Geological History we’ve been in now since the commencement of the Quaternary. We have not had any really major disturbances other than the general dominance of high latitude Continental Glaciation for much of the Q. But no really big extraterrestrial strikes, no widespread volcanic catastrophes, etc. Not if but when the next one of these happens, if we are still below 500ppm I worry that photosynthesis will behave as if the level were far lower (e.g. due to the impacts of the disturbance). From there, a mass die off of photosynthesis based life could occur.

  16. gymnosperm says:

    I personally believe that the isotopic signature in the current atmosphere is probobably anthropogenic. But you have hit on one of the most important mysteries in earth science: the PETM isotopic “excursion”. It has been asserted that the PETM was caused by fossil fuel burning as rifting in the north Atlantic separated Greenlandfrom Europe, but the timing really doesn’t work and current rifting through Africa and the Red Sea does not seem to be producing clouds of smoke from the ample petroleum in the region.

    I once suggested tounge-in- cheek on Sks that a burst of cosmic rays converted nitrogen to C14, but this would not explain the C13, would it?

  17. Julian Flood says:

    The increase in light isotope C must be caused by fossil fuel burning because we can’t think of any other reason.

    Except that warming seas become more stratified and starve the calcareous phytoplankton which usually preferentially fix light C and export it to the deep ocean. So, fewer phytos, less light C pull down, more 12C in the atmosphere.

    Oh, yes, we’ve disrupted vegetation cover causing a lot of dust. Dissolved silica runs into the oceans where it feeds diatoms which are the little beasties that get first helpings of nutrients until the silica runs out. Diatoms are not as discriminatory against 13C as the calcareous phytos, so they export proportionately less 12C, signal in atmosphere goes up.

    Oh, and of course there’s the fact that oil and surfactant polluted seas warm faster, stratify more, starving the phytos. And waves break less, less CO2 is driven into the ocean which means that phytos are CO2 starved. Some change their metabolism to C4 ( a better way of fixing carbon in times of C famine), C4 phytos outcompete C3 types and, as any fule know, C4 metabolism is less discriminatory against 13C which means proportionately more heavy C is exported to the deep ocean.

    And oil polluted seas engage less with the wind,: this reduces currents, pulling up less nutrient-rich water from below. So this starves the phytos which export less light C.

    But it must be us burning fossil fuel, because we can’t think of anything else it can be.

    Unless the introduction of European earth worms has altered the silica run-off from those areas where they have been introduced to improve agriculture.

    Or something else is happening we haven’t noticed yet.

    But it must be us.

    The graph used on Sceptical Science should be compared with others: far be it from me to suggest that Mr Cook would use sharp practice in his articles, but other depictions show that the ‘anthropogenic’ 12C signal begins in about 1700AD. Which is odd as even the intelligent men in Ironbridge hadn’t yet started destroying Gaia at that date. But it must be us. We can’t think of anything else. [puts fngers in ears] I’m not listening.

    JF
    PETM: sea erosion breaches a major oil reservoir. Kriegesmarine Effect happens. Big temperature rise. Would such a small event have such a large effect? Well, we are dumping enough light oil down our rivers every fortnight to cover the entire ocean surface and that’s giving us about .2 deg C/decade. During WWII the spilled oil was enough to drive the temperature up by .3 deg C in a few months. I think. All wwe need to do is clean up our act and watch what happens. I bet on cooling.

  18. Bart says:

    There is also the question of diffusion, i.e., how long it takes for the C12 rich gas input to disperse throughout the system. This topic was discussed on a recent thread.

    An analogy is as follows. Suppose you have a bucket of water with an incoming flow at the top, and an equal outgoing flow from a hole at the bottom. To the incoming flow, you add about 3% more of blue dyed water. A new equilibrium will be established when the height of the water in the bucket increases 3%. But, before the dye has thoroughly diffused, the water will be bluer at the top than it is at the bottom.

    Now, pump in an additional clear water flow near the bottom from an unknown source at a rate which continually increases the level in the bucket over the observation time interval. Where does the blue water now aggregate?

  19. MrD says:

    Can anyone please explain to me why the measured increase in atmospheric CO2 is almost linear; yet the worlds population increase & usage of CO2 generating fuels would more likely be exponential during the 20th C?
    Something is not right!

  20. clivebest says:

    The SUESS effect was first noticed to correct carbon dating before the 1950s when bomb testing first started. C14 is naturally produced by cosmic rays in the upper atmosphere and about 10kg are produced each year this way. After the industrial revolution the concentration of C14 began to get diluted slightly as fossil fuels were burned. This is because fossil fuels essentially contain no C14. The effect was first noticed by Suess who introduced a correction for carbon dating. A recent study from 2002[6] has measured that the effect up until 1950 was to decrease C14 concentrations by 2.4+- 0.35%. By 1950 CO2 levels had risen above pre-industrial values by about 12%. This also provides evidence that just 20% of the increase in CO2 levels by 1950 was due to fossil fuels.

    Both these results imply that a maximum of just one quarter of the increase in CO2 concentrations since 1750 are of fossil fuel origin. This means that at least 75% of the observed increase in CO2 is of natural origin. Perhaps a further 15% of this could also be due to human causes – land change, deforestation but it is hard to avoid the conclusion that the majority of it is natural. How can this be ? Have we disrupted the overall carbon cycle such that each year there is a surplus in the recycling of natural CO2 ? Or is this 60% effect due to natural warming which would have occurred anyway ? It seems to me that there could be an error in the estimates that the IPCC use for the lifetime(s) of CO2 in the atmosphere?

    The lifetime of a given sample of CO2 molecules is the time needed for 1/e of the CO2 molecules to leave the atmosphere. An unintended experiment was carried out in the 1960s due to nuclear testing which released large amounts of radioactive C14 into the atmosphere. C14 measurements show how this pulse of CO2 decayed with time and derive a lifetime value. The evidence from the delta C13 measurements, and the Seuss effect would support a lifetime of about 7 years. The direct C14 measurements give a value around 10 -14 years. In both cases the fraction of CO2 molecules in the atmosphere for current emission levels reaches a limit of < 10% of today’s atmosphere. It is only by assuming much higher lifetimes of over 100 years that the IPCC predictions are possible.

    So the whole AGW model depends on a long lifetime for CO2. The IPCC carbon model (WG1) is described on page 213 of WG1 states :

    The CO2 response function used in this report is based on the revised version of the Bern Carbon cycle model used in Chapter 10 of this report (Bern2.5CC; Joos et al. 2001 [1] ) using a background CO2 concentration value of 378 ppm. The decay of a pulse of CO2 with time t is given by:

    a0 + sum(i=1,3)(ai.exp(-t/Taui)) , Where a0 = 0.217, a1 = 0.259, a2 = 0.338, a3 = 0.186, Tau1 = 172.9 years, Tau2 = 18.51 years, and Tau3 = 1.186 years.

    If you look carefully at this formula you will see that it is made up of 3 independent CO2 lifetimes each with different amplitudes, plus a constant term implying that 22% of anthroprogenic CO2 will remain in the atmosphere for ever!

    One objection I have to the form of this model is the concept of using 3 different lifetimes purely from a logical viewpoint, as it kind of assumes that there are 3 different types of CO2 molecule in different queues waiting to leave the atmosphere. I suspect that the model in this form also violates the second law of thermodynamics, since whether there are 3 holes in a bucket of water or just 1 large hole is irrelevant to the rate at which the water leaks out of the bucket !

  21. clivebest says:

    The SUESS effect was first noticed to correct carbon dating before the 1950s when bomb testing first started. C14 is naturally produced by cosmic rays in the upper atmosphere and about 10kg are produced each year this way. After the industrial revolution the concentration of C14 began to get diluted slightly as fossil fuels were burned. This is because fossil fuels essentially contain no C14. The effect was first noticed by Suess who introduced a correction for carbon dating. A recent study from 2002 has measured that the effect up until 1950 was to decrease C14 concentrations by 2.4+- 0.35%. By 1950 CO2 levels had risen above pre-industrial values by about 12%. This also provides evidence that just 20% of the increase in CO2 levels by 1950 was due to fossil fuels.

    Both these results imply that a maximum of just one quarter of the increase in CO2 concentrations since 1750 are of fossil fuel origin. This means that at least 75% of the observed increase in CO2 is of natural origin. Perhaps a further 15% of this could also be due to human causes – land change, deforestation but it is hard to avoid the conclusion that the majority of it is natural. How can this be ? Have we disrupted the overall carbon cycle such that each year there is a surplus in the recycling of natural CO2 ? Or is this 60% effect due to natural warming which would have occurred anyway ? It seems to me that there could be an error in the estimates that the IPCC use for the lifetime(s) of CO2 in the atmosphere?

    The lifetime of a given sample of CO2 molecules is the time needed for 1/e of the CO2 molecules to leave the atmosphere. An unintended experiment was carried out in the 1960s due to nuclear testing which released large amounts of radioactive C14 into the atmosphere. C14 measurements show how this pulse of CO2 decayed with time and derive a lifetime value. The evidence from the delta C13 measurements, and the Seuss effect would support a lifetime of about 7 years. The direct C14 measurements give a value around 10 -14 years. In both cases the fraction of CO2 molecules in the atmosphere for current emission levels reaches a limit of < 10% of today’s atmosphere. It is only by assuming much higher lifetimes of over 100 years that the IPCC predictions are possible.

    So the whole AGW model depends on a long lifetime for CO2. The IPCC carbon model (WG1) is described on page 213 of WG1 and states :

    The CO2 response function used in this report is based on the revised version of the Bern Carbon cycle model used in Chapter 10 of this report (Bern2.5CC; Joos et al. 2001 [1] ) using a background CO2 concentration value of 378 ppm. The decay of a pulse of CO2 with time t is given by:

    a0 + sum(i=1,3)(ai.exp(-t/Taui)) , Where a0 = 0.217, a1 = 0.259, a2 = 0.338, a3 = 0.186, Tau1 = 172.9 years, Tau2 = 18.51 years, and Tau3 = 1.186 years.

    If you look carefully at this formula you will see that it is made up of 3 independent CO2 lifetimes each with different amplitudes, plus a constant term implying that 22% of anthropogenic CO2 will remain in the atmosphere for ever!

    One objection I have to the form of this model is the concept of using 3 different lifetimes purely from a logical viewpoint, as it kind of assumes that there are 3 different types of CO2 molecule in different queues waiting to leave the atmosphere. I suspect that the model in this form also violates the second law of thermodynamics, since whether there are 3 holes in a bucket of water or just 1 large hole is irrelevant to the rate at which the water leaks out of the bucket !

  22. Dixon says:

    I heard about ‘fingerprinting’ CO2 emissions from burning coal based on carbon isotope ratios, down to particular production regions about 10 years ago, but it didn’t strike me as being convincing (I probably didn’t understand the science!). But as I recall anything to do with carbon isotopes always needs a fair pinch of salt, it’s one of those ‘great in theory, but damn hard in practice’ things. Can one of the regular commentators provide an overview primer of carbon isotopes as a post? As a commentator on this thread has already pointed out, living organisms are good at altering isotope ratios. As another pointed out, anthropogenic sources for CO2 might be plausible, but have the other mechanisms been ruled out, or is this just another Climate Science mantra reinforced by repetition rather than hard science?
    Has anyone sampled the isotope ratio in carbon being emitted from black smokers?
    Interesting comment about spilled oil, I need to think that through…

  23. Julian Flood says:

    Dixon wrote

    ‘spilled oil. I need to think that through.’

    Search for the Ceres picture of the world, zoom in on the Mississippi overflow into the Gulf.
    Find the earlier pictures of the Gulf oil spill and see the way the air above the slick is eating stratocumulus clouds at the edges.

    Thinking is good! Wigley should have done it, then he would not have needed to ask ‘why the blip’.

    JF

  24. FerdiEgb says:

    [You seem to be quick to think that your contributions are not being dealt with quickly enough . . they fall into the spam bin along with hundreds of other spam postings and it takes time to sift through the pile to release valid responses. . . reposting is pointless as are attempts to spur moderators to attend to your concerns . . everything is dealt with seriatim, you will be heard . . kbmod]

    Well, it seems that this is one of the discussions which will return to WUWT every (few) month(s)…
    One need to make a differentiation between direct measurements of the C13/C12 ratio and different proxies which have some relation with that ratio, but where confounding factors may be at work. That is especially the case for organic materials, influenced by a host of factors, like available light, nutritients even the CO2 concentration itself and also for inorganics made by organisms in shallow waters where pH, local concentration and depletion may play a role in de d13C ratio.

    Ice cores give direct measurements of the C13/C12 ratio of CO2 in trapped air. These were measured by cold crushing the ice, cryogenic freezing, distillation of CO2 and measuring with a mass spectrometer.

    The d13C level in the atmosphere over the Holocene can be followed in the Taylor Dome ice core:
    http://medias.obs-mip.fr/paleo/taylor/indermuehle99nat.pdf
    The average variability is +/- 0.15 per mil over the Holocene, up to 1,000 years ago.
    The next ice cores one can use are the Law Dome ice cores. The combination of ice cores, firn and direct measurements allows us to reconstruct the full Holocene d13C changes up to today with increasing better resolution:
    http://www.mendeley.com/research/stable-isotope-constraints-on-holocene-carbon-cycle-changes-from-an-antarctic-ice-core-1/
    This can be compared to a proxy that is living in shallow and deeper waters (down to 200 m) where coastal influences are minimal: coralline sponges. The calcite deposit is isotopic identical to the surrounding seawater, which in the Carribean is rather fast refreshed and largely similar over the whole North Atlantic Gyre. The resolution of the calcite d13C ratio is 2-4 years over the past 600 years:
    http://www.agu.org/pubs/crossref/2002/2001GC000264.shtml the full article is pay walled, but the most important graph, combining ice cores, firn and air d13C measurements with ocean surface measurements is here:
    http://www.ferdinand-engelbeen.be/klimaat/klim_img/sponges.gif

    This shows some small pre-industrial variability of +/- 0.15 per mil d13C. Since about 1850, there is a faster and faster continuous drop of d13C of nowadays already -1.6 per mil d13C. There is no knowledge of non-human reasons like burning down about 1/3rd of all land vegetation or a similar natural disaster involving gas, oil or coal burning, And human releases fit the equation more than necessary to explain the downward trend…

    Thus all together, the ice cores show conclusively the influence of human activities on the d13C ratio of the atmosphere. Proxies in the oceans need to be used with caution, as the influence of temperature on the d13C ratio must be separated from the influence of the addition of fossil fuel burning. As the first influence on coralline sponges is rather limited (+/- 0.15 per mil d13C over 350 years) and there is a direct correlation (with lag) between the measured d13C change in the atmosphere and in the sponges for recent years, the sponges show that humans are responsible for the d13C changes in the ocean’s surface layer.

  25. FerdiEgb says:

    clivebest says:
    March 29, 2012 at 2:00 am

    A recent study from 2002 has measured that the effect up until 1950 was to decrease C14 concentrations by 2.4+- 0.35%. By 1950 CO2 levels had risen above pre-industrial values by about 12%. This also provides evidence that just 20% of the increase in CO2 levels by 1950 was due to fossil fuels.

    The common problem with this is that one need to make a distinction between the origin of the CO2 molecules which are in the atmosphere and the origin of the increase in total amount of CO2 in the atmosphere. Look at the example that Bart showed: we add a some blue colored water to a bucket where clear water is added to the top and leakes away at the bottom and is recirculated via a huge tank with near unlimited capacity. The water in the bucket wil be colored somewhat by the blue addition (which shows the origin), how much, that entirely depends of the ratio between colored and clear water addition. But the addition of blue water also increases the height of the waterlevel in the bucket. That is INdependent of the original flow in- and out. The original height of course depends of the initial flow, but the increase in height only depends of the additional flow.

    So what is important in this case? What rests in the atmosphere of original human emissions (the blue coloured ones…) is not important at all, only the total increase (the increase in height) is important. The bomb 14C decline ratio only shows how fast the atmosphere is exchanging CO2 with other reservoirs (about 20% per year or a residence time of ~5 years), but that doesn’t say anything about how fast an excess amount of CO2 in total is removed (that is 4 GtC/year of the total 800 GtC in the atmosphere, or a 1/e decay time of ~55 years). Two completely different time constants without any relationship. Here a graph which shows (based on realistic figures) the difference between what happens with the total amount of CO2 in the atmosphere if humans should add 200 GtC from fossil fuel at once to the pre-industrial atmosphere and what happens to the human “fingerprint”:
    http://www.ferdinand-engelbeen.be/klimaat/klim_img/fract_level_pulse.jpg where FA is the fraction of “human” CO2 in air, FL the fraction in the ocean surface (not important here), tCA total carbon in air and nCA natural carbon in air.
    The human fingerprint is gone after some 50 years, but the effect of the one-time addition on the total amount still is measurable after 160 years…

    While I don’t agree with the Bern model, what they do is comparing the decay time between the atmosphere and different compartiments: the fastest is for the ocean’s surface, but that has a limited capacity (~10% of the increase), the medium term for the deep oceans and vegetation and the lowest for long-term processes like rock weathering, carbonate sedimentation,… My objection is that there is currently no limit in sight for the deep ocean and vegetation uptake, thus the slowest and residual terms are highly questionable.

  26. FerdiEgb says:

    climatereflections says:
    March 28, 2012 at 5:16 pm

    I run a small business on a cash basis.

    Good analogy, except that in this case you know from the “red dot” customer that he added 2 dollars per year to your bussiness. A simple calculation learns you dat without that customer, you would have had a net loss of 1 dollar per year. The number of red dot bills still left in your cash register is not important, the in-out of total bills and specific red dot bills is what is important.

    The same for the CO2 levels: we add about 8 GtC/year (based on fuel inventories -taxes- and fuel burning efficiencies) and we measure an increase of about 4 GtC/year. Thus nature as a whole is a net sink for atmospheric CO2, regardless of how much is exchanged with other compartiments during that year.

  27. Carbon dating is over-rated and based on simplistic assumptions. First that all atmosheric C-14 is from N-14 decay and that this decay rate is constant based on non-constant solar/cosmic rays. The non-constant production rate becomes a greater problem over time, causing an increased proxy error. Carbon dating is based on the assumption that C-13/14 ratios are set by metabolism with atmospheric Carbon and then begin a fixed decay rate upon the death of the organism. Biologists in the sixties divided life into “Bacteria” and “Eukaruota”, only to further divide the single celled life forms into “Bacteria” and “Archaea” a decade later. This was based on RNA and metabolism differences of lifeforms in the worlds most extreme environments. Living in the intestional tracts of termites and cattle, thriving at high-temperature, high-pressure thermal vents, these “new” life-forms are abundant in the Antarctic and feed on “elemental” CO2 and CH4 flowing from under-sea vents. These “natural” Carbon sources have reduced C-14 and therefore, the marine animals that are fed further up the food chain have reduced C-14 ratios as well. Fresh killed seals and penquins have a “Carbon dated age” of over 3,000 years old. The “elemental” production of Carbon is NOT constant, and is UNKNOWN, introducing further errors.

    See “Amazing ! New ! Wrongco’s Proxy Crock !” for more of the ridiculous proxy madness.

  28. FerdiEgb says:

    MrD says:
    March 28, 2012 at 11:50 pm

    Can anyone please explain to me why the measured increase in atmospheric CO2 is almost linear; yet the worlds population increase & usage of CO2 generating fuels would more likely be exponential during the 20th C?

    The increase of CO2 in the atmosphere is slightly exponential, hardly visible as it is a fraction of the accumulated human emissions, which increase rather linearly over time. Here an oversight:
    http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_emiss_increase.jpg

  29. FerdiEgb says:

    Julian Flood says:
    March 28, 2012 at 10:30 pm

    It is simple to show that the ocean temperature increase is not the cause of the CO2 increase or d13C decline: the temperature influence on CO2 pressure in seawater is too small (16 microatm/degr.C) and seawater CO2 has a too high d13C level (0-1 per mil for deep ocean waters, 1-4 per mil for ocean surface waters, the atmosphere is at -8 per mil). Thus any substantial release of CO2 from the oceans would increase the d13C level of the atmosphere while we observe a fast decline.

    It is impossible to make a differentiation between the use of fossil fuels and of burning/decayling vegetation. But there is an alternative: we know with reasonable accuracy how much oxygen our fossil fuel burning uses. We know with some accuracy since 1990 how much oxygen is removed from the atmosphere. The difference is what the total biosphere is using or producing. It shows that the total biosphere (land and sea plants, animals and insects) is producing more oxygen that it uses. Thus the total biosphere is a net source of oxygen, thus a net sink for CO2 and preferably 12CO2. Thus leaving relatively more 13CO2 in the atmosphere and not the cause of the decline in d13C.

    As oceans and biosphere are the only main huge sources and sinks, there is little doubt left that humans are entirely responsible for the d13C decline (and the CO2 increase). Other sources are too high in d13C (volcanoes, carbonate rock weathering) and too small in emissions. The difference in methabolism between C4 and C3 plants plays no role here, as both have d13C levels below atmospheric, thus both increase the d13C level when there is more growth than decay. And the earth is greening…

  30. FerdiEgb says:

    Mods, some large comment of mine disappeared in cyberspace… Thanks!

  31. Werner Brozek says:

    MrD says:
    March 28, 2012 at 11:50 pm
    Something is not right!

    Exactly how linear and how exponential are we talking about? See the graph below. Would you happen to have a graph that shows the use of fuels is more exponential?

    http://www.woodfortrees.org/plot/esrl-co2/from:1958/plot/esrl-co2/from:1958/trend

  32. BioBob says:

    FerdiEgb says: “It is simple to show…”

    PLEASE. You make me cringe when I see such statements. You make it sound like humans have precise, extensive and comprehensive data and knowledge about biotic and geochemical process when, in fact, we have very little.

    Can you give me accurate numbers for “delta” biotic, soils, & bedrock carbon mobilization resulting from the acidification of precipitation for the past 50 to 100 years over extensive portions of continents ? No.

    Can you tell me the decadal variability of carbon mobilization from crustal movement, subduction, etc. No.

    Can you tell me anything with known quantitative accuracy about the historical and / or spatial variability of geochemical processes ? No.
    Can you tell me anything with known quantitative accuracy about the historical and / or spatial variability of biotic-chemical processes ? No

    Restrain yourself to reality, please. We know just enough to begin interesting research which will decrease our ignorance about the issue.

  33. FerdiEgb says: “A simple calculation learns you dat without that customer, you would have had a net loss of 1 dollar per year.”

    No. It is true that at some level we could argue that I wouldn’t have gained the extra dollar if I didn’t have that customer. But you are ignoring all the other customers who paid in much greater sums. It doesn’t make any sense to say that the guy who paid me an extra $100 wasn’t responsible for the increase, while the guy who paid me an extra $1 is responsible for the whole increase. Especially if there would have been an offsetting purchase from another customer if my $1 customer didn’t his $1 worth of my goods.

    *Even if* humans were the only possible source of CO2-12, which is very doubtful, to conclude that humans are causing the general increase in CO2 requires two massive unproven assumptions: (i) we know what all the other sources and sinks are and what their amounts are, and (ii) we know how all the sources and sinks interact with each other with enough precision to be able to calculate how they interact with humans’ minor contribution.

  34. clivebest says:

    FerdiEgb says: While I don’t agree with the Bern model, what they do is comparing the decay time between the atmosphere and different compartiments: the fastest is for the ocean’s surface, but that has a limited capacity (~10% of the increase), the medium term for the deep oceans and vegetation and the lowest for long-term processes like rock weathering, carbonate sedimentation,… My objection is that there is currently no limit in sight for the deep ocean and vegetation uptake, thus the slowest and residual terms are highly questionable.

    I understand and agree with your point about the incremental increase to atmospheric CO2. However the problem I have with the BERN model is their constant – a0 term. This says that the response to a pulse of 1 unit of CO2 added to the atmosphere are 3 independent exponential decays PLUS a constant term a0 = 0.21. This would imply that 20% of man made CO2 will remain forever in the atmosphere! This cannot be correct since we know that 50 million years ago CO2 levels were several times greater than today.

    So let’s instead take a simple model with a single (average) lifetime – Tau. We represent all human CO2 emissions as being one annual pulse per year added to an unperturbed atmosphere before the industrial revolution balanced at 750 Gtons of CO2. Then once a year a pulse of N0 = 5.5 Gtons of CO2 is added to the atmosphere due to human fossil fuel emissions. Each pulse then decays away with a lifetime Tau. Emissions at this level by man are assumed to continue forever. Then the accumulation of total CO2 in the atmosphere for year n is simply given by.

    CO2( n) = N0( 1 +sum(i=1,n-1) (exp(-n/Tau)))

    If we assume that n is very large then we can treat this sum as an infinite series and the atmosphere will eventually saturate at a certain percentage of anthropogenic CO2 concentration.

    Multiplying both sides by exp(1/Tau) we can derive that the sum in the limit as n-> infinity is

    CO2(n) = N0/(1-1/exp(1/Tau))

    Taking some possible values for Tau we can calculate converged CO2 levels:
    Tau Fossil Limit (Gtons) Fraction of 750 Gtons

    5 30.3 4.0%
    7 41.3 5.5%
    10 57.8 7.75%
    14 74.3 10%
    50 272.3 36%
    100 547.2 73%
    200 1103 147%

    In other words if mankind simply continued burning fossil fuels for ever at current rates – then the atmosphere would eventually stabilize at about double pre-industrial CO2 levels. So this on its own would lead to a ~ 1 degree rise in temperatures, ignoring climate feedbacks.

  35. Bart says:

    clivebest says:
    March 29, 2012 at 1:57 am

    “If you look carefully at this formula you will see that it is made up of 3 independent CO2 lifetimes each with different amplitudes, plus a constant term implying that 22% of anthropogenic CO2 will remain in the atmosphere for ever!”

    The idea here is to model a “fat tail” response with a sum of exponentials. Presumably, the constant term models an exponential which has a time constant much longer than any interval of interest.

    I’m not saying it is an accurate equation, just helping understand the theoretical basis.

    FerdiEgb says:
    March 29, 2012 at 7:27 am

    “Ice cores give direct measurements of the C13/C12 ratio of CO2 in trapped air. These were measured by cold crushing the ice, cryogenic freezing, distillation of CO2 and measuring with a mass spectrometer.”

    And, there is no reference, no “control” experiment possible to verify that the measurements of ancient CO2 are valid. We do not really know how the trapped gases diffuse through the ice over eons of time. We have only a model.

    FerdiEgb says:
    March 29, 2012 at 8:10 am

    “…we add a some blue colored water to a bucket where clear water is added to the top and leaks away at the bottom and is recirculated via a huge tank with near unlimited capacity.”

    It isn’t all recirculated. A goodly part is sequestered more or less permanently. The relevant question is, how fast is the rate of semi-permanent sequestration? I have seen no evidence which convinces me that anyone has a good handle on that rate.

  36. FerdiEgb says:

    clivebest says:
    March 29, 2012 at 11:04 am

    The a0 term is explained by the IPCC as extremely slow geological processes which remove CO2 from the atmosphere. That may be important if all other processes are exhausted, but the problem is in the a2 term: they limit the capacity of the deep oceans (and vegetation) to 34% of the emissions, while there is no reason for that. The deep oceans are far from saturated in CO2, thus can dissolve a lot more CO2. As the deep ocean carbon content is ~37,000 GtC all the CO2 emitted by humans since the start of the industrial revolution (~370 GtC) indiuced an increase of some 1% in the deep oceans, if that was the only sink. After some 800 years of mixing, that would return to the atmosphere and ultimately increase the atmospheric CO2 content with 1%, more or less permanently, awaiting the action of the slower removal processes. Only if we burned all available oil and a lot of gas and coal (3,000-5,000 GtC), that would significantly increase the atmosphereic CO2 content with a substantial amount over a long period of time.

    Your calculation is right if you have a constant addition of CO2 by humans, but the human emissions are quite linearly increasing, leading to a slightly exponential increase in the atmosphere with an incredible lineair ratio to the accumulated emissions:
    http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2_1900_2004.jpg
    As long as the year by year emissions increase, I don’t think that there will be a limit to atmospheric CO2 levels…

  37. FerdiEgb says:

    climatereflections says:
    March 29, 2012 at 10:58 am

    (i) we know what all the other sources and sinks are and what their amounts are, and (ii) we know how all the sources and sinks interact with each other with enough precision to be able to calculate how they interact with humans’ minor contribution.

    We only know to a certain extent what the individual sinks and sources are and their variability. And we have little idea what the interactions are. But that is not important at all: we know quite exactly the result at the end of the year. Not only in gain or loss, but also the variability in gain or loss over the past 50+ years. Even if all or some of the input flows doubled or halved, that is near fully compensated by a similar increase or decrease of the output flows. See:
    http://www.ferdinand-engelbeen.be/klimaat/klim_img/dco2_em.jpg

    The average increase in the atmosphere is around 50% of the emissions, the variability of the increase is also about 50% around the trend. That is mainly a result in sink capacity changes due to temperature variability. But in all years nature as a whole was a net absorber of CO2, not a source. In this case, human emissions are the single non-natural source of CO2 (and hardly a sink). Thus one must compare the non-natural source to the combination of natural sources and sinks, no matter what the individual natural sources and sinks did or how they changed.

    Even if you don’t do any bookkeeping at all during the day, and only know that you have added some 2 dollars of your own money at the beginning of the day to your cash register, you know that your bussiness is not going well if you find only 1 dollar extra in cash at the end of the day… And if that remains so for 50+ consecutive days, better look for another job…

  38. George E. Smith says:

    “”””” Gail Combs says:

    March 28, 2012 at 7:40 pm

    Since Coal is from dead plants so that is not the origin, I was wonder where the C-13 actually came from and ran into this little gem…

    Many thanks to Geophysical Institute, University of Alaska Fairbanks for permission to use the following extract…

    … The very rare carbon 14 is another matter, though, because it is radioactive. By losing an electron, every atom of C-14 eventually will decay into an atom of N-14; that is, it will turn into ordinary nitrogen….

    1998 by Macquarie University
    http://dwb4.unl.edu/Chem/CHEM869Z/CHEM869ZLinks/www.all.mq.edu.au/online/edu/egypt/carbdate.htm

    That mess brings to mind this article:

    …..“Publishers now employ more people to censor books for content that might offend any organized lobbying group, than they do to check the correctness of facts.” Unchecked errors spread: in 1999 the Boston Globe reported, “Some educators have traced the transmission of errors from one textbook to another and compare the process to the spread of a virus through a population.” “””””

    Well Gail, how right you are; and the BGs 1999 report.
    I just got back from two weeks in New Zealand; during which I visited the University of Auckland Physics Department, where I had meetings with three different Profs, including Prof Roger Davies, who authored the recent “Sky is falling” (clouds anyway!). So we had a good chat on that, and I got an unexpurgated copy of the paper.
    Friend Myrrh will be horrified to learn that Prof Davies told me bluntly, that “there is no such thing as “heat” “. He might very well have added “or “light” either. Both are simply human psycho-physical responses to different parts of the electro-magnetic radiation energy spectrum. He jumped at my suggestion that “heat” is a verb; not a noun; he even liked that. He’s a Prof in the Environental Science section of the Physics Departmentwhich is not part of the Political Science department.

    Prof Davies introduced me to Assoc. Prof Phil Yock, who is a particle Physicist and Astro-Physics also. Prof Yock was the Mentor of Dr Charles Alcock, who is now the Director of the Harvard Smithsonian Institute for Astrophysics, and presumably the boss of Dr Willie Wei Hock soon, and formerly Dr Sally Baliunas; who is now retired. I was there at the dinner, where Dr Alcock received a Distinguished Alumni Award from the Alum assn; they jokingly refer to them as the Iniversity Knighthoods.
    So I was introduced to Dr Alcock, and mentioned Willie and Sallie to him, and he smiled when I mentioned Willie Soon, and said, he doesn’t always agree with Willie.
    But back to Assoc. Prof Phil Yock, who called up my old Electronics instructor Prof Brian Earnshaw, now retired, and we had a beer and lunch together (with Yock).
    So I happened to mention that every elementary text on electricity or electronics, contains a completely incorrect statement of “Ohm’s Law”.

    Yock agreed, and then said; “we still teach it that way.”

    So what they teach as “Ohm’s Law” says :- E = I x R, or I = E / R, or R = E / I ,your choice.

    So then who made this discovery, and stated THIS law ?

    “For a certain class of materials; namely metallic conductors, when all other physical conditions are held constant, the current flowing in the circuit, is linearly proportional to the applied Voltage.”

    In other words; the ratio of the applied Voltage to the current flowing is a constant.

    So r (ratio) = E / I = R = constant.

    Well it actually WAS George Simon Ohm who made that discovery; so “Ohm’s Law” actually is:-

    R = Constant. E = I x R is merely the definition of R (resistance).

    And for most conductive materials, Ohm’s Law is NOT obeyed. Some folks say that incandescent lamps don’t obey Ohm’s Law; but they forget that little clause; “when all other physical conditions are held constant” ; and that includes the Temperature, which is nowhere near constant with an incandescent lamp, which actually DOES obey Ohm’s Law.
    Prof Yock was not apologetic, that they still teach students that E = I x R is Ohm’s law.

    How about I = Io.exp(qV/kT-1) which is the current relationship for LEDs (and other semiconductor diodes).

    So failure to teach the original research results of science; but revamping it in other words, often leads to quite eroneous conclusions, and teachings.

    Prof Davies introduced me to

  39. FerdiEgb says:

    Bart says:
    March 29, 2012 at 11:37 am

    And, there is no reference, no “control” experiment possible to verify that the measurements of ancient CO2 are valid. We do not really know how the trapped gases diffuse through the ice over eons of time. We have only a model.

    The gas diffusion through ice was (theoretically) calculated, based on the “warm” (-20 degr.C) Siple Dome ice core which shows some remelt layers. That gives a theoretical broadening of the resolution for middle depths from 20 to 22 years and for the near bottom part from 20 to 40 years. But even so, that doesn’t change the average levels over that broader period of time, only that faster variations than the resolution wouldn’t be observed.

    Even if that gives some fractionation of the isotope ratios, that would be seen in high fluctuations from sample to sample (if the sampling was over a too short time span). But the resolution gets better with increased accumulation rates, including a 20 years overlap with direct measurements at the South Pole for the period 1960-1980.

    For the colder (-40 degr.C) ice cores in central Antarctica, there is no sign at all for any migration over 800,000 years. If that was the case, the rather constant ratio between CO2 levels and temperature (proxy) would fade over time with each 100,000 years period back in time.

  40. FerdiEgb says:

    BioBob says:
    March 29, 2012 at 10:48 am

    I totally agree that we do know very little about a lot of processes which influence the carbon cycle on seasonal to geological scales. But there are fundamental points which can be explained in a quite simple way.

    We know that all oceans at all depths (except at the inflow of rivers) have a d13C level of ~0 to +5 per mil. We know that the atmosphere had an average of -6.4 to nowadays -8 per mil d13C. So whatever the exchanges were, it is quite certain (even including the fractionation at the sea-air border) that the oceans are NOT the source of the d13C decline in the atmosphere and thus NOT the cause of the CO2 increase. That is the only important point.

    There may be other increased natural sources with low d13C (seeping methane, burning coal seems,…), but as nature as a whole is a net sink for CO2 over the past 50+ years, that means that either other natural sources decreased at a similar rate or some sinks increased at a similar rate. Thus however natural sources and sinks individually behaved over the past 50 years, the sum of all them together was a net sink, all 50+ years.

    On the other hand, we know that if all human emissions remained in the atmosphere, the increase would have doubled and the d13C decline would have tripled, compared to what is measured. Thus not only is nature a net sink for CO2, but there is a natural exchange with higher d13C level CO2 (probably from the deep oceans) which replaced about 2/3rd of the human induced CO2 over time.

    The change in d13C ratio and oxygen use (and other human induced gases like CFC’s) can be used to track several CO2 flows into where they are going and at what rate (including diffusion rates in firn for ice cores and distribution of flows in the -deep- oceans). See e.g.:
    http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf

    So, indeed we know little, still have much to learn, but we do know several important things.

  41. clivebest says:

    Reply: FerdiEgb

    As long as the year by year emissions increase, I don’t think that there will be a limit to atmospheric CO2 levels…

    It is clear that emissions cannot increase forever. We have about 50-100 years of economic Oil and Coal left . Optimistically there are probably also another 50 years of natural gas. Therefore emissions are bound to stabilise and atmospheric CO2 will level off by the end of this century and then slowly decline. This will happen independently of green eco-politics and anti-growth hype. We have a choice whether to use the next 50 – 100 years to develop radical new energy sources or follow the eco-route back to low density living. Should we give up growth and return to a quasi-neolithic “green” society based on sustainable energy ( wind, wood burning, and the sun) which could at most support 1/10th of the current world population, or should we invest in nuclear fusion ? All renewable energy is way too low density( 2-3 watts/m2 ) to support urban life – so It is either nuclear or neolithic. Take your choice.

  42. FactChecker says:

    Does anyone know what happened to Murry Salby? Did he disappear down a black hole? I haven’t heard mention of that guy for a long time now… anyone knows what happened to him?

    http://wattsupwiththat.com/2011/08/05/the-emily-litella-moment-for-climate-science-and-co2/

  43. Bart says:

    FerdiEgb says:
    March 29, 2012 at 12:19 pm

    “The gas diffusion through ice was (theoretically) calculated, based on…”

    Repeating what I stated, albeit with flourishes and handstands, does not change what I said.

    “But that is not important at all: we know quite exactly the result at the end of the year.”

    Still flogging that dead horse, I see. I honestly had a little glimmer of hope we had gotten through to you last time.

  44. FerdiEgb says:

    Bart says:
    March 29, 2012 at 1:26 pm

    Repeating what I stated, albeit with flourishes and handstands, does not change what I said.

    See http://ns.geocraft.com/WVFossils/Reference_Docs/CO2_diffusion_in_polar_ice_2008.pdf
    The estimate of migration speed in the Siple Dome is based on direct measurements, not on a model. Still theoretical, as migration near remelt layers is not necessary the same as through “normal” ice layers. Anyway migration speed is very low and doesn’t change the averages in levels or d13C ratio. Only changes the resolution.

  45. Bart says:

    FerdiEgb says:
    March 29, 2012 at 2:57 pm

    “The estimate of migration speed in the Siple Dome is based on direct measurements, not on a model.”

    Not a chance. Nobody was around in the deep past to sample the air, record it, and have it available to compare to the derived measurement today.

    Nothing is completely reliable until it has been tested in the lab, and the theory compared to observation in a closed loop fashion. That is why all new commercial products are tested thoroughly before they go to market, and sample tested thereafter to ensure maintenance of performance. You never know for sure what will come out when the theory is tested against reality. A precise match between prediction and observation on the first test run is, by far, the exception rather than the rule.

  46. FerdiEgb: “we add about 8 GtC/year (based on fuel inventories -taxes- and fuel burning efficiencies) and we measure an increase of about 4 GtC/year. Thus nature as a whole is a net sink for atmospheric CO2, regardless of how much is exchanged with other compartiments during that year.”

    Setting aside for a moment the question of whether human emissions can be said to have caused the increase, which is an interesting question, it occurs to me that there is another interesting issue here. If we go off of these numbers, it looks like natural sinks are increasing their rate of uptake by about 4GtC/year. This suggests that natural sinks have an ability to uptake much more today than they were uptaking, say, 50 years ago. After a decade, for example, natural sinks would be uptaking about 40GtC/year more than they were a decade previously. This seems to be in contradiction to the statements we sometimes hear that there is a particular amount of “normal” natural uptake (apparently not true) or that there is a careful balance beyond which the natural sinks cannot uptake any more (possibly true, but unknown).

    Is this additional uptake over the last several decades reflected primarily in vegetation? Other sinks? Is it temporary?

    Do the numbers for increases in CO2 overall match up with this increased uptake ability in nature and increased human emissions?

  47. Bart says:

    FWIW to anyone reading this thread: The fundamental reason I doubt that the recently recorded rise in CO2 is most significantly of human origin is the simple fact that accidents do not happen in Nature. If the feedback loop governing CO2 concentration is so weak as effectively to allow 100% accumulation of the anthropogenically released CO2 in the oceans and atmosphere, then it is too weak to have established an equilibrium and maintained it tightly for thousands of years before the Industrial Age.

    Ferdinand has constructed a narrative which, superficially, appears plausible. But, it is based on unfounded confidence in measurements which have large error bars, models for the carbon cycle which have not been completely validated and are very likely substantially incomplete, and neglect of the fundamental dynamism of the system.

    A similar narrative was constructed for Anthropogenic Global Warming and, so long as the Global Average Temperature Metric (GATM) appeared to be rising in the latter third of the 20th century, researchers had high confidence that the hypothesis was correct. But, then they hit a brick wall when the GATM stalled after 1998. The evidence that a global cooling cycle has now commenced, which will endure for the next 20-30 years, is compelling. And, it is now apparent that inconvenient facts which were neglected or ignored in constructing the AGW narrative should never have been ignored, e.g., in particular, the rising GATM of the early third of the 20th century which, with hindsight, we can now see is nearly identical to the rise in the latter third.

    You cannot just neglect fundamental discrepancies with the knowledge base, and a plausible narrative, especially one which takes short cuts in neglecting inconvenient data or knowledge, is NOT proof. Until the discrepancies are resolved, the hypothesis remains just that.

  48. FerdiEgb says:

    climatereflections says:
    March 29, 2012 at 4:04 pm

    If we go off of these numbers, it looks like natural sinks are increasing their rate of uptake by about 4GtC/year. This suggests that natural sinks have an ability to uptake much more today than they were uptaking, say, 50 years ago. After a decade, for example, natural sinks would be uptaking about 40GtC/year more than they were a decade previously.

    The uptake by nature seems rather linear with the increase in the atmosphere. From the long term past (ice cores) there is a quite nice relationship between CO2 en temperature (CO2 following temperature with a lag) of about 8 ppmv/°C. Based on that relationship, the CO2 level at the current temperature should be around 290 ppmv. In reality the CO2 levels are near 400 ppmv. That gives more pressure for CO2 to sink into the cold polar waters towards the deep oceans (and less pressure difference at the equator at the upwelling places) and more pressure to dissolve in alveoles water of plant leaves, all other confounding variables being equal. Compared to the steady state level of 290 ppmv, the extra sink rate is near linear in ratio with the pressure difference. All together, it looks like that nature as a whole is behaving as a simple first order process coping with a disturbance.

    The emissions and increase in the atmosphere are directly coupled:
    http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2_1900_2004.jpg
    not directly because of the emissions, but because the emissions lead to increased atmospheric CO2 pressure which leads to increased uptake. On a year by year base that gives:
    http://www.ferdinand-engelbeen.be/klimaat/klim_img/dco2_em.jpg
    where the variability around the trend is mainly caused by temperature variability (explaining ~60% of the variability). The 1992 Pinatubo eruption and the 1998 El Niño have a measurable impact. Using that impact, the short term influence of temperature on the rate of change is ~4 ppmv/°C.
    Besides the natural variability, which doesn’t seem to increase or decrease over time, it looks like that the increase in uptake and the increase in the atmosphere are in a near constant ratio with the emissions, probably because the emissions continue to increase over time. I need to make an update for the past years, as there may be some impact from the economic crisis.

    The uptake capacity of the deep oceans is enormous, as they are far from saturated for CO2. The same for vegetation, which have theoretically an unlimited storage capacity. The limiting factor is diffusion speed in the oceans and diffusion + reaction speed in plants. While the atmospheric CO2 pressure difference with the steady state doubles, the uptake speed in average increases with 50-55%.

    Based on oxygen and d13C measurements, one can estimate where the extra CO2 is sequestered:
    http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf

  49. FerdiEgb says:

    Bart says:
    March 29, 2012 at 4:25 pm

    If the feedback loop governing CO2 concentration is so weak as effectively to allow 100% accumulation of the anthropogenically released CO2 in the oceans and atmosphere, then it is too weak to have established an equilibrium and maintained it tightly for thousands of years before the Industrial Age.

    The deep oceans and vegetation have sufficient capacity to allow sequestering of 100% of the emissions. As already explained to climatereflections, the limiting factor is the diffusion speed, which is directly proportional to the pressure difference between pCO2(atm) and pCO2(aq), all other confounding variables (water temperature, wind speed, sink and upwelling flows) being equal. The time factor is important here: historical CO2 had multi decades to millennia to maintain equilibria around the temperature dictated setpoint. The current injection of human emissions is higher than what the decay rate (~55 years e-fold factor) can cope with on short time intervals.

  50. Bart says:

    FerdiEgb says:
    March 30, 2012 at 2:01 am

    “The time factor is important here: historical CO2 had multi decades to millennia to maintain equilibria around the temperature dictated setpoint.”

    It is important. As already explained, it is inconsistent with a tightly regulated atmospheric CO2 concentration.

    “The current injection of human emissions is higher than what the decay rate (~55 years e-fold factor) can cope with on short time intervals.”

    You think. We shall see.

  51. John Whitman says:

    FactChecker says:
    March 29, 2012 at 1:22 pm

    Does anyone know what happened to Murry Salby? Did he disappear down a black hole? I haven’t heard mention of that guy for a long time now… anyone knows what happened to him?

    FactChecker,

    Murry Salby published his new textbook ‘Physics of the Atmosphere and Climate’ in Jan 2012 by Cambridge University Press. I have it and use it for reference often.

    I do not know the status of his paper on the carbon cycle and the atmosphere.

    John

  52. John Whitman says:

    If the IPCC centric view is correct that variation of CO2 will cause a variation of GMT, then why are those two main proxies of pre-modern (pre-instrumental) period not compatible over +800 yrs of the last +1,000 yrs?

    GMT proxies show clearly visible century scale variation over more than the last +1,000 yrs. But CO2 proxies over the same period show a nearly non-variation except for the last ~100 yrs.

    If GMT varies due to changes in CO2 as current IPCC climate science paradigm requires (ignoring in this discussion for the time being that proxy records show CO2 increase lagging GMT increase by ~500 to 1,000 yrs) then why doesn’t the CO2 proxy at least vary with the centennial variation of the GMT proxy? It implies both GMT and CO2 proxies cannot be right if the IPCC centric paradigm is right about CO2 variation causing GMT variation.

    This question stands out from my reading of “Physics of the Atmosphere and Climate” by Murry L. Salby published Jan 2012 by Cambridge University Press.

    John

  53. gavincawley says:

    Some of the discussion here questions whether the observed rise in atmospheric CO2 is anthropogenic. It undoubtedly is, and there are many lines of evidence that establish that this is the case, see Ferdinand Engelbeens’ excellent webpage on the subject http://www.ferdinand-engelbeen.be/klimaat/co2_measurements.html .

    I have looked into this subject in some detail in the process of writing a rebuttal of Prof. Robert Essenhigh’s paper on the residence time of CO2, which was published by the journal, see http://pubs.acs.org/doi/abs/10.1021/ef200914u

    On the Atmospheric Residence Time of Anthropogenically Sourced Carbon Dioxide
    Gavin C. Cawley*
    Abstract: A recent paper by Essenhigh (Essenhigh, R. H. Energy Fuels 2009, 23, 2773−2784) (hereafter ES09) concludes that the relatively short residence time of CO2 in the atmosphere (5–15 years) establishes that the long-term (≈100 year) rise in atmospheric concentration is not due to anthropogenic emissions but is instead caused by an environmental response to rising atmospheric temperature, which is attributed in ES09 to “other natural factors”. Clearly, if true, the economic and political significance of that conclusion would be self-evident and indeed most welcome. Unfortunately, however, the conclusion is false; it is straightforward to show, with considerable certainty, that the natural environment has acted as a net carbon sink throughout the industrial era, taking in significantly more carbon than it has emitted, and therefore, the observed rise in atmospheric CO2 cannot be a natural phenomenon. The carbon cycle includes exchange fluxes that constantly redistribute vast quantities of CO2 each year between the atmospheric, oceanic, and terrestrial reservoirs. As a result, the residence time, which depends upon the total volume of these fluxes, is short. However, the rate at which atmospheric concentrations rise or fall depends upon the net difference between fluxes into and out of the atmosphere, rather than their total volume, and therefore, the long-term rise is essentially independent of the residence time. The aim of this paper is to provide an accessible explanation of why the short residence time of CO2 in the atmosphere is completely consistent with the generally accepted anthropogenic origin of the observed post-industrial rise in atmospheric concentration. Furthermore, we demonstrate that the one-box model of the carbon cycle used in ES09 directly gives rise to (i) a short residence time of ≈4 years, (ii) a long adjustment time of ≈74 years, (iii) a constant airborne fraction, of ≈58%, in response to exponential growth in anthropogenic emissions, and (iv) a very low value for the expected proportion of anthropogenic CO2 in the atmosphere. This is achieved without environmental uptake ever falling below environmental emissions and, hence, is consistent with the generally accepted anthropogenic origin of the post-industrial increase in atmospheric carbon dioxide.

    This paper summarises the evidence that establishes that the origin of the rise is indeed anthropogenic (Ferdinand’s web page is referenced in my article, it is strongly recommended).

    The challenge to any theory of even a partially natural origin of the observed increase is to explain how the annual rise can be less than anthropogenic emissions, without contravening the principle of conservation of mass.

  54. FerdiEgb says:

    John Whitman says:
    March 30, 2012 at 10:06 am

    GMT proxies show clearly visible century scale variation over more than the last +1,000 yrs. But CO2 proxies over the same period show a nearly non-variation except for the last ~100 yrs.

    Three problems: the influence of temperature on CO2 levels is rather small (~8 ppmv/°C), that is well established over very long time scales (ice ages – interglacials). On shorter time scales the ratio may be smaller (for the seasonal variations up to decennia it is 4-5 ppmv/°C). Secondly, the influence of CO2 on temperature is quite small, even if you believe the central estimate of the IPCC. A change of 8 ppmv has no detectable influence on any kind of temperature proxy… And thirdly ice cores are smoothing out the CO2 variations from 8 years averaging over the past 150 years to 560 years over the past 800,000 years, depending of snow accumulation rate and thus speed of sealing of the gas bubbles.

    Despite that, one of the Law Dome ice cores shows a CO2 dip of ~6 ppmv over the MWP-LIA cooling, which again gives a ratio of ~8 ppmv/°C, if you agree with the “bathtube” reconstruction of Moberg and others (~0.8°C temperature drop between the MWP and LIA). The ratio is higher if you believe that Mann’s HS is the only truth (~32 ppmv/°C for a ~0.2°C drop in temperature), but I think that we can agree that Moberg’s work is a little more realistic…
    See further:
    http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_1000yr.jpg

  55. Lars P. says:

    FerdiEgb says:
    March 29, 2012 at 7:27 am
    “Ice cores give direct measurements of the C13/C12 ratio of CO2 in trapped air. These were measured by cold crushing the ice, cryogenic freezing, distillation of CO2 and measuring with a mass spectrometer.
    The d13C level in the atmosphere over the Holocene can be followed in the Taylor Dome ice core:
    http://medias.obs-mip.fr/paleo/taylor/indermuehle99nat.pdf
    The average variability is +/- 0.15 per mil over the Holocene, up to 1,000 years ago.”

    Ferdinand, this seems to be supported only by the Antarctica ide cores and not by Greenland? Whilst from Antarctica we have only a couple of points for 100 years in Greenland ice core we have 100+, so I wonder if we do not lose a lot of natural variability using the Antarctica data for C13 as well as CO2 concentration due to the long time of about 80 years until the air is !trapped! in the antarctic ice?

  56. Lars P. says:

    climatereflections says:
    March 29, 2012 at 4:04 pm
    “Is this additional uptake over the last several decades reflected primarily in vegetation? Other sinks? Is it temporary?”

    Would say it is not at all temporary and it is natural that it increase: the plants start to feel well:
    http://www.co2science.org/data/plant_growth/plantgrowth.php
    an impressive calculation was shown here at WUWT:
    40 petagrams per year during ice age – plants must have been close to CO2 starvation
    80 during LIA and 120 now:
    http://wattsupwiththat.com/2011/11/21/carbon-on-the-uptake/

  57. FerdiEgb says:

    Lars P. says:
    March 30, 2012 at 1:38 pm

    Ferdinand, this seems to be supported only by the Antarctica ide cores and not by Greenland? Whilst from Antarctica we have only a couple of points for 100 years in Greenland ice core we have 100+, so I wonder if we do not lose a lot of natural variability using the Antarctica data for C13 as well as CO2 concentration due to the long time of about 80 years until the air is !trapped! in the antarctic ice?

    The Greenland ice cores have a quite good resolution (even yearly for the ice layers). Unfortunately the CO2 and d13C levels are unreliable. There is some seasalt/carbonate dust deposit (as good as is the case for Antarctica, mainly for coastal cores), which doesn’t interfere with the CO2 levels, except when highly acidic volcanic dust from Iceland is also settled down in the ice, which frequently is the case. That increases the measured free CO2 levels in situ and probably increases the d13C levels too (I haven’t seen any figures of d13C measurements from the Greenland cores), as sea carbonate is 0-5 per mil d13C while air d13C was around -6.4 per mil…

    The resolution of the ice cores heavily depends of the accumulation rate, which is very high near the coast (Law Dome, Siple Dome) with a range of 8-40 years, but as drawback that the measured time period is rather short (150-1000 years for Law Dome), as you have less ice layers when bedrock is (nearly) reached. Taylor Dome goes back several 10 kyr, but its resolution is worse (don’t know it exactly). Vostok and Dome C go back 420 kyr and 800 kyr with a resolution of some 600 years.

  58. Bart says:

    gavincawley says:
    March 30, 2012 at 11:50 am

    “It undoubtedly is, and there are many lines of evidence that establish that this is the case…”

    The are many lines of evidence which are not inconsistent with the hypothesis, but that does not establish the hypothesis as true. This is sloppy logic.

    “…it is straightforward to show… that the natural environment has acted as a net carbon sink throughout the industrial era, taking in significantly more carbon than it has emitted…”

    In other words, through process of elimination, you have concluded that the natural environment has emitted less than it has taken in. But, process of elimination only works when you can be sure you have the full set of possibilities. This is an argumentum ad ignorantiam logical fallacy.

    “The challenge to any theory of even a partially natural origin of the observed increase is to explain how the annual rise can be less than anthropogenic emissions, without contravening the principle of conservation of mass.”

    Now, you’re completely off the rails. You are positing that there are no sinks in the land and the oceans, and there assuredly are.

    Consistency is not proof. The eruption of a volcano is consistent with the notion that the Volcano God is angry, and demands a sacrifice. And, in earlier days when people had no knowledge of geologic processes, many cultures assented to that interpretation. It was wrong.

  59. Bart says:

    Lars P. says:
    March 30, 2012 at 1:48 pm

    climatereflections says:
    March 29, 2012 at 4:04 pm
    “Is this additional uptake over the last several decades reflected primarily in vegetation? Other sinks? Is it temporary?”

    It is expected in the models that roughly half, more or less, of whatever goes into the atmosphere will end up in the oceans without considering any other sinks. So, again, there is consistency with the hypothesis that the rising atmospheric concentration is due to anthropogenic inputs. However, this expectation is more or less ex post facto, and we do not fundamentally know what share should end up in the oceans from basic principles.

    The natural flows both in and out are huge, on the order of at least 30 times greater than the anthropogenic input flux. It does not take a lot of long term variation in the natural flows to completely swamp out the anthropogenic signal.

  60. FerdiEgb says:

    Bart says:

    The are many lines of evidence which are not inconsistent with the hypothesis, but that does not establish the hypothesis as true. This is sloppy logic.

    Besides that all observations (mass and isotopic balance in the atmosphere, isotopic balance, pH and DIC in the oceans, greeing earth) are consistent with the hypothesis, all alternative hypothesis of a natural cause of the increase are INconsistent with one or more observations.

    While it is impossible to prove that a hypothesis is true, it is easy to prove that a hypothesis is false, one only need one observation which is inconsistent with the hypothesis.

    For the oceans as main source, the increase in oceanic carbon mass and decreasing d13C in air and oceans are sufficient proof that the oceans are not the source. For the biosphere, the oxygen balance is sufficient proof that the biosphere is not the source. What rests are minor sources on short term, even if these may be huge sources of change on geological times.

    At what point ends a hypothesis as hypothesis and do you accept that it is accepted knowledge?

  61. FerdiEgb says:

    Bart says:
    March 30, 2012 at 5:42 pm

    The natural flows both in and out are huge, on the order of at least 30 times greater than the anthropogenic input flux. It does not take a lot of long term variation in the natural flows to completely swamp out the anthropogenic signal.

    As Gavin already said:

    However, the rate at which atmospheric concentrations rise or fall depends upon the net difference between fluxes into and out of the atmosphere, rather than their total volume, and therefore, the long-term rise is essentially independent of the residence time.

    It doesn’t matter at all that the natural flows in and out are 3 times or 30 times or 300 times the human emissions, it only matters what the difference is between the natural inflows and outflows at the end of the year. Nature as a whole is a net sink for CO2, proven at least for the past 50+ years. Even if one of the natural inflows doubled in some years and halved in other years, that doesn’t matter, as the net balance over the past 50+ years shows that in every year nature as a whole was more sink than source. The observed natural variation around the trend is about +/- 2 GtC for an increase currently around 4 GtC/yr with human emissions around 8 GtC/yr. Thus there is no sign of a swamp out, neither of huge natural variations.

  62. gavincawley says:

    Bart wrote: “The are many lines of evidence which are not inconsistent with the hypothesis, but that does not establish the hypothesis as true.”

    There are lines of evidence that are inconsistent with the natural environment being a net carbon source. This means that the natural environment must therefore be a net carbon sink and hence is opposing the arise in atmospheric CO2. We know that the rise is of anthropogenic origin because the observation is consistent with that hypothesis, but inconsistent with the hypothesis of a natural origin.

    “In other words, through process of elimination, you have concluded that the natural environment has emitted less than it has taken in. But, process of elimination only works when you can be sure you have the full set of possibilities. “

    No, it is not a process of elimination, it is a logical deduction. If we assume conservation of mass (i.e. the annual increase in atmospheric CO2 is the difference between the total flux of carbon into the atmosphere minus the total flux of carbon out of the atmosphere) and that there are only anthropogenic emissions and natural emissions and uptake (i.e. the carbon cycle is essentially a closed system), then the observation that the annual rise being less than annual anthropogenic emissions means that total natural emissions must be less than total natural uptake.

    To disprove this deduction, it would be necessary to either disprove the assumptions (which seem rather solid to me) or show that the observations were incorrect (which seems rather unlikely as the difference between annual increase and annual anthropogenic emissions is small compared to the uncertainties in either measurement).

    “Now, you’re completely off the rails. You are positing that there are no sinks in the land and the oceans, and there assuredly are.”

    No, quite the reverse, the mass balance analysis shows that the sum of all natural sinks (on land and ocean) have been stronger for at least the last 50 years than the sum of all natural sources.

    “Consistency is not proof.”

    I fully agree, however inconsistency does constitute disproof (contingent on the assumptions made and on the uncertainty of the observations). In this case the observations are consistent with an anthropogenic cause, but inconsistent with a natural cause, therefore we can be quite sure that the rise is of purely anthropogenic origin.

  63. John Whitman says:

    The attribution of increases in atmospheric CO2 since ~1850 to man’s burning of fossil fuel is said by the IPCC centric scientists ( in FAR, SAR, AR3 and AR4) to be unequivocally established by a construction (from earlier proxies and recently measurements) of two concurrent opposing trends in the composition of the atmosphere. Those two concurrent opposing constructed trends in atmospheric composition (which the IPCC scientists say is the fingerprint of mankind’s effect on atmospheric composition) are the decline in the relative concentration of atmospheric carbon 13 (parts per thousand referred against a standard value of C13 concentration) and the increase of volume mixing ratio (ppmv) of atmospheric CO2.

    If either of these opposing trends is shown not to be primarily driven by man’s activities then the IPCC’s anthropogenic case is significantly weakened to the state of being refuted.

    There are large uncertainties in the produced amounts from natural sources of CO2 which have the same carbon 13 concentration as CO2 from man’s burning of fossil fuels. Until these uncertainties are reduced by further research then the IPCC’s anthropogenic case for changes in the composition of the atmosphere then the IPCC’s case is based on ignorance of those natural sources.

    Significant funds need to be timely diverted to the natural sources of atmospheric carbon away from the IPCC centric scientist’s/institution’s bias and myopic focus on fossil fuel burning.

    This would allow a more respectable independence in the science, some overdue advance toward balance and certainly some restoration of the declining trust in climate science which has been caused directly and entirely by the IPCC.

    John

  64. gavincawley says:

    John Whitman The IPCC mention several lines of evidence that establish that the rise in atmospheric CO2 is of anthropogenic origin. See section 1.2.5 of the FAR on page 14. These include the mass balance argument:

    “Since the start of atmospheric monitoring in 1958, the annual atmospheric increase has been smaller each year than the fossil CO2 input. Thus oceans and biota together must have been a global sink rather than a source during all these years”

    I suspect that the reason the IPCC reports do not devote a great deal of space to this particular question is simply because the evidence is conclusive and can be checked by anybody that wishes to do so. This really is one of the sort of arguments that Prof. Singer urges sceptics to drop in order to strengthen their position.

    It is true that there are large uncertainties in our best estimates of the natural fluxes into and out of the atmosphere. However this is not relevant to the mass balance argument as the mass balance argument is used to infer the difference between total natural emissions and total natural uptake, which is equal to the difference between the annual increase in atmospheric CO2 and annual anthropogenic emissions. Both of these are known with more than sufficient accuracy for there to be considerable certainty in the conclusion.

  65. Bart says:

    FerdiEgb says:
    March 31, 2012 at 12:42 am

    “For the oceans as main source, the increase in oceanic carbon mass and decreasing d13C in air and oceans are sufficient proof that the oceans are not the source.”

    No, it isn’t. This is a dynamic system, and you are using static models.

    “At what point ends a hypothesis as hypothesis and do you accept that it is accepted knowledge?”

    When it stops assuming the answer before it is proven, and starts relying on confirmational data.

    “It doesn’t matter at all that the natural flows in and out are 3 times or 30 times or 300 times the human emissions, it only matters what the difference is between the natural inflows and outflows at the end of the year.”

    Wrong. Wrong, wrong, wrong, wrong, wrong. We’ve been over this too many times for me to have any hope that you will get it, but it is stunningly bad logic.

    gavincawley says:
    March 31, 2012 at 4:09 am

    “We know that the rise is of anthropogenic origin because the observation is consistent with that hypothesis, but inconsistent with the hypothesis of a natural origin.”

    With your concept of what “natural sources” can do tied in a straightjacket of a priori baseless assumptions.

    “…then the observation that the annual rise being less than annual anthropogenic emissions means that total natural emissions must be less than total natural uptake.”

    NO!!!! It does not mean that at all. You are assuming the sinks do not expand due to an increase in atmospheric partial pressure. They do. You are wrong.

    You guys… you do not even realize you are heading down the same path that led church leaders of old to proclaim that the Sun revolved around the Earth, or the ancient shamans to believe that the Volcano God had to be appeased. In each case, those guys thought they were basing their beliefs on the best available evidence, too. Your arguments are mind-numbingly flaccid, and you do not even realize it. This is not to say that you may not be right, but if so, only in the sense that a stopped clock may be right twice a day. Your arguments are not conclusive in any way, shape, or form.

    I’m done with this thread. We’ve said all there is to say. Further lack of response on my part should not be taken as evidence of acquiescence. We will know the truth as the data record of reliable measurements increases. In the meantime, it is rather a moot point, since temperatures are not increasing in line with the AGW hypothesis anyway.

  66. John Whitman says:

    Let’s take the combined natural sources of atmospheric CO2 to be on the order of 150 CtC/yr and the anthropogenic source to be on the order of 6 CtC/yr. What is the uncertainty in the amount of the natural 150 CtC/yr CO2 production that has the same net carbon 13 conc as CO2 from burning fossil fuels? Is it’s production uncertainty higher than the total of mankind’s production? It appears to be the case. So the IPCC’s argument about anthropogenic caused changes in atmospheric composition is based fundamentally on a very incomplete quantitative knowledge of the natural carbon cycle.

    We need much more of the independent vehicle of skeptical science to counter the grossly overfunded myopic CAGWism of the IPCC. In other words, we need to restore the more open scientific process that preceded the manipulation by the UN to create the completely political body that is the IPCC.

    John

  67. Bart says:

    Bottom line: This is a dynamic system, and you guys are doing static analysis. And, you are assuming greater precision in the quantification of natural fluxes than actually exist, and when anthropogenic influx is less than 3% of natural fluxes, you do not need a lot of error to destroy the conclusion.

  68. Bart says:

    This is all elementary to someone who analyzes dynamical systems every day. You guys apparently lack the tools to address this problem rigorously.

  69. gavincawley says:

    Bart writes “With your concept of what “natural sources” can do tied in a straightjacket of a priori baseless assumptions.”

    No, the mass balance argument makes no assumptions about the nature of the sources or sinks. It is away of inferring something we can’t directly measure (the difference between total natural emissions and total natural uptake) from two quantities that we can directly measure, namely anthropogenic emissions and the annual rise in atmospheric CO2. I would be happy to go through the argument with you step by step if you like and you can point out the step where the error in the argument appears.

    “NO!!!! It does not mean that at all. You are assuming the sinks do not expand due to an increase in atmospheric partial pressure. They do. You are wrong.

    No, this is not correct, the mass balance argument makes no such assumption. Furthermore in my paper I use a one-box model of the carbon cycle very similar to that used by Essenhigh, where the flux out of the atmosphere is proportional to the atmospheric CO2 concentration (starting on page 5508). Thus my analysis explicitly includes the expansion of the sinks.

  70. gavincawley says:

    John Whitman As I pointed out, the conclusion that the rise in atmospheric CO2 is based on a number of lines of evidence. The mass balance argument is the most elementary of these, and only relies on observations with uncertainties not nearly low enough to cast any doubt on the conclusion. While you may not be convinced of isotopic evidence due to observational uncertainties, you cannot dismiss the conclusion without addressing other arguments that demonstrate that the observed rise is not a natural phenomenon.

    I would recommend that you read the very clear explanation of the mass balance argument on Ferdinand Engelbeen’s web page .

  71. gavincawley says:

    Bart wrote “Bottom line: This is a dynamic system, and you guys are doing static analysis.”

    This incorrect, in my paper I discuss a simple one-box model of the carbon cycle, which is a dynamical system described by a differential equation. It is not a static analysis.

    “And, you are assuming greater precision in the quantification of natural fluxes than actually exist”

    The mass balance argument does not require any knowledge of the magnitudes of the natural fluxes, hence the uncertainty of our best estimates of them is irrelevant. The mass balance argument relies only on knowledge of anthropogenic emissions and of atmospheric concentrations, both of which are known with more than adequate certainty for the purposes of the mass balance analysis.

    “and when anthropogenic influx is less than 3% of natural fluxes, you do not need a lot of error to destroy the conclusion.”

    This is incorrect, as has been pointed out earlier in the thread, the rate of increase in atmospheric CO2 depends on the difference between total uptake and total emissions, not the magnitude of the fluxes themselves, and anthropogenic emissions are large compared to the difference between total natural emissions and total natural uptake.

    However, the mass balance argument does not depend on our knowledge of the magnitude of the natural fluxes, so this objection is irrelevant.

  72. FerdiEgb says:

    Bart says:
    March 31, 2012 at 9:56 am

    Bottom line: This is a dynamic system, and you guys are doing static analysis. And, you are assuming greater precision in the quantification of natural fluxes than actually exist, and when anthropogenic influx is less than 3% of natural fluxes, you do not need a lot of error to destroy the conclusion.

    Bart, again (for others, as you have an idee-fixe about the dynamics of the system), we don’t need to quantify any dynamics of any of the natural fluxes involved, as that doesn’t tell us anything about what the cause of the increase in the atmosphere is. Only the difference between all natural inflows and all natural outflows together is important. And that is quite exactly known and was negative (more sink than source) at least over the past 50+ years.

    The dynamics of the difference is important, and based on observations, the variability of the difference is only halve what humans add as emissions, around the trend which is about halve the emissions. Even taken into account the error margins of the emissions estimates and the measurement error of the CO2 levels, the natural variability in difference is only 1.5% of the total in or outflows. Thus there is no reason to assume that some natural variability may be larger than the human emissions, that is proven wrong for the past 50+ years.

  73. FerdiEgb says:

    John Whitman says:
    March 31, 2012 at 9:54 am

    What is the uncertainty in the amount of the natural 150 CtC/yr CO2 production that has the same net carbon 13 conc as CO2 from burning fossil fuels?

    There are only rough estimates of the CO2 production from natural sources with a low 13C/12C ratio. That are mainly vegetation decay/burning and natural “fossil” carbon from methane and oil leaks and coal or peat burning.

    That may be important if there were huge natural disasters in the recent past, but that is not the case, taking into account that the measured increase in CO2 and decrease in d13C is the equivalent of burning down 1/3rd of all land vegetation (!).

    Even if there was some extra natural supply from low 13C sources, the total d13C decrease caused by all human use of fossil fuels is high enough to have caused a threefold drop in d13C as what is observed, Thus any extra source must have a higher d13C level than the atmosphere, not a lower one. And not a source, but a replacement, as an extra source in mass would give an increase in the atmosphere higher than the human emissions, not lower. As both the ocean surface and the biosphere have a limited storage capacity and most of what is absorbed in one season returns in the next, mainly the deep oceans are responsible for most of the high d13C exchange.

    One can calculate how much carbon with the deep oceans need to be exchanged to get the right d13C drop in the atmosphere:
    http://www.ferdinand-engelbeen.be/klimaat/klim_img/deep_ocean_air_zero.jpg
    The deviation until 1960 might be caused by the biosphere (as a net source), which is not taken into account in this calculation.

  74. John Whitman says:

    FerdiEgb says:
    March 30, 2012 at 1:20 pm

    Despite that, one of the Law Dome ice cores shows a CO2 dip of ~6 ppmv over the MWP-LIA cooling, which again gives a ratio of ~8 ppmv/°C, if you agree with the “bathtube” reconstruction of Moberg and others (~0.8°C temperature drop between the MWP and LIA). The ratio is higher if you believe that Mann’s HS is the only truth (~32 ppmv/°C for a ~0.2°C drop in temperature), but I think that we can agree that Moberg’s work is a little more realistic…

    FerdiEgb,

    Hey, I noticed you shortened your handle here at WUWT!

    NOTE: Let’s use of the multi-proxy reconstruction of GMT during the last two millennia from Moberg et al (2005) and judiciously ignore Mann’s much more problematical AGW-marketing oriented reconstruction.

    The observed (proxy plus measurement) increase in atmospheric CO2 in the twentieth century was about 80 ppmv. The part of the atmospheric CO2 increase which could be considered as resulting from the temperature rebound from the LIA over the same period roughly 55 ppmv. So, if those figures are reasonable then we have, in the twentieth century, about 50% of the atmospheric CO2 increase being naturally the result of that part of the LIA temperature rebound that occurred in the twentieth century.

    So I find little to support the idea that increases in CO2 release to the atmosphere from a naturally occurring increased temperature of land and sea are insignificant when compared to anthropogenic releases of CO2 during the twentieth century.

    I am using as a reference and an educational guide the textbook ‘Physics of the Atmosphere and Climate’ by Murry L. Salby (published Jan 2012 by Cambridge University Press). I have found it to most informative.

    John

  75. gavincawley says:

    John Whitman If you use the Law dome CO2 data to extend the mass balance analysis back prior to to the start of the Mauna Loa record, it still shows that the annual rise in atmospheric CO2 was less than total anthropogenic emissions (land use change + fossil fuel) going back at least as far as 1840 (see figures 4 and 5 of my paper). This indicates that the natural environment has been a net carbon sink going back at least as far as that, and hence has been opposing the observed rise rather than causing it. This contradicts the hypothesis that the rise is partly due to a rebound from the LIA.

    The airborne fraction (the ratio of the rise in CO2 and cumulative anthropogenic emissions) has stayed pretty much constant at about 0.45 going right back to the 1840s. It would be quite a coincidence if a rebound from the LIA caused an increase in atmospheric CO2 that was in so close a relationship to anthropogenic emissions!

    I would be interested to see Prof. Salby’s paper, so if anyone can tell me the identity of the journal or news about likely publication date I would be grateful. I did send him a pre-print of my paper, but I recieved no response.

  76. Bart says:

    gavincawley says:
    March 31, 2012 at 10:44 am

    “The mass balance argument does not require any knowledge of the magnitudes of the natural fluxes, hence the uncertainty of our best estimates of them is irrelevant.”

    The “mass balance argument” is, there is no way to sugarcoat this, stupid.

    FerdiEgb says:
    March 31, 2012 at 11:05 am

    “Only the difference between all natural inflows and all natural outflows together is important.”

    Again, sorry, it has to be said… Stupid.

  77. FerdiEgb says:

    John Whitman says:
    March 31, 2012 at 11:34 am

    Hey, I noticed you shortened your handle here at WUWT!

    Not my intention, I still am the same Ferdinand Engelbeen, but the new WordPress rules which needed a login. Seems that I ever used that shortened login. Did cause me to resent the first comment here which were both promptly sent to the dust bin by WordPress and prompted a reaction of one of the Mods, because I was too impatient to wait for the dust bin to be searched by the poor Mods (sorry)…

    The part of the atmospheric CO2 increase which could be considered as resulting from the temperature rebound from the LIA over the same period roughly 55 ppmv.

    That is a little too high: even if we assume a full degree C increase of the ocean surface since the LIA, that wouldn’t be more than 16 ppmv. That is the increase in “fugacity”, or steady state equilibrium level with the above atmosphere for seawater for 1°C temperature increase. As increased land temperatures give more CO2 sequestering by plants, the overall increase in atmospheric CO2 at steady state probably is in the order of 8 ppmv, as was the case for the previous 800 kyr. Thus at maximum 8 ppmv of the 100+ ppmv rise in the past 160 years is from the rebound from the LIA.

    What is the base of the temperature caused 55 ppmv increase by Prof. Salby?

  78. gavincawley says:

    Bart. If you feel there is an error in the mass balance argument, then the sensible thing for us to do is to go through it step by step and you can point out the specific error when it ocurrs. This is what I did when I heard about Prof. Essenhigh’s paper, I had an open mind about it and went through the paper line by line and equation by equation and identified errors in the reasoning.

    Step #1: Do you agree that the carbon cycle obeys the principle of conservation of mass, i.e. any carbon that is emitted into the atmopshere that is not taken up by oceanic and terrestrial sinks remains in the atmosphere? Yes, or no. If no, then explain why this is not the case.

    I am willing to put my understanding to the test in a public forum. I am confident that you will not be able to find a flaw in any step. Are you willing to do the same?

  79. John Whitman says:

    FerdiEgb says:
    March 31, 2012 at 11:31 am
    There are only rough estimates of the CO2 production from natural sources with a low 13C/12C ratio. That are mainly vegetation decay/burning and natural “fossil” carbon from methane and oil leaks and coal or peat burning.

    FerdiEgb,

    And in addition the significant uncertainty extends to the concept of significantly varying amounts of relatively low carbon 13 concentrations being emitted from the upper ocean marine organic matter. For the IPCC’s AGW fingerprint from lowering carbon 13 relative concentration in the atmosphere to hold any validity it must be assumed by the IPCC that the oceans must emit CO2 with standard reference atmosphere carbon 13 relative concentrations; oceans assumed emitting CO2 without the leanness in carbon 13 of that is contained in man’s burning of fossil fuels; it is odd the IPCC does that given that the oceans are the dominant actor in the earth’s carbon cycle by far. Yet, there is quite insufficient science showing that IPCC assumption is credible. It is like the IPCC has a conclusion that man was responsible and is arguing backwards to justify it and in the process proceeds by just hand waving forth an assumption about the dominant part of the carbon cycle, the oceans, without doing the science.

    Carbon cycle science is primitive and needs independent skeptical attention. Funding orgs need support it independent of the IPCC’s advocacy of only research whose outcome supports their predetermined conclusions.

    John

  80. gavincawley says:

    John Whitman If you doubt that the IPCC’s conclusion that the rise in atmospheric CO2 is anthropogenic in origin, then I suggest that you also engage in the step-by-step derivation of the mass balance argument that demonstrates they are correct, that started in my previous post. I invite skeptical attention, I would very much like to be proven wrong, and the challenge is yours to accept.

  81. FerdiEgb says:

    John Whitman says:
    March 31, 2012 at 1:52 pm

    And in addition the significant uncertainty extends to the concept of significantly varying amounts of relatively low carbon 13 concentrations being emitted from the upper ocean marine organic matter.

    Some error here: plant life in the upper oceans use preferentially 12C for their organics, which leaves more 13C in the surrounding waters. That makes that surface waters are higher in 13C than the deep ocean waters. Thus any release from the deep oceans (at around zero per mil d13C) or the ocean’s surface (at 1-5 per mil) will increase the d13C level of the atmosphere (currently at -8 per mil).

    Don’t underestimate what is already known from the carbon cycle. Not everything is known in detail but the main flows are quite well known.

  82. Bart says:

    gavincawley says:
    March 31, 2012 at 12:59 pm

    “If you feel there is an error in the mass balance argument, then the sensible thing for us to do is to go through it step by step and you can point out the specific error when it ocurrs”

    Been there, done that Gavin. We’ve been going back and forth on this issue for years with Ferdinand. Last go around, I thought he had finally seen the light. Instead, he just breaks off when the going gets tough, and comes back spouting the same argumentum ad nauseam. I am sick of it.

    This is very, very elementary. You guys are assuming you know more about the system than you do. The equations, based on what is definitely known, are underdetermined, and you are resolving the ambiguity in the solution by choosing one which fits your preconceived biases.

  83. Bart says:

    FerdiEgb says:
    March 31, 2012 at 2:34 pm

    “… the main flows are quite well known.”

    More argument by assertion. Countless failed hypotheses have been buried with similar epitaphs on their headstones.

  84. FerdiEgb says:

    Bart says:
    April 1, 2012 at 9:12 am

    It is not because I had left the discussion after we agreed that we didn’t agree, that you may assume that I have seen “the” light…

    Some fresh thoughts from a different person may be of help. You are right that we don’t know what the carbon cycle is doing in detail, but we do know the two most important items: how much humans emit and what the increase in the atmosphere is.

    Again, it seems very difficult for a lot of people to understand that the natural flows between the atmosphere and the other reservoirs are of not the slightest interest to know how much nature supplies to or removes from the atmosphere. The two known variables (including their error margins) are sufficient to know the difference between the unknown sum of all natural inflows and unknown sum of all natural outflows. That is all what matters for the increase or decrease of CO2 in the atmosphere…

  85. FerdiEgb says:

    Bart says:
    April 1, 2012 at 9:17 am

    More argument by assertion. Countless failed hypotheses have been buried with similar epitaphs on their headstones.

    See:
    http://www.sciencemag.org/content/287/5462/2467.abstract

  86. Lars P. says:

    I found a new paper discussed at Jo’s site on the C13 concentrations and the oceans which seems to be much aligned to what David is telling:
    http://joannenova.com.au/2012/03/in-ice-ages-co2-hides-in-the-oceans-yes-we-knew-that/

  87. John Whitman says:

    FerdiEgb says:
    March 31, 2012 at 12:21 pm

    What is the base of the temperature caused 55 ppmv increase by Prof. Salby?

    FerdiEgb,

    I liked your full name better as a handle. : ) It was more dignified.

    For us to dialog on my interpretations of Prof Salby’s treatment of the delta natural CO2 emission resulting from delta surface temperature (the temperature-CO2 climate feedback) then I suggest you first read chapter 8-Radiative Transfer, section 8.7-The Greenhouse Effect, subsection 8.7.1-Feedback in the Climate System in Prof Salby’s book ‘The Physics of the Atmosphere and Climate’ (published Jan 2012 by Cambridge University Press). The references in that subsection will take you to many other chapters within his book so you would be looking over 70 pages of his almost 700 page book.

    It looks to me like there are significant oceanic sources emitting natural CO2 which is carbon 13 lean; natural ocean sources of emission with the similar carbon 13 leanness as the leanness in CO2 from man’s burning of fossil fuels; the magnitudes of emission rate of those natural oceanic sources of carbon 13 lean CO2 appear to be on the order of magnitude of the emission rate of the anthropogenic CO2 sources from burning fossil fuel over comparable time periods like the twentieth century. A finding like that would significantly weaken the basis of the IPCC’s anthropogenic CO2 fingerprinting which they say shows predominately anthropogenic causes for increased modern era CO2.

    As we hopefully, in the future, have a common base (Prof Salby’s treatment in his book) then I look forward to your continued discussion on this matter.

    John

  88. FerdiEgb says:

    Lars P. says:
    April 1, 2012 at 11:01 am

    Thanks for the link. The full (not paywalled) paper from Science can be found at:
    http://www.climate.unibe.ch/~stocker/papers/schmitt12scix.pdf

    It is a very interesting paper with a detailed description of what is expected that has happened with ocean flows and vegetation over the last ice age – interglacial transition.

    The variability in d13C was measured in three ice cores with different methods in different laboratories. While the ice core filtering is at multi centennial scale, the average variation over the last glacial maximum – Holocene era was not more than 0.6 per mil d13C. That includes quite huge changes in SST and vegetation area/growth. Since the start of the industrial revolution we have had a drop of 1.6 per mil d13C in only 160 years…

  89. John Whitman says:

    FerdiEgb says:
    March 31, 2012 at 11:31 am

    Even if there was some extra natural supply from low 13C sources, the total d13C decrease caused by all human use of fossil fuels is high enough to have caused a threefold drop in d13C as what is observed, Thus any extra source must have a higher d13C level than the atmosphere, not a lower one. And not a source, but a replacement, as an extra source in mass would give an increase in the atmosphere higher than the human emissions, not lower. As both the ocean surface and the biosphere have a limited storage capacity and most of what is absorbed in one season returns in the next, mainly the deep oceans are responsible for most of the high d13C exchange.

    FerdiEgb,

    Again, my interpretation of Salby’s treatment in his new book, is that the natural variation (excluding variation from fossil fuel burning) in carbon 13 relative concentration in the atmosphere for the satellite era (past thirty years) does seem to be inconsistent with your statement. I think it shows there are natural sources of carbon 13 lean CO2 that have emission rates comparable in magnitude to the sources from mankind burning fossil fuels over the same period. That would effective counter the assumption of yours that we would need massive vegetation destroying natural disasters of global dimension over the satellite era to have a major natural source of carbon 13 lean CO2 comparable to the anthropogenic source of CO2 from the burning of fossil fuels.

    John

  90. John Whitman says:

    FerdiEgb says:
    March 31, 2012 at 2:34 pm

    Some error here: plant life in the upper oceans use preferentially 12C for their organics, which leaves more 13C in the surrounding waters. That makes that surface waters are higher in 13C than the deep ocean waters. Thus any release from the deep oceans (at around zero per mil d13C) or the ocean’s surface (at 1-5 per mil) will increase the d13C level of the atmosphere (currently at -8 per mil).
    Don’t underestimate what is already known from the carbon cycle. Not everything is known in detail but the main flows are quite well known.

    FerdiEgb,

    If current carbon cycle is as you say ‘[n]ot everything is known in detail but the main flows are quite well known’ and if as you say it includes the concept that lean carbon 13 CO2 emissions from natural sources, on the order of anthropogenic sources, cannot be occurring in modern times yet observation contradicts what you say is known then we do not have as you say an ‘error’. We have a significant open discourse on the science involving the carbon cycle and the Earth-atmospheric system.

    Look forward to discussion of Prof Salby’s work on this matter.

    John

  91. gavincawley says:

    Bart, If you feel that the mass balance argument is based on assumptions that are incorrect, or information that we don’t actually know, it would be very easy for you to point out the step where the problem ocurrs and I will be proven wrong. It is hard to understand your reluctance just to go through about six steps saying whether you agree with them or not. It would be ar less typing than was involved in your previous post. Do you agree with step #1? If you do, we will have narrowed down the steps where the error may lie. If you don’t then it is your chance to prove me wrong.

  92. gavincawley says:

    John Whitman wrote: “A finding like that would significantly weaken the basis of the IPCC’s anthropogenic CO2 fingerprinting which they say shows predominately anthropogenic causes for increased modern era CO2.”

    No, this is not correct. The mass balance argument proves beyond reasonable doubt that the rise in atmospheric CO2 is anthropogenic in origin. Questioning the validity of isotopic arguments is perfectly reasonable, but it doesn’t change the fact that the mass balance argument demonstrates that the IPCC’s position is correct.

  93. FerdiEgb says:

    John Whitman says:
    April 1, 2012 at 12:09 pm

    Most of all natural CO2 is around zero per mil d13C: that is all inorganic carbon (carbonate -rock- layers from plankton shells), sclero sponges, corals,… That is also the case for the inorganic carbonates dissolved in the (deep) oceans and ocean sediments, therefore also for volcanic CO2 from subduction volcanoes.

    Low 13C CO2 comes mainly from organics and some from fractionation processes in the deep mantle (but even mantle plume volcanic releases still are around/above atmospheric d13C). Thus any substantial reduction of atmospheric d13C, which is already low, comes from organics. Either from living organisms or from fossil organics. See:
    http://homepage.mac.com/uriarte/carbon13.html

    Thus while the bulk exchanges between the oceans and the atmosphere provide the atmosphere with a positive d13C CO2, some seeping of methane, oil or other organics from the (deep) oceans may influence the atmospheric d13C to the negative side.

    The problem is that all these exchanges had only a small variability (+/- 0.15) around -6.4 per mil over the 450 years before the start of the industrial revolution. The same for the ocean surface waters: +4.95 +/- 0.15 at Jamaica (broadly the same over the whole North Atlantic Gyre). See:
    C:\Users\Familie\Documents\Thuis\telenet\klimaat\klim_img\sponges.gif

    Since about 1850, there is a constant accellerating drop in d13C as well as in the atmosphere as in the ocean’s surface and at the same time an increase of CO2 in the atmosphere and in the ocean’s surface. That is incompatible with an extra release from the oceans: both the d13C drop as the DIC (dissolved inorganic carbon) increase in the oceans is opposite that expectation. The only alternative possibility is an enormous release (and oxydation) of organics from the (deep) oceans, be it methane clathrates or oil leaks. But think about the quantities involved: the BP oil spill of the Gulf is not even measurable in the CO2 increase. Moreover, that would be additional to the human emissions, but the human emissions are already twice what is observed as increase in the atmosphere. As the conservation of mass dictates: the difference with what is observed must be absorbed somewhere. The only alternative that is fast enough is the biosphere. That should sequester all the extra carbon from the oceans plus halve that of the human emissions. But that gives another contradiction: if that was true, the low 13C carbon from the oceans + halve the human emissions would be completely replaced by high 13C carbon from what remains from photosynthesis, the net result is that only the human emissions are responsible for the increase in the atmosphere and the d13C decline and that nature only shuffled some organic carbon from the ocean reservoir to the biosphere reservoir.

    In reality, not such an increase of extra organics releases from the oceans is observed. And both oceans and the biosphere are net sinks for CO2.

  94. Bart says:

    FerdiEgb says:
    April 1, 2012 at 9:34 am

    “It is not because I had left the discussion after we agreed that we didn’t agree, that you may assume that I have seen “the” light…”

    No, it was before that. I showed that the only variable you could know was a difference, which did not tell you what the natural flows were. You sidestepped the issue, continued stonewalling, and eventually, I gave up.

    “Again, it seems very difficult for a lot of people to understand that the natural flows between the atmosphere and the other reservoirs are of not the slightest interest to know natural flows between the atmosphere and the other reservoirs .”

    I think you got a little tongue twisted there. The “natural flows between the atmosphere and the other reservoirs” obviously IS the “natural flows between the atmosphere and the other reservoirs.” If you meant to argue that anthropogenic flows into the system have no effect on the amount nature removes, then you are wrong.

    gavincawley says:
    April 1, 2012 at 12:54 pm

    ” It is hard to understand your reluctance just to go through about six steps saying whether you agree with them or not.”

    It would not be hard if you had been a part of this fruitless conversation from way back. I am, justifiably, reluctant to continue to waste time with people who refuse to think.

    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.

    “Do you agree with step #1?”

    Step #1: Do you agree that the carbon cycle obeys the principle of conservation of mass, i.e. any carbon that is emitted into the atmopshere that is not taken up by oceanic and terrestrial sinks remains in the atmosphere?

    Well, it could have vanished into the wormhole which is transporting Phil Jones missing heat to the depths of the ocean without leaving any intervening trace of its passage. But, no, we do not do such pseudo-science here. The question is, how large are those sinks, how do they expand or contract in response to atmospheric concentration, and what is the rate at which at least semi-permanent sequestration occurs?

    gavincawley says:
    April 1, 2012 at 12:59 pm

    “The mass balance argument proves beyond reasonable doubt that the rise in atmospheric CO2 is anthropogenic in origin.”

    The mass balance proves nothing. It does not tell you individually how much input and output is coming from and going into natural sources and sinks.

  95. Bart says:

    FerdiEgb says:
    April 1, 2012 at 9:39 am

    “See: http://www.sciencemag.org/content/287/5462/2467.abstract

    Reminds me of this.

  96. gavincawley says:

    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.”

    The mass balance argument does not tell us the magnitudes of the natural fluxes, and indeed I have made it clear in my posts on this thread that we do not know them, nor do we need to know them to know that the natural environment is a net carbon sink.

    As you say “the difference between natural inflow and outflow as being the only fundamental quantity known” if we know that the difference between natural inflow and natural outflow is negative, that means that natural uptake must exceed natural emissions. Therefore the natural environment is a net carbon sink and has been actively opposing the rise in atmospheric CO2 rather than causing it. I am glad we agree that we do know the difference between natural inflow and natural outflow, that is real progress.

    “Well, it could have vanished into the wormhole which is transporting Phil Jones missing heat to the depths of the ocean without leaving any intervening trace of its passage. But, no, we do not do such pseudo-science here. The question is, how large are those sinks, how do they expand or contract in response to atmospheric concentration, and what is the rate at which at least semi-permanent sequestration occurs?”

    Sadly this sort of evasion rather than giving a direct answer to a direct question is all too common in discussion of climate science. Fortunately you had already conceded that we know the difference between natural inflow and natural outflow. When we look at the data we find that natural uptake has been greater than natural emissions for every year for at least the last 50 years (see my paper, or Ferdinand Engelbeen’s website or figure 1 of Raupach et al etc. or download the data from the Carbon Dioxide Information and Analysis Center and perform the analysis for yourself).

    So my question to you is how can the natural environment be causing a rise in atmospheric CO2 while taking in more CO2 than it emits?

  97. FerdiEgb says:

    Bart says:
    April 1, 2012 at 3:26 pm

    No, it was before that. I showed that the only variable you could know was a difference, which did not tell you what the natural flows were.

    Again, it is totally unimportant what the absolute height of any of the in and outflows are, it is only important what the difference between all the inflows and all the outflows is. It doesn’t make any damn change to the amounts in the atmosphere, as long as the total flows into and the total flows out are equal. No matter if these are 10 or 100 or 1000 GtC/year. Only the difference between ins and outs is important and that is what we know: the difference between what humans emit and what we measure as increase.

    Again, it seems very difficult for a lot of people to understand that the natural flows between the atmosphere and the other reservoirs are of not the slightest interest to know natural flows between the atmosphere and the other reservoirs .

    That is not what I said. I said:

    Again, it seems very difficult for a lot of people to understand that the natural flows between the atmosphere and the other reservoirs are of not the slightest interest to know how much nature supplies to or removes from the atmosphere.

    What nature supplies or removes to/from the atmosphere is not inflows or outflows, but the difference between inflows and outflows. If inflows and outflows are equal, there is zero supply and no change in the total amount present in the atmosphere. Again flows are not important, the difference at the end of the year is important.

  98. Bart says:

    gavincawley says:
    April 2, 2012 at 4:09 am

    “So my question to you is how can the natural environment be causing a rise in atmospheric CO2 while taking in more CO2 than it emits?”

    Like this:

    M = measured concentration
    A = anthropogenic emissions
    N = natural emissions
    U = natural uptake

    We know M = A + N – U. We measure M. We calculate A. From that, we know N-U, and we know that A is approximately twice M, so we know N-U is negative. As you say, it is a net sink.

    But, that’s all we know. We do not know N or U individually.

    The reservoirs expand in response to both natural and anthropogenic emissions. This is the nature of a DYNAMIC SYSTEM.

    Thus, we can take U as composed of two terms:

    UA = natural uptake of anthropogenic emissions
    UN = natural uptake of natural emissions

    So, we only know N-UA-UN. Suppose UA = A. Then M = N – UN, N is greater than UN, and the rise is entirely natural. Equality would never be precisely the case, but it depends on the sequestration time. If that time is arbitrarily small, then it is possible to within an arbitrarily small deviation to have UA = A. We simply do not know. As the sequestration time increases, anthropogenic emissions induce a greater share of the measured concentration. But, we do not know the sequestration time.

    This is a DYNAMIC SYSTEM. It actively responds to changing inputs. You cannot do a static analysis on such a system and expect generally, or even usually, to get the right answer.

  99. Bart says:

    FerdiEgb says:
    April 2, 2012 at 4:34 am

    “Again flows are not important, the difference at the end of the year is important.”

    It is useless. See above.

  100. Phil. says:

    Bart says:
    March 31, 2012 at 12:01 pm
    gavincawley says:
    March 31, 2012 at 10:44 am

    “The mass balance argument does not require any knowledge of the magnitudes of the natural fluxes, hence the uncertainty of our best estimates of them is irrelevant.”

    The “mass balance argument” is, there is no way to sugarcoat this, stupid.

    Really?

    The rate of growth in CO2 in the atmosphere can be represented by the following DE:

    d[CO2]/dt = Fossil Fuel Combustion+ Natural Sources-Natural Sinks

    Anything stupid about this?

    Measured values over the last 50 years yield the following to sufficient accuracy:
    d[CO2]/dt = Fossil Fuel Combustion(FF)/2

    So substitute that back in the original equation:

    FF/2 = FF+ Natural Sources-Natural Sinks

    Therefore -FF/2 = Natural Sources-Natural Sinks

    So the measurements over the last 50 years show that Fossil Fuel Combustion is responsible for the growth. QED

  101. gavincawley says:

    Bart, I agree that the carbon cycle is a dynamical system, as I said in my paper I use a one-box model of the carbon cycle (essentially the same as Prof. Essenhigh’s) to capture the first order dynamics of the system, defined by a differential equation, which provides a crude model of the expansion of the sinks. It gives the same story as the mass balance argument.

    I’m glad we agree that the environment is a net carbon sink. You have yet to explain how the natural environment can be causing atmospheric CO2 to rise whilst being a net sink. It is a bit like saying I can cause my bank balance to increase by withdrawing more money than I deposit (see the last part of my post for a more detailed explanation).

    It is important to note that the mass balance analysis is not a model of the carbon cycle, and it applies equally well whether the carbon cycle is static or dynamic. It doesn’t predict anything, it just uses a principle of physics (conservation of mass) that allows you to infer the difference between natural uptake and natural emissions. This is true whether natural emissions are constant or whether they are variable.

    As for the carbon cycle being dynamic, rather than M in your equation, it should be dM as it is the change in the mass of the atmospheric reservoir, rather than the mass itself. The equation is then more properly represented as

    dM = A + N – U

    This is a difference equation, and hence does define a simple dynamical system if you want to view it that way. If A, N and U were constant, then dM would also be constant, but of course nobody is claiming that any of these quantities are constant. N-U changes from year to year, as clearly demonstrated by the figures you were invited to investigate in my previous post.

    Now if you wanted to make even the simplest model of the carbon cycle, it would have to include the expansion of the sinks (as you point out) due to the rise in atmospheric CO2, so lets do that. Essenhigh forms his one-box model by making U proportional to M (if you look at the data this clearly isn’t a reasonable assumption, which is why I use a linear relationship with an intercept). We then have

    dM = A + N – kM

    where k is a constant. Now if you want a continuous time model, you can use a differenttal equation instead, which gives you (c.f. equation 4 in my paper).

    dM/dt = A + N – kM

    If you solve the equation you will still find that if the rate of growth of atmospheric CO2 is less than the rate of anthropogenic emissions then the rate of natural emissions must be less than the rate of natural uptake. That is because conservation of mass applies to both static and dynamical systems, and the mass balance argument is merely an application of conservation of mass, nothing more.

    Now if you want to separate natural uptake into uptake of “anthropogenic” CO2 and “natural” CO2, then that is fine. Indeed that is exactly what I do in my paper (c.f. equations7 and 8). If you do that, you still end up with a situation where if the rate at which CO2 is increasing in the atmosphere is less than the rate of anthropogenic emissions then the rate of natural uptake must be greater than the rate of natural emissions.

    you write “So, we only know N-UA-UN. Suppose UA = A. Then M = N – UN, N is greater than UN, and the rise is entirely natural.” This is an absurd argument, which we can see if we recast it in a more familiar setting (as indeed I did in my paper in an analogy adapted from one of Ferdinands):

    Consider a husband and wife that share a jar in which they keep their savings. He deposits 8 euro per month, all in Belgian minted coins, and never makes any withdrawals. She on the other hand deposits 1000 euro a month, all in French minted coins (so we can tell the difference) but withdraws 1004 euros a month from the jar. Clearly the total amount in the jar will rise by 4 euro a week, and most people would agree that the rise in their savings is purely due to the husband (as his deposits exceeded his withdrawals) and not his wife (as her withdrawals exceed her deposits).

    Your argument is akin to saying that if the wifes withdrawals contained 8 Belgian coins then that particular month the increase in their savings was purely due to her having taken four more coins out of the jar than she had put in, which is clearly absurd.

  102. FerdiEgb says:

    Bart says:
    April 2, 2012 at 10:03 am

    UA = natural uptake of anthropogenic emissions
    UN = natural uptake of natural emissions
    So, we only know N-UA-UN. Suppose UA = A. Then M = N – UN, N is greater than UN, and the rise is entirely natural.

    Let us use your own example of the bucket. Some huge, clear, waterflow is added at the top of a bucket and flows away via a hole in the bottom. At steady state, the height of the water in the bucket is constant and delivers the right pressure to make that the outflow exactly matches the inflow.

    Now we add a smaller blue colored waterflow at the top of the bucket. That mixes readily with the inflow of clear water, giving a fainted blue color, its intensity depending of the ratio between the inflows. The extra inflow also causes an increase of the water height in the bucket, INdependent of the height of main inflow or the height already in the bucket, which only accomodates the extra inflow, until a new steady state is reached where the extra outflow = extra inflow.

    Alternatively, we add the extra blue waterflow at the bottom of the bucket, near the output hole. The blue water is immediately gone into the drain, but despite that, we see exactly the same rise in height of total water in the bucket, still near only composed of clear water. Thus according to your reasoning, the rise is only due to clear water. According to our reasoning, the rise still is the result of the addition of blue water, no matter how fast it is replaced by clear water.

    To this example one can add the variability of the clear water inflow and the slightly exponentially increasing blue water inflow over time, to make it more realistic, but the basic point remains the same…

  103. Bart says:

    Phil. says:
    April 2, 2012 at 10:52 am

    gavincawley says:
    April 2, 2012 at 11:05 am

    FerdiEgb says:
    April 2, 2012 at 11:36 am

    I honestly can’t see how to answer you fellows without becoming churlish and abusive, so I will be brief: This is pitiful stuff.

    Go back and read what I wrote at 10:03 am, this time for comprehension. Because, you guys are embarrassing yourselves.

  104. gavincawley says:

    Bart, to help me understand where we disagree, please can you give a direct answer to this question:

    Consider a husband and wife that share a jar in which they keep their savings. He deposits 8 euro per month, all in Belgian minted coins, and never makes any withdrawals. She on the other hand deposits 1000 euro a month, all in French minted coins (so we can tell the difference) but withdraws 1004 euros a month from the jar. Clearly the total amount in the jar will rise by 4 euro a month, and most people would agree that the rise in their savings is purely due to the husband (as his deposits exceeded his withdrawals) and not his wife who was actively opposing the rise (as her withdrawals exceed her deposits).

    In this particular analogy (forgetting for the moment whether it is appropriate to a discussion of the carbon cycle) would you agree that it would be absurd to claim that the wife was responsible for the rise in the couples savings, even if she deliberately took out the 8 Belgian coins that had been deposited each month by her husband, despite the fact that she withdrew four more Euro coins than she deposited each month?

    A “yes” or “no” answer would be best, if “no”, explaining why.

  105. Bart says:

    gavincawley says:
    April 2, 2012 at 2:33 pm

    Gavin – why don’t you try reading and understanding what I wrote at 10:03 am? You’re just digging your hole deeper.

    Your analogy fails because you have artificially contrived a situation in which all of the inputs and outputs are known. It is equivalent, in my example, to saying you know both N and U individually. You DO NOT.

    There are children pilfering coins from the jar. The taxman steals in occasionally to grab his share. And, a rich uncle occasionally makes a contribution. You have no idea how much each of these is contributing or taking away, so you have excluded them from your calculation. And, your result is useless for drawing up a budget, or determining which coins came from where or from whom.

  106. Bart says:

    Furthermore, this a DYNAMIC SYSTEM we are talking about. in effect, the jar shrinks and expands based on inputs and outputs, automatically drawing more coins in and expelling them in response to the inputs.

    Before we go further down the road of trying to make your jar analogy apply better to the actual system, read my post at 10:03 am until you understand it!!!

  107. FerdiEgb says:

    Bart says:
    April 2, 2012 at 1:49 pm

    Bart, I have reread that comment:

    UA = natural uptake of anthropogenic emissions
    UN = natural uptake of natural emissions

    So, we only know N-UA-UN. Suppose UA = A. Then M = N – UN, N is greater than UN, and the rise is entirely natural. Equality would never be precisely the case, but it depends on the sequestration time.

    What you suppose there is that the anthro CO2 is sequestered near instantly, while the natural CO2 largely remains in the atmosphere. That is impossible. Both anthro and natural CO2 are 99% 12CO2. Natural sinks don’t make any differentiation between anthro or natural 12CO2. And the differences in the 13CO2 are too small to make a substantial difference in mass transfer. Thus there is no practical difference in sequestration time between anthro and natural CO2.

    The current amount sequestered by oceans and biosphere together is about 4 GtC/year. With a current CO2 level about 210 GtC above steady state (for the current temperature), that gives an e-fold time of about 52.5 years, far from instantly. No matter the origin of the CO2 molecules flying around in the atmosphere.

    Thus we have a yearly, growing, addition of 8 GtC of human CO2 and a natural sink capacity of only 4 GtC/year (growing in near constant ratio with the emissions) at the current extra CO2 pressure in the atmosphere. There is no way that you can explain that any natural source is responsible for the increase in the atmosphere, while the human emissions are not…

  108. gavincawley says:

    Bart, I wrote in my post “forgetting for the moment whether it is appropriate to a discussion of the carbon cycle”, I even put it on bold to make sure you didn’t miss it. Thus complaining that “Your analogy fails because you have artificially contrived a situation… “ is merely evasion.

    A minimal answer to the question would have required only two or three characters, depending on your view, so the effort of typing a response could not be the issue as your actual response was much longer than that, without actually introducing any more information to the discussion.

    The reason I asked the question was to see whether the concept of being “the cause of the increase” meant something different to you than it does to me. So any direct answer you could have given would have been helpful in understanding your point of view.

    So please, give a direct answer to the question as posed. A “yes” or “no” answer would be preferred, if “no” an explanation would be appreciated.

  109. gavincawley says:

    To reinforce Ferdinand’s comment above, I also agree that the uptake doesn’t significantly differentiate between anthropogenic CO2 and natural CO2 (indeed it can’t 12C is 12C is 12C, it isn’t labelled by source). So the one box dynamical model of the cabon cycle used in my paper divides the uptake according to the mixing ratio.

  110. Bart says:

    FerdiEgb says:
    April 2, 2012 at 3:19 pm

    “What you suppose there is that the anthro CO2 is sequestered near instantly, while the natural CO2 largely remains in the atmosphere.”

    Size matters. A small input to a negative feedback system with adequate bandwidth to respond can be easily attenuated to negligibility, whereas a large input creates… a larger excursion. Since we do not have any direct measurement of everything that is coming in from nature (e.g., an extended expulsion from upwelling of deep ocean currents), we cannot rule out the possibility.

  111. Bart says:

    FerdiEgb says:
    April 2, 2012 at 3:19 pm

    “With a current CO2 level about 210 GtC above steady state (for the current temperature)…”

    How do you calculate the steady state for the current temperature? If it is based on ice core data, I would consider such an estimate tentative and unproven, at the very least.

  112. Bart says:

    Before we get too far afield, let us pause to make the current point. You are now arguing, Ferdinand, that you have a problem with the sequestration rate being what you think is required. That’s fine, and a valid argument to have. But, in doing so, we must acknowledge that the mass balance argument is insufficient to convict anthropogenic emissions of the crime of increasing atmospheric concentrations, and you must rely upon other data to prosecute the case.

    If I can only get that concession from you, I will be happy for now.

  113. Bart says:

    FerdiEgb says:
    April 2, 2012 at 3:19 pm

    One final point on your last post:

    “The current amount sequestered by oceans and biosphere together is about 4 GtC/year.”

    How do we know what the current amount is? Don’t list for me all the known sinks and their estimated capacities. Justify that the list is exhaustive (something more compelling than “we don’t know of any others”), and that the estimates are supremely accurate (remember, it takes less than 3% variation of what we currently “know” to completely swamp the anthropogenic input).

  114. gavincawley says:

    Bart wrote: “How do we know what the current amount is?” The figure of 4GtC per year is the difference between natural uptake and natural emissions. You have already conceded that the mass balance argument allows us to infer this from knowledge of anthropogenic emissions and the observed rate of increase, and that is indeed how the figure is estimated.

  115. Phil. says:

    Bart says:
    April 2, 2012 at 4:39 pm
    FerdiEgb says:
    April 2, 2012 at 3:19 pm

    One final point on your last post:

    “The current amount sequestered by oceans and biosphere together is about 4 GtC/year.”

    How do we know what the current amount is? Don’t list for me all the known sinks and their estimated capacities. Justify that the list is exhaustive (something more compelling than “we don’t know of any others”), and that the estimates are supremely accurate (remember, it takes less than 3% variation of what we currently “know” to completely swamp the anthropogenic input).

    We don’t need to know what it is, just that on an annual basis over the last 50yrs it has never exceeded the growth in anthropogenic input! That’s the point of the mass balance equation, you’re looking at the result. You don’t need to know a detailed breakdown of all the known non-anthropogenic sinks and sources because what the results of the mass balance tells you, with certainty, is that sinks exceed sources, whether they are all known or not.

  116. Bart says:

    gavincawley says:
    April 2, 2012 at 4:46 pm

    “The figure of 4GtC per year is the difference between natural uptake and natural emissions.”

    This is circular logic.This is N – U, not U. You have built in the a priori assumption that N = 0.

    Phil. says:
    April 2, 2012 at 5:14 pm

    “We don’t need to know what it is, just that on an annual basis over the last 50yrs it has never exceeded the growth in anthropogenic input!”

    I do not doubt that is all you need to know. People who understand the issue need more.

  117. Bart says:

    gavincawley says:
    April 2, 2012 at 4:10 pm

    “So please, give a direct answer to the question as posed.”

    No. It is a red herring. Read my post at 10:03 am. When you understand it… I was going to say, get back to me, but when you do, you will have no further questions.

  118. Bart says:

    gavincawley says:
    April 2, 2012 at 11:05 am

    Perhaps it will help you to grasp what I have been telling you by addressing the problem on your own ground.

    “dM/dt = A + N – kM

    If you solve the equation you will still find that if the rate of growth of atmospheric CO2 is less than the rate of anthropogenic emissions then the rate of natural emissions must be less than the rate of natural uptake.”

    No. You won’t.

    Let us begin by stipulating that this model is way too simplified to capture the actual system. But, we will make do for now. At the very least, you have to modify it for ocean dynamics, making it

    dM/dt = c*(A + N) – kM

    where 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. Now, you have stipulated that

    dM/dt < A

    What does this tell us? Not much.

    In fact, dM/dt is observed to be approximately equal to c*A, but this is not actually known to be more than happenstance. If k is large (high bandwidth, rapid sequestration), then the solution will have M approximately equal to (c/k)*(A+N). The larger k is, the bigger N has to be in order that observations of M show it to be roughly equal to the integral of A times c. Furthermore, to maintain pace with the integral, N has to be increasing.

    Perhaps you might think it is unlikely that N would be increasing similarly to a scaled and biased plot of the integral of A. But, it is not. When you are dealing with functions which behave like a low order polynomial expansion, the set of all possibilities which produce similar results relative to bias and scaling is large.

    Now, if k is small, then, and only then, is M approximately the integral of c*(A+N), which would necessitate N being small.

    It all depends on the rate of sequestration, which is what I have been telling you.

  119. gavincawley says:

    Bart wrote: “This is circular logic.This is N – U, not U. You have built in the a priori assumption that N = 0.

    No Bart, the 4GtC/year is the amount sequestered by the natural environment, not the amount taken in, they are not the same thing. If you were familiar with carbon cycle you would know that the total uptake U is much larger than that, so it is obviously not an estimate of U itsel.

    Consider the oceans, according to fig 7.3 in the IPCC AR4 WG1 report, the oceans emit about 90.6 GTC/year into the atmosphere, but also takes about 92.2 GTC/year out of the atmosphere. So most of the flux between the oceans and atmosphere is an exchange flux that exchanges molecules of CO2 from the atmosphere, however an exchange does not alter the mass of the atmopsheric reservoir. However ocanic uptake is 1.6GTC/year higher than oceanic emissions, so 1.6CTG/year of carbon goes into the ocean and doesn’t come back out again. So the amount sequestered is the difference between the amount taken in and the amount taken out.

    Sequestration and uptake are not the same thing; sequestration is N-U, uptake is U. We don’t need to know the precise value of U to know the value of N-U, as you have already conceded the mass balance argument tells us that.

  120. gavincawley says:

    Bart wrote “No. It is a red herring”

    Bart, I explicitly said in the question that an answer was wanted forgetting for the moment whether the analogy was appropriate or not. So yet again you have filed to give a direct answer to a direct question, and typed a much longer answer than would have been required to answer the question.

    In a rhetorical debate, the object is simply to win, regardless of whether you are actually correct. In rhetorical arguments it is common to ask direct questions to paint your opponent into a corner, but it is very common for your opponent to give a direct answer to the question as (i) it gives a hostage to fortune in that you then have to remain consistent with that answer to avoid contradicting yourself and (ii) you will be painted into a corner. So in a rhetorical debate, it is common for your opponent to engage in evasion and avoid anserwing direct questions at all costs.

    In a scientific discussion however, both parties are seeking the truth and trying to identify errors in both their opponents reasoning and their own. Thus is again common to ask direct questions to try and understand your opponents argument and to narrow down on the precise source of error in the argument. The difference between a rhetorical and scientific debate is that in a scientific debate, your opponent ought to be keen to give a direct answer to your question, as they are as interested in getting to the truth as you are.

    In a scientific discussion it is also common to go through an argument, step by step, testing each link in the chain of reasonong one by one, as this is the easiest way to find a weakness in one of the links, but if you can’t to reach the conclusion that the chain of reasoning is sound.

    So constantly avoiding answering questions, of avoiding point-by-point analysis of the argument is making it look as if you are engaging in a rhetorical debate and are only interested in winning the argument, rather than a scientiic debate where you are interested in determining the truth. Was this what you intended?

  121. gavincawley says:

    Bart wrote:
    dM/dt = c*(A + N) – kM

    where 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.

    No bart, i you did that your model would violate the principle of conservation of mass. 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.

  122. FerdiEgb says:

    Bart says:
    April 2, 2012 at 6:11 pm

    gavincawley says:
    April 2, 2012 at 4:46 pm

    “The figure of 4GtC per year is the difference between natural uptake and natural emissions.”

    This is circular logic.This is N – U, not U. You have built in the a priori assumption that N = 0.

    Your differentiation between N and U is artificial, 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. And in this case it is proven that N is smaller than 0, for every year in the past 50+ years. That is not an a priory assumption, that is measured.

    The equation is:

    dM/dt = A + N – kM

    if we start at point zero without any A, the zero time equation is:

    dM/dt = N – kM

    where M is the increase in mass above the steady state, whatever that may be.

    at the first step of injecting A we have:

    dM/dt = A + N – kM
    where dM/dt and A are known:

    1/2 A = A + N – kM
    or
    N – kM = -1/2 A
    thus the sink rate in natural sinks kM is larger than the extra supply N from natural sources. With a small ratio of A in the total mass Mt (thus not only with the mass M above steady state), most of the removed CO2 is from Mt + N, only a small fraction is from A:

    kM = k((Mt + N + A) – Msts)
    where Msts is the mass at steady state and Mt is the current mass, all natural, and N is all natural and A is only a small fraction of the total Mt. Thus more natural CO2 is removed from the atmosphere than the theoretical supply by N. Which is not a net supply, as the overall natural balance is negative.

    You may repeat that for the 50+ measured steps, but that doesn’t change the negative balance, whatever N was, some sinks were growing more than N was increasing (if N increased at all) over the past 50+ years. Even if the fraction of A in the current atmosphere is growing, that hardly matters, until an equilibrium is reached between A and the removal of A via kM. That means that only at an 100% fraction of A in the atmosphere, there would be a reduction of 50% in A mass in the atmosphere. Excluding simple back and forth exchanges with other reservoirs.

  123. FerdiEgb says:

    Bart says:
    April 2, 2012 at 4:21 pm

    Size matters. A small input to a negative feedback system with adequate bandwidth to respond can be easily attenuated to negligibility, whereas a large input creates… a larger excursion. Since we do not have any direct measurement of everything that is coming in from nature (e.g., an extended expulsion from upwelling of deep ocean currents), we cannot rule out the possibility.

    We don’t know the variability of most natural inflows and outflows with sufficient accuracy, but we do know the variability of the net natural balance. That is +/- 1.5% of the estimated total inflows and outflows. Or a variability of about halve the human emissions total inflow. Thus any response to a change in the natural balance must be equal to or faster than a response to the human emissions…

    A response from the natural sinks to any increase in the atmosphere must be the same whatever caused the increase. The current response is about 4 GtC/year, while the emissions are at about 8 GtC/year…

  124. FerdiEgb says:

    Bart says:
    April 2, 2012 at 4:24 pm

    How do you calculate the steady state for the current temperature? If it is based on ice core data, I would consider such an estimate tentative and unproven, at the very least.

    Ice cores have only one real problem: they are smoothing the results over 8-600 years, depending of the accumulation rate. That doesn’t change the average, only the resolution. Within all resolutions, we see about 290 ppmv for the current temperature. With backcalculation we can estimate 300 ppmv at zero human emissions…

  125. FerdiEgb says:

    Bart says:
    April 2, 2012 at 4:31 pm

    Before we get too far afield, let us pause to make the current point. You are now arguing, Ferdinand, that you have a problem with the sequestration rate being what you think is required. That’s fine, and a valid argument to have. But, in doing so, we must acknowledge that the mass balance argument is insufficient to convict anthropogenic emissions of the crime of increasing atmospheric concentrations, and you must rely upon other data to prosecute the case.

    If I can only get that concession from you, I will be happy for now.

    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. If the increase in the atmosphere was more than the emissions, then we would have a part from the emissions and a part from nature adding to the increase. In both cases, the sequestering is less than the emissions or less than the sum of the emissions + extra natural supply. If there was no increase or even a decrease in the atmosphere, then the sequestration rate was larger than the emissions and any additional supply by nature.

  126. Bart says:

    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.

  127. Bart says:

    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.

  128. Bart says:

    [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.

  129. Phil. says:

    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.

  130. gavincawley says:

    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?

  131. gavincawley says:

    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?

  132. tallbloke says:

    Bart: you are banging your head against one of the tablets of stone here.
    Use a jackhammer and a dust mask.

  133. gavincawley says:

    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.

  134. Bart says:

    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.

  135. Bart says:

    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).

  136. gavincawley says:

    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?”

  137. tallbloke says:

    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.

  138. FerdiEgb says:

    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…

  139. gavincawley says:

    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.

  140. clivebest says:

    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 !

  141. gavincawley says:

    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 .

  142. tallbloke says:

    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.

  143. gavincawley says:

    @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?

  144. tallbloke says:

    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.

  145. gavincawley says:

    @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?

  146. Bart says:

    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.

  147. gavincawley says:

    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?

  148. tallbloke says:

    OK, the teabreak obviously did Bart a power of good, so I’m gracefully heading back to look after my blog at this point…

    :-)

  149. Bart says:

    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.

  150. Bart says:

    “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.

  151. Bart says:

    tallbloke says:
    April 3, 2012 at 1:22 pm

    Well, drop back later. I’m bailing out. I’m really sick of this. Whatever the triplets write after this, the reader should be aware that it has been demonstrated that they did not know what they were talking about before this post, and it is unlikely they will have gained greater wisdom or knowledge after.

  152. gavincawley says:

    Shame you are off tallbloke, it is sad that so few are willing to actually go through the steps one by one and prove me wrong. You should however read Fred Singers article “Climate Deniers Are Giving Us Skeptics a Bad Name”

    http://www.independent.org/newsroom/article.asp?id=3263

    I personally would try to avoid using the word “Denier” as name-calling is rarely productive (see above). However the basic point Prof. Singer makes is a pretty good one, which is that skeptics that cling onto arguments that are known to be false (such as that the greenhouse effect violates the second law of thermodynamics) only serves to marginalise them from the climate debate as it makes them look as if they don’t understand the science. Another one of the arguments that Prof. Singer says should be dropped is the argument that the rise in CO2 is natural, perhaps you should ask him to expand on this in a blog post here?.

    The reason I wrote my rebuttal of Essenhigh’s paper is basically the same, I don’t want to see skeptics make themselves look foolish any more than you do. Repetition of such canards does neither side of the debate any good. Follow Singers advice and drop them

  153. tallbloke says:

    What? Are you talking to me Gavin you cheeky oik?

    Where did I in my interaction with yu discuss thermodynamics of the radiative greenhouse effect or reach any judgement about the proportion of the airborne fraction that belongs to humans?

  154. gavincawley says:

    tallbloke, read a bit further, where I wrote “Another one of the arguments that Prof. Singer says should be dropped is the argument that the rise in CO2 is natural, perhaps you should ask him to expand on this in a blog post here?.”

    I mentioned the second law thing as it is the first “denier argument” that Prof. Singer mentions. The argument that the rise in CO2 is natural is if anything worse than the second law canard; anyone capable of balancing a bank account ought to understand how we know the rise in CO2 is anthropogenic.

  155. Phil. says:

    Well it’s model with approximations not a mass balance equation and omits Henry’s Law, the equation should at least have one more constant, i.e.:
    Mdot = N + A + a*(O – b*M) where b is order 10 to account for the Henry’s Law coeff etc.
    I like the way your model can ‘magic’ away half the total input (1-c)*(A+N), nice sleight of hand, no sink terms to the ocean in the equation just permanent sequestration which you say is small and no treatment of land at all!

  156. tallbloke says:

    gavincawley says:
    April 3, 2012 at 2:21 pm

    tallbloke, read a bit further, where I wrote “Another one of the arguments that Prof. Singer says should be dropped is the argument that the rise in CO2 is natural,

    It should be obvious enough that I “read a bit further” Gavin, hence my question:

    “Where did I, in my interaction with you, discuss the thermodynamics of the radiative greenhouse effect or reach any judgement about the proportion of the airborne fraction that belongs to humans?”

    So would you answer the question now please.

    Thanks.

  157. Phil. says:

    Tallbloke, he doesn’t say you did, that was Singer’s illustration of a flawed argument that gives ‘sceptics a bad name’.

  158. FerdiEgb says:

    Bart says:
    April 3, 2012 at 12:30 pm

    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.

    Bart, nobody is interested in how much of the total CO2 in the atmosphere is natural or anthro of origin, neither how much of what is going into the sinks is natural or anthro of origin. The only point of interest is what the origin of the increase in total mass of CO2 in the atmosphere is. That is the only point of interest for any effect that it may or may not have on the temperature at the surface.

    The question you don’t agree with is not the same question that Gavin asked, as the mass balance is about total quantities of CO2 going into natural sinks, not total natural CO2 into natural sinks.

    Even if all anthro CO2 was taken away by the next trees within a minute that it was released, that would not make any difference for the total increase in the atmosphere, as that simply is replaced by natural CO2 which should have been captured instead, but now stays longer in the atmosphere.

  159. tallbloke says:

    Phil. says:
    April 3, 2012 at 4:13 pm
    Tallbloke, he doesn’t say you did, that was Singer’s illustration

    You having as many comprehension difficulties as Gavin Phil?

    gavincawley says:
    April 3, 2012 at 1:44 pm
    You should however read Fred Singers article “Climate Deniers Are Giving Us Skeptics a Bad Name” …I don’t want to see skeptics make themselves look foolish any more than you do. Repetition of such canards does neither side of the debate any good. Follow Singers advice and drop them

    Gavin’s final sentence is clearly attributing the ‘canards’ Singer outlines to me is he not?

    I’d like a yes or no answer please.

  160. Bart says:

    FerdiEgb says:
    April 3, 2012 at 4:13 pm

    “Even if all anthro CO2 was taken away by the next trees within a minute that it was released, that would not make any difference for the total increase in the atmosphere, as that simply is replaced by natural CO2 which should have been captured instead, but now stays longer in the atmosphere.”

    Again, your static thinking is evident. When trees capture CO2, they grow. When they grow, they soak up more CO2, and they reproduce to produce more CO2 gobbling trees.

    All of the CO2 sinks do this -their capacities grow with increasing CO2. The only question is, how fast do they grow?

  161. Phil. says:

    I read that he was disappointed that you weren’t going to be around to inlist your help in defeating the canards which were not of your origin.

  162. Phil. says:

    Bart, in answer to your question the data tells us that it doesn’t grow fast enough the catch up, just follow at a distance.

  163. tallbloke says:

    Phil. says:
    April 3, 2012 at 7:17 pm

    I read that he was disappointed that you weren’t going to be around to inlist your help in defeating the canards which were not of your origin.

    Ah, that explains why your logic is up the spout then. You and Gavin don’t read what people actually write.

    Bart says:
    April 3, 2012 at 1:37 pm

    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.

    Bart, I see your problem, and empathize.

  164. Bart says:

    Phil. says:
    April 3, 2012 at 7:56 pm

    “…it doesn’t grow fast enough the catch up, just follow at a distance”

    The data tell us nothing of the kind.

    Phil. says:
    April 3, 2012 at 2:23 pm

    “Well it’s model with approximations not a mass balance equation and omits Henry’s Law, the equation should at least have one more constant…”

    No doubt, you have seen that I addressed that at 1:35 pm. Here’s the problem: you do that, and you no longer get a nice roughly 50/50 split between CO2 in the atmosphere and CO2 in the oceans when “k” is small. And, that ~50/50 split is part of the Alarmist case: they claim the theory predicts such a split and, mirabile dictu, there is the split right there in the data.

    In fact, they’ve gone to a lot of trouble to fudge together “buffer factors” which will dispense with Henry’s Law and allow them to assign the coupling constants arbitrarily so that they can make the claim. I, frankly, chose values giving the 50/50 split because I did not want to wade into those waters – one poorly reasoned argument to take down at a time. But, if you want to insist on a non-50/50 split, you are not arguing against me, but with me.

  165. gavincawley says:

    Tallbloke, I said “such as”, indicating that this was an example of the kind of “denier argument” that Singer saus should be dropped so that the skeptics can retain credibility. This in no way implies that you had used that argument, I’m sorry that you have taken umbridge over this, but the error is in your parsing of the sentence, not in my writing.

  166. gavincawley says:

    BTW, Phils comment was pretty much what I had in mind. All of the “denier arguments” (sorry I don’t like the d-word either) that Fred Singer mentions should be dealt with. Not everybody here believes in all of them, but there are many here who each believe at least one of them. What we need is to go through the argument step by step and find out whether they are true or not. I was dissapointed that you abandoned the exercise so early as it could have gone a long way to discarding this particular canard, but the opportunity was lost.

    I appologise for any implication that you thought the second law canard was true. The wording seems clear to me,and indeed to Phil, but obviously it isn’t as clear as I thought.

  167. Bart says:

    Bart says:
    April 3, 2012 at 12:30 pm

    I wish to point out a small matter here in my derivation.

    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)

    I should not have dropped the “s” in the numerator of the first Laplace transform version of the transfer function. The zero at “a” is actually “activated” before the pole at “2*a” in the frequency response plot. If doing it over again, I would write:

    Under the assumption that “a” is much greater than “k”, then this transfer function is approximately

    H(s) := (s+a) / ( (s+2*a) * (s+k) )

    The term (s+a) / (s + 2*a) is the transfer function of a wide bandwidth lead/lag network with dc gain of 1/2. Thus, we can further approximate

    H(s) := 0.5 / (s + k)

    Nothing important changes – I just like to have things in perfect order.

  168. FerdiEgb says:

    tallbloke says:
    April 3, 2012 at 4:56 pm

    I don’t know how you think about the greenhouse effect, not my topic, but I have the impression that you are supporting Bart’s stance on the CO2 increase. It is that where we differ. Thus please, don’t let that interfere with the positive discussion you had with Gavin.

    To give you some aid for question 2:

    Increasing vegetation also increases the amount of rotting wood/leaves debris at the end of the seasons and over longer periods. But that is what is going back and forth in exchanges with the atmosphere. From the atmospheric viewpoint most of that is throughput: what goes out by vegetation CO2 uptake lagely comes back as vegetation decays in another season. That adds to the turnover of CO2 within a year but largely doesn’t give a change in total atmospheric CO2 at the end of the year.

    How do we know that vegetation is growing? That can be deduced from the oxygen balance: slightly less oxygen is used than calculated from the use x efficencies of fossil fuel burning. That means that some O2 is produced by the total biosphere, thus more CO2 is captured by the biosphere than produced. The amounts are roughly known, since the analytical techniques to detect small changes of less than 1 ppmv in 200,000 ppmv O2 have evolved over time. The result: some 1 +/- 0.6 GtC as CO2 is sequestered in the biosphere:
    http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf

  169. FerdiEgb says:

    Bart, let’s start with the basic equation
    dM/dt = c*(A + N) – kM

    With as constraint that 0 < dM/dt < A

    For brevity and clarity, let us assume that the throughput from oceans and vegetation is roughly constant and that kM is entirely into the oceans. N is solely an increase in output from volcanoes, so that there is no return flow, at least not on non-geological times…
    As well as for human emissions as for volcanic releases, there is no transfer function for their release into the atmosphere, that is simply additional. Thus c = 1, which BTW always is the case for A.

    As M is constantly measured, we know the change over a year, for the past 50+ years. That can be expressed as dM/dt = b*A, where 0 < b < 1.
    Be aware that dM/dt is about total quantity, regardless of the ratio between N and A in M.

    By substitution in the basic equation, that gives;
    b*A = A + N – kM
    or
    N = kM – (1-b)*A
    as b < 1, that means that kM > N, what is observed. Thus in fact, N is only throughput, but we can make that clear in the next item.

    In another year, a huge solar flare hits the earth and awakens all volcanoes, so that they double their emissions. The above equation now is:

    2*N = kM – (1-b)*A

    To reach that, either k or M should be (near) doubling. That is only possible by an increase of k or an increase of M. Either way, kM remains higher than 2*N as the observed term (1-b)*A hardly changed but anyway still is positive.

    Thus despite a doubling of the extra natural input, there is no change in the observed atmospheric increase. That is only possible if the sinks increased at (near) the same rate as the sources increased. Thus simply doubling the throughput without adding anything net to the mass in the atmosphere. An increase in k is very unlikely (one expects even a decrease, as more constraints in oceanic uptake come in), an increase (near doubling!) in M beyond 0 < dM < A is not observed either.

    The only alternative explanation which fits all equations and observations is that N is small, compared to A. Over the past 50 years, that is what is observed: natural variability around the trend is about +/- 2 GtC while the emissions currently are at 8 GtC/year.

  170. gavincawley says:

    Further to Ferdinand’s comment above, I am still happy to go through the mass balance argument step by step with anybody who is interested in its validity. All I ask is that at each stage your agreement is unambiguosly stated before proceeding onto the next step.

    Sometimes it is possible to prove something using two different methods of proof. Just because you can’t prove it by method A becuase you don’t know the value of X does not imply that you can’t prove it by method B if method B doesn’t rely on knowledge of the value of X. Thus the only way to demonstrate that method B (in this case the mass balance argument) is incorrect is to identify an error in the chain of reasoning in method B, discussion of method A (e.g. Bart’s model of the carbon cycle) is utterly irrelevant.

  171. tallbloke says:

    Hi Ferdi:

    Your area is not my primary interest either, so i don’t want to derail this discussion with my less than perfect understanding of the issues. However, I think what i was getting at was better expressed by bart in a comment you haven’t replied to.

    Bart said:
    “Again, your static thinking is evident. When trees capture CO2, they grow. When they grow, they soak up more CO2, and they reproduce to produce more CO2 gobbling trees.

    All of the CO2 sinks do this -their capacities grow with increasing CO2. The only question is, how fast do they grow?”

    Now it seems to me that however you answer this, it has to avoid d13-d12 ratio arguments, aince Idso’s paper in 2003 hasn’t been properly answered so far as I know. Your oxygen ratio argument is interesting, but oxygen is a highly reactive gas which gets used up in many other processes besides the carbon cycle, for example ozone production.

    So although I’m very willing and happy to listen to all the deductions you make, I think there are areas of uncertainty which have to be explicitly brought out, examined and if possible quantified (within error limits) before we go forward to drawing conclusions.

  172. gavincawley says:

    Tallbloke, I would be happy to discuss the uncertainties in the mass balance argument where they arise in each step. We were at step #2.

    Step #2 Do you agree that the carbon cycle is a closed system, where the sources and sinks are either “natural” or “anthropogenic” and carbon does not enter or leave the atmosphere by any other route?

  173. FerdiEgb says:

    tallbloke says:
    April 4, 2012 at 3:46 am

    Bart said:
    “Again, your static thinking is evident. When trees capture CO2, they grow. When they grow, they soak up more CO2, and they reproduce to produce more CO2 gobbling trees.

    All of the CO2 sinks do this -their capacities grow with increasing CO2. The only question is, how fast do they grow?”

    The Idso’s have a very good database for the reaction of a lot of different species on increased CO2. In average, plants grow with 50% when CO2 is doubled, in the best circumstances. In the real world, the circumstances are mostly less than best, thus the 50% is a maximum. More plants is more problematic (and much slower), as seedlings in dense forests have little chance of growing, except if an old tree falls down, thus mainly replacement. The main way to obtain more plants is when the area expands, as (land) glaciers melt and/or tundra becomes forest and/or deserts become tundra. That played a role mainly during the glacial – interglacial transitions, where the increase in temperature of the oceans dominated the CO2 levels, plant area only played a secondary role but relative more important once the interglacial was reached (+/- 10 ppmv over the Holocene).

    Oxygen for ozone formation (and back…) is an equilibrium process, mainly in the stratosphere. In the troposphere typical at 80 ppbv, or 0,08 ppmv, hardly of influence on the oxygen levels (10% of the measurement error of the oxygen measurements). Near everything else on earth that could be oxydised is already oxydised: metals, silicon and other minerals…
    Based on the oxygen and d13C measurements, some 20% of human emissions (in quantity) is captured by the vegetation cycle and 30% by the oceans. No static thinking at all, as the total quantity captured follows broadly the emissions with a surprising stable ratio over the past 50 years.

  174. Bart says:

    FerdiEgb says:
    April 4, 2012 at 1:21 am

    “That adds to the turnover of CO2 within a year but largely doesn’t give a change in total atmospheric CO2 at the end of the year.”

    From that point of view, a crystal radio receiver could never work, because every rectified half wave would have the same area.

    FerdiEgb says:
    April 4, 2012 at 3:26 am

    Pitiful. Absolutely pitiful. You cannot even solve a differential equation. And, you destroyed your argument from the moment you chose c = 1 (see response to Phil at April 3, 2012 at 11:29 pm).

    gavincawley says:
    April 4, 2012 at 3:41 am

    “…I am still happy to go through the mass balance argument step by step with anybody who is interested in its validity.”

    I have already satisfied mass balance, and shown that M can still be driven mostly by N while maintaining conservation of mass in the atmosphere and oceans. The argument fails, and you are in denial.

  175. Bart says:

    Guys… your argument hinges on c being approximately 1/2. Your brothers in arms have gone to A LOT of trouble to construct their “theories” about how CO2 passes between atmosphere and ocean to make it so. If you do not even know enough to know this, then you do not know enough to be pontificating about the matter at all.

    I didn’t make this up.I didn’t choose c := 1/2 out of a hat. I would LOVE for you to insist that c is something other than approximately 1/2. It totally kills your argument at its very foundation.

  176. clivebest says:

    AFAICS the fundamental difference between Bart (B) and Ferdinand/Gavin (FG) is that FG assume natural carbon sources N remain constant, whereas Bart assumes N varies.

    FG: dM/dt = A + N – kM
    B: dM/dt = c(A+N) – kM with approximations C=1/2

    So before 1750 (A=0, M=M0)
    FG) N=k*M0 –> k=N/M0
    B) N/2=k*M0 –> k=N/(2M0)

    now:
    FG) kM = A/2 + N (k depends on A for constant N)
    B) kM = N/2 ( k depends on N)

    For FG the net increase in CO2 is only due to A and sinks increase linearly with net partial pressure.
    For B the net increase in CO2 is due to A – PLUS an increase in N . The sink increases ONLY in response to the natural increase in N, because (he argues) they are coupled together.

    What I learned was:
    - There is always an equilibrium value for CO2 concentrations in any period on Earth. When volcanic activity was much higher a major source of CO2 was from the Earth’s crust and equilibrium levels were > 1000 ppm. Currently volcanic sources are about 1% of anthropogenic sources – although that could increase at any time. Without human emissions the equilibrium content of CO2 in the atmosphere would be ~ 290 ppm.
    - The Net e-folding time for CO2 is ~52.5 years. This means that if humans stabilize emissions at roughly current values of 8Gt per year, and continue to emit 8 Gt/year forever then….

    the final CO2 content of the atmosphere will be 500 ppm. Is this so terrible ?

    Fitting the observed temperature rises to SB response to CO2 forcing gives DT = 2.5 Ln(C/C0) and a final temperature rise of 1.5 deg.C ! The climate could turn out to be actually better for mankind and the natural world !

    Another ice is a far more serious threat !

  177. Bart says:

    Perhaps there is some confusion because I did not define the following terms clearly (amended here):

    A = anthropogenic input flux
    N = natural input flux

    These are the time derivatives of concentration, not the concentration itself. M is the time integral of terms in A, N, and M itself.

    The “k” term is a constant. It does not change. It quantifies the expansion of the sinks as M increases, i.e., it is a sensitivity term. In the real world, it may vary somewhat, but you should assume it is constant.

    Ferdinand, your fundamental argument is that M := 1/2 * integral(A). Keep that in mind when looking at the conclusions you are driven to with your math. E.g.,

    N = kM – (1-b)*A

    means

    M = (N + (1-b)*A)/k

    A is on the order of something like a couple of ppmv/year equivalent/ If “k” is “large”, then it cannot possibly account for the measured concentration. That is the point I have been driving at all along.

    IF “k” is “small”, then the equation works out to approximately

    M = c*integral(A + N)

    with c = 1/2 and N = 0, this gives the solution you want. But, it is not the only solution which is allowed by the observations.That is the point I have been driving at all along.

  178. Bart says:

    Bart says:
    April 4, 2012 at 9:27 am

    “Pitiful. Absolutely pitiful.”

    My apologies for intemperate remarks. My anger is not at your making mistakes – I am very patient with my students when they are trying to learn, and making mistakes is a very good way to learn.

    My anger is that you guys seem not to know even half of the actual arguments which have gone into the present state of the science over a span of decades, and yet you have set yourself up as authorities to proclaim how “skeptics can retain credibility”.

    That really is unforgivable hubris.

  179. gavincawley says:

    Bart writes “From that point of view, a crystal radio receiver could never work, because every rectified half wave would have the same area.”

    You have missed Ferdinand’s point. As you have used an analogy, so will I. If I have jar containing 30 sweets, and every day I take 20 sweets out and eat them, but also buy a packet of 20 sweets and put them in the jar, then there has been a turnover of 20 sweets, but it hasn’t affected the number of sweets in the jar at the end of the day.

    Likewise the oceans emit about 90GtC/year of carbon into the atmosphere each year (IIRC) but take in about 92GtC/year. So the oceans cause a turnover of about 90GtC/year, which has no effect on the amount of CO2 in the atmosphere, and a net flux of about 2GtC/year, which means the oceans also take about 2GtC/year out of the atmospheric reservoir.

    You can disagree with the figures if you like, however Ferdinand’s point about an exchange flux not affecting atmospheric CO2 levels stands.

    Also you may think think your model obeys mass balance, you have not gone through the mass balance argument step by step. For a very good reason, which is that you know that if you did go through it step by step you would not be able to identify a flaw, hence your unwillingness to give direct answers to direct questions.

  180. gavincawley says:

    clivebest wrote: “AFAICS the fundamental difference between Bart (B) and Ferdinand/Gavin (FG) is that FG assume natural carbon sources N remain constant, whereas Bart assumes N varies.”

    This is not correct, as I have stated several times the mass balance argument makes no assumption that anything is constant. The model of Essenhigh that I adapted to show the difference between residence time and adjustment time does, however it is the mass balance argument that demonstrates that the rise is anthropogenic. The one box model just shows that the observations are consistent with a simple model of the carbon cycle based on mainstream science.

  181. gavincawley says:

    clivebest wrote “The Net e-folding time for CO2 is ~52.5 years. This means that if humans stabilize emissions at roughly current values of 8Gt per year, and continue to emit 8 Gt/year forever then….the final CO2 content of the atmosphere will be 500 ppm. Is this so terrible ?”

    This is not correct. It is the difference in partial pressure between the atmosphere and surface ocean that drives the oceanic sink. If the atmospheric concentration stabilises, then as the surface ocean takes up more CO2, the partial pressure difference falls as they come back into equilibrium and the sink would shrink. While we keep anthropogenic emission at current rates the atmospheric concentration will continue to rise. If the sinks can’t deal with our emissions now, why should they be able to cope with the same levels in the future when they are heading towards saturation (thankfully they are not there yet)?

  182. clivebest says:

    Gavin,

    That simply can’t be right. The earth maintained CO2 levels of over 1000 ppmv for millions of years during the dinosaur era, presumably because volcanic sources of CO2 were many times greater than today’s anthropogenic sources. The atmosphere stabilized then as it will do in the future if man can remove the second derivative ( an increase of the increase).

    Every year man adds a pulse of N0= 8 Gt of CO2. This then decays away with a lifetime Tau. The accumulation of fossil CO2 in the atmosphere for year n is simply given by.

    CO2( n) = N0( 1 +sum(i=1,n-1) (exp(-n/Tau)))

    If we assume that n is very large then we can treat this sum as an infinite series and the atmosphere will eventually saturate at a certain value of anthropogenic CO2 concentration.

    Multiplying both sides by exp(1/Tau) we can derive that the sum in the limit as n-> infinity :

    CO2(n) = N0/(1-1/exp(1/Tau))

    For tau = 53 years we get CO2(infinity) = 1.7*(pre-industrial values) or about 500 ppmv.
    The Mauna Loa data is rising approximately linearly because we are accelerating emissions. All we have to do is stabilize them at some reasonable value. Even if we just burned all fossil fuels it would still eventually stabilize. The danger facing western civilization right now is economic suicide through climate change hysteria.

  183. Bart says:

    clivebest says:
    April 4, 2012 at 9:53 am

    “For B the net increase in CO2 is due to A – PLUS an increase in N . The sink increases ONLY in response to the natural increase in N, because (he argues) they are coupled together.”

    No, I am not arguing that at all. The sinks do not discriminate. But, if the sinks are strongly activated, they will bleed out the anthropogenic component before it can build up. Therefore, in that case, the natural input has to be the driver. Since the natural component cannot be quantified by current knowledge, there is no limit on how large it can be, so there is no way to eliminate the possibility.

    gavincawley says:
    April 4, 2012 at 10:59 am

    “You have missed Ferdinand’s point.”

    If I have a bucket into which I am alternately pouring in a liter of water, then emptying it out, then my average volume of water is 1/2 liter. If I now alternatingly put in 2 liters and empty it out, my average volume is 1 liter. The exchange volume matters.

    “Likewise the oceans emit about 90GtC/year of carbon into the atmosphere each year (IIRC) but take in about 92GtC/year.”

    You do not KNOW this. These are estimates which are calculated under the constraint that your model for the entire system is correct. You have to impose such constraints to get an answer, because you have too many unknowns for the equations. But, it is circular logic. It proves nothing.

    “…if you did go through it step by step you would not be able to identify a flaw…”

    I have already identified the flaw. I have repeated it over and over and over. It just sails right over your head. The flaw is this: you are assuming that the atmosphere acts as a pure accumulator (no ultimate sinks) and that the natural balance is perfectly steady. There is no evidence available which confirms either of these assumptions.

    Look, this is very simple. The response to both N and A is precisely the same. If the constant “k” is large (sinks are very active), then the atmospheric concentration will closely track (c/k)*(N+A). In this case, A is not large enough to account for the measured concentration, so N has to be the driver. In the case where “k” is small, the concentration will track c*integral(N+A). If “c” is close to 1/2, then the accumulation has to be driven by A. If “c” is substantially less than 1/2, then N is playing a significant role, too.

  184. Phil. says:

    clivebest says:
    April 4, 2012 at 9:53 am
    AFAICS the fundamental difference between Bart (B) and Ferdinand/Gavin (FG) is that FG assume natural carbon sources N remain constant, whereas Bart assumes N varies.

    Not at all, the only assumption in the mass balance equation that F, G & I use is the that the rate of change of atmospheric CO2 is given by the sum of Anthropogenic flux (A) and all other source fluxes (N) minus the sum of all sink fluxes (S):
    d[CO2]/dt = A + N – S

    These variables are free to vary as much as they like, and they have varied over time, however d[CO2]/dt≈A/2 over the last 50 years, therefore (N-S) has consistently been negative (i.e. a net sink). This is a proper mass balance, despite being asked Bart has avoided saying what’s wrong with this equation, other than to say it’s not complicated enough, which he solves by removing half of the source flux and making the sink terms a linear function of CO2! Bart is trying to produce a much more complicated model involving magically losing about half of the source flux, introducing variables he never defines and admittedly uses incorrect values for others, which doesn’t answer the question being asked anyway.
    Regarding his constant ‘k’, it is variously:
    The “k” term is a constant. It does not change. It quantifies the expansion of the sinks as M increases, i.e., it is a sensitivity term……
    If “k” is “large”, then it cannot possibly account for the measured concentration. That is the point I have been driving at all along.

    IF “k” is “small”, then the equation works out to approximately

    M = c*integral(A + N)

    with c = 1/2 and N = 0, this gives the solution you want….

    But we are also told:
    the term involving “k” represents ultimate sequestration in the ocean…
    Under the assumption that “a” is much greater than “k”,
    ………
    Which is to say that the differential equation is approximately

    Mdot := 0.5*(N + A) – k*M

    So are these different variables or not? According to the latter definition k*M goes into the ocean permanently and 0.5(N + A) goes into the ocean temporarily but never comes back out!
    Bart, take a deep breath and sort it out because this is a real mish-mash.

    And preferably stop generally insulting and abusing anyone who doesn’t agree with you!

    “Pitiful. Absolutely pitiful”, “WHICH IS WHAT I EFFING SAID SEVERAL POSTS AGO!!!!! But, apparently, I have to spoonfeed it to these youngsters”, “The “mass balance argument” is, there is no way to sugarcoat this, stupid”, “Again, sorry, it has to be said… Stupid”

  185. gavincawley says:

    Bart wrote: “If I have a bucket into which I am alternately pouring in a liter of water, then emptying it out, then my average volume of water is 1/2 liter. If I now alternatingly put in 2 liters and empty it out, my average volume is 1 liter. The exchange volume matters.”

    That is an inappropriate example. The average volume of water in the bucket is only 1/2 becase you are putting one liter in as a discrete action and then taking one liter out as a discrete action. However the carbon cycle is continuous, not discrete. If you put one liter in and took one liter out, but by alternating putting one tea spoonfull in and one spoonful out then the average amount of water in the bucket would be half a teaspoon full, but the volume of the exchange would be the same. At the end of the exercise the level of water in the bucket would be exactly the same as it was at the start. This is because an exchange doesn’t affect the volume of the reservoir. To do that you need a difference between the amount in and amount out, and it is this difference that matters, not the volume.

    “I have already identified the flaw. I have repeated it over and over and over.”

    No you have not identified a flaw as you refused to go through the step by step analysis and instead went off at a tangent based on an issue that is not actually part of the mass balance argument. If you really want to prove me wrong, then the easiest way is to go through the six steps one by one, saying where you agree and where you dont. By continually avoiding this you are just demonstrating that you know as well as everybody else that you will not be able to identify the flaw.

  186. gavincawley says:

    clivebest David Archer has written a primer on the carbon cycle that explains in great detail how the carbon cycle will respond, it is a lot more complex than the very simple models being discussed on this thread (which is why I gave the caveat in my paper that such simple models are of little use for quantative rather tha qualatative analyses, and gave some details of the shortcomings of such models). It is well worth a read.

    However, I have already pointed out the flaw in your argument, which is that as the oceans take up carbon the partial pressure difference between oceans and atmosphere will be reduced and so will the flux of carbon into the oceans. Thus CO2 concentrations cannot stabilise unless we reduce anthropogenic emissions to the point where they match the capacity of the natural sinks. However the growth of the natural sinks is a result of increasing CO2, so if levels stabilise they will no longer expand, but will instead shrink.

  187. Bart says:

    gavincawley says:
    April 4, 2012 at 12:32 pm

    “The average volume of water in the bucket is only 1/2 becase you are putting one liter in as a discrete action and then taking one liter out as a discrete action. However the carbon cycle is continuous, not discrete.”

    We were speaking specifically of vegetation, and eras of growth and decay.

    But, you do bring up a point about why I made the crystal radio receiver analogy. The continuous action of varying rates of growth and decay across the entire spectrum of vegetation would tend to low pass filter the cycling, and the average difference becomes a steady difference. Just like in a crystal radio, where the signal is rectified, then smoothed through a low pass filter. The average of the rectified signal is then what comes out of your speaker.

    A final way to look at it: take the reductio. Are you telling me there would be no difference in CO2 concentration if the Earth were a dead planet, with no vegetation at all, compared to what it is now?

    “If you put one liter in and took one liter out, but by alternating putting one tea spoonfull in and one spoonful out then the average amount of water in the bucket would be half a teaspoon full, but the volume of the exchange would be the same.”

    Take a breath. Try again. Think it through.

    “If you really want to prove me wrong…”

    I have already proven you wrong. I have laid it out for you on a silver platter with bone china and crystal goblets. If you do not understand now, I do not see much hope that you ever will.

  188. FerdiEgb says:

    Bart says:
    April 4, 2012 at 10:03 am

    M := 1/2 * integral(A)

    That M is about halve the integral of A over time is what is observed, but nobody insists that it must be that (not even the IPCC), M may be negative or zero or higher than integral(A) over time, as the real M := integral(A) + integral(N) – integral(kM)

    where M = difference with the historical Mo for the current temperature.
    and k = ~210/4 = ~52.5 (the current M / observed sink rate).
    and integral(kM) > integral(N) at least over the past 50+ years, including kM > N in every individual year (a nice but not necessary condition).

    That means that integral(N) is simple throughput – turnover through the atmosphere, where the difference between integral(kM) and integral(N) is the observed sink capacity of nature as a whole, whatever the height of integral(N) or its variation. The only constraint is that the measured increase over the full period is less than integral(A), even if in one or more years N > kM.

    The equation M = c*integral(A + N) has no single solution, because both c and N are undefined, while the above equations have a single solution for the increase in the atmosphere as result of integral(A) and the known difference between integral(N) and integral(kM), whatever these two terms individually may be. If k didn’t change too much over time, it is even possible to calculate integral(N), which probably is near zero (as it was in pre-industrial times).

    BTW, the CO2 storage in reservoirs and the fluxes between them can be compared to a capacitor in a radio circuit. Your radiowave passes the capacitor without problems, but doesn’t leave any change in storage on the capacitor at the end of any full wave…

  189. gavincawley says:

    Bart wrote “I have already proven you wrong. I have laid it out for you on a silver platter with bone china and crystal goblets.”

    no, you have attacked the straw man of an argument I did not make, not the mass balance argument. You can tell this by the fact that we only got as far as step #1 in the argument I am actually making.

    “If you do not understand now, I do not see much hope that you ever will.”

    Well perhaps going through my argument step by step and point out my error when I make it. That will make it much easier for me to understand where I am going wrong. Unfortunately you seem to be extremly unwilling to do the one simple thing that would resolve the issue very quickly,

  190. clivebest says:

    Gavin: However, I have already pointed out the flaw in your argument, which is that as the oceans take up carbon the partial pressure difference between oceans and atmosphere will be reduced and so will the flux of carbon into the oceans.

    Perhaps in the short term. However, in the longer term an equilibrium must be attained so long as fluxes remain sufficiently stable over many decay lifetimes – and CO2 becomes distributed throughout the ocean depths leading to long term sequestration. Otherwise how the hell did life and liquid oceans survive for the last 3 billion years ? I have the feeling that this is an argument that cannot be resolved by resorting to more complex models.

  191. gavincawley says:

    Clivebest wrote “However, in the longer term an equilibrium must be attained so long as fluxes remain sufficiently stable over many decay lifetimes”

    However I have pointed out that the fluxes will not remain stable as the net oceanic sink will dissapear as the partial pressure of the surface waters equilibriates with the atmosphere. At that point the adjustment time will grow as the uptake into the thermocline is no longer the bottleneck.

    I have the feeling that this is an argument that cannot be resolved by resorting to more complex models”

    Yes, exactly, such as CEOCARB or the type of model that Archer describes in his primer (and research articles). As I said, such simple models as those discussed on this thread are only really useful for qualitative analysis of the most basic behaviour of the carbon cycle and we need to bear their limitations in mind.

    The mass balance argument however is not a model, and it is useful for quantative analysis of the observations.

  192. Bart says:

    gavincawley says:
    April 4, 2012 at 12:45 pm

    “…it is a lot more complex than the very simple models being discussed on this thread…”

    Under very general conditions, the system can always be linearized such that the atmospheric concentration is governed by an equation of the form

    dM/dt := c*(N+A) – k*M

    Please note that all of the terms in the above equation are anomalies from the state at which the linearization was performed. This equation will hold approximately within a local neighborhood of the current state and time.

    “However, I have already pointed out the flaw in your argument, which is that as the oceans take up carbon the partial pressure difference between oceans and atmosphere will be reduced and so will the flux of carbon into the oceans.”

    Again, the flaw in your argument here is that you are assuming that there are no significant permanent (or, “semi-permanent”) ocean sinks. There are many, and more are being discovered every day.

    “Thus CO2 concentrations cannot stabilise unless we reduce anthropogenic emissions to the point where they match the capacity of the natural sinks.”

    The sinks do not have any known capacity limit. Dissolution in the ocean is not really a “sink”, per se, as it does not remove the carbon from the system on either a permanent or long-term basis.

    “However the growth of the natural sinks is a result of increasing CO2, so if levels stabilise they will no longer expand, but will instead shrink.”

    No, the increased uptake of the sinks is a result of increasing CO2. If anthropogenic input stabilizes, then the portion of the rise attributable to them will stabilize. That portion may be roughly 50%, or it may be very small. We simply do not have enough information beyond our personal biases to determine it.

    gavincawley says:
    April 4, 2012 at 1:17 pm

    I’m not going through your playschool argument with you.

  193. gavincawley says:

    Further to what Ferdinand has just said, the one box model of the carbon cyle used in my paper produces a constant airborne fraction of IIRC about 0.58 as a consequence of exponential growth in anthropogenic emissions (which is a reasonable approximation to what we have actually seen); it isn’t an assumption that is built into the model. The reason that it is 0.58 rather than 0.45 is that the model is based on a differential equation that is only a first order local approximation of reality at best, but produces results in good qualatative agreement with reality.

  194. Bart says:

    FerdiEgb says:
    April 4, 2012 at 1:17 pm

    “… as the real M := integral(A) + integral(N) – integral(kM)…”

    That is really infuriating. It shows complete lack of understanding, and willful insistence on plowing ahead with your own otherworldly reality regardless. I’m not going to dignify your post with any further comment.

  195. FerdiEgb says:

    gavincawley says:
    April 4, 2012 at 12:45 pm

    David Archer has written a primer on the carbon cycle that explains in great detail how the carbon cycle will respond, it is a lot more complex than the very simple models being discussed on this thread

    This is the only point where I differ with you in your essay. Archer sees different constraints, some true, some questionable. The constraint in uptake for the ocean surface is certainly true for the Revelle factor, as can be seen in the increase of DIC (dissolved inorganic carbon) which is only 10% of the increase of CO2 in the atmosphere. Thus even if the equilibrium between the atmosphere and the ocean’s mixed layer is very fast (order of ~1.5 years), that reservoir can only take in 10% of the increase. The deep ocean exchange is quite different: the main intake is in the polar waters, mainly in the NE Atlantic where the CO2 partial pressure difference pCO2(atm) – pCO2(aq) is about 250 microatm (400-150 microatm), as the waters there are extremely cold. This pressure difference pushes a lot more CO2 directly in the deep oceans, which are at some 5 degr.C. The deep ocean waters contain some 37,000 GtC as DIC, but are far from saturated. Thus any extra CO2 coming in via the THC will simply mix up with the rest of the carbon mass, depending how readily that mixes and comes up some 800-1000 years later into the warm equatorial Pacific. There a lot of CO2 is released, due to the high temperature.

    Archer now uses the same 10% rule for the deep oceans as for the ocean surface, but that isn’t true, as the deep oceans still are far from saturated and any considerations of the Revelle factor only holds for the air-ocean surface interchange (which at polar waters only increases), not for deep ocean waters. Thus if we assume that the ~370 GtC that humans have emitted ultimately all end in the deep oceans, that would increase the deep oceans carbon content with ~1%. At the ultimate steady state with the atmosphere, that would also give a 1% rise in the atmosphere above the pre-industrial CO2 level, or 3 ppmv.

    The reasoning also holds a fortiory for the biosphere: there is no limit in the storage capacity of the biosphere, as the millions of years old gigantic coal beds show. This too is a relative fast and increasing (semi) permanent storage. Thus there is no reason to think that some 30% of the increase in the atmosphere remains there near forever…

  196. gavincawley says:

    Bart wrote “I’m not going through your playschool argument with you.”

    Going through an argument step-by-step is not a playground argument, it is how science actually operates. The reason for going through the argument step by step is that it means you cannot substitute a straw man argument in place of the argument I am actualy making. The reason you will not engage in that exercise is that you know tha on that basis you will fail to identify an error and will be proven wrong.

  197. gavincawley says:

    Ferdinand, I would agree that things get more difficult as you get into the more advanced issue and things become more uncertain and I am comfortable with there being disagreement. My primary interest is to try and put an end to the argument that the rise in atmospheric CO2 is natural; this sort of argument is enormously damaging to the “skeptic camp” and does neither side of the discussion any good. It would be nice if the advanced issues could be discussed once the very basics are more widely accepted.

  198. Bart says:

    Phil. says:
    April 4, 2012 at 12:22 pm

    “k” can be “small” with respect to “a” without being “small” with respect to evolution of the system within time intervals of interest.

    I made the variable “c” and said it could be near 1/2, because 1/2 is the line of those who attribute the rise to humankind. I agree completely that it is probably much less, and that would KO the anthropogenic attribution argument.

    For the rest… just read more carefully.

    “And preferably stop generally insulting and abusing anyone who doesn’t agree with you!”

    I’ve been holding back. It isn’t the disagreement, particularly, that I find annoying. It is disagreement for reasons which aren’t even remotely valid by people who have set themselves up as experts.

  199. Bart says:

    gavincawley says:
    April 4, 2012 at 2:01 pm

    “The reason you will not engage in that exercise is that you know tha on that basis you will fail to identify an error and will be proven wrong.”

    No. It is because I know the error in your reasoning, and going through it with you will do me no good. You are trivially wrong.

    It will not do you any good, either, because you appear not to know when you are making implicit assumptions and, when I point them out to you, you deny them.

    This system is trivially Controllable through N. It is elementary that you can therefore always find a natural forcing which will produce the output you want. The size of N (or, rather, the deviation from historical norms) needed is what counts. If it is “small” compared to A, then it is not significantly driving the rise. If it is large, however, then it is. How large or small it will be depends completely on the parameters, which I have reduced to “c” and “k” in the model I have profferred. If the sinks are active, then the rise is not most significantly anthropogenically driven. If the diffusion of CO2 into the oceans is not approximately 1/2 of the net atmospheric transfer, then the rise is not most significantly anthropogenically driven. If the sinks are weakly active and the diffusion is about equal, then the rise is anthropogenic.

    Those are the twin pillars upon which anthropogenic attribution is founded: weak sinks, and even atmospheric/ocean distribution. That edifice was not constructed by me on that foundation, but by the authors of papers stretching back decades who recognized the requirements for anthropogenic attribution. There is a mound of modeling assumptions which have gone into that construct, from buffering action of the oceans to discounting of unknown processes. It is a shaky foundation. Whether it stands far into the future, we will just have to wait to see.

    “My primary interest is to try and put an end to the argument that the rise in atmospheric CO2 is natural; this sort of argument is enormously damaging to the “skeptic camp” and does neither side of the discussion any good.”

    I have not been arguing that it is natural. I have been saying that there is not enough information to clinch the argument. Given popular perceptions, maybe it harms the skeptic camp. Than again, maybe it doesn’t. Since it isn’t a front burner issue right now, given the very obvious shortcomings in the rest of the AGW conjecture after a decade of stagnation in the temperature metric, I doubt it is hurting anything right now.

    I am much more put off by those who deny the basic greenhouse physics through misguided appeals to the 2nd law or whatever. But, again, the basic stagnation and incipient downturn in temperatures will carry the day, and I am not overly concerned about it.

  200. gavincawley says:

    Bart wote “No. It is because I know the error in your reasoning, and going through it with you will do me no good. You are trivially wrong.”

    Sorry, I am happy to have a civil discussion of the science, but you have made it abundantly clear that you will not engage with the actual argument, just the straw man of your own devising and can’t conduct a discussion in a reasonable polite manner. There is little point in continuing, but I will just point out again that this is exactly the sort of behaviour that Prof. Singer says gives the skeptics a bad name (it is one of the obviously incorrect arguments that he mentions in his article).

  201. Smokey says:

    gavincawley says:

    The average volume of water in the bucket is only 1/2 becase you are putting one liter in as a discrete action and then taking one liter out as a discrete action. However the carbon cycle is continuous, not discrete. If you put one liter in and took one liter out, but by alternating putting one tea spoonfull in and one spoonful out then the average amount of water in the bucket would be half a teaspoon full, but the volume of the exchange would be the same.

    I can’t see that one analogy is any different than the other. Only the volumes are different; 1 tsp vs 0.5 litre. Also, the sawtooth chart of MLO CO2 looks pretty ‘discrete’ to me, so your analogy is no different than Bart’s.

  202. FerdiEgb says:

    April 4, 2012 at 1:44 pm

    Bart, you are much better in the theory than I have ever been, most is too long ago and I haven’t practiced it for over 45 years, because of a quite different carrier. So I am a bit slow and need to think twice to ten times about what is said.

    But I am a practical boy. Any increase in CO2 mass in the atmosphere over time is the integral of human additions + the integral of natural additions – the integral of natural sequestering of all known years in the past 50+ years. That may sound as a horror to you, who are thinking in linear equations, but as good as the old slide rule gives an approximation that 2 x 2 = 4 and a calculator gives a more exact result, your linear approach gives an approximation, while my much simpler approach gives the same result.

    In the above you may combine the last two terms as the integral of (natural additions – natural sequestering) as that is what is known for each year in the past 50 years. And I made an error in the calculated k I sent, as that is the e-fold time, while the factor k is the reciprocal of that, thus the current k = 4 / 210 = 0.019. The smaller that k is, the more CO2 remains in the atmosphere.

    But let us focus on
    dM/dt := c*(N+A) – k*M
    which can’t be solved, as both c and N are undefined, except if N ~ 0.

    We have some historical integrations of N over time spans of 8-600 years in ice cores. These all show N ~ 0, except if the temperature changes. Then N integrates to new values in ratio with the temperature change.
    For changes of about 10°C, there is a change of 80 ppmv (~170 GtC) over a period of 5,000 years, or average 0.034 GtC/year. Not really spectacular, compared to the 8 GtC/yr humans release nowadays. The MWP-LIA temperature change shows a change of ~6 ppmv (or ~13 GtC) over 50 years or de decrease of 0.26 GtC/year. Of course, the smoothing of the ice cores prevent the view on changes with higher frequenties.

    We have some modern measurements too: mainly temperature driven year by year variations of +/- 2 GtC around the trend. Integrated over 2-3 years that gives near zero deviation from the trend.

    While that isn’t a solid proof that N ~ 0, it looks quite like that over small to very long integrated periods.

  203. gavincawley says:

    smokey – in barts analogy the average volume in the bucket is half a litre, in mine it is half a teaspoon full, i you used 1ml pipette it would be half a millilitre, but the exchange is a litre in each case. Consider what happens when the exchange is performed one molecule at a time. The fact that the two almost identical analogies produce different results illustrates the flaw in the analogy.

    The point is that the increase or decrease in the contents of the bucket depends on the difference between total flow into the bucket minus total flow out of the bucket. If you make the flow in the same as the flow out, you can have an exchange as large as you like, but it doesn’t change the level in the bucket.

  204. gavincawley says:

    smoky, also the saw tooth behaviour in the Mauna Loa series is due to annual growth/dieback in the region. However if you look at measurements from othe stations (e.g. in Antarctica there is no saw tooth pattern, just a steady rise with a small ripple in it).

    The mass balance argument is usually described in terms of annual fluxes and changes, so that the irrelevant seasonal fluxes cancel out over the course of the year. The annual growth/dieback pretty much balances eachother out, if there is any imbalance it is reflected in the annual measurements.

  205. Smokey says:

    gavincawley,,

    Analogies are meant to simplify. Both analogies look to me to be the same. Maybe try a different one.

  206. Bart says:

    FerdiEgb says:
    April 4, 2012 at 3:32 pm

    “…which can’t be solved, as both c and N are undefined…”

    But, solutions can be determined in the limit as k either goes to zero or becomes large. Those solutions are

    k small: M approaches c*integral(N + A)

    “c” is assumed to be constant here.

    k large: M approaches (c/k)*(N + A)

    “We have some historical integrations of N over time spans of 8-600 years in ice cores.”

    As you say, the smoothing of the ice cores prevent the view on changes with higher frequenties. For modern measurements, I see no reason the trend cannot itself be due to N.

    gavincawley says:
    April 4, 2012 at 3:40 pm

    “… but the exchange is a litre in each case.”

    You have explained this very poorly. I think you are saying that you first put in 1 liter + 1 teaspoon, then empty it, so that cycle averages to 1/2 of 1 liter plus one teaspoon. Then, the next cycle, you put in 1 liter minus 1 teaspoon, so the average is 1/2 of 1 liter minus 1 teaspoon, so the average over two cycles is still 1 liter.

    If that is the case, it is trivially true, but has no bearing on the problem at hand, where there is continuous upward plant growth due to continuous increase in CO2.

    “The annual growth/dieback pretty much balances eachother out, if there is any imbalance it is reflected in the annual measurements.”

    Not if there is a sustained increase in growth. Again, go for the reductio: Are you telling me there would be no difference in CO2 concentration if the Earth were a dead planet, with no vegetation at all, compared to what it is now?

  207. Bart says:

    “Are you telling me there would be no difference in CO2 concentration if the Earth were a dead planet, with no vegetation at all, compared to what it is now?”

    Understand – there is copious carbon tied up in all the living creatures on Earth. If you get more and bigger plants and animals, that is more carbon tied up in them. It does not matter if they live and die. If the population is stable, the carbon is continuously deposited there.

    And, that doesn’t even get into the fact that much of that carbon does not return to be recycled through the system. E.g., the creation of fossil fuels, which is one of many permanent or semi-permanent carbon sinks which exist both in the oceans and on land. New sinks are being discovered all the time. Here is one which particularly piqued my interest. I have read recently that rock weathering sinks far more carbon than scientists previously thought.

    We just do not know everything about the Earth and all the very complex processes happening on it.

  208. gavincawley says:

    smokey, the standard analogy is that of having a basin with a hot tap (representing anthropogenic emissions) a cold tap (representing natural emissions) and a drain (representing natural uptake). Start with the hot tap being shut, then if the water flowing in through the cold tap balances the flow of water through the drain, then the level of water in the basin will remain constant. This is true regardless of the magnitude of the flows, it is true for 1 litre per hour, or 10 or 1000 etc. In order for the level of water to change there needs to be a difference between the flow into the basin and the flow out of the basin, if total inflow exceeds total outflow then the level will rise, if total outlow exceeds total inflow, then the amount will fall.

    So consider the case where we have a flow-meter that tells us how much water is flowing through the hot tap, and a depth guage which allows us to work out the volume of water in the basin. We don’t know how much water is flowing into the basin through the hot tap nor how much is flowing out through the drain, but we know that if the rate at which the volume of water in the basin is rising at a rate less than is flowing through the hot tap, then we know that there must be more water flowing out through the drain is greater than the amount flowing in through the cold tap. This is simple artihmetic.

    Note that as I have said multiple times before, we can know that natural uptake, U, is greater than natural emissions, N, without knowing the values of either U or N, provided we assume conservation of mass.

    This is also true whether the rate at which water is flowing through the drain and cold tap is constant or varies in some way. That is because conservation of mass holds regardless of the flow rates.

  209. Bart says:

    gavincawley says:
    April 5, 2012 at 2:43 am

    “This is simple artihmetic.”

    Very simple. Way, way too simple.

    Water flows out of the bottom in proportion to the pressure at the outlet. And, pressure is proportional to the height of the water column above the hole.

    If you have 100 parts cold water flowing in and have stabilized at the appropriate level, and you add an additional 1 part hot water, then the water level will rise at most 1 part in 100 or 1%.

    If the water level rises 2%, then you know someone has turned up the cold water, because the hot water cannot raise it more than 1%.

    This is your flaw. This is your mistake. You have assumed that any rise must be attributable to the hot water, because the cold water incoming rate is constant. But, you do not know that rate, and have no means of determining whether it is constant or not. And, you do not know take account of the fact that the outflow rate increases with the added pressure.

    This is a dynamic system. It does not respond based on simple accounting principles.

  210. Bart says:

    It helps to use the language of mathematics, so let’s parse this:

    “We don’t know how much water is flowing into the basin through the hot tap (we do, let’s call it H) nor how much is flowing out through the drain(call it D) , but we know that (1) if the rate at which the volume of water in the basin is rising (call it Vdot) at a rate less than is flowing through the hot tap (H, again), then (2) we know that there must be more water flowing out through the drain is greater than the amount flowing in through the cold tap (call it C).”

    Since I cannot use less than – greater than signs with html, I will use .lt. and .gt. instead.

    What this says is

    Vdot .lt. H

    We can say

    Vdot = H + C – D

    (1) says

    Vdot .lt. H

    Does this imply, as the final statement (2) says, that

    D .gt. C

    ?

    Yes. It says

    H + C – D .lt. H

    or

    C .lt. D

    Does this tell us that the observed rise is attributable to H? No. Because D is variable. It has a part which has responded to C, and a part which has responded to H. Call them DH and DC. We have

    C .lt. DC + DH

    If we send H to zero, will Vdot go negative?

    Initially, yes. But, when H goes to zero, DH also goes to zero, with a characteristic time dependent on the feedback (sink) strength, and we are left with

    Vdot = C – DC

    Now, can we say

    C .lt. DC

    ?

    No, we cannot. We only know that

    C .lt. DC + DH0

    where DH0 is DH evaluated at the time H was being input.

  211. gavincawley says:

    Bart wrote “C .lt. D Does this tell us that the observed rise is attributable to H? ”

    Yes (as you agree) more is flowing out through the drain than is coming in through the cold tap. Thus if it were not for the water coming in through the hot tap H, the level in the basin would be falling instead of rising. For most people who have ever run a bath, this would be entirely obvious.

    If I half fill my bath, pull out the plug and then adjust the cold tap so that the level in the bath is falling at 1cm per minute Your argument appears to be that if I then put the hot tap on full that the resulting rise in the level of water in the bath cannot be attributed to the hot tap being on. That conclusion would be to say the very least “counterintuitive” to most people!

    Note in this case the amount of water flowing out through the drain would have increase slightly as the level of water in the bath rose. It is still the water from the hot tap that is responsible for the rise.

  212. Bart says:

    gavincawley says:
    April 5, 2012 at 10:57 am

    “Yes (as you agree) more is flowing out through the drain than is coming in through the cold tap. Thus if it were not for the water coming in through the hot tap H, the level in the basin would be falling instead of rising.”

    I showed that was not the case. Read.

  213. Bart says:

    Of course, H is responsible for some rise.

    The point is, its responsibility can be infinitesimal.

    It all depends on the rate of sequestration, which is what I have been telling you.

  214. gavincawley says:

    Bart, you last post does not address my analogy at all, it is just bluster to hide the fact that your position has been demonstrated to be absurd. H is responsible for ALL of the rise, because if not for the water coming from the hot tap, the level in the bath would be FALLING instead of rising.

  215. Bart says:

    Maybe some sims will help. Here is a notional CO2 model. I could play with the parameters all day and produce different results, but this will do to demonstrate the concepts.

    The model is in Simulink, an industry standard dynamical systems modeling software package to solve differential equations.

    At the left, I first generate a natural input and an anthropogenic input. At top, I feed the natural input alone into the model

    Mdot = (1/2)*(N + A) – k*M

    I chose k = 0.1 to be a fairly strong sink feedback.

    In the middle, I add in the anthropogenic input.

    At bottom, I feed in 1/2 the accumulation of the anthropogenic input.

    As may be seen in the output plot here, the effect of the natural input and the integral of 1/2 the anthropogenic input is roughly comparable (yellow and cyan lines). The output of the model with both anthropogenic and natural effect is just a little greater than with the natural input alone.

    I could play around the with parameters and make the gap infinitesimal. But, hopefully, this will illustrate my point. With an arbitrary natural input, and rapid feedback in the system, I can make the output dance to whatever tune I choose.

    Does the anthropogenic input increase the output? Yes. But not necessarily significantly. Everything which is true about the Earth’s CO2 system is true about this one.

  216. gavincawley says:

    Bart, ignoring the issue won’t make it go away. We know the water coming in through the hot tap is responsible for 100% of the rise becase the amount of water coming out of the cold tap is less than the amount flowing out through the drain. Thus if not for the water from the hot tap, the level of water in the bath would be falling, not rising.

    The same is true of the carbon cycle. Natural emissions are less than natural uptake, so if it wasn’t for anthropogenic emissions, CO2 levels would be falling rather than rising. It isn’t hard to see why this should be the case, the uptake of CO2 by the oceanic sink depends on the difference in partial pressure between the atmosphere and the surface waters. If we stopped all anthropogenic emissions today, this difference in partial pressures would still exist, so natural emissions would still be less than natural uptake and CO2 levels would be falling. So there again we know that anthropogenic emissions are solely responsible for the observed rise, at least over the last 50 years.

  217. FerdiEgb says:

    Bart says:
    April 5, 2012 at 12:12 pm

    Maybe some sims will help. Here is a notional CO2 model. I could play with the parameters all day and produce different results, but this will do to demonstrate the concepts.

    Bart I have looked at that conscept, but I don’t see how picture 1 can be true: the human input, directly injected into the atmosphere is twice what the endresult is. As said before, there is no reason why that should be halved. What happens is that the input of any source into the atmosphere as a whole gives more pressure to push more CO2 into the oceans and vegetation. That is the term -kM which is also implemented on the combined inputs. If you halve the inputs ánd implement -kM you are double accounting in the sinks.

  218. Bart says:

    gavincawley says:
    April 5, 2012 at 1:13 pm

    Gavin, I have explained to you in excruciating detail why you are wrong. If repetition ad nauseam is the best you can do, then there is no point in continuing.

    Argument from Repetition – Ad Nauseam

    The argument from repetition fallacy is where an argument is repeated over and over until no further progress can be made and all points are exhausted. Normally a person will have a belief or position that does not have evidence, is blatantly false, or is fallaciously structured. They will repeat this over and over no matter what contradictory argument is laid before them.

  219. gavincawley says:

    Bart, your post is merely a tacit admission that you have no answer to the argument I made in my preceding point.

    The natural sources are less than natural sinks, CO2 levels would be falling if it were not for anthropogenic emissions. Thus it is obvious that anthropogenic emissions are the cause of the rise.

    The error in your model (double accounting of the uptake) was pointed out to you earlier in the thread. It is a pity that you are unable to accept criticism, being wrong and understanding your error is a very good way of learning.

  220. Bart says:

    FerdiEgb says:
    April 5, 2012 at 1:45 pm

    “As said before, there is no reason why that should be halved.”

    Ferdinand – I explained the origin of the 1/2 factor in, again, excruciating detail at April 3, 2012 at 12:30 pm. I noted at April 3, 2012 at 1:35 pm that, in fact, the factor “c” could be anything, but that climate modelers prefer a value of 1/2 because of the superficial agreement with observations. Phil pointed out at April 3, 2012 at 2:23 pm that the number should, in fact, be much smaller to be in agreement with Henry’s law, and I agree that he is probably right.

    The conceptual problem you are having is when you say “the term -kM which is also implemented on the combined inputs”. But, the dissolution into the ocean is not a function of the atmospheric concentration alone, but in the weighted difference of the ocean concentration and the atmospheric concentration. If that were not the case then, in the absence of inputs, the oceans would continue absorbing until all the CO2 was gone from the atmosphere. But, we know quite well the dissolution would only continue until an equilibrium has been established with some CO2 in the air, and some dissolved in the oceans.

    If it helps you conceptualize it, use the equations I gave at April 3, 2012 at 1:35 pm

    Mdot = N + A + a*(O – 0.5*M/c)

    Odot = a*(0.5*M/c – O) – 2*k*O

    If you simulate this, choosing the constant “a” to be much greater than “k”, you will find that the output M is very nearly approximated by

    Mdot = c*(N + A) – k*M

  221. Bart says:

    gavincawley says:
    April 5, 2012 at 2:05 pm

    I have no more time for such foolishness. Good-bye, Gavin.

  222. Bart says:

    “If you simulate this, choosing the constant “a” to be much greater than “k”, you will find that the output M is very nearly approximated by

    Mdot = c*(N + A) – k*M”

    And, do please note, Ferdinand, that this is only a side issue. I insist on putting a factor “c” in there because it is the correct way to create the model. But, it is not necessary to prove the point. I have complete freedom to choose a time varying input “N” and a constant “k”. As I said, I can make the output dance to any tune I please with that.

  223. gavincawley says:

    Bart wrote: “If that were not the case then, in the absence of inputs, the oceans would continue absorbing until all the CO2 was gone from the atmosphere.

    Which is why in the model I used in my paper I made U a linear function of atmospheric concentration, rather than simply being proportional. However it is no excuse for you to put a fiddle factor into your model to double-count the uptake. I know you have explained your reasoning for putting c into the D.E. but that doesn’t mean that your reasoning right, and ignoring criticism of your model is deeply unconvincing.

  224. Bart says:

    Ferdinand – if it will make you happy, here is a bogus CO2 model with c = 1.

    Here is the output. I also tuned the feedback to be stronger so I could show than I can make the gap arbitrarily close, and the anthropogenic input less and less important, that way. And, I adjusted the natural input to produce the agreement with all the outputs you see.

  225. Bart says:

    As you see, with feedback and a properly selected natural input, I can make the output do anything I please to within an arbitrary tolerance.

    I can do this so easily. It is why I have been after you about this silly mass balance business all along. Now, maybe you can see.

  226. Bart says:

    gavincawley says:
    April 5, 2012 at 2:27 pm

    Good. Bye. Gavin.

  227. gavincawley says:

    Actually Bart, it points out that your model is useless (any model that can explain absolutely anything is of no value for the same reason that astrology is meaningless even though it can explain anything). The mass balance argument however cannot explain everything. It can only explain what is consistent with conservation of mass and the observations of anthropogenic emissions and the observed rise in atmospheric CO2.

  228. Bart says:

    gavincawley says:
    April 5, 2012 at 2:43 pm

    Nope.

  229. FerdiEgb says:

    Bart says:
    April 5, 2012 at 2:11 pm

    Sorry Bart, but I disagree: there are indeed constraints in the output to the ocean surface (which is saturated with a factor 0.1 against the atmospheric increase), but not in the input to the atmosphere. And not in the deep oceans (at least not on short term) or vegetation.

    The saturation of the ocean surface is very fast, in the order of 1.5 years half life time and as the ocean surface contains ~1000 GtC, its concentration increased with ~3% (30 GtC) where the atmosphere increased with 30% (210 GtC) in the same period.

    That part of the oceans thus is only of minor interest, the bulk of the current sinks is in the deep oceans (via the THC in the NE Atlantic), and in vegetation. These have, at least for now, no constraints in mass accumulation. The deep oceans take at least 800 years to return any change in CO2 mass increase back to the surface and vegetation can store any amount of carbon indefinitely.
    The only constraints are the speed of transfer to the deep oceans and of CO2 (semi) permanent sequestering by photosynthesis (regardless that a large part returns in another season). Both seems directly in ratio with the distance between current M and Mo (whatever that may be). Thus -kM is the only term of interest for the uptake flow.

    I didn’t realize that in the mat, but your scheme makes it pretty clear: if the human emissions are halved at the input, where then goes the other halve? Theoretically your scheme might be right for the ocean surface layer with restricted uptake, but practically it is impossible…

  230. Bart says:

    FerdiEgb says:
    April 5, 2012 at 2:56 pm

    “I didn’t realize that in the mat, but your scheme makes it pretty clear: if the human emissions are halved at the input, where then goes the other halve?”

    Into the oceans..

  231. Bart says:

    Anyway, it’s a moot question (see post @ April 5, 2012 at 2:33 pm). The mass balance argument still does not eliminate the possibility that the rise is natural.

  232. FerdiEgb says:

    Bart says:
    April 5, 2012 at 4:35 pm

    Into the oceans…

    Sorry, but that is not what your scheme says. What you have done is that you transferred a part of the observed change in increase of M from the output to the inputs. That may be mathematically sound and even the overall mass balance may not be violated (for halve the inputs), but it violates the mass balance of the total inputs. Whatever happens with the inputs, even if any human (or natural) input was catched by oceans or vegetation within a second, it must be added to the total mass of M before it can be removed.

    Your scheme only shows halve the real inputs to the atmosphere, where the increase in mass partly is removed into the oceans, while the other halve isn’t shown and bypasses the whole process to disappear spontaneously into the same oceans. That can’t be true. Your scheme doesn’t reflect reality.

    About the possibility that the rise is natural: that can be right momentarily, when the C input rises, but it can’t be right integrated over the longer term, as long as the increase in M is less than expected from H alone. Thus the C input may give a short rise during the positive flank of the variability (the AC component), but doesn’t give a rise due to the natural throughput (the DC component).

  233. gavincawley says:

    Bart wrote “Anyway, it’s a moot question (see post @ April 5, 2012 at 2:33 pm). The mass balance argument still does not eliminate the possibility that the rise is natural.”

    So even though we know that natural uptake exceeds natural emissions (via the mass balance argument) and that atmospheric CO2 would be falling if not for anthropogenic emissions (because the partial pressures of CO2 in the oceans and atmosphere are not in equilibrium), that doesn’t rule out the possibility that the rise is natural?

    The bath analogy I gave earlier demonstrated that this argument is absurd, which is why Bart is unwilling to address it. It isn’t difficult to come up with another one:

    Consider I share a savings jar with my wife (with video surveilance and a team of loyal ninja to make sure that nobody else interfers with it*). If I put in £8 a week and notice that the balance is only rising at £4 as week, then that DOES rule out the possibility that that the rise in our savings is in any way due to my wife. Whatever the amount of money she has put into the jar, conservation of money means that she must have taken more out of the jar than she put in, and hence she is OPPOSING the rise in our savings, not causing it. If you disagree, I a have a business proposal for you ;o)

    * yes I included that bit to prevent the inevitable over-extension of the analogy by those who want to avoid the key issue, for instance by saying that thieves may be taking money out of the jar without my knowledge. However if you relate that back to the carbon cycle it would be like saying that in addition to anthropogenic and natural sources and sinks there are other sources/sinks. However, if these sources and sinks aren’t anthropogenic and they are not natural, that only leaves exraterrestrial or supernatural inluences, so it is like saying space-pixies are stealing CO2 from the atmosphere. I’d say that wasn’t exactly the strongest argument ever made in the climate debate! ;o)

  234. Bart says:

    FerdiEgb says:
    April 6, 2012 at 12:03 am

    “Sorry, but that is not what your scheme says.”

    Yes, it is exactly what it says. By assuming “a” is much greater than “k”, I am assuming the dynamics for movement of the mass into the oceans is “fast”. The system described by the first order differential equation

    Mdot = c*(N + A) – k*M

    is merely an approximation to the output “M” from the set of equations

    Mdot = N + A + a*(O – 0.5*M/c)
    Odot = a*(0.5*M/c – O) – 2*k*O

    when the exchange into the ocean is “rapid”. Mass is conserved because

    Mdot + Odot = N + A – 2*k*O

    which is the natural and anthropogenic inputs minus the amount which gets permanently sequestered in the oceans.

    gavincawley says:
    April 6, 2012 at 2:40 am

    Nope.

  235. Bart says:

    Ferdinand, what I have told you above is not controversial. These are standard equations. If you do not understand what I am doing, you should not be opining so strenuously on the topic.

    Without at least a familiarity with the math involved, you are a blind man trying to describe a rainbow. Gavin is blind, and deaf as well. I urge you not to stop up your ears as he has.

  236. gavincawley says:

    Sorry Bart, your behaviour is *exactly* the kind of thing that Singer says gives the skeptics a bad name, and on that point he is right (although as I said I wouldn’t use his terminology).

    It is you that is ignoring the arguments posed against you. “nope” and rhetorical posturing is no substitute for a substantive response. The reason you won’t reply to either of the two analogies I have posted is simply becuase your position is absurd and your evasion is tacit admission that you know it.

  237. gavincawley says:

    Bart, in your equation

    Mdot = c*(N + A) – k*M

    the first term assumes there is some mechanism that somehow knows was anthropogenic and natural emissions actually are and automatically takes up half of it. This is clearly nonsense as the mechanisms that govern the sinks respond to the concentration of carbon dioxide in the atmosphere, and have no way of telling what either N nor A are at any particular time, only M. Therefore your model bears no relation to reality to the physical world.

    Yes, I know that the airborne fraction is about a half, but my model reproduces that as a concequence of the emissions, and doesn’t need a bodge to hardcode it into the model.

  238. Bart says:

    I am going to make an amendment to the equations here. I originally started with

    Mdot = N + A + a*(O – M)
    Odot = a*(M – O) – 2*k*O

    This is the standard form which usually appears in the literature, and assigns 1/2 of the input to the atmosphere and 1/2 to the oceans, in superficial agreement with observations.The output “M” of this model can be reliably approximated by the first order differential equation

    Mdot = (1/2)*(N + A) – k*M

    whe a is much greater than k.

    I then worked out on my own equations

    Mdot = N + A + a*(O – 0.5*M/c)
    Odot = a*(0.5*M/c – O) – 2*k*O

    and said the output “M” here could be approximated by the rist order differential equation

    Mdot = c*(N + A) – k*M

    when a and a/c are much greater than k. I made an ERROR here. The second order set of equations should have been

    Mdot = N + A + (a/c)*(c*O – (1-c)*M)
    Odot = (a/c)*((1-c)*M – c*O) – (k/(1-c))*O

    The output “M” for this set of equations can be approximated by

    Mdot := c*(N + A) – k*M

    when a is much greater than k*c/(1-c). It may be seen that, when c = 1/2, these equations become the first ones on this page.

    The equation for “O” becomes approximately

    Odot := (1-c)*(N + A) – k*O

    Approximately a fraction of “c” goes into the atmosphere, and (1-c) goes into the oceans. Mdot + Odot in this approximate model is equal to N+A – k*(M+O), the natural plus anthropogenic inputs minus the part which is sequestered, so mass balance holds here, too.

  239. Bart says:

    gavincawley says:
    April 6, 2012 at 10:08 am

    Gavin – you are flailing. When you find yourself in a hole, stop digging. It is painful to watch.

  240. gavincawley says:

    Bart, all you have done is show you have no answer to that criticism either.

    BTW, your new model still has the airborne fraction hard-coded into the model. What you don’t seem to realise is that the constant airborne fraction is not a law of physics, it is a consequence of exponentially rising emissions. The model I use in my paper produces a constant airborne fraction as a consequence of the observed emissions (or at least an exponential approximation to those observations, which is a pretty good approximation). So why do you need to hard-code it into your model?

    Hint: If you drive a first order linear system with an exponential signal, you get out an exponential signal with the same time constant, but different amplitude. Divide one exponential by another exponential with the same timeconstant and the result is a constant value – the airborne fraction.

    This is before we get to the issue that the oceans can only see M, so they can’t obey a law that says its uptake is determined by A and N.

  241. Bart says:

    Of course, the model I have presented only takes into account atmosphere and ocean. Including land will alter the allocations and time constants. If broad decoupling assumptions hold, I would expect something like

    Mdot := c1*(N + A) – (k1+k2)*M

    Odot := c2*(N + A) – k1*O

    Ldot := (1-c1-c2)*(N + A) – k2*L

    In addition, I expect that the decay is not really simple exponential, and k1 and k2 might need to be expressed as differential equation operators rather than simple gains to give a “long tail” response. The terms c1 and c2 might be similarly more complicated than simple gains.

    But, the basic conclusion still holds: If ocean and land permanent and semi-permanent sinks are sufficiently active, then there is no reason that the rise we have observed should necessarily be due to anthropogenic forcing.

  242. Bart says:

    gavincawley says:
    April 6, 2012 at 11:00 am

    Gavin, you have completely lost touch with reality.

  243. Bart says:

    I’ve done all I can for your two. I have given you a lot of my time (which generally costs dearly, I can assure you). I have shown you using rigorous mathematics why your assumptions have been overly simplified. I have led you to the water, but it is up to you to drink. There is nothing more I can do.

    So, until we meet again, I am signing off and deleting this link from my queue.

  244. FerdiEgb says:

    Bart says:
    April 6, 2012 at 11:20 am

    Gavin, you have completely lost touch with reality.

    Bart, as said by Gavin, there is no physical way that the oceans or vegetation know what the input flows are. Thus your constants c, c1, c2,… on the input flows are physically impossible, however nice the math sounds. The only way to have a sink in any of the (semi) permanent storages is by a pressure difference between the atmosphere and the oceans and/or water in the plant alveoles. That is the term -kM, whatever k may be.

    BTW, k is observed to be ~4/210 or ~0.02 if we may assume that the current levels are 100 ppmv above steady state.

  245. tallbloke says:

    All,
    There will be a post up on my site tomorrow which should add something more to this debate. Feel free to stop by and contribute.

    Cheers

    Rog Tallbloke

  246. tallbloke says:

    All:
    I’m putting up a new post tomorrow which will hopefully add to this debate. Feel free to drop by and comment.
    Cheers
    TB

  247. Myrrh says:

    fraction that belongs to humans?

    gavincawley says:
    April 3, 2012 at 2:21 pm
    tallbloke, read a bit further, where I wrote “Another one of the arguments that Prof. Singer says should be dropped is the argument that the rise in CO2 is natural, perhaps you should ask him to expand on this in a blog post here?.”

    I mentioned the second law thing as it is the first “denier argument” that Prof. Singer mentions. The argument that the rise in CO2 is natural is if anything worse than the second law canard; anyone capable of balancing a bank account ought to understand how we know the rise in CO2 is anthropogenic.

    ========

    How can you know?

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