Sinkin’ the Source

UPDATED: I misread the graph, thanks to TTCA who has done a good post on it here.

This post at WUWT is not a small development in global warming. Anyone with any interest at all in global warming needs to read it and understand what it is saying.

The graph below has a thick black line indicating the output from human industry each year. The lines below are the rate of change of CO2 in the atmosphere. If correct the CO2 emitted is being absorbed ever faster rather than building up unchecked.

Figure 1. The annual increase in atmospheric CO2 (as determined from ice cores, thin dotted lines, and direct measurements, thin black line) has remained constantly proportional to the annual amount of CO2 released by human activities (thick black line). The proportion is about 46% (thick dotted line). (Figure source: Knorr, 2009)


Here is the abstract from GRL:

Several recent studies have highlighted the possibility that the oceans and terrestrial ecosystems have started losing part of their ability to sequester a large proportion of the anthropogenic CO2 emissions. This is an important claim, because so far only about 40% of those emissions have stayed in the atmosphere, which has prevented additional climate change.

This study re-examines the available atmospheric CO2 and emissions data including their uncertainties. It is shown that with those uncertainties, the trend in the airborne fraction since 1850 has been 0.7 ± 1.4% per decade, i.e. close to and not significantly different from zero. The analysis further shows that the statistical model of a constant airborne fraction agrees best with the available data if emissions from land use change are scaled down to 82% or less of their original estimates. Despite the predictions of coupled climate-carbon cycle models, no trend in the airborne fraction can be found.

If anyone has a copy of this paper they could share please email me at jeffid1 at gmail dot com.

45 thoughts on “Sinkin’ the Source

  1. I’ve got a copy now here is the conclusions section.


    [25] From what we understand about the underlying
    processes, uptake of atmospheric CO2 should react not to a
    change in emissions, but to a change in concentrations. A
    further analysis of the likely contributing processes is nec-
    essary in order to establish the reasons for a near-constant AF
    since the start of industrialization. The hypothesis of a recent
    or secular trend in the AF cannot be supported on the basis of
    the available data and its accuracy.
    [26] Given the importance of the AF for the degree of
    future climate change, the question is how to best predict its
    future course. One pre-requisite is that we gain a thorough
    understand of why it has stayed approximately constant in
    the past, another that we improve our ability to detect if and
    when it changes. The most urgent need seems to exist for
    more accurate estimates of land use emissions. Another
    possible approach is to add more data through the combi-
    nation of many detailed regional studies such as the ones by
    Schuster and Watson [2007] and Le Quere et al. [2007], or
    using process based models combined with data assimila-
    tion approaches [Rayner et al., 2005]. If process models are
    used, however, they need to be carefully constructed in
    order to answer the question of why the AF has remained
    constant and not shown more pronounced decadal-scale
    fluctuations or a stronger secular trend.

  2. Of course another explanation is that co2 levels have ALWAYS been higher in the past than currently stated, as records from 1830 onwards show.

    Callendar cherry picked his 300ppm for his 1938 co2 thesis.(I have got his archives) Keeling picked it up. Callendar subsequently decided he wasn’t at all sure he was right.

    Keeling also admitted in later life that the old records were much better than he initially thought(when he was a 25 year old newly qualified phd with no experience at all of Climate science when asked to run Mauna Loa.)

    Greater variabilty of co2 than we currently see in the ML records would make sense, as the natural co2 component far outweighs the man made version and this should be reflected in the mauna loa figures-but it isn’t.

    How about a guest post from Ernst Beck, Jeff?


  3. Two of the interesting points of AR4, from page 501 Chapter 7 Summary:

    Carbon dioxide cycles between the atmosphere, oceans and
    land biosphere. Its removal from the atmosphere involves a
    range of processes with different time scales. About 50% of
    a CO2 increase will be removed from the atmosphere within
    30 years, and a further 30% will be removed within a few
    centuries. The remaining 20% may stay in the atmosphere
    for many thousands of years.

    Improved estimates of ocean uptake of CO2 suggest little
    change in the ocean carbon sink of 2.2 ± 0.5 GtC yr–1
    between the 1990s and the first five years of the 21st
    century. Models indicate that the fraction of fossil fuel
    and cement emissions of CO2 taken up by the ocean will
    decline if atmospheric CO2 continues to increase.

    If these two points were correct, the CO2 levels would be increasing faster, since uptake was to decline. The opposite is happening. This challenges some of the predicted warmth since it was assumed in the models that the 2.2 GT/yr sink would decline as CO2 continued to rise. It also challenges the concept that we must do something now because of our CO2 lasts hundreds of years. This shows a constant percent removal or better.

    The third thing it challenges is the concept of western properous nations owe the third world countries for using up the CO2 sinks. Instead this implies that after about 5 years, what was emitted is about zero. Thus China, India, and many others are now as guilty as we are, since it is about 5 years since China, India, and all third world emitters became the largest contributer to CO2.

  4. I forgot to add: my model says that uptake is proportional to the difference between current CO2 concentration and pre-industrial levels (~285 PPM), so the fraction being absorbed in any one year will depend on both the emissions for that year and the atmospheric concentration. If you cut the emissions next year by 50% compared to this year, then about 100% of the emissions would be picked up by the ocean…. no increase in atmospheric CO2.

    The other interesting thing the model says is that the absorption rate will be much higher with higher CO2 levels. For example, at 450 PPM the rate of absorption will be about (450-285)/(385-285) = 1.65 times higher than today. So CO2 emissions would have to be ~65% higher than today to maintain the same rate of increase in CO2 concentration in the atmosphere, which is about 2.1 PPM per year. Assuming no change in energy efficiency, the world economy would have to grow by some 65% over 30 years to reach 450 PPM over 30 years. Even modest improvements in energy efficiency (which are inevitable as less developed countries become more modern and technology advances) mean that the world economy would have to grow by much more than 65% over than period (100% growth or more seems reasonable) to maintain the current pace of CO2 increase.

  5. You seem to have got the sense of your title wrong: the faucet is still running faster than the drain. I don’t see this as all that controversial and it certainly doesn’t put a stake through the heart of global warming.

  6. Rattus:

    You seem to have got the sense of your title wrong: the faucet is still running faster than the drain. I don’t see this as all that controversial and it certainly doesn’t put a stake through the heart of global warming.

    It is a bit controversial because it is at odds with several recent studies (that are cited in the article) that suggest that the drain may be clogging up. That conclusion does not appear to be borne out with this paper.

    The fact that the sink is increasing suggests something rather starting. It raises the question of what happens if we hold anthropogenic CO2 emission levels constant. Almost certainly, based on this data, the CO2 sink would continue to grow for some time, and atmospheric CO2 levels might actually drop before we started decreasing anthropogenic CO2 levels.

    That seems pretty interesting to me, though no it’s no stake through the heart of AGW. (You need to remember that “A”, few argue that the globe is heating up, that’s entirely noncontroversial).

  7. Please pardon if this is already accounted for in the paper, which I have not located yet.

    “Following the 1997-1998 Indonesian burning season, the growth rate of atmospheric CO2 shot from 3.2 gigatonnes (Gt) per year to 6.0 Gt – the highest proportion ever recorded. Smoke from burning trees was partially responsible for the emissions, but more problematic was the 2.57 Gt of pollution which originated from smouldering peat bogs. The total emissions figure was equivalent to 13-40% of the amount released by global fossil fuel burning that year, and greater than the carbon uptake of the world’s biosphere.”

    Presumably the carbon isotope signature of the CO2 from peat resembles that of coal and gas used in power plants. If not accounted for, and if all this is correct, the curves would change a little.

  8. In my reading of studies done with plant growth in increased CO2 environments, there are some interesting results. One of the main issues is that plants in enhanced CO2 seems to be much more drought resistant. In the first year of the FACE study (Duke University) of forest sweetgum trees in a CO2 fumigation setting, August was dryer than average. Control trees grown in ambient CO2 showed reduced photosynthesis in August compared to June of that year. The trees in the CO2 enhanced environment showed no decrease in photosynthesis in August.

    So the issue is very complicated because you have not only generally increased photosynthesis, but you have different responses to conditions. Plants growing in higher concentration of CO2 may not experience drought stress in a dry period so that their overall production of biomass might be greater than simply that increase generated by only CO2 in a more optimal environment. In other words, photosynthesis might generally increase over 150% in a doubled CO2 environment, all other things being equal, but might be 200% greater under drought conditions than for trees grown in an environment with less CO2. So CO2 enhancement, at least for sweetgum, would be expected to result in a much greater delta of biomass production in dry periods.

  9. the faucet is still running faster than the drain.

    The way I read it is that when you open the faucet more, the drain opens wider. The more CO2 you add to the system, the more efficient the system becomes in removing it.

  10. Do the units on the Y-axis apply to all three traces?

    If so, the drain is certainly not bigger than the faucet.

    The drain seems to be proportional to the faucet, with a second or third order term.

    Carrick, on the way up I do not see a lag between output change and uptake change. Your statement “based on this data, the CO2 sink would continue to grow for some time” needs to be supported with a correllation exercise. I do not see it.

  11. Yes, title should be something like
    “As the faucet gets bigger, so does the drain”.
    Though we would call it a ‘tap’!

  12. No, just misleading/exagerating. I chalk it up to excitement over new found data, which seems to be a universal. Honestly, if the drain is bigger than the tap, then the concentration has to go down not up. Anyway, the new title is less interesting and emphatic, but is unimpeachably honest.

    This debate reminds me of effects I see in software engineering.

    There will be some highly evolved, poorly documented system (climate) developed by a group that is not available for comment (god/4 billion years of random processes) and the first thing the green replacement engineers (climate modelers) do every time is start removing bits of code that “don’t make sense” or “don’t do anything important”. The new revision of the system (current climate models) is hopelessly full of basic errors that the 3rd world newbies must relearn one nuance at a time, with the best early hackers gaining name recognition (Mann) through credit taking and self promotion. In the mean time management (The IPCC) has a vested interest in maintaining the illusion that replacing the expensive old engineers with low wage replacements is a smashing success and refuses to acknowledge errors and slow progress. Upper management (world governments) does not care if quality sucks as long as margins (tax revenue) are good.

  13. #21, I absolutely never mislead or exaggerate to make a point here, although I do make mistakes.

    Just to let you know, when I first read the graph I misunderstood the bottom half curves to be absolute measures rather than delta’s. TTCA pointed it out in comment #1 within minutes. I rewrote the entire post except the title and linked to his. I had dropped a link on CA’s open thread that reads like this

    jeff id:
    November 11th, 2009 at 1:02 pm

    Sweet, first comment on unthreaded.

    Anthony Watts did a report on a CO2 paper that demonstrates CO2 is not building up in the atmosphere and the trend we see cannot be statistically differentiated from the annual output as would be the case if the sinks were smaller than the source. I did a quick link to it at tAV because it seemed like a lot of people were missing the point.

    Has anyone ever read anything like this before? I’m hoping someone can share a copy of the paper also.
    reply and
    paste link
    Anastassia Makarieva:
    November 11th, 2009 at 1:30 pm

    Re: jeff id (#2), Actually he is not saying that CO2 is not building up in the atmosphere. If X Gt carbon are emitted per year into the atmosphere due to human activities, of which Y are buried somewhere by natural processes (e.g., in the ocean) and Z = X – Y stay in the atmosphere, what he says, as I understand, is that the ratios Z/X = 0.4 and Y/X = 0.6 remain roughly the same during the last hundred years. This means that the natural sinks are not saturated, in contrast to what some have previously argued.

    In my view, there are gross uncertainties in this estimate, like diminishing the emission from agricultural land by severalfold to match the conclusion.
    reply and
    paste link
    jeff id:
    November 11th, 2009 at 1:37 pm

    Re: Anastassia Makarieva (#3),

    You’re right Timetochooseagain already made the same point. That’s the great thing about open blogging. If you’re wrong, you’ll hear about it in minutes. 😀

    So within minutes of posting this post, I was corrected twice here. Over on WUWT I left these two.

    Jeff Id (10:19:35) :

    There are a lot of people missing the point of this paper. What it says is, yes there is statistically more CO2 but that CO2 isn’t building up. It’s being absorbed as fast as we emit it.

    The drain is bigger than the faucet.

    —-which received at least one reply

    So I left this one

    I was wrong above. Timetochooseagain pointed out that the lower part of the graph is ‘change in co2′ rather than co2 level. My bad.

    The paper means the sinks are working harder not that they’re keeping up.
    In short I screwed up the initial interpretation of the graph, nothing more. That’s why i linked ot TTCA’s post above. I do apologize for not changing the title, you never know how people will interpret your stuff in blogland but I promise not to intentionally mislead or exaggerate (unless it’s in fun).

  14. What I don’t understand is why anyone would be surprised that CO2 sink rates are proportional to concentration. That would be Chem 101 level I would have thought. The question is whether they are linearly dependent. I did an empirical fit to the Mauna Loa data that suggests that it isn’t linear and that the rate of increase is increasing over time. The fitted equation was 316*exp(0.002625*(year-1959)+2.98E-05*(year-1959)^2). To a very good approximation over the time scale of interest, CO2 emissions have been increasing linearly with time. If the sink rate were linearly proportional to concentration, the quadratic term in the exponential fit wouldn’t be there.

  15. DeWitt Payne said,

    ” The question is whether they are linearly dependent. I did an empirical fit to the Mauna Loa data that suggests that it isn’t linear and that the rate of increase is increasing over time. ”

    I have plotted each months rate of change for the MLO data set between 1960 and 2007, please see below linked to diagram.
    Please note the vertical scale, what increasing rate ?

    All years plotted fall within plus or minus a single ppm Rate of change of the overall monthly means.
    It looks rather constant when done in a simple take one from the other maths terms.
    Are your maths DeWitt Payne confusing the issue perchance..

  16. Derek,

    When you point by point differentiate, you decrease the signal to noise ratio. Here’s my plot of the annual data and the exponential fit: . Note the concavity of the curve. The change in rate over time is obvious. Annual-Fit is the Mauna Loa data and the exponential fit is unlabeled.

    With a linear increase in emission, a sink rate proportional to concentration produces a quadratic concentration curve. To get a linear concentration curve, the sink rate has to increase faster than the concentration. In order to have a sink rate that increased faster than the concentration, you would have to have some sort of bi-molecular reaction. One of the major sinks, dissolution in the ocean, certainly doesn’t fit that description. I’m pretty sure photosynthesis doesn’t either.

    Think about the ocean. At equilibrium, the rate of absorption and emission of CO2 are equal, all other things like temperature held constant. Now raise the concentration of CO2 in the atmosphere by a very small amount. The rate of absorption increases and the concentration starts to drop, but because diffusion and mixing aren’t instantaneous, the decrease is not instantaneous, but rather a decay back to the equilibrium value over years. But that assumes that the ocean has infinite capacity. It doesn’t and the emission rate is also a function of the concentration of dissolved CO2. The same goes for biomass, btw. So if you change the atmospheric concentration by a large value, the decay isn’t to the original equilibrium value, but to a higher value. Feed the differential equations describing that with a linear increase in emission and you get a concentration that increases faster than a quadratic because the sink rate is the difference between absorption and emission and the emission rate also increases with time.

  17. Derek,

    Why do you think that a plot of within-year variations says anything about year to year variation? Within-year variation is all about the fact that there is more land in the NH than the SH and so the annual temperature range is greater in the NH than the SH.

  18. DeWitte,

    I think the CO2 net absorption rate for the ocean has also to depend on the concentration already in the ocean in deep waters. When the concentration increases in the atmosphere, it is the increase over the background “deep ocean concentration” of CO2 that matters. The ocean is structurally similar to a thin skin (100 meters?) of relatively warm water sitting over a deep pool of very cold water. The thin skin has relatively small CO2 capacity compared to the deeper ocean; only this thin surface layer will on average approximate a relatively fast (a few years to a couple of decades) equilibrium with the atmospheric CO2 concentration.

    It is the relative rates of desorption/absorption of upwelling cold water warming at the surface in temperate and tropical regions, and sinking cold going to the deep in arctic/antarctic regions that determines the net flux of CO2 into the ocean. Since ocean turnover is quite slow, the desorption rate from warming upwelling water is set mainly by the CO2 concentration when that upwelling water last was in contact with the atmosphere; ~1000 years ago when CO2 was near 285 PPM, which means about 285 PPM atmospheric equivalent in the upwelling water. Absorption by sinking water (at cold high latitude locations) is set by the current atmospheric absorption (386 PPM). So the net absorption rate should be roughly proportional to (atmospheric CO2 – 285PPM).

    The quadratic term in your fitted curve is mostly needed to account for the non-linearity that arises from this difference term.

    Of course, far in the future (at least 400-500 years), the CO2 concentration in upwelling water will begin to increase, so the net absorption capacity will fall. But by then, humankind will be long past the “age of carbon”, and atmospheric CO2 will already have declined greatly.

  19. Steve Fitzpatrick,

    That’s not my understanding of how the deep ocean circulation works. You get downwelling of surface water that has increased salinity due to evaporation as it circulates to higher latitudes and is then cooled to further increase its density. Upwelling then occurs everywhere, more in some areas and less in others. The evidence for this is the stability of the depth of the thermocline(s) on an annual average basis. Absent upwelling of cold water, the thermocline would increase in depth over time as heat is transferred from the surface by eddy diffusion. Transfer of CO2 to and from the deep ocean has a long time constant, on the order of 1000 years. The effect of such a slow process should not be detectable in a record covering only fifty years.

    There’s some interesting stuff about Heinrich events and Melt Water Pulses on line. One paper ( ) suggests that MWP 1a, possibly originating in Antarctica, was the cause of both the Bolling-Allerod warming and the Younger Dryas cooling.

  20. DeWitt Payne, regardless of your long “explanation”, what increasing rate. ?
    The monthly figures ain’t producing anything different, as my plot clearly shows,
    regardless of your hubris.

    BTW – Do you think of MLO data as empiracal. ? Or reliable. ?
    If either please, show us the raw data, the factors measured and quantified to reject “raw data”, and the algorithms to process the raw data to produce the, and this really is not a joke, but it should be, here is the official description…
    “raw hourly averages”.
    The figures you and I have been looking at DeWitt are all from the “raw hourly averages”, processed into daily, weekly or monthly figures.

    I think most will understand my maths using the published monthly figures, yours, I certainly do not.
    Most will also understand that an average is processed, so therefore is not raw data.
    MLO is a sixty year record with
    1) no raw data,
    2) no quantified factors for rejection, and
    3) no algorithm used to process the actual but never released raw data.

    Brilliant certainly, but the scientific method, it most certainly is not.
    It is greatly empowering the scientific method, people who are not experts, can check how the “scientists” or “experts” have come to their conclusions,
    The scientific method often shows there is much to be lamented, MLO being a case in point.
    (and any conclusions drawn from the MLO “data”. False “data” equals false conclusions, and apparently dodgy Dim Witt maths….)

  21. BTW DeWitt,
    I looked at the CO2 monthly released data at,
    For no particular reason I chose May.
    I subtracted Aprils figure for Mays figure in each year.
    I then added up the ten figures for May in each decade, ie 1960 to 1969.
    Here’s what I got.
    1960 to 1969 – 5.76
    1970 to 1979 – 4.61
    1980 to 1989 – 6.1
    1990 to 1999 – 5.84
    2000 to 2009 – 4.56

    I repeat again, what increasing rate. ?

  22. Derek November 13, 2009 at 4:23 pm

    DeWitt Payne, I have reacted at about 5-6 blogs (didn’t count the total number) on what Derek writes about Mauna Loa figures… But if one doesn’t want to be convinced, one is unconvincable, whatever argument and data are supplied. Here is what Derek says:

    I think most will understand my maths using the published monthly figures, yours, I certainly do not.
    Most will also understand that an average is processed, so therefore is not raw data.
    MLO is a sixty year record with
    1) no raw data,
    2) no quantified factors for rejection, and
    3) no algorithm used to process the actual but never released raw data.

    1) Indeed MLO doesn’t have the raw voltage measurements (about 8 million/year) of the instrument on line. What they have on line is the calculated average CO2 levels, based on 2×20 minutes intake with 10 second voltage reading snapshots. The calculation is based on 3×2 minutes of reference gases of known composition, again with 10 second voltage snapshots. In between, the lines are cleaned with the next air inlet or reference gas.
    This results in “raw” hourly averages, not altered in any way and the standarddeviation of the calculatid CO2 levels (out of the 10 second snapshots). These are on line for four of the baseline stations (BRW, MLO, SMO and SPO): up to 2008

    2) The raw hourly averages are eventually “flagged” for known, pre-quantified reasons. The criteria for not inclusion in averages(and the quality control procedures) are clearly outlined here:

    3) The algorithm is clearly outlined in the previous link. And there is no problem to obtain the raw voltage values if one want them. A simple mail to Pieter Tans of NOAA is sufficient. I received a few days of data on simple request to test the algorithm and obtained the same results (including flagging with the outlined criteria, except for U – upslope wind – which need data from the nearby meteorological station) as stored in the online hourly averages. One can check the complete dataconversion (here for one hour) that I have done on an Excel sheet:

    Further, taking the derivative of a growing value does not show what the real value does. Again Derek is looking at the seasonal change, which is relative constant (as plant growth and decay and ocean uptake and release is), but that doesn’t say anything about what the (cumulative) trend does.

    If one looks at the real trends, it is a different story:


  23. Yes, Ferdinand does seem to need to follow me about.
    I havn’t a clue why. ?
    But he does seem intent on leaving loads of links to his website wherever he follows me
    – maybe his site ain’t getting enough traffic, I don’t know (Ferdy old bean, try some scantily clad female pictures – that might help).

    BTW – I have subtracted each months released CO2 figure as measured at MLO from the previous months figure (rate of change) for the whole data set mentioned above.
    Each months RoC for a decade is summed, then each decade can be plotted as a line. ie, 1960s.70s,80s,90s, and 00s.
    If the rate of increase is increasing as Ferdinand also now here strongly suggests, with equally complicated maths I note,
    then it would seem obvious that the plotted lines would show a definate pattern…
    Being a helpful sort, I have plotted the resulting lines and uploaded them to a (public) photobucket account.


    Niether way of plotting the resulting figures shows an increasing rate of increase that I can see.
    Obviously my maths is not complicated enough…………

    Or, possibly, just possibly the rate of increase is NOT actually increasing.
    Perish the thought.

  24. Ferdinand,
    in reply to your reply to my 3 points above.

    1) No raw data – We have discussed elsewhere, and at length the “raw data”, it had not been made publicly available, or published.
    I do not know if this has been altered recently and is now online. However as I stated to you in another forum, if all the “raw data” was now released, how would we know that it was actually THE raw data.
    Your answer was simple and straight forward.
    “We would not.”

    2) OK, so your point 2 is slightly different to my point two in some respects, but the nub of the matter remains the same, you use the phrase,
    “The raw hourly averages are eventually “flagged” for known, pre-quantified reasons. The criteria for not inclusion in averages(and the quality control procedures) are clearly outlined here:”
    The factors used were not openly quantified as you suggest, untill possibly very recently. I remember reading your exchanges with Dr. Glassman at the Rocket Scientists Journal blog, specifically this thread,titled the acquittal of CO2,
    Dr. Glassman also explained that the factors used to exclude “raw data” were not quantified.
    Again the question is, are the now (supposedly) quantified factors the same as used previously.
    We do not know, they were not made available.
    Later, you telling stated that you tried with Dr. Glassman, but had given up.
    The replies to each other in that thread are well worth reading………..

    3) The missing MLO algorithm – It had never been released. Last year, if i remember correctly you yourself stated that MLO had sent you 2 days of raw data (not much out of a 60 year record really..) and that you were learning “R” or something to make you own algorithm. This you proudly announced sometime later gave (virtually) exactly the same results from the raw data that MLO released as the hourly averages.
    So, “that” was not THE algorithm used by MLO, and there is no way to know if the algorithm has been altered over the years,
    regardless of whether “it” is now available or not…..

    I prefer simple, understandable maths, there is less likelyhood of hidden or unintensional “effects” (assumptions) on the processing of the data.
    If there are any “hidden” assumptions (I’m not aware of any) in the ten year RoC sums I have used here to illustrate my point,
    then please explain what they are.
    I will leave others here to explain the “effects” of yours, and DeWitt’s maths.

    I can not reasonably say the MLO “data” is reliable.
    I can not reasonably say that it is shown that there is an increasing rate of CO2 accumulation in the atmosphere as you and DeWitt here state.

    I am concerned that both are incorrect, and so anything based off them is built off a false foundation.

  25. Derek,

    I am not interested in how many people see my web site, what I write there is my own opinion (and a lot of pictures of my trips around the world). I even have no counter to monitor the visits…

    1. Indeed we have had a lot of discussions on what raw data are. In this case you don’t have the (millions of) voltage readings on line, neither do you have the (millions of) satellite readings which are at the base of the UHA/RSS satellite temperature calculations. So these are not to be trusted too? Or do you only trust the data you like?

    As long as many people in different labs and different organisations with different methods find the same values within tight limits, I have no reason to suspect that the data are manipulated, except if you have some proof for it.

    2. As far as I know, the same criteria for rejection (not deletion!) of the raw hourly averages for daily/monthly/yearly averaging is the same over 60 years. The difference is that it is mostly automated nowadays, while it was all calculated by hand in the early years from stripchart readings.

    In essence, the algorithm is simple: two (or nowadays three) reference gases are used to frequently calibrate the instrument and to make a calibration curve. The voltage readings then are translated to the CO2 reading. That is all. Only in the case that one of the reference gases shows a drift, the whole chain of voltage readings of the instrument are reused for recalculation of the CO2 levels.

    Here some background from 2003 (but I have seen similar ones of much earlier date):
    All you need is checking the net for older files…

    The problem with Glasman in discussions, is that his answers are drowning the main points in a lot of sideways…
    But the criteria for rejection were published much longer than his critique.

    3) You are confusing an algorithm with a program. An algorithm can be explained in simple text or algebra, it only describes what needs to be done. It doesn’t matter in what computer language a program is written, as long as the algorithm, the way the program calculates something, is the same as described. In the case of MLO, the algorithm was roughly known (and very simple), but now described in detail by Pieter Tans on the forementioned web page about CO2 measurements at MLO. You can write your own program in any language you like (I simply used Excel), as long as the calculations do what the algorithm describes.

    Here the 60-year old algorithm used by the late C.D. Keeling and his successors all over the world:
    CO2(measured) = CO2(min_reference) + voltage(measured)/(voltage(max_ref)-voltage(min_ref))*(CO2(max_ref)-CO2(min_ref))
    The only change is that they now use a three-reference higher order curve for the references, to have an even more accurate result (the instrument voltage reading (= IR absorption) is non-linear vs. CO2, but that has little effect if the reference gases are close beyond the measurements).


    Again, the differentials you take over two months have very little to do with the year by year increase in the atmosphere, these only show what happens during spring, thus what the start of vegetation growth does (which is more or less the same, a little increasing, over the years) with CO2 levels at MLO. That is seasonal noise, not the signal: the year by year increase of CO2 in the atmosphere, one is interested in. If you want to show what the ratio between emissions and increase in the atmosphere is, then you must compare (accumulated) emissions with accumulation in the atmosphere over the years. Not two-month differentials.


    In my opinion, with the knowledge I have gathered, the MLO (and other station) data are reliable and present the true CO2 levels of the atmosphere in large parts (about 95%) of the earth.

  26. “Again, the differentials you take over two months have very little to do with the year by year increase in the atmosphere, these only show what happens during spring,”

    Ferdinand, and summer, and autumn, and winter. Did you look at the plots…

    “1. Indeed we have had a lot of discussions on what raw data are. In this case you don’t have the (millions of) voltage readings on line, neither do you have the (millions of) satellite readings which are at the base of the UHA/RSS satellite temperature calculations. So these are not to be trusted too? Or do you only trust the data you like? ”

    That is not an answer to the actual question, and avoids your earlier elsewhere response to it of “We would not.”

    I will not respond to your other comments but just leave others to work them out for themselves.

    As for what causes CO2 variation on an apparently seasonal basis at MLO,
    again another subject we disagree on, there are plenty of papers showing vegetation varying differently to the CO2 measured by MLO concentration. on the volcanic island itself, and the Northern Hemisphere. ?
    Little seems to be known or accounted for regarding the warming and degassing ocean (and it’s phases, as well as “warm pools”) the island is located in, and it is also seasonally traversed by the trade winds that cross said ocean….

    Then there are the underwater volcanoes around the island that are rarely if ever mentioned..

    The MLO results to me are too “pat”, but,
    time will tell.

  27. Ferdinand,

    Have you ever tried to fit the MLO data with a combined forcing of global temperature and a linear increase in emissions using a multi-year time constant? It looks like the monthly average data is inversely proportional to the global average temperature with a 90 degree phase shift, implying a time constant much longer than one year. I was going to do Barrow, but the CO2 response to temperature looks to be highly non-linear as well as having a smaller phase shift. That’s not surprising considering that Barrow is north of the Arctic circle.

  28. 37.Derek said
    November 19, 2009 at 11:25 am

    “Ferdinand, and summer, and autumn, and winter. Did you look at the plots…”

    Sorry, did only look at slide 2, and did interprete the plot wrongly, thought it were again the spring-only plots. But nevertheless, what you are looking at is the derivative of the trend, where the variability is caused mainly by temperature, in this case the temperature change over the seasons. That doesn’t say anything about the trend itself, which is quite linear with the emissions and more clear if you take yearly averages. The change in CO2 levels is about 2 ppmv/year, that means 0.2 ppmv/month and only slightly changing over decades (0.6 ppmv/yr in the ’60s), that means that the rate-of-change caused by the trend itself is a more or less fixed bias in the monthly derivatives and only shifts the decadal sums to a slightly higher level, without much trend…

    With yearly averages, one removes the seasonal trend, which is of no interest at all, only the changes after a full seasonal cycle are of interest. See the increase in the atmosphere vs. the accumulated emissions with yearly averages over the past 60 years:

    The variability around the atmospheric trend mainly from temperature variations, which influence the sink capacity of the oceans and vegetation.

    There is no vegetation at all surrounding the MLO station, but when (mainly in the afternoon) there is upslope wind, the CO2 levels may be some 4 ppmv lower. As Hawai doesn’t have much change in vegetation over the seasons, the seasonal changes are not the result of local growth or decay, but of vegetation growth and decay mainly in the mid-latitudes of the NH, with a delay of 1-2 months to reach a maximum or minimum at the altitude of MLO.

    The outgassing of the oceans (by deep ocean upwelling) in the mid-Pacific is of minor influence, as the speed of transfer between the ocean surface and the atmosphere is quite low. The near sealevel CO2 measurements of Hawai and MLO at 3400 m altitude show near the same trends, regardless of wind direction or wind speed.

  29. 38.DeWitt Payne said
    November 19, 2009 at 3:37 pm

    I haven’t used a time constant, but the endresult (at current increasing emission rates) is quite linear with the emissions (as the article of Knorr also found): at about 55% of the emissions plus a variability around the trend, caused by temperature, of about 4 ppmv/K (based on short term 1992 Pinatubo and 1998 El Niño reactions of CO2 on temperature changes). The time constant for excess CO2 is about 55 years (e-fold) or 38 years (half life), based on the work of Peter Dietze (see: ), but the simple forrmula, without time constant is here:

    C(new) = C(old) + 0.55*C(emissions) + 4*dT

    Where emissions are only from fossil fuel burning in the period of interest (Knorr includes land use changes, resulting in 45% increase in the atmosphere, but the extent of land use change is far less certain) and dT is the change in temperature in the period of interest.

    For the past 50 years: here the plot of calculated and observed increase in the atmosphere (compared to MLO, Barrow is more variable, probably less smoothed due to nearby tundra and ice cover changes): not bad for a first approximation.

    Pieter Tans of NOAA (responsible for MLO and the other baseline stations) included precipitation as factor in vegetation growth, his plot is here (second part of the paper):

  30. Ferdinand,

    I can fit the seasonal MLO data very well using the NH and SH temperatures separately with a one month lag and a time constant of 1.5 months. Rsquared was 0.9946. I did have to remove the year over year increase from the CO2 data. I did that by subtracting delta*(month number)/12 from each of the monthly averages. Now I’ll try to fit the annual data if I can find everything I need.

  31. Apparently there are unresolved differences between La Quere 2009 and Knorr 2009.

    There are several differences in methodology between Knorr 2009 and Le Quere 2009. Knorr’s result does not include the filtering for ENSO and volcanic activity employed by Le Quéré. However, when Knorr does include this filtering in his analysis, he finds a trend of 1.2 ± 0.9% per decade. This is smaller than Le Quere’s result but is statistically significant.
    Knorr also finds the 150 year trend while Le Quéré looks at the last 50 years. This may be significant. If the airborne fraction is increasing, it is possibly a recent phenomenon due to natural carbon sinks losing their absorption ability after becoming saturated. Several studies have found recent drops in the uptake of CO2 by oceans (Le Quere 2007, Schuster 2007, Park 2008). However, with such a noisy signal, this is one question that will require more data before being more fully resolved.

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