Saturday, April 27, 2013

New paper demonstrates temperature drives CO2 levels, not man-made CO2

A recent paper published in Nature Climate Change finds a disconnect between man-made CO2 and atmospheric levels of CO2, demonstrating that despite a sharp 25% increase in man-made CO2 emissions since 2003, the growth rate in atmospheric CO2 has slowed sharply since 2002/2003. The data shows that while the growth rate of man-made emissions was relatively stable from 1990-2003, the growth rate of atmospheric CO2 surged up to the record El Nino of 1997-1998. Conversely, growth in man-made emissions surged ~25% from 2003-2011, but the change in the growth rate of atmospheric CO2 has flatlined since 1999 along with global temperatures. The data demonstrates temperature drives CO2 levels due to ocean outgassing, man-made CO2 does not drive temperature, and that man is not the primary cause of the rise in CO2 levels.

Man-made CO2 emissions shown in black, growth rate of atmospheric CO2 shown in blue
Fig. 2 from Francey et al. The CO2 growth rate has declined in 2002 despite increasing emissions

Plot for yourself here a single graph that simultaneously demonstrates the clear observational evidence that 
  • temperature drives CO2
  • CO2 does not drive temperature
  • man is not the primary cause of the rise in CO2 levels
The effect follows the cause; the cause does not follow the effect. Short-term global temperature changes precede CO2 levels by about 1 year as shown by observations, and by 800+ years in ice core data.

Atmospheric verification of anthropogenic COemission trends

Nature Climate Change 3, 520–524 (2013) doi:10.1038/nclimate1817 

Abstract: International efforts to limit global warming and ocean acidification aim to slow the growth of atmospheric CO2, guided primarily by national and industry estimates of production and consumption of fossil fuels. Atmospheric verification of emissions is vital but present global inversion methods are inadequate for this purpose. We demonstrate a clear response in atmospheric CO2 coinciding with a sharp 2010 increase in Asian emissions but show persisting slowing mean CO2 growth from 2002/03. Growth and inter-hemispheric concentration difference during the onset and recovery of the Global Financial Crisis support a previous speculation that the reported 2000–2008 emissions surge is an artefact, most simply explained by a cumulative underestimation (~ 9PgC) of 1994–2007 emissions; in this case, post-2000 emissions would track mid-range of Intergovernmental Panel on Climate Change emission scenarios. An alternative explanation requires changes in the northern terrestrial land sink that offset anthropogenic emission changes. We suggest atmospheric methods to help resolve this ambiguity.


  1. The graph of atmospheric CO2 at Mauna Loa ( shows quite a different curve, and none of the "flatlining" shown in the paper. Do you know if Francey et al. have used different data?

    1. The Francey et al graph is of rate of change of both CO2 emissions and CO2 levels, whereas the Mauna Loa data is just the absolute values.

    2. Ah, now I see. Thank you. Although I did just discover they used data from Cape Grim, Tasmania, not Hawaii.

  2. "An alternative explanation requires changes in the northern terrestrial land sink that offset anthropogenic emission changes"

    The observations do suggest just that as I pointed out here:

    Stephen Wilde: Evidence that Oceans not Man control CO2 emissions

    Thursday, April 26th 2012, 12:39 PM EDT

    "There is little or no significant excess CO2 above or downwind of major population centres such as Western Europe or the North Eastern USA."

    Elsewhere I specifically stated that our emissions were obviously being captured by the local or regional biospheres.

    Increased CO2 is equally obviously arising from more sunshine on oceans when global cloudiness falls as it did during the recent warming spell.

    Global cloudiness is now increasing again and if it does so for long enough then the CO2 trend should eventually follow by turning downward.

    Stephen Wilde.

  3. So isn't the term 'flatlining' not representating what's going on?

    I mean, people think 'flatlining' means staying the same generally.

    But technically, y=999999x is a 'flat line' but it's definitely increasing, and if CO2 was going up at that rate, we'd all be dead in like 5 minutes.

    So, my main question is why do people only look at information that validates their beliefs instead of looking for information that validates information?

    1. The growth rate has flatlined, not growth.

      This was pointed out at least 4 times above.

      Your main question should instead be why do some people such as yourself fail to understand the most basic principles of science and mathematics?

  4. or, to point out the errors in the first statements.

    1. ' the growth rate in atmospheric CO2 has slowed sharply since 2002/2003'

    2. ' the growth rate of atmospheric CO2 has flatlined since 1999'

    it cannot be slowing sharply and flatlining. If the growth rate slowed, then the rate would go towards in the negative direction. If the growth rate is flatlining, then the growth rate would approach zero.

    This just doesn't make any sense.

    1. The abstract itself states the data "show persisting slowing mean CO2 growth from 2002/03." This is confirmed by the flattening out of the dCO2/dT blue line shown in Fig 3.

      If dCO2/dT is about the same in 2011 as it was in ~1998, the change in the growth rate [second derivative] of atmospheric CO2 has flatlined and slowed to near zero.

      During the same period, man-made CO2 emissions have increased 25%, therefore the disconnect and questionable attempts by the authors to explain why.

  5. I would add that this post is confirmed by other independent research by Humlum, Salby, Frölicher, et al.


  6. There is one natural mechanism for this. The more CO2 emitted, the more plants grow eating up the extra CO2 thereby reducing the CO2 in the atmosphere.

    1. Posts on CO2 fertilization:

  7. I'm not a scientist, but I want to understand what all this means.

    I gather that a total atmospheric CO2 is growing, either at an increasing rate (an upwardly curving line), a zero rate (a straight line), or decreasing rate (a downward curving line). Despite the curvature of the plotted line, atmospheric CO2 is nevertheless growing.

    What I don't understand is the significance of the growth of TOTAL atmospheric CO2 over time versus the RATE at which atmospheric CO2 grows over time, and why scientists (seem to) focus on the rate of growth instead of total growth?

    Jeff Morton

    1. Total atmospheric CO2 has been increasing naturally since the last ice age primarily due to outgassing from the oceans, as well as outgassing from land-based sources.

      The IPCC thought atmospheric CO2 would increase at an accelerated rate due to man-made CO2 emissions, and programmed its computer models to assume a large acceleration of the increase in CO2, with correspondingly dire projections of the alleged effects of CO2.

      Acceleration is defined mathematically as the second derivative, i.e. how the rate of change of a quantity is itself changing. In the first graph above the the rate that growth in CO2 over time [dCO2/dt] [blue line] is changing since 2002/2003 is essentially zero, therefore, there is no evidence of the acceleration that the IPCC claimed would happen.

      Not only that, there is no acceleration in atmospheric CO2 despite a 25% increase in man-made emissions.

      Thus, the IPCC assumptions and computer modeling are incorrect, and it's projections greatly exaggerated.

  8. Funny how "everyone" seems to know that water evaporates at a higher temperature, thereby supposedly causing more/bigger storms, but it is never mentioned that higher ocean temp.'s decrease the solubility of CO2 causing more in the atmosphere. Just google solubility of CO2 and look at images for the graphs. Yet supposedly, the warmer oceans are now more acidic because somehow the warmer oceans are holding more CO2?? WUWT?


  9. Good stuff. If temp is responsible for outgassing CO2, is the amount of man made CO2 decreasing the outgassed
    potential? Or does the man made version have no effect on the outgassed rate or quantity.
    Lastly, is the man made version of CO2 the same as the outgassed version?
    Thank you.

    1. Outgassed CO2 is only dependent on ocean temperature, not man-made CO2.

      Higher temperature decreases solubility of CO2 and vice versa. Same thing happens when a glass of soda warms - the CO2 bubbles out of solution.

      Man-made CO2 is the same molecule as outgassed CO2. There are highly technical arguments regarding CO2 isotopes for those interested here:

  10. It makes sense that rising temperatures would spark ocean outgassing of CO2, because when it is warmer, plants want to grow and they need more CO2. When it gets colder, just the opposite happens. That is the way the bio-system is designed (and we didn't do that).

  11. Ok, then how are you and your colleagues going to convince the EPA, Congress, multiple corporations including energy companies, etc., that
    we have been lied to - oops, that the calculations were wrong. How do we
    negate the brainwashing going on in thousands of classrooms and millions of students?
    How do we convice those that outgassing far outdistances man made CO2 as the "problem". In fact, is it really a problem?
    When does THIS research get accepted by the mainstream media?

  12. Tallbloke has reblogged this post here

    And I wholeheartedly agree with his comment:

    tallbloke says:
    May 1, 2013 at 7:16 am

    Roger A: I think the correct understanding of this requires an appreciation of the vast size of the carbon cycle context in which the ‘fossil carbon’ is emitted. As usual the problem is ‘static thinking’ concerning sources and sinks. If Cardellini et al are correct, and 9Gigatonnes per year are being emitted from the decomposing volcagenic soils of central Italy alone, then the whole discussion changes. We are no longer talking about relatively static ‘net’ sources and sinks, plus anthropogenic emissions. We need to consider human emissions in the context of a natural carbon cycle in which both sources and sinks have increased during the warm period.

    when you do that, it’s pretty obvious that increasing sources will outstrip increasing sinks when warming is occurring, because it takes time for additional vegetative biomass to ‘catch up’ with the increased availability of airborne co2.

    The graph in the the headline post tells us there is no simple relationship between human emissions and increased airborne co2 in which ‘natural’ sources and sinks stay constant relative to each other. If there was, then the rates of increase would match. Therefore natural sources and sinks have been changing too, QED. We also know that sinks are bigger than sources, since the increase in the airborne fraction is only around half of human emissions. So the logical deductions are that:

    1) Both sources and sinks have increased, but the increase in sources (including human emissions) outstripped the increase in sinks during the warming period
    2) Since ~2000AD The sources are no longer increasing at a faster rate than the sinks, even though human emissions have accelerated

    And the logical deduction from that is:

    3) The changes in the ‘natural’ part of the carbon cycle are (considerably) bigger than the changes in the anthropogenic element.

    When we add in the fact that rates of change of emission atmospheric co2 level closely follow changes in temperature we can further logically deduce that

    4) The majority of change in Co2 level has been caused by temperature rise (probably due to decreased cloud 1980-1998), not human emission (since changes in co2 lag changes in temperature at all timescales).

    From that we can deduce that the atmospheric ‘decay’ (e-folding time) and residence times are much less than the figures the IPCC has plucked out of its arse, because otherwise, airborne co2 levels would by now be vastly higher than they are.

  13. This analysis posted in the comments at Tallbloke's blog is also excellent and concludes:


    From the analyses shown, it can be seen that there is no evidence to suggest that carbon dioxide from the burning of hydrocarbons has any influence on atmospheric levels. There is significant correlation of atmospheric CO2 with ocean temperature which might be explained by Henry's law of gas solubility in water. It is also shown that changes in CO2 occur after changes in temperature, and in particular ocean temperature. An apparent periodicity in the correlation may suggest a link to ocean circulation patterns.

    The idea of natural saturating CO2 sinks as suggested by the UN IPCC has been shown to be flawed because it simply is not supported by the data.By example it has been shown that cumulation of all positive time series with a slight upward trendcan be made to closely match the Mauna Loa atmospheric CO2 record even when there is no linkage between datasets. This process cannot be used to demonstrate a relationship between anthropogenic releases of CO2 from burning hydrocarbons as it is inappropriate and leads to the spurious long atmospheric lifetimes for CO2 used by the IPCC.

    Although not dealt with in detail in this work, isotopic changes in atmospheric carbon dioxide(13C/12C ratio) could be explained by dynamic fractionation taking place at the air/ocean interface.Global average out-gassing of carbon dioxide would inherently crate a change in atmospheric isotopic ratio.Since there is no significant linkage between atmospheric CO2 and burning hydrocarbons; and an incorrect longevity has been assigned to CO2 emissions; and an invalid relationship between atmospheric CO2 and global temperature used in climate models the results from them, i.e. future climate scenarios, are without doubt worthless. Thus all policies based upon the proclamations of the UN IPCC are simply ideology, have no scientific grounding, and should be either ignored or re-evaluated.

  14. CO2 levels have risen at the same rate for past 18,000 years

  15. Also highly recommended:

  16. Fig 2. uses the same data as Fig 1. but only the last 2,500 years are displayed. If “Climate Scientists” had used the EPICA data to vindicate Arrhenius they would need to explain why the Keeling Curve Hockey Stick (CO2 concentration) did not produce the expected 8 K temperature rise in the last 160 years. The actual “Global Warming” since 1850 was only 0.8 K, an order of magnitude less than than the EPICA data suggests.

    Unanswered Questions

    To make the calculated data in Fig 1 (red plot) agree with the measured data (blue plot) I had to set the sensitivity constant to 16 K/Doubling of CO2, whereas to make the modern data fit (1850 to 2013) observations the sensitivity constant needs to be 1.6 K/Doubling. Who can believe that the sensitivity constant remained at 16 K/Doubling for 800,000 years and then suddenly changed to 1.6 K/Doubling in 1850?

    There is an explanation that makes sense. The fluctuation of CO2 concentrations over the last 800,000 years were caused by fluctuations in ocean temperatures. The solubility of CO2 in sea water is a function of temperature. This hypothesis also accounts for the 500 year delay between rising temperature and rising CO2 concentration.

    That still leaves the question of what caused the temperature changes associated with the last eight glacial cycles. Many people think that Milankovich cycles are responsible for the recent ice ages but the mathematics is a little shaky. Do you know anyone who can tell you when the next glaciation will start based on Milankovich’s theories?

    It also leaves the question “What caused the 0.8 K global warming since 1850”? If CO2 lived up to Arrhenius’ expectations we would be in no doubt at all.

  17. Swedish climate blog also agrees man is not the primary cause of the rise in CO2 levels:

  18. relevant to outgassing argument:


  20. Highly recommend & agree with the comments of Bart on this topic:


  22. Comment to me from Bart on WUWT:

    The important thing to understand here is that it isn’t just outgassing of the ocean the way a warm coke on the counter outgasses. It is not a static situation.

    It is a continuous flow problem. The oceans are continuously upwelling CO2 laden waters in the tropics, and downwelling them at the poles. If there is any imbalance between those two flows, then CO2 is either going to accumulate or drain from the surface system.

    Since the amount which outgasses from the upwelling or gets absorbed in the downwelling is proportional to temperature, that gives an affine expression for the rate of change of CO2 in the surface system of

    dCO2/dt = k*(T – Teq)

    where k is a coupling constant, and Teq is an equilibrium temperature required to balance the upwelling and downwelling flows.

    And, that is precisely the relationship we see in the data.



  25. What you don't seem to understand is that both man made emissions AND variability in the climate system are important for controlling the net growth rate of CO2 in the atmosphere.

    The oceans and land surface (forests and soil) have a seasonal cycle, whereby they release and take up CO2 from the atmosphere throughout the year. The relative amount of uptake and release was in relative balance until humans began to increase the abundance of atmospheric carbon dioxide. The additional warming and fertilisation of plants due to the additional atmospheric CO2 has resulted in the oceans and plants taking up more carbon and becoming a net SINK. They currently take up HALF of the CO2 emissions that WE produce.

    The amount of atmospheric CO2 taken up by the natural sinks varies significantly from year to year due to internnual climate variability such as that caused by ENSO (this is OBVIOUS, when there is drought, plants don't take up as much carbon). Think about it... we release CO2 into the atmosphere. Approximately half of this is taken up by the oceans and forests, the rest remains in the atmosphere and accumulates (which is why the total amount of atmospheric CO2 has just reached 400ppm compared to 320ppm only 40 years ago). Yes emissions are increasing, but the strength of the natural sink is also hugely significant for determining the growth rate.

    With regards to "single graph demonstrates CO2 is not the driver of global warming": this graph simply demonstrates that interannual variability in the climate is important (AS WELL AS ANTHROPOGENIC EMISSIONS) in determining the overall growth rate of CO2 in the atmosphere.

    With regards to "CO2 levels have risen at the same rate for the past 18000 years": WE HAVE MEASUREMENTS THAT SHOW THAT THIS ISN'T THE CASE.

    Greenhouse gases keep this planet warm enough to sustain life. It was shown around 100 years ago that CO2 is an important greenhouse gases and that more CO2 has a warming effect. It's old news. Climate change will adversely affect millions, if not billions of people on this planet. 97% of scientists are convinced by the evidence of anthropogenic climate change. There is no conspiracy here, just alot of smart people trying to work towards a better world for everyone.

    1. Your comment is loaded with misconceptions and alarmist talking points. Here's the facts:

      1. Man only produces 4% of CO2 emissions, nature 96%
      2. Carbon sinks can't distinguish between CO2 produced by man or nature.
      3. The half life of CO2 in the atmosphere is about 5-10 years, whether produced by man or nature
      4. Quoting from the post:
      A recent paper published in Nature Climate Change finds a disconnect between man-made CO2 and atmospheric levels of CO2, demonstrating that despite a sharp 25% increase in man-made CO2 emissions since 2003, the growth rate in atmospheric CO2 has slowed sharply since 2002/2003. The data shows that while the growth rate of man-made emissions was relatively stable from 1990-2003, the growth rate of atmospheric CO2 surged up to the record El Nino of 1997-1998. Conversely, growth in man-made emissions surged ~25% from 2003-2011, but the change in the growth rate of atmospheric CO2 has flatlined since 1999 along with global temperatures. The data demonstrates temperature drives CO2 levels due to ocean outgassing, man-made CO2 does not drive temperature, and that man is not the primary cause of the rise in CO2 levels.
      5. There is no proof the anthropogenic emissions are important in determining the growth rate of CO2, as demonstrated by the paper which is the subject of this post showing the disconnect between emissions and growth.
      6. That CO2 levels have risen at the same rate for the past 18000 years is clearly demonstrated by the data in the graph in the post I linked.
      7. More CO2 has a trivial warming effect and definite fertilization effect and is thus beneficial to the planet.
      8. Haven't you heard? The 97% statistic is bogus and science is not done by consensus.

  26. link to full paper here:

  27. MS,

    Some comments:

    1. Nature emits 96% of all CO2, but you forget that nature also absorbs 98% of all CO2, 2% remains in the atmosphere. Thus nature is a net sink for CO2, not a source.
    2. Agreed.
    3. The half life of CO2 in the atmosphere is about 40 years. The 5-10 years is turnover time, which exchanges large amounts of CO2 without affecting quantities, nothing to do with the amount that is removed. The latter is ~2 GtC/year, while we are at 210 GtC above equilibrium. That gives an e-fold time of ~53 years.
    4. The paper only shows that nature became a larger sink in the past years, still not a source.
    5. The paper shows that human CO2 emissions are the sole cause of the increase in the atmosphere, but that nature removes a larger part than in previous years.
    6. Except for the past 160 years:
    For the past 800 kyears the ratio was 8 ppmv/°C but in the past 160 years that increased to over 100 ppmv/°C, just by coincidence when humans started to use fossil fuels in increasing amounts...
    7. Agreed.
    8. Agreed.