Uncertainty: The origin of the increase in Atmospheric CO2

Posted: April 18, 2012 by tallbloke in atmosphere, Carbon cycle, data, methodology, volcanos
Tags: , , , , , ,

One of the ‘Tablets of Stone’ in the argument for ‘Anthropogenic Global Warming’ is that human emission of co2 through the burning of fossil fuel is responsible for the increase in the atmospheric level of this trace gas since pre-industrial times, which now constitutes 0.039% of Earth’s atmosphere. It is claimed that this can be logically deduced and calculated and  there is no doubt we are the guilty species.

But there’s a problem…

One of the central planks of the argument is that we know the sources and sinks of atmospheric co2 well enough to determine the proportion that belongs to us. Another is that the changing ratio of two isotopes of carbon (d13 and d12) is a ‘fingerprint’ of human emission. Another is that the ratio of Oxygen to CO2 is consistent with combustion estimates. But what about volcanoes?  These are not thought by the proponents of the AGW argument to figure largely in the carbon cycle on an annual basis. As Ferdinand Engelbeen put it on a recent WUWT thread ‘Dusting for Fingerprints in the Holocene‘:

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. 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.

Ferdi is a competent and honest researcher, and a pleasant and easy person to talk to about this issue. But when I tried to point up some new research linked on a website I’ve been reading, my comment got deleted. So I’ll raise it again now. The website in question is that of consulting geologist Timothy Casey. In his article on Volcanic Carbon Dioxide he has this to say:

A brief survey of the literature concerning volcanogenic carbon dioxide emission finds that estimates of subaerial emission totals fail to account for the diversity of volcanic emissions and are unprepared for individual outliers that dominate known volcanic emissions. Deepening the apparent mystery of total volcanogenic CO2 emission, there is no magic fingerprint with which to identify industrially produced CO2 as there is insufficient data to distinguish the effects of volcanic CO2 from fossil fuel CO2 in the atmosphere. Molar ratios of O2 consumed to CO2 produced are, moreover, of little use due to the abundance of processes (eg. weathering, corrosion, etc) other than volcanic CO2 emission and fossil fuel consumption that are, to date, unquantified. Furthermore, the discovery of a surprising number of submarine volcanoes highlights the underestimation of global volcanism and provides a loose basis for an estimate that may partly explain ocean acidification and rising atmospheric carbon dioxide levels observed last century, as well as shedding much needed light on intensified polar spring melts. Based on this brief literature survey, we may conclude that volcanic CO2 emissions are much higher than previously estimated, and as volcanic CO2 contributions are effectively indistinguishable from industrial CO2 contributions, we cannot glibly assume that the increase of atmospheric CO2 is exclusively anthropogenic.”


“It seems that Gerlach (2011) drew his interpretation from a preference for the “global” “magmatic” carbon dioxide emission estimate of Marty and Tolstikhin (1998) which was devoloped from the generalisation of isotope ratios across provinces of varied geochemistry. This multimodal generalisation, as I have shown in the example of Laki (Section 2, above), can be spectacularly inaccurate. Gerlach reports this figure in the following contrastive statement:

“The projected 2010 anthropogenic CO2 emission rate of 35 gigatons per year is 135 times greater than the 0.26-gigaton- per-year preferred estimate for volcanoes.”

In the units I am using here, that translates to a “preferred” estimate of worldwide volcanic carbon emission at 0.071 GtCpa. At this point, I think it worth contrasting this with a quote from Cardellini et al. (2011) who are actually engaged in some real research:

“Quantitative estimates provided a regional CO2 flux of about 9 Gt/y affecting the region (62000 km2), an amount globally relevant, being ~ 10% of the present-day global CO2 discharge from subaerial volcanoes.”

That 9GtCO2pa translates to 2.45 GtCpa for just one region, which is more than 34 times the latest personally “preferred” “global” estimate offered by Gerlach (2011). One may well be keen to ask how it is possible that anyone would prefer to propagate a “global” estimate which is almost 35 times smaller than only one of the many provincial figures that must be summed in order to arrive at a worldwide estimate in the first place?

So the empirical evidence from Cardellini et al has the ‘preferred estimate’ of worldwide emission of co2 from volcanic sources in big trouble. But what about the isotope argument? Ferdi Engelbeen is sure that volcanic  sources of co2 are  too high in the lighter isotope d13C to account for the falling ratio. But if the ‘preferred estimate’ is itself derived from isotope ratios, then since annual emission of co2 from volcanic sources may be  equivalent to or higher than emission from human sources as the empirical work of Cardellini et al shows, the falling isotope ratio and oxygen ratio argument’s calculations are thrown into uncertainty,  and another AGW ‘Tablet of Stone’ is shattered.

This then is good reason to remind ourselves of the work of Murry Salby, the Chair of Climate Science at Macquarie University.  Joanne Nova tells us He’s held visiting professorships at Paris, Stockholm, Jerusalem, and Kyoto, and he’s spent time at the Bureau of Meterology in Australia. If you are not already familiar with Salby’s work, visit the link to the video presentation he gave to the Sydney Institute, which is well worth watching.

Ferdi comments on that Jo-Nova thread:

That humans are the cause is quite sure:
– The mass balance: It is impossible that nature was a net contibutor to the increase, because the measured increase is less than the emissions. Thus nature was a net sink for CO2 over the past at least 50 years.

I think that in the light of the evidence from Cardinelli et al (whose work is only available as an abstract from the EGU proceedings so far), this whole line of argument needs reconsidering. If we managed to miss 90 Gigatons of emission from volcanic lava in our estimates, then our knowledge of the carbon cycle is woefully lacking. Sinks are obviously much bigger than previously estimated too, and human emission is an even smaller part of the overall carbon cycle than the 5% previously believed.

Ferdi’s argument above only makes sense if the isotope ratio argument holds too, otherwise the increase in atmospheric co2 could quite easily be due to some natural balance shift between sources and sinks which has nothing to do with human emission. But Murry Salby. Timothy Casey and Cardellini et al have strong evidence that the isotope ratio argument is false.

The cracks in the Anthropogenic Global Warming argument are getting wider.


Cardellini, C., Chiodini, G., Caliro, S., Frondini, F., Avino, R., Baldini, A., & Donnini, M., 2011, “CO2 fluxes from Earth degassing in Italy”, Geophysical Research Abstracts, Vol. 13, EGU2011-7778-1. http://meetingorganizer.copernicus.org/EGU2011/EGU2011-7778-1.pdf

No ‘it’s’ were used in the making of this post. 🙂

  1. Peter Whale says:

    The cracks are becoming great rifts but still the dogma holds. There is too much prestige, money and jollies to be had among those who refuse to see and choose ignorance to maintain their positions.

  2. Did Salby ever get around to publishing his paper on the isotope ratios which he hinted at in his presentation last year?

  3. Stephen Wilde says:

    I’ve been unhappy about the isotope ratio as a diagnostic indicator for some time.

    Murry Salby points to ocean CO2 release rates as the primary factor in atmospheric CO2 quantities and adds soil moisture CO2 content on the landmasses to the mix.

    That would fit nicely to the fact that the rate of the recent rise in CO2 amounts seems to be unaffected by the changing trends in human CO2 emissions.

    The neatest solution to that steady rise is slow long term changes in ocean temperatures possibly as slightly warmed water from the MWP now emerges from the thermohaline circulation after a 1000 year journey.

    If the isotope ratio is discredited as a diagnostic indicator then a whole lot of AGW theory folds.

  4. steveta_uk says:

    I can’t find any mention of Salby since the big bru-ha-ha around his talk – no paper, no book, not even a Wikipedia entry.

    Does he really exist?

    [Reply] Sounds like he’s now an un-person.
    Tsk, Steve, try a bit harder.

  5. tallbloke says:

    Expert reviews of Salby’s book:

    “The first edition is a classic. As a textbook it is unequalled in breadth, depth and lucidity. It is the single volume that I recommend to every one of my students in atmospheric science. The new edition improves over the previous edition, if that is possible at all, in three aspects: beautiful illustrations of global processes … from newly available satellite data, new topics of current interest … and a new chapter on the influence of the ocean on the atmosphere. These changes make the book more useful as a starting point for studying climate change.” – Professor Yuk Yung, California Institute of Technology

    ” … an informative and insightful tour through the contemporary issues in the atmospheric sciences as they relate to climate. … a valuable resource for educators and researchers alike, serving both as a textbook for the graduate or advanced undergraduate student with a physics or mathematics background and as an excellent reference and refresher for practitioners. … a welcome addition to the field.” – Professor Darin W. Toohey, University of Colorado at Boulder

    ” … an essential reference for researchers and graduate and advanced undergraduate students who wish to have a rigorous source for a wide range of fundamental atmospheric science topics. Atmospheric and climate scientists will find this book to be an essential one for their libraries.” – Associate Professor Hampton N. Shirer, Pennsylvania State University

    “I recommend it as a foundation for anyone who wants to do research on the important open questions about aerosols, radiation, biogeochemisty, and ocean-atmosphere coupling.” – Professor Jim McWilliams, University of California, Los Angeles

    Book Description
    Murry Salby’s new book provides an integrated treatment of the processes controlling the Earth-atmosphere system, developed from first principles through a balance of theory and applications. This is an ideal intermediate-level undergraduate textbook and reference text for graduates and researchers, supported by student problems, with detailed solutions provided online for course instructors.

  6. Joe Lalonde says:


    With radiation in it’s many forms, the CO2 theory trumps the many different factors of heat. Absorption, circulation, planetary tilting, friction, insulation changes of the atmosphere, volcanic activity heat, ocean content changes, etc., etc.,etc.

  7. TB, I have little time for Ferdinand Engelbeen. He vigorously opposed the work of Beck who was always polite and thorough in his look through historical literature. Beck’s daughter maintains his website (http://www.biomind.de/realCO2/realCO2-1.htm ) where there are many downloadable files. I have personally, made measurements of CO2 in the atmosphere, in mines and in furances with instruments using chemicals. For important measurements instruments were calibrated using certified analysed bottled gases from suppliers such as Linde & BOC. One of the arguments against Becks findings were that measurements were localised and often at ground level and not representative of atmospheric CO2. He answered that with a paper with a French professor which relates average CO2 atomperiic levels and wind speed and then put an error band around this actual reported levels.
    The ignoring of accurate past CO2 measurements is a similar fraud to Mann’s Hockey Stick graph. Engelbeen appears to be a supporter of this fraud.

  8. Josh says:

    Here is a great video lecture by Murry Salby http://www.youtube.com/watch?v=YrI03ts–9I a must view for anyone interested in this area I think.

  9. Chris M says:

    Judith Curry had a topic last year about Murry Salby’s talk. She was acquainted with his work in the USA and considers him a credible scientist. It wouldn’t surprise me if his paper’s still stuck in “peer” review.

  10. tallbloke says:

    CaF: I said Ferdi was easy to talk to, not that he was right… 😉

    Josh: Great artwork mate, thanks again.

  11. Michael Hart says:

    Stephen is probably being too generous.

    A rotating earth acts as a giant centrifuge, acting to fractionate all isotopes of all elements all of the time. The effect varies with latitude, being maximal at the equator, decreasing to zero at the poles.

    Continuous fractionation occurs due to gravitational forces and also due to simple diffusion across, say, the ocean-atmosphere boundary.

    It also operates in ice cores and by chromatographic processes as water moves through sediments under pressure. It is affected by temperature. Charged molecules such as carbonate and bicarbonate observe isotopic effects under electric field gradients.

    Simple chemical reactions frequently display isotope effects.

    Photosynthesis and respiration are not the only isotope-selective processes in the biosphere. Enzymatic processes can accelerate isotope fractionation in exchange reactions requiring no solar input. Carbonic anhydrase accelerates enormously the interconversion of carbonic acid to water and carbon dioxide and thus affects exchange rates between compartments of the carbon cycle.

    It seems easier to ask which processes do not influence isotope ratios. Some of these are hard to detect over short time-scales in the laboratory. But over years and climatic/geological time-scales? Have all these processes really been adequately quantified or simply dismissed in carbon cycle models that cannot account for the ~50% of anthropogenic carbon that goes missing from the budget every year?

  12. TB, Beck was also critised for his interest in looking at possible cycles related to phases of the moon.-see at the bottom of the website page I gave above and the mentioned in this http://www.biomind.de/realCO2/literature/evidence-var-corrRSCb.pdf with regard to the 1.5 year continuous measurements by Kreutz 1941. The Kreutz paper is very interesting in the amount of data collected (including radiation, temperature, pressure, humidity, precipitation etc). Engelbeen, who claimed to have read the German paper, has misrepresented some of the data. Kreutz made measurements of CO2 at four different heights three times a day but there were periods (one over a week long) when he made measurements every twenty minutes. Kreutz’s interpretation (ie his statistics) are not too good. He did not consider lags. My look at his graphs indicate radiation leading temperature which leads CO2 both on a daily and seasonal basis. It seems that Beck got hold of some of the raw data but unfortunately he has passed away with cancer.

  13. Anything is possible says:

    Some figures pertaining to mass, which may (or not) prove helpful……

    Total mass (Ta) of atmosphere = 5.14×10^18 kg.

    Mass of CO2 (Tc) in atmosphere = 2.3 x 10^15 kg

    Proportion of CO2 in atmosphere by mass (Tc/Ta) = 0,000447 or 447ppm.

    This number is somewhat higher than the measured 392ppm by volume, but since CO2 is heavier than air, this make sense, at least to me.

    Now, let’s assume that all other things are equal, and the CO2 emitted by man simply accumulates in the atmosphere.

    Anthropogenic CO2 emissions (2009) amounted to 3.0398 x 10^13 kg.

    Total mass (Ta1) of atmosphere now = 5.14003 x 10^18 kg

    Mass of CO2 (Tc1) in atmosphere now = 2.3304 x 10^15 kg

    Proportion of CO2 in atmosphere by mass (Tc1/Ta1) now = 0.000453 or 453ppm.

    Theoretical increase in mass of atmospheric CO2 year-on-year (2009-10) =+6 ppm

    Actual observed increase in volume of atmospheric CO2 year-on-year (2009-10) = +2.40 ppm.


  14. Roger Andrews says:


    Your numbers check out. About half of the anthropogenic CO2 emitted in any year gets absorbed by the oceans or by vegetation, The rest stays in the atmosphere.

  15. Edim says:

    The increase in 2011 was about 1.8 ppmv I think. It will be very interesting to see how it responds to cooling.

  16. Stephen Richards says:

    Available as an e-book from Kindle £37.

  17. CO2 flux is 97% natural and 3% from human sources. Annual CO2 cycle is greater than the annual increase. Sinks of CO2 are apparently increasing and have been for decades. There is no correlation between CO2 and emissions. There is relatively high correlation between CO2 and temperature particularly ocean temperature (T leads CO2 by about 5 months). Multiple processes are known to alter isotopic signatures and hydrocarbon d13C vary substantially.

    Summation of just about any, all positive, increasing dataset can be made to resemble MLO CO2 trend by choosing suitable lifetime and airborne faction.

  18. Brian H says:

    In Feb. I emailed Salby, and got this response on Feb. 20:

    Dear Brian,

    Apologies for the belated reply; we’re on summer break here.

    The technical paper underpinning my presentation to the Sydney Institute
    has certainly not been withdrawn. The cycle of scientific publication is slow,
    typically about a year. For a subject as political as this one, it can
    be very slow.
    The fiasco surrounding Spencer and Braswell (2011), a thinly-veiled exercise
    in coercion, didn’t help. But, with patience, we will eventually get there.

    Upon formal release, a notice will be sent to the numerous interested parties.
    In the meantime, a couple of matters of possible interest:

    (1) About half of the material in the Sydney Institute presentation
    is developed in Physics of the Atmosphere & Climate,
    a peer-reviewed volume that is now out.
    Although developed for a technical audience,
    elements should be comprehensible to the non-specialist.
    Highlighted in the attached is material of relevance.

    (2) In the coming weeks, a video of the presentation will be made available
    through the Sydney Institute – inclusive of full graphics. Stay tuned.

    Murry Salby

  19. tchannon says:

    Wonderful Josh writing the commandments is stone.

    Ah well, keep taking the tablets.

    (anyone know how Josh actually draws? I assume it is paper expressive yet some of that would be difficult without a computer.)

  20. Michael Hart says:

    Tamsin Edwards has just posted this paper on Bishop Hill:
    High sensitivity of future global warming to land carbon cycle processes

    Click to access 1748-9326_7_2_024002.pdf

    Not read it yet, but this quote from the abstract looks guaranteed to get attention:

    “We find a plausible range of climate–carbon cycle feedbacks significantly larger than previously estimated. Indeed the range of CO2 concentrations arising from our single emissions scenario is greater than that previously estimated across the full range of IPCC SRES emissions scenarios with carbon cycle uncertainties ignored.”

  21. tallbloke says:

    Tim: Josh uses an Ipad I think. I gave him the concept of the tablet of stone being shattered by the paper dart for this artwork and he did a great job of translating my idea into the finished drawing.

  22. jorgekafkazar says:

    @Michael Hart and his “A rotating earth acts as a giant centrifuge, acting to fractionate all isotopes of all elements all of the time….”

    If this were true, Michael, all life on earth at sea level would have suffocated in argon gas long ago.

  23. jorgekafkazar says:

    The only place I know of on earth where a significant volcanic gas emission can be captured, measured, and analyzed is Lake Nyos. The lake’s CO2 smothered 1,700 people in an area roughly 20 miles in diameter when the water layers turned over. Based on measurements of Lake Nyos CO2 seepage, total worldwide emissions of CO2 may be as much as two orders of magnitude greater than currently thought.

  24. wayne says:

    Here’s a link that should show up as what the uTube presentation looks like:
    The CO2 increase is not created by mankind… finally with scientific proof.
    Accolades to Dr. Salby and his team!

    I like his words… all bets are now off!
    Now let’s see who emerges as being a real scientist, and who is not. Their reaction to this paper should show it clearly. Been waiting for this chance for a long time.

  25. Estimates of CO2 emissions for volcanoes include only eruptions in most cases. All volcanoes, even some dormant for hundreds to thousands of years, leak CO2 and other gases on their flanks, not just the from crater.. Almost Invariably, emissions from erupting or volcanoes are measured just below the crater, and flank emissions (over an area vastly bigger than the crater) are ignored.

    I’ve read a couple of reports on measurements made on Mount St. Helens, before and after the big eruption in 1980, and it’s clear to me that annual emissions since are a sizeable percentage of the emissions during that event.

    Couple that with our lack of knowledge of undersea volcanoes and vents, given that the oceans cover two-thirds of the planet, and that 0.26-gigaton- per-year “estimate” looks risible.

    I wonder if seismic records can distinguish between undersea ‘quakes and eruptions? I’m fairly sure they can, so why is that record ignored? Is there an agenda here? “If we didn’t see it it didn’t happen”. Look the other way, dear. A sceptic could use that to debunk my last paper.

  26. tchannon says:

    Am I correct in saying volcanic CO2 originates from subducted carbonate?

  27. Roger Andrews says:

    Maybe as much as 80% of the CO2 emitted by continental volcanoes originates from subducted carbonate units. but no one knows for sure.

    The CO2 emitted by oceanic volcanoes (mid-ocean ridge volcanoes, submarine volcanoes, sea floor vents etc.) originates from basaltic magma.

  28. Bart says:

    “The mass balance: It is impossible that nature was a net contibutor to the increase, because the measured increase is less than the emissions.”

    As nice a guy as Ferdinand is, that argument is so awful, I am embarrassed on his behalf. As you know, Rog, we argued it intensely here, and I showed conclusively to anyone who understands the mathematics of differential equations that he was wrong.

    But, the mathematics are not really necessary. The counterargument is simply this: in this dynamic feedback system, the permanent sinks expand in response to increased partial pressure in the atmosphere. If they expand rapidly enough, then the anthropogenic input will be rapidly sequestered, and the overall increase in atmospheric content due to anthropogenic emissions will be small. In that case, any extensive build-up one sees must be due to natural forcing.

    The key point is this: the permanent sinks expand in response to increased partial pressure in the atmosphere. This is why Ferdinand’s very simplistic argument fails. He treats the sinks as if they were static, and can only handle so much CO2 at a time. But, that is an erroneous assumption.

  29. tallbloke says:

    Hi Bart, thanks for dropping by.

    I agree with you.

    As I understand it, all bets have been off for a long time. In Feb 2009 I made this comment at another forum:

    Click to access Quay1992_15383.pdf

    “It’s data comes from a small number of locations spanning a limited area covering 1/6 of the earths circumference, and from 29N to 50S.

    It takes no account of the increase in atmospheric co2 due to increasing temperature. The solubility of co2 in sea water drops as the temperature rises.

    On closer reading, the paper relies on an estimation that the turnover in d13C in woody plants is around 30 years. It has recently been shown that trees are getting bigger as a result of increased co2 levels. They have been starved of it for a long time, and are lapping it up. Commercial greenhouse growers use a level of co2 three times higher than atmospheric in order to increase yields.

    Therefore the change in the ratios of the carbon isotopes attributed to human emitted co2 is overestimated

    94% of the carbon in the atmosphere has the same isotopic signature as the natural background.
    6% signals an organic origin, fossil fuels included.
    Half of that organic source, 3% is what the IPCC itself says man is contributing.”

  30. Tenuc says:

    The biosphere provides a massive sink for CO2. Plants grow faster with higher levels of atmospheric CO2 and use less water for photosynthesis – natural negative feedback to increasing levels of CO2…

    The Earth’s biosphere is booming, data suggests that CO2 is the cause, part 2…

    A good example of a dynamic sink for CO2.

  31. paulinuk says:

    There’s no way to tell the difference between carbon burnt in volcanic subduction zones and carbon burnt by man: both have the same isotopic d12/d13 ratio. Furthermore you can’t assume that the amount of carbon burnt in magma remains constant. The carbon we burn must be magic carbon then?

  32. This is a useful reference to check d13C values: http://pubs.usgs.gov/wri/wri014222/pdf/wri01-4222.pdf Pages 20-29

  33. br1 says:


    ““The mass balance: It is impossible that nature was a net contibutor to the increase, because the measured increase is less than the emissions.”

    As nice a guy as Ferdinand is, that argument is so awful, I am embarrassed on his behalf. As you know, Rog, we argued it intensely here, and I showed conclusively to anyone who understands the mathematics of differential equations that he was wrong.”

    I found this comment a bit strange, so I went and read the WUWT discussion linked. I would say I understand differential equations, but I still found the statement strange (though I am not at this stage saying I disagree with it, but would like to learn more).

    My problem is that the data said the atmospheric CO2 increase was less than the anthropogenic emissions. In the ‘Bart models’ the A and the N terms were both positive. Depending on feedback, when one combines A and N, the total increase can be just a small bit larger than either A or N on its own.

    But what is needed to make the combined increase to be less than A? (“A+N=0.4A”, that is, presuming agreement on what ‘Anything is possible’ says: on April 18, 2012 at 6:18 pm)

    It seems to me that either N has to be negative, or the feedback terms have to be inverted somehow (is that even realistic?). Either way it makes N a sink.

    Maybe I am missing something, I am willing to listen.

  34. tallbloke says:

    From Jo-Nova’s site:

    Click to access TomQuirkSourcesandSinksofCO2_FINAL.pdf

    Tom Quirk showed that while most man-made CO2 is released in the Northern Hemisphere, and the southern Hemisphere stations ought to take months to record the rises, instead there did not appear to be any lag… (ie. the major source of the CO2 is global rather than from human activity).

    Over 95% of [man-made emissions of] CO2 has been released in the Northern Hemisphere…

    “A tracer for CO2 transport from the Northern Hemisphere to the Southern Hemisphere was provided by 14C created by nuclear weapons testing in the 1950’s and 1960’s.The analysis of 14C in atmospheric CO2 showed that it took some years for exchanges of CO2 between the hemispheres before the 14C was uniformly distributed…

    “If 75% of CO2 from fossil fuel is emitted north of latitude 30 then some time lag might be expected due to the sharp year-to-year variations in the estimated amounts left in the atmosphere. A simple model, following the example of the 14Cdata with a one year mixing time, would suggest a delay of 6 months for CO2 changes in concentration in the Northern Hemisphere to appear in the Southern Hemisphere.

    “A correlation plot of …year on year differences of monthly measurements at Mauna Loa against those at the South Pole [shows]… the time difference is positive when the South Pole data leads the Mauna Loa data. Any negative bias (asymmetry in the plot) would indicate a delayed arrival of CO2 in the Southern Hemisphere.

    “There does not appear to be any time difference between the hemispheres. This suggests that the annual increases [in atmospheric carbon dioxide] may be coming from a global or equatorial source.”

    Tom has done a lot of work on this:

    The constancy of seasonal variations in CO2 and the lack of time delays between the hemispheres suggest that fossil fuel derived CO2 is almost totally absorbed locally in the year it is emitted. This implies that natural variability of the climate is the prime cause of increasing CO2, not the emissions of CO2 from the use of fossil fuels.

    ‘Sources and Sinks of Carbon Dioxide’, by Tom Quirk, Energy and Environment, Volume 20, pages 103-119.

  35. Bart says:

    br1 says:
    April 20, 2012 at 5:28 pm

    “But what is needed to make the combined increase to be less than A?”

    Increase U.

  36. Michael Hart says:

    jorgekafkazar says:
    April 19, 2012 at 8:17 pm

    @Michael Hart and his “A rotating earth acts as a giant centrifuge, acting to fractionate all isotopes of all elements all of the time….”
    If this were true, Michael, all life on earth at sea level would have suffocated in argon gas long ago.

    I don’t think so jorge. What I didn’t say was that, of course, movement, turbulence and diffusion counteract this effect. So the degree of fractionation is limited, but not zero. Quantification being difficult over short time periods. The effect in less fluid matrices like ice and sediment would be more pronounced. Analytical ultracentrifuges are widely used in biochemical applications. Better known applications include radioisotope separation in nuclear fuels/weapons.

  37. Clive Best says:

    “There does not appear to be any time difference between the hemispheres. This suggests that the annual increases [in atmospheric carbon dioxide] may be coming from a global or equatorial source.”

    This makes me think that the seasonal variation could be mainly due to the Southern Oceans. Henry’s law says that the solubility of CO2 in water is proportional to the partial pressure of CO2. The Earth’s orbit s elliptical and the perihelion coincides with southern summers causing them to receive 6% more radiation than northern summers. When you also consider that the Southern hemisphere is 80% water and the northern hemisphere is less than 40% water makes me think that the Earth is breathing. In southern summers net CO2 is emitted as temperatures rise and then absorbed in southern winters. Vegetation growth in the northern hemisphere reinforces absorption. However, maybe it is the asymmetry in summer/winter radiation for the bulk of the oceans which cause the seasonal change.

    This could also explain why CO2 also varies with Ice age glaciations. Interglacials coincide with maxima of eccentricity when the asymmetry between hemispheres is at the greatest.

    Another (crazy?) thought is that atmospheric tides will vary with sun-earth distance. These permanent pressure effects are very small compared to weather – but they are global. So net CO2 levels could be slightly effected over the very long term by changes in partial pressure. No-one knows really in detail what causes ice ages. Perhaps the fact that there as been a growing assymetry between land cover in Southern and Northern hemispheres for the last 50 million years could be real reason.

  38. tallbloke says:

    Clive: What you are saying about time of perihelion/aphelion in relation to seasonal co2 level fluctuation may well be relevant. In terms of glacial interglacial timescales however, it must be remembered that the precession cycle is four times shorter than the eccentricity cycle, thereby reversing the proximity of the hemispheres to the incident Sunlight at perihelion about every 25Kyr.

  39. Hans says:

    Clive Best says: April 21, 2012 at 3:52 pm

    “No-one knows really in detail what causes ice ages.”

    It would be more accurate to say that no one knows (as far as I know) the dominant reason for ice ages and interglacials to occur. Some details are knows such as the Milankowitch theory which is not the dominant cause.

  40. Stephen Wilde says:

    Clive Best

    Not so crazy.

    The asymmetry between the hemispheres as regards land / ocean distribution is integral to the way the Earth currently redistributes energy and I would expect it to have an effect on CO2 distribution too.

    In particular I note from recent CO2 distribution data that the highest concentrations are downwind of oceanic regions and NOT downwind of regions of high human population density.

    That is a critical observation that is currently not being given proper weight.

  41. Roger Andrews says:


    “In particular I note from recent CO2 distribution data that the highest concentrations are downwind of oceanic regions and NOT downwind of regions of high human population density.”

    Can you tell me where I can find these data?

    I’ve been doing some work on global CO2 distributions relative to emissions sources and have come up with some interesting results. However, it will take a little time to put it together.

  42. Stephen Wilde says:

    All the highest concentrations are downwind of warm water.

    The Mediterranean gets very warm in summer so you can see the plume across the Middle East.

    Australia gets CO2 from the ocean between it and South Africa.

    South America gets CO2 from the Pacific upwind.

    Western USA from the Pacifdic upwind .

    Southern Asia gets CO2 from the Indian Ocean upwind.

    There is a plume of CO2 downwind of the warm Gulf of Mexico.

    and so on.

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

    The relatively low CO2 quantities above the equator are due to the clouds and rain of the Intertropical convergence zone.

    The two main bands of higher CO2 concentration are under the subtropical high pressure systems in each hemisphere where most sunshine gets into the oceans to warm the sea surfaces.

    Atmospheric CO2 is clearly driven by sea surface temperatures affecting oceanic absorption capacity and the AIRS results are proof but so far as I know no one else has pointed it out as yet.

    Sea surface temperatutres are in turn affected by cloudiness and albedo changes and I have extensively described the causes of that elsewhere.

  43. Clive Best says:

    The almost instantaneous correlation of widely spaced CO2 measurements for both the seasonal AND anthropogenic/natural increases needs to be explained. It must be a global phenomenon – so the Ocean must play a major role. How does Ferdinand explain the quasi-instantaneous transport of CO2 molecules from sources in say China to the South Pole ?

    Regarding Ice Ages: I spent a long time trying to figure out Milankowitz cycles and their correlation with the paleoclimate ocean sediment data see Phenomenology of Ice Ages and the following 2 posts. Any theory for ice ages has to answer the following observations:

    1. The observed gradual decrease in temperatures starting just over 3 million years ago.

    2. The 43,000 year continuous signal dominated until about 1 million years ago when the onset of 70-100,00000 glacial cycles begin. Why did this happen ?

    3. What is the cause of the recent 100,000y glacial cycles, since Insolation changes caused by ellipticity are too small to be an explanation ?

    4. Why did the frequency change from about 70,000 years between 900-700,000 ybp to the current cycle of 100,000 years ?

    5. Why is the larger 400,000 year eccentricity signal absent from recent data ?

    Variations in insolation can explain the 43,000y obliquity and 23,000 y precession signals observed in the data. However another explanation is needed to explain the remaining points.

    The pression of the equinoxes would have no effect without an elliptic orbit. The net annual insolation change from eccentricity is almost zero – but it does change strongly the summer winter balance when one hemisphere is close to perihelion.

  44. Stephen Wilde says:

    Clive, nice site.

    I’ll dig into it over time because I think the timing of ice age / interglacial switching is in some way linked to ocean cycling being in or out of phase with solar cycling.

    The Milankovitch processes and the other orbital features that you mention load the gun but the sun and oceans combine to decide when it fires.

    And in the end whatever happens from whatever cause ( including variations in GHG amounts) the energy budget changes are neutralised by changes in the speed of energy flow through the system via changes in atmospheric heights and the latitudinal positions of the permanent climate zones.

  45. Roger Andrews says:

    Thanks Stephen:

    I find the northeast USA particularly interesting. It’s one of the the world’s major CO2 emission sources, and in July everyone there has their ACs turned on and power plants are blasting megatons of CO2 into the atmosphere trying to keep up with demand. Yet there’s no sign of this CO2 on the plot.

    But as soon as we move out to sea CO2 jumps up.

    So CO2 is anomalous where anthropogenic CO2 isn’t being emitted but non-anomalous where it is.


  46. RKS says:

    I had a bad dream last night. I dreamt I was a born again 100% non sceptical warmist zealot tasked with preparing a presentation showing the effect of back radiation from CO2 on Global Warming.

    I’d start with Trenberth’s cartoon showing that energy flux at the surface of 390Wm^2 is some 40% greater than insolation of 240Wm^2, and that this is all simply explained by Back Radiation from CO2.

    A quick look at the properties of CO2 would show an emissivity of 0.001 [for a presentation I’ll call this 0.01] and, being a gas, emitted radiation [stick to Back Radiation] would be in all directions with perhaps at best 10% having any meaningful interaction with the surface.

    I’d set up the model with 1m^2 of the surface radiating with a flux of 240Wm^2

    To demonstrate the principle I’d initially assume emissivity of 1 – or better still represent CO2 as a perfect reflector with 100% of Back Radiation directed to the surface.

    Obviously the reflector must be less than 1m^2 or I’d end up with 480Wm^2 so I’d have to resize it to represent the atmospheric concentration of CO2 of .039% which leaves me with a reflector size of 0.00039m^2.

    This means a Back Radiation of 0.039% of 240Wm^2, that is 0.0936Wm^2.

    Multiply that by emissivity of 0.01 and multiply by 10% to allow for the multi direction nature of the ‘Back Radiation’ and I end up with a total Back radiation of 0.0000936Wm^2 [0.000039%].

    Bugger!, Where has all my Back Radiation gone?

    I started out looking for 40% and end up with nowt.

  47. Michael Hart says:

    Clive, or anyone else,
    Do you have access, or a link, to raw data from atmospheric 14C measurements that were made after the atmospheric nuclear weapon tests during the cold war? I’d love to have a detailed look, I tried once before but couldn’t get any actual numbers without paying.

  48. tchannon says:

    CO2 spread is not particularly even on an annual timescale.

    The south varies less and there are nulls, maybe South Africa is one.

    Quite some time ago I posited that MLO annual CO2 follows Arctic ice, with a lag of just over a month, walking speed from Alaska. This can to a degree be mapped but the state of regional datasets is terrible. (don’t want to go into that one)

    Most have said that tundra growth is the reason for the sharp annual pattern in far north CO2 but I disagree. There is more.

    Quick look at what is already online (much more on disk here)

    As I recall this was difficult, some of the data is short and very poor. Gives the general idea.

    Barrow is one of the more interesting sites, poor data.

    Although I can’t remember why I was particularly interested in CO2 and winter conditions in Finland as offering a key to what is going on, but I stopped.

  49. Michael Hart says:

    The solubility of CO2 in ice is very small compared to water, by about two orders of magnitude. So when a cubic metre of seawater freezes, where does the CO2 go?

    I would make the working assumption that some of it goes into the surface seawater under the ice [which is no longer mixed by wind] But for how long, and what fraction is expelled into the atmosphere as a result of the freeze/thaw process?

    If a significant amount of CO2 is lost to the atmosphere, then the difference [not the absolute amount] between summer and winter ice-area takes on a new meaning [to me at least].

  50. Tenuc says:

    tchannon says:
    April 21, 2012 at 9:00 pm
    “…Quite some time ago I posited that MLO annual CO2 follows Arctic ice, with a lag of just over a month, walking speed from Alaska. This can to a degree be mapped but the state of regional datasets is terrible. (don’t want to go into that one)…”

    Great find, Tim. How long does it take the cold Arctic deep current to resurface at Mona Loa?

  51. tchannon says:

    Yes that is my guess too, went into some of this in detail.

    Remember this is complex because solubility in water is greatest at freezing point, with various effects coming to mind.

    Also, there is a russian arctic team who say there is something strange about CO2 up there, rather played down by many although there is an admission there is an excess of CO2 to the *north* of the northern industrial zone.

    I suppose I should have written this stuff up. There was an offer from a journal editor but without help that is beyond me.

  52. tchannon says:


    I’ve tried to find out, without spending a long time, too much else going on.

    Lot of figures around, with deep ocean overturn ranging to >10k years.

    Seems likely the water which surfaces is a blend of old and new.

    Looks like I have a lot of files from 2009, not sure if it is worth the effort showing anything.

  53. Stephen Wilde says:

    “How long does it take the cold Arctic deep current to resurface at Mona Loa?”

    About 1000 years or so which is the approximate length of the Thermohaline Circulation and therefore consistent with current CO2 levels being affected by slightly warmer and CO2 enriched ocean water resurfacing from the MWP.

    “there is an excess of CO2 to the *north* of the northern industrial zone.”

    If so, I would expect that to be the result of a plume of CO2 emanating from the warm water flowing along the Gulf Stream and resurfacing around Sptzbergen with the westerly wind blowing it across Russia north of the main industrial zone.

  54. br1 says:

    ” “But what is needed to make the combined increase to be less than A?”

    Increase U. ”

    seeing as U is natural, then this makes nature a net sink. This is true even if the rate N is positive.

    Somehow you seem to be saying the opposite of your maths.

    I read the WUWT thread in detail (no need to ask me to read it). The only way in your model I can reconcile the view that nature can be a net contributor to CO2 is if c<0.4. This implies that for every 1000 tons of CO2 thrown into the atmosphere, less than 400 tons makes it into the greater circulation while 600 tons is 'instantly/locally' deposited. I can see why this could be something like the case if we consider carbon (as opposed to carbon dioxide). Imagine throwing a piece of coal into the atmosphere – it will just fall out again and be deposited. Similarly for burning coal – there will be soot and ash thrown into the atmosphere which will just fall out again. But for CO2 I find it hard to imagine how such a large proportion can just 'stick' or be absorbed by nearby surfaces. That may be my shortcoming, I'll look into it, but would appreciate some help. Does anyone have a link to where the IPCC imply that c=0.5?

  55. br1 says:

    Stephen Wilde:

    All the highest concentrations are downwind of warm water.”

    Very interesting! High concentration seems to be in large bands about 30-45 degrees North and South of equator, and at South Pole. Surely there must be some ‘official explanation’ of this? I’ll do some googling.

  56. br1 says:

    I said:
    “Does anyone have a link to where the IPCC imply that c=0.5?”

    just to clarify – I know of the claim that dM/dt=0.5A, but that is different to saying that only half of the man-made CO2 emitted from a chimney makes it into the greater atmosphere (c=0.5).

    I guess the point is that we don’t know what this fraction is?

  57. Stephen Wilde says:

    “High concentration seems to be in large bands about 30-45 degrees North and South of equator,”

    Under the subtropical high pressure belts where sunlight warms the oceans more than anywhere else.The ITCZ prevents such warming over the equator itself.

    I think the colour at the south pole is an artifact of some sort.

    This gives me an even better mechanism than the proposition that current CO2 increases are result only of returning warm water from the MWP.

    That may still be a contributing factor but it is likely that another cause of rising atmospheric CO2 over the period since the LIA is poleward shifting climate zones giving wider subtropical high pressure cells and more CO2 emissions from the warmed ocean surfaces.

    So what we are seeing all links together. The climate zones cyclically shift poileward and equatorward in time with solar variability and the warming of the oceans under the subtropical high pressure cells varies accordingly with a consequent effect on both troposheric air temperatues AND atmospheric CO2 amounts.

    However that gives us a query as to why an 800 year lag appears in the ice core record and for that we still need at least some element of returning warm water from a previous warm period.

    So I think we have two processes acting together. Short term climate zone shifting altering short term (500 year) CO2 trends with a longer term underlying trend in CO2 amounts from the returning thermohaline circulation (approximately 800 to 1000 years).

    The upshot is that we would see naturally rising atmospheric CO2 from LIA to date and naturally falling atmospheric CO2 from MWP to LIA.

  58. Michael Hart says:

    The figure you linked is for July. Is there a corresponding one for winter, and does it show a decline that might be attributable to reabsorption my the Mediterranean, with respect to the prevailing wind direction/strength in winter?

    [Perhaps answering my own question, I think I’ve read that the Baltic has a CO2 concentration about double that of typical ocean]

  59. Michael Hart says:

    Hmm…. perhaps I should of taken the trouble to look before posting.

    The first figure here
    indicates that the gulf stream/conveyor is a net sink. [But is that all based on measurements or models?].

  60. Stephen Wilde says:


    Haven’t found a winter version yet. The same point occurred to me.

    However, as per the Baltic, the colder any body of water the more CO2 it will hold on to.

  61. tchannon says:


    Something dodgy looking about that.
    Prior work here showed South Africa CO2 is almost constant during the year, dead flat.

    I also seem to recall various conflicts between information. Might be an idea to revue what Beck and others had to say about the spatial distribution.

  62. Stephen Wilde says:

    “Prior work here showed South Africa CO2 is almost constant during the year, dead flat.”

    South Africa has large expanses of water in three directions and a long wind fetch across the southern Atlantic.

    I would expect it to have little seasonal variation in CO2 levels. Likewise the seasonal variation at Mauna Loa is very small compared to the underlying long term trend.

    Here is some stuff on Beck’s work:


  63. Clive Best says:

    The Airs CO2 data are available from JPL via http://disc.sci.gsfc.nasa.gov/AIRS/data-holdings . The search interface is here. The one of interest is I think Level-3 CO2. However the monthly data seems to be only available in HDF format rather than images. The July 2009 data is their pin-up. You then need software like IDL to read HDF format . I will look for some freeware alternative.

  64. Roger Andrews says:

    An interesting comparison of ppm CO2 anomalies vs. ocean/land ratio by latitude.

    Not sure what it means yet

  65. Bart says:

    br1 says:
    April 22, 2012 at 9:01 am

    “…seeing as U is natural, then this makes nature a net sink.”

    It is a net sink. But, it sinks both natural and anthropogenic emissions. And, it dynamically changes relative to the overall concentration. Therefore, if anthropogenic emissions ceased, U would become smaller, and nature might then become a net source.

    You see, the sinks are opposing both natural and anthropogenic inputs. That they should be taking out more than nature is putting in alone is therefore no surprise. It’s like being shocked that a scale reads more than your weight when someone else has his toe on it.

    That is the whole point of the discussion. The sinks are dynamic and respond to anthropogenic forcing. Thus, just because they occur in nature does not mean you can isolate them in the “natural” column, and claim that nature is a net sink of natural inputs alone.

  66. br1 says:

    “It is a net sink. But, it sinks both natural and anthropogenic emissions. And, it dynamically changes relative to the overall concentration.”

    ok, makes sense now, thank you.

  67. br1 says:

    Roger Andrews:
    “An interesting comparison of ppm CO2 anomalies vs. ocean/land ratio by latitude.

    which presumably shows relative values compared to some time in the past, and interesting to compare to the picture posted by Stephen:

    which shows absolute values.

    So it seems that the high concentration of CO2 in the Southern hemisphere band of -30 to -50 degrees latitude is a persistent feature, and is also getting *less*! (according to the anomaly graph, it has a value of -2 ppm). Weird.

    Out of interest, where did the anomaly graph come from?

  68. br1 says:

    “I also seem to recall various conflicts between information.”

    there probably are, but in the case of South Africa one has to be careful between the absolute value (which seems to be higher than global average), and the change in the value (which seems to be dropping compared to what it used to be).

    I’m not sure why gas giant planets end up with bands in their atmospheres – is it possible something similar is happening here, on a smaller scale?

    Does anyone have a good ‘change in ocean temperature’ graph to compare to? I’m not sure the figures in this http://icecap.us/docs/change/OceanMultidecadalCyclesTemps.pdf are what we want.

    Oops, must remember that this thread is about volcanoes. Hope the discussion on CO2 and oceans is not too off-topic.

    [Reply] Not a problem. The thread is on the origin of the increase in the airborne fraction, not volcanoes specifically.

  69. br1 says:

    I wrote:

    “I’m not sure why gas giant planets end up with bands in their atmospheres – is it possible something similar is happening here, on a smaller scale?”

    Did some googling on atmospheric bands (Jupiter, etc). Came across a figure here http://en.wikipedia.org/wiki/Hadley_cell

    Not sure why there would be a cause and effect here for CO2 conc (anybody?), but there is quite a similarity, and it even has the Antarctica peak.

  70. Michael Hart says:

    I expect one would need (at least) to overlay the effects of the hydrological cycle on these graphs. Presumably the evaporation and condensation of water at all times will have significant effects due to temp/pressure/salinity CO2 solubility-curves. Especially at ground level.

  71. br1 says:

    I wrote:
    “Did some googling on atmospheric bands (Jupiter, etc). Came across a figure here http://en.wikipedia.org/wiki/Hadley_cell

    Sorry for hogging the thread, but had another thought: CO2 is heavier than an average air molecule. When there is an updraught (for example around the equator), then this has the effect of making gravity ‘less’. When there is a downdraught (in the subtropics) this has the effect of making gravity ‘greater’. Obviously gravity is not changing, but there is a potential energy function along the air flow, and this will either add to or take away from the graviational potential energy.

    From the barometric formula we know that concentration drops with increasing potential energy as a function of both height and molecular mass. Hence, on average, CO2 mass integrated in a vertical column of fixed height will be less in an updraught and greater in a downdraught as compared to air in general.

    Hence cause and effect between the AIRS data and the Hadley cell data.

    There will also be lateral flows due to concentration gradients, but as far as I know, that is the first I heard of such an explanation. Any objections? Could it be right?

  72. br1 says:

    Michael Hart:
    “I expect one would need (at least) to overlay the effects of the hydrological cycle on these graphs. Presumably the evaporation and condensation of water at all times will have significant effects due to temp/pressure/salinity CO2 solubility-curves. Especially at ground level.”

    I expect you are right.

    It brings up another question – is the AIRS CO2 graph linked above a measure of the ground level only, or integrated over the vertical column? (the answer won’t affect my previous post which works in either case, but it would be nice to know).

  73. br1 says:

    Roger Andrews:
    “An interesting comparison of ppm CO2 anomalies vs. ocean/land ratio by latitude.

    Not sure what it means yet”

    I had another look at this graph. One thing I find strange is that if one excludes one data point at latitude +76 degrees, the area under the graph seems consistent with zero. It gives a first impression that all the anomaly is happening in the Northern hemisphere, presumably due to industry, but one could easily draw a straight line from (-60, -2) to (+60, +2). This implies that the CO2 in the Southern hemisphere has somehow moved into the Northern hemisphere, but the net anomaly seems to be zero.

    I dunno – does that imply something about the seasons? I guess this figure should be a multi-annual average, but is it?

  74. Roger Andrews says:


    Answers to your questions are forthcoming, but it will take me a little while to get the data (and my thoughts) together.

  75. Roger Andrews says:


    Re your questions as to how CO2 moves around the globe, here are some more graphs

    First, http://oi43.tinypic.com/13z724m.jpg

    plots four records from the Scripps CO2 data base (http://cdiac.ornl.gov/trends/co2/sio-keel.html) over the period of common readings from 1982 through 2007. These are South Pole (90S), American Samoa (14S), La Jolla, California (33N) and Point Barrow, Alaska (71N). All four records track each other very closely, with the only difference being that Barrow runs consistently about 1 ppm higher than La Jolla, about 3 ppm higher than Samoa and about 5 ppm higher than the South Pole (note that the records are twelve-month smoothed to remove seasonal fluctuations)

    Second, http://oi39.tinypic.com/33xzxc5.jpg

    plots trend lines through the four records. They are effectively identical. Between 1982 and 2008 CO2 increased at almost exactly the same rate at the South Pole, in the Arctic and on the Equator.

    Which is interesting, to say the least.

    How does this result fit in with theories? The reason I plotted the La Jolla record is that at latitude 33N it’s close to the latitude mode point for global CO2 emissions (which peak at around 40N) and also because it’s in Southern California, one of the world’s major CO2-emitting areas. So if the increase in global CO2 is indeed being caused by CO2 spreading out from major emission centers we would expect to see higher CO2 at La Jolla than elsewhere.

    But we don’t.

    And if CO2 is spreading out from mid-northern latitudes we might also expect to see CO2 increases in other parts of the world lagging the CO2 increase in mid-northern latitudes. We can broadly quantify these lags using the intercepts of the trend lines on the X-axes on the second graph, and when we do this we find that La Jolla leads Samoa by about a year and the South Pole by up to two years. But then we find that Barrow leads La Jolla by up to 6 months, or in other words than the CO2 got to the Arctic 6 months before it was emitted.

    In short, the results don’t fit the anthropogenic CO2 theory.

    Regarding your comments as to movement of CO2 from the NH to the SH, or vice-versa, there’s no way of telling from these results which way the CO2 goes, but my guess is that moving gigatons of CO2 from one hemisphere to the other across the ITCZ could be a slow process.

    And what about the wiggles in the CO2 plots in the first graph? Well,

    shows what they look like after the records are detrended using the trend lines in the second graph. The wiggles line up. There are no obvious lags between the South Pole, the Arctic and the Equator. So whatever caused these wiggles in the CO2 record seems to have impacted all parts of the globe pretty much simultaneously. Again, interesting.

  76. Roger Andrews says:

    AIRS animation of CO2 moving around the world:

  77. br1 says:

    Roger Andrews:

    Nice video!

    I did some more browsing and found this one http://www.youtube.com/watch?v=l8tPKj20GFo

    which has a daily picture for a whole year!

    This looks like it should contain loads of useful information on sources and transportation. The description under the video is a bit confusing ‘Based on observations and model’ – what is that supposed to mean?

  78. Michael Hart says:

    Very interesting indeed. Lots to think about.

    Do you know why the video only runs until July 2008? I am sure that there are usually good/innocent reasons but, well, it’s a sign of the times that these days I often find myself suspicious about data that doesn’t run up to the present.

  79. tallbloke says:

    The alarmism is quite well done in that video. The opacity of the colours increases towards the hot end, so the world get’s more obliterated as time goes on. Nothing to do with science, but obvious to a trained digital resources guy like me.

  80. Michael Hart says:

    Yes, I also wondered about the specific model used in the video you linked to.

    Also, note the invitation to “Note sources and sinks through the seasons.” It would be easy to interpret that as implying that the CO2 is being transported laterally from “source” to “sink”. That might be correct, but equally the “source” and “sink” could also be the same location.

    Take, for example, the apparent accumulation of CO2 in the far North during the month of January. As water [land or ocean] freezes is it expelling CO2 in to the atmosphere as mentioned above by Tim and myself? Or is it being rapidly transported by wind [also carrying CO2 dissolved in cloud droplets] from warmer more humid latitudes?

    I would suggest that CO2 contributed from decaying plant matter will be very small in January because deep winter will have already slowed the biological processes to a standstill in those regions.

  81. Roger Andrews says:

    According to conventional wisdom the recent global increase in CO2 was all caused by anthropogenic CO2, about 95% of which is emitted in the Northern Hemisphere

    But br1’s daily CO2 video for 2008 shows effectively zero transfer of CO2 from the NH to the SH.

    And in 2008 CO2 increased by about 1.5 ppm in both Hemispheres.


  82. Tenuc says:

    br1 says:
    April 24, 2012 at 1:58 pm
    “…‘Based on observations and model’ – what is that supposed to mean?

    Probably means, ” We didn’t like the look of the observations as for some reason they don’t match what we expected. So we tweaked a few parameters to get observations closer to the reality of our understanding of how atmospheric CO2 should behave. After all, we know/believe CO2 is a well mixed gas and burning fossil fuel is the cause of any increase.”… 🙂

  83. Michael Hart says:

    “But br1′s daily CO2 video for 2008 shows effectively zero transfer of CO2 from the NH to the SH.”

    Keep in mind the granularity of the data that has been chosen. It is possible for two regions to share the same colour yet still have CO2 transfer [flux] between them. If the CO2 enters a sink [water or biosphere] then the satellite will no longer “see” it, and vice versa.

    Interesting that the seasonal variation in the North goes from maximum to minimum in ~1 month [June]. I would also like to see a better indication of the maxima and minima. With the scale as presented, large areas could double or halve in CO2 concentrations and you simply wouldn’t see it at all.

    Every now and again I think that showing just Mauna Loa data actually detracts significantly from efforts to truly understand what is going on.

  84. Roger Andrews says:

    Michael Hart

    Interesting paper on this at

    Click to access fuelberg-gregory-1999.pdf

    From the abstract:

    “The ITCZ and SPCZ are major upwelling regions within the South Pacific and, as such, create boundaries to exchange of tropospheric air between regions to the north and south. Chemical data obtained in the near vicinity of the ITCZ and the SPCZ are examined. Data measured within the convergent zones themselves are not considered. The analyses show that air north and south of the convergent zones have different chemical signatures and the signatures are reflective of the source regions and transport histories of the air. Air north of the ITCZ shows a modest urban/industrialized signature compared to air south of the ITCZ. The chemical signature of air south of the SPCZ is dominated by combustion emissions from biomass burning, while air north of the SPCZ is relatively clean and of similar composition to ITCZ south air. Chemical signature differences of air north and south of the zones are most pronounced at altitudes below 5 km, and, as such, show that the ITCZ and SPCZ are effective low-altitude barriers to the transport of tropospheric air. At altitudes of 8 to 10 km, chemical signatures are less dissimilar, and air backward trajectories( to 10 days) show cross-convergent-zone flow. At altitudes below about 5 km, little cross-zone flow is observed.”

    http://www-gte.larc.nasa.gov/img/pemtcirc.gif shows ITCZ and SPCZ locations:

  85. Stephen Wilde says:

    Interesting that the tongue shaped area between the ITCZ and the SPCZ is the same area in which the warm and cold ENSO waters come to the surface.

  86. Roger Andrews says:

    Getting a little O/T, but I think the interesting thing is why El Niños and La Niñas always surface almost exactly at the Equator regardless of where the ITCZ is.

  87. Brian H says:

    br1 says:
    April 22, 2012 at 9:15 am

    saying that only half of the man-made CO2 emitted from a chimney makes it into the greater atmosphere (c=0.5).

    Greedy plants? Noon in sunshine in a cornfield CO2 can go to ~0, and the corn stops growing until late afternoon breezes blow some more in. Suggests to me they should be trickle-irrigated with fizzy soda water!

  88. Stephen Wilde says:

    “why El Niños and La Niñas always surface almost exactly at the Equator regardless of where the ITCZ is.”

    One of the reasons why we need a top down influence on the air circulation.

    Otherwise the latitudinal position of the ITCZ would be tied to ENSO sea surface temperatures. It isn’t over longer time periods such as decadal, multidecadal and centennial.

  89. […] sono strane e imprevedibili almeno quanto quelle del clima. Alcuni giorni fa ho intercettato su Tallbloke il commento ad un articolo scritto da alcuni ricercatori Italiani, un paper comunque attualmente […]

  90. Nick Stokes says:

    Estimates from various sources are that volcanic emissions are two orders of magnitude down from fossil fuel carbon. That’s not based on isotopes but on direct observation of volcanoes. And OK, undersea volcanoes are not well observed, but there’s a huge gap to make up.

    Then there’s the argument – if volcanoes have been producing, say, 10 Gtons C per yer for millions of years, where has it all gone? And why has past CO2 (say 400,000 years) been so uniform? And if they’ve only just started, then why now?

    But my general issue with Slaby et al is, we’ve burnt about 350 Gtons C. The increase in the atmosphere is about 200 Gtons. If that isn’t ours, then where did ours go?

  91. FerdiEgb says:

    Dear Tallbloke.

    I was not aware of this article of yours, as I was on a nice 5-weeks trip in Western Australia (Perth to Darwin)… So for the delayed comment. I will not react on all items, only the volcanic point:

    Several land volcanoes and vents were measured and the rest was extrapolated. That shows that land volcanoes are a minor source and all are above the current (and the recent past) 13C/12C ratio of the atmosphere.

    Underwater volcanoes are more difficult to measure, but the CO2 emissions from these readily mix with the deep ocean carbon. As the deep oceans are undersaturated in CO2, there is little, if any CO2, that escapes directly to the atmosphere. Most is dissolved in the huge mass of CO2 which is already in the deep oceans, taking into account the enormous pressures in the deep. The 13C/12C ratio of the deep oceans is at near zero per mil d13C, thus any CO2 release from the deep oceans would increase the 13C/12C ratio of the atmosphere, currently at -8 per mil d13C… But we see a steady decrease…

    Best for now,

    Ferdinand Engelbeen

  92. tallbloke says:

    Hi Ferdinand, thanks for calling by, and I hope you had a great trip.

    You said:
    “Several land volcanoes and vents were measured and the rest was extrapolated. ”

    Who’s work are you referring to?



  93. […] et al’s 2011 empirical work on measuring the co2 emission from old lava fields in central Italy at 9 Giga-tons a year is a case […]

  94. marchesarosa says:

    Dear Tallbloke,

    I am interested in the Cardelloni et al paper measuring CO2 outgassing in Italy and though I would dearly love to believe their 9 gigatons per annum estimate which, if true, would change the whole argument over CO2, I cannot help but be a leetle circumspect in accepting it. I too have argued elsewhere that the components of the carbon cycle are ill-quantified and that this could EASILY affect the proportion of the annual increase in CO2 attributed to the burning of fossil fuels and therefore the whole furore over CO2-induced anthropogenic global warming.

    BUT after reading the Cardellini abstract you linked to and then the Terry Gerlach paper here http://www.agu.org/pubs/pdf/2011EO240001.pdf I cannot help but wonder, and this was my second reaction after initially being elated that someone had made such a vastly increased estimate of CO2 from volcanic lands, have the Italians made an error with a few noughts in their sums? Have the Cardellini results been replicated or “audited” anywhere else?

    There is, of course, also the possibility that Gerlach and others who estimate global volcanic sources of CO2 at less than half a gigaton per annum have got their arithmetic or even the whole basis of their calculation wrong. Does anyone know of corroboration of either Gerlach or Cardellini?

    I don’t wish to appear a wet blanket but neither do I wish to be shot down in flames for naiveté! I do not understand atmospheric physics but arithmetic IS well within my capabilities. Please don’t be offended by this enquiry from an interested layperson.

  95. marchesarosa says:

    By the way, I am definitely not rubbishing the Cardellini findings. I have the greatest respect for what Italians may have to say about vulcanism. They are the experts!

  96. tallbloke says:

    Hi Marhesarosa and welcome. I haven’t heard any further news on the Cardellini et al paper. I hope it hasn’t been blocked for any reason we’d disapprove of.

    I’ve found one of Cardellini’s earlier papers on soil degassing of co2
    Soil CO2 emissions at Furnas volcano, São Miguel Island, Azores archipelago: Volcano monitoring perspectives, geomorphologic studies, and land use planning application

    Fátima Viveiros
    Centro de Vulcanologia e Avaliação de Riscos Geológicos, Universidade dos Açores, Portugal

    Carlo Cardellini
    Dipartimento di Scienze della Terra, Università di Perugia, Perugia, Italy

    Teresa Ferreira
    Centro de Vulcanologia e Avaliação de Riscos Geológicos, Universidade dos Açores, Portugal

    Stefano Caliro
    Osservatorio Vesuviano INGV, Naples, Italy

    Giovanni Chiodini
    Osservatorio Vesuviano INGV, Naples, Italy

    Catarina Silva
    Centro de Vulcanologia e Avaliação de Riscos Geológicos, Universidade dos Açores, Portugal

    Carbon dioxide (CO2) diffuse degassing structures (DDS) at Furnas volcano (São Miguel Island, Azores) are mostly associated with the main fumarolic fields, evidence that CO2 soil degassing is the surface expression of rising steam from the hydrothermal system. Locations with anomalous CO2 flux are mainly controlled by tectonic structures oriented WNW–ESE and NW–SE and by the geomorphology of the volcano, as evidenced by several DDS located in depressed areas associated with crater margins. Hydrothermal soil CO2 emissions in Furnas volcano are estimated to be ∼968 t d−1. Discrimination between biogenic and hydrothermal CO2 was determined using a statistical approach and the carbon isotope composition of the CO2 efflux. Different sampling densities were used to evaluate uncertainty in the estimation of the total CO2 flux and showed that a low density of points may not be adequate to quantify soil emanations from a relatively small DDS. Thermal energy release associated with diffuse degassing at Furnas caldera is about 118 MW (from an area of ∼4.8 km2) based on the H2O/CO2 ratio in fumarolic gas. The DDS also affect Furnas and Ribeira Quente villages, which are located inside the caldera and in the south flank of the volcano, respectively. At these sites, 58% and 98% of the houses are built over hydrothermal CO2 emanations, and the populations are at risk due to potential high concentrations of CO2 accumulating inside the dwellings.

  97. […] those uncertainties, I think the correlation Bart has found and the recent discovery of the much larger than previously estimated volcagenic sources have moved this debate along, and a […]

  98. adolfogiurfa says:

    Chances are that CO2 is politically dependent 🙂

  99. […] almost nothing to the similar warming between 1910 and 1950 so it may be a lot less. Humans are only responsible for at most around 50% of the airborne increase in co2, so we are responsible for, at most, around 15% […]