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  1. Thank you for a useful and much needed explanation about this basic fact of volcanic emissions. Your graph in your EOS article is especially telling.

    [Response: – gavin]

    Comment by Richard Harvey — 4 Aug 2011 @ 8:04 AM

  2. There are authoritative sources of this information already. See for example:

    Volcanic Contributions to the Global Carbon Cycle
    British Geological Survey, 2005.

    This gives similar figures:
    Human caused emissions of CO2 = c. >30 Gigatons/year
    Volcanic (both terrestrial and submarine) = c. 0.3 Gigatons/year

    ie. volcanic emissions of CO2 are about 1% of anthropogenic emissions.

    Someone claiming that volcanic emissions of CO2 exceed human emissions is not a climate sceptic: he/she is either ignorant or is deliberately trying to mislead people.

    Comment by Slioch — 4 Aug 2011 @ 8:39 AM

  3. The damage was done by the broadband hyping of supervolcanos on ‘educational’ TV. Half a decade ago I blogged that:

    ‘ the New York Times / Discovery Channel’s “Supervolcano” and PBS’s “Strange Days On Planet Earth”. They round out a quadraphonic post-Tsunami barrage of volcanic doom and gloom on educational and cable TV. It includes every eruption you’ve ever heard of, ranging from Thera to Tambora by way of Pompeii…

    Supervolcano and Strange Days feature a virtual planet from Hell that crackles with the day glow shock fronts only high resolution software can generate. Gone is the good gray PBS screen that used to educate and inform, replaced by a surrealist billboard for images intense enough to brand themselves into the popular imagination — we are being shown the future by design…

    The Earth spewing enough incandescent gore to gag Quentin Tarentino may seem a hard act to follow, but with the explosive growth of computer animation, anything goes. The New York Times’ pop science outlet, the Discovery Channel, has joined with the BBC to bring us high budget hype for high definition TV… The New York Post’s Adam Buckman admits “Discovery has had a reputation for emphasizing science over fiction” which makes “the whole thing seem entirely plausible.”

    Comment by Russell — 4 Aug 2011 @ 8:44 AM

  4. Gavin, your response doesn’t seem to be live.


    Comment by Tim Jones — 4 Aug 2011 @ 8:47 AM

  5. When Eyjafjalajokull was erupting and shut down European/N. Atlantic air traffic for more than a week, folks were trying to estimate the change to carbon emissions… the result I remember was that CO2 emissions into the atmosphere dropping at least 10-fold for that period. Yes, the volcano emitted a lot, but the amount not emitted just from having no European air traffic was much greater.

    Comment by Daniel Curewitz — 4 Aug 2011 @ 8:59 AM

  6. The paper gives the figure for 2010 anthropogenic emissions at 35 Gt. I had heard a bit lower than that. Does this include other, non-CO2 GHGs?

    What is the level for total accumulated emissions of CO2. The graph above seems to indicate that it is less than 200 gt, but I had always assumed it was more than that, since we are now emitting more than 30Gt of the stuff per year.

    Thanks for the great paper.

    Comment by wili — 4 Aug 2011 @ 9:04 AM

  7. Thanks for some vivid comparisons to help drive this point home. Unfortunately, in the polarized and politicized context we’re living in, this sort of thing can’t be said often enough.

    Comment by Kevin McKinney — 4 Aug 2011 @ 9:05 AM

  8. This image should convince anyone. Try to spot the volcanic impact on the CO2….

    Of course, they are important for sustaining the levels of CO2 over geologic time.

    Comment by Chris Colose — 4 Aug 2011 @ 9:07 AM

  9. I am not an expert in volcanology, but I am trying to figure out why an eruption would contain significant amounts of CO2, unless the volcano was located over an oil or gas field.

    [Response: Volcanoes are bringing up magma from the crust – which is often subducted ocean sediments (think the ‘ring of fire’ in the Pacific) which are heavy in carbonate rocks. There is probably more to this though… Maybe some passing volcanologist can chime in with a good reference? – gavin]

    [I’m no expert on this either, but I can dust off my undergrad thesis a bit…. You don’t even need the carbonate rocks — that’s just calcium plus dissolved CO2. Plenty of deep ocean water — generally saturated in CO2 — gets subducted along with the sea floor rocks and sediment. You’re both right, of course, that the amount of CO2 in volcanic eruptions varies from place to place of course, depending on what the rock type is, though the idea of a volcano ‘over’ a gas field doesn’t make sense. The roots of a volcano are deep — so if there’s a volcano around, you can be sure there are no oil and gas deposits right underneath it. Interestingly enough there’s a rare type of volcano that actually produces carbonate rock (carbonotite) instead of the normal silicate (basalt, andesite etc.) rock we’re used to thinking of from places like Hawaii or Stromboli. Such a volcano [presumably] emits far more CO2 that others, but there are only a handful of these.–eric]

    Comment by Gordon McGrew — 4 Aug 2011 @ 9:17 AM

  10. #8–Yes, it should. . .

    Comment by Kevin McKinney — 4 Aug 2011 @ 9:29 AM

  11. As I recall, Peter Ward makes an argument that most of the mass extinctions on the planet can be tied to changes in the atmospheric concentration of CO2 (which leads to other effects in the Canfield Ocean that has apparently has dominated the oceans through much of the planet’s history).

    These mostly are attributable to certain large scale volcanic events unlike anything seen in recent geologic history. His comparison is to where we are today compared to what the paleotological evidence suggests. His conclusion is that we are poking a tiger with a stick.

    Comment by Gsaun039 — 4 Aug 2011 @ 10:47 AM

  12. With all due respect, the graph inserted by Gavin as a response/clarification to post #1 does not convey information as it was perhaps intended to: “…with a minimum of technical jargon for a broad spectrum of Earth science researchers and educators, students, policy makers, the media, and the general public.” [the OP].

    For evidence of this, see #6. (“What is the level for total accumulated emissions of CO2. The graph above seems to indicate that it is less than 200 gt…”) It’s a graph of a multiplier, front and center: the most critical takeaway of the article (an excellent one, for all of that, and thank you Mr. Gerlach). But it took me a minute. Speaking as a more-or-less scientifically literate member of the public, without context it’s not something the general public will wrap their heads around easily or intuitively.

    * sigh * Everything I read these days, I read through the lens of Tom Curtis’ comment – almost a year ago, here:

    “Whenever your simplify the explanation of a significant theory sufficiently to make it understandable to high school graduates of average education, you also make it misrepresent the science sufficiently that unscrupulous people can make a plausible case that you are wrong. This is particularly true of descriptions of complex systems such as climate.”

    …the most striking and disheartening word-bite I can recall ever having read on the internet.

    Comment by Jaime Frontero — 4 Aug 2011 @ 12:00 PM

  13. I’m missing a “line of defence”.

    Yes, volcanic CO2 emissions are small compared to the emissions from human activities. We can proof that. But that has no meaning. Central point is that human emissions are additional. Even if volcanic emisions were twice the amount we emit, it would not matter. There is no indication that volcanic activity has increased the last few centuries, so they can not be an explanation for present rising CO2 levels.
    Just imagine that we can convince the deniers (no, we can not) about the vulcanos, they can easely switch to an other natural source. At the end, the human emissions are still small compared to the total natural carbon cycle. See this graph. For example, the emissions by oceans are 10 times larger than antropogenic emission. But these large emissions by the oceans are not the problemen because they are part of a well balanced system, in balance for thousends of years.
    Nevertheless it is good to have articles like this available to educate the journalist who shoud educate the public. (And I can use it too. Thanks).

    Comment by Hans Kiesewetter — 4 Aug 2011 @ 2:30 PM

  14. Thanks for publishing this. An excellent article that I will direct my learned comrades to in the event of ignorance or misunderstanding of the scientific consensus.

    The whole issue of anthropogenic climate change is one that should remind us that we, as a scientific community desiring a well-educated populace, need to push for better science and math education in the public schools. I agree that this is NOT an article that is accessible to the lay reader, though portions of it SHOULD be. It is the relative opacity of scientific literature, combined with scientific illiteracy in the general population, that has enabled so many charlatans to put doubt and denial into the public psyche regarding ACC. Ignorance does not respond well to reason.

    Great article, nonetheless.

    Comment by Hansi Singh — 4 Aug 2011 @ 2:44 PM

  15. regarding eric’s comment about different types of volcanos: IIRC the skeptic claim (e.g. Plimer) seems to be that the official figures don’t include underwater volcanic activity (which appears not to be true anyway). However, I would have thought that they would be the low CO2 type of eruptions as they would be less likely to be bringing up magma from subducted crust (I am thinking here of e.g. the mid-Atlantic ridge)?

    Comment by Dikran Marsupial — 4 Aug 2011 @ 2:47 PM

  16. 9 Gordon McGrew: The coal seam or petroleum source could be above and the magma source below. Then the magma would flow through the fossil fuel. I read somewhere about that happening in the Siberian traps [volcanic “stairsteps” region] 250 million years ago.

    Comment by Edward Greisch — 4 Aug 2011 @ 2:55 PM

  17. In your opening paragraph you comment:

    “TV screen images of erupting and exploding volcanoes spewing forth emissions are typically spectacular, awesome, and vividly suggestive of huge additions of gas to the atmosphere. By comparison, the smokestack and exhaust pipe venting of anthropogenic emissions is comparatively unexciting, unimpressive, and commonplace”.

    In australia at least and possibly in other countries, the media when discussing carbon dioxide and anthropogenic global warming invariably decorate their piece with pictures of “smoke” plumes from cooling towers That these are plumes of water vapour and not smoke is never mentioned. Perhaps this is because such pictures are not “comparatively unexciting, unimpressive, and commonplace” even though they may be misleading

    Comment by Ian — 4 Aug 2011 @ 3:28 PM

  18. Thanks for the RC post, and especially for your article in EOS. Back in June I used it as a basis to refute yet another of the foolish claims about volcanic activity dominating the growth of atmospheric CO2:

    Comment by tamino — 4 Aug 2011 @ 4:07 PM

  19. Hans @13 wrote: “For example, the emissions by oceans are 10 times larger than antropogenic emission.”

    But note that there are two arrows for the ocean in that graph (and for vegetation and land), one for emission, and one for absorption, and that the one for absorption is larger than the one for emission.

    That means emission from the ocean is more than offset by absorption of CO2 by the ocean. The ‘sceptics’ aka deniers never mention the absorption arrow.

    However, there is only one arrow for the burning of fossil fuels. Our power plants and automobiles don’t absorb any CO2.

    That is to say, the ocean absorbs as much CO2 as it emits, plus more than a quarter of what we humans emit each year, which is why the pH of seawater is falling.

    Similarly, CO2 emission by volcanic activity is roughly offset by geologic absorption of CO2 through carbonate shell deposition and silicate rock weathering.

    Those who bring up CO2 emission from the ocean and volcanoes are misleading people, often deliberately, by using only half the truth.

    Comment by Jim Eager — 4 Aug 2011 @ 4:22 PM

  20. Neither link in the posting seems to work.

    [Response: Possibly related to today being the deadline for abstract submission to Fall AGU. I have put another copy of the main file here. – gavin]

    Comment by Stuart Levine — 4 Aug 2011 @ 4:24 PM

  21. #6 wili

    Between 1850 and 2000 the total recorded human caused emissions of CO2 amounted to 1620 billion tons CO2. The increase in atmospheric CO2 was 640 billion tons. Most of the difference (about 1 trillion tons CO2) has been absorbed by the oceans and terrestrial sinks. The oceans are a net sink of CO2 at present, ie. they are not expelling net CO2, even though they are warming, because the effect of the increase in partial pressure of CO2 in the atmosphere more than compensates for the warming.

    [Info. from the Carbon Dioxide Information Analysis Centre: with masses C converted to CO2 by multiplying by 44/12)]

    As for the total accumulated emissions of CO2, each increase of 1ppmv of CO2 represents an extra 7.81Gtons CO2 in the atmosphere (see cdiac above), so the increase from c.280ppmv pre-industrial levels to the present 394ppmv means an extra 890Gtons CO2 in the atmosphere. This does not, of course, represent the total human emissions, since rather more than half of anthropogenic emissions have been absorbed by oceans and land.

    Comment by Slioch — 4 Aug 2011 @ 4:46 PM

  22. Yes Ian (@17), the use of images of power pant condensing/cooling towers in media stories is a common and misleading occurrence, especially when those towers are actually at a nuclear plant, but they are also used at some fossil fuel thermal plants, so it’s hardly the same as deliberately misleading people about the size of volcanic emissions, which are in fact less than 1% as large as those from the burning of fossil carbon fuels, now is it?

    Comment by Jim Eager — 4 Aug 2011 @ 4:56 PM

  23. Thanks Terry for a useful weapon in the battle against misinformation. (I come from the land of Ian Plimer, so I know something about that.) A small technical matter which I found frustrating – I tried to access your paper using the URL supplied, but whichever link I used (including Googling the paper title) I kept getting redirected to the AGU Fall meeting flyer – . Is there a bug in the system or am I missing something? (No, I’m not paranoid.)

    Comment by Peter Boyer — 4 Aug 2011 @ 5:52 PM

  24. The mass balance margin of error is what is laughable, eh CSU carbon-cycle physicist?

    Texas is praying for hurricanes – come on NOAA, deliver.

    Comment by thomas hine — 4 Aug 2011 @ 5:59 PM

  25. Useful article.

    Plimer states: “Over the past 250 years, humans have added just one part of CO2 in 10,000 to the atmosphere. One volcanic cough can do this in a day.”

    This hyped version of his own claim, came out close to an important debate in the Australian Parliament. It was also on Plimer’s web site. When I asked a geologist about it, he suggested that the solubility of CO2 in magma under pressure would probably be too low to make this possible. But it was not a definitive reply.

    Plimer’s assertion was also on the ABC.
    Points of possible confusion result from the need to learn more than one point.

    People who have been encouraged to trust the experts have problems with being told that Ian Plimer , described as a geologist, can possibly be so wrong about a geological topic like this. This can be a major stumbling block.

    If they can get their head round that one, they are then surprised to discover that volcanoes actually cool the planet in the short term. But it doesn’t end there. They have to learn that the emergence of life required that the Earth should be able to boot itself out of a snowball state and that the best explanation is that this was due to the warming caused by the very slow emission of CO2 over geological time.

    Comment by Geoff Wexler — 4 Aug 2011 @ 7:26 PM

  26. Re 3 Russell – I remember thinking that the Discovery Channel movie “Supervolcano” was not particularly unrealistic (except perhaps for the low probability that it would go off in any one time period (but they weren’t saying ‘this will happen now’)- but it easily could happen again someday, possibly when there are still technologically-advanced humans about) – certainly more realistic than either “Armageddon” or “The Day After Tomorrow”, and way way way more realistic than “The Core” (all good movies, though). There were no claims made about the CO2 emissions from the volcano – that I can recall. The movie depicted global cooling, which would certainly happen – about the duration and magnitude, I’m not sure (about reality or the movie).

    The problem perhaps is that there aren’t enough realistic AGW movies (I’d recommend “Earth 2100” (the only one I know of) – very very depressing).

    [Response: If you want to be really depressed, go to the unforced variations thread, and read about Judith Curry’s latest incredible jump into unscience….–eric]

    Comment by Patrick 027 — 4 Aug 2011 @ 8:30 PM

  27. “though the idea of a volcano ‘over’ a gas field doesn’t make sense. The roots of a volcano are deep — so if there’s a volcano around, you can be sure there are no oil and gas deposits right underneath it”

    You can’t be so sure, since there are in fact a few oilfields beneath volcanos. They are rare, but occur where the a non-vertical magma vent and relatively shallow chamber produces a volcano at the surface which overlies sedimentary rocks in the subsurface. Quite a geologic novelty, but yes, they do occur.

    [Response: Fair enough. Thanks! –eric]

    Comment by Bryan S — 4 Aug 2011 @ 9:07 PM

  28. “Such a volcano [presumably] emits far more CO2 that others, but there are only a handful of these”

    Is Mt. Etna of this category? I’m fairly sure I remember reading that Mt. Etna by itself accounts for a significant percentage of the total volcanic emissions worldwide…

    [Response: No, Etna is a regular old stratovolcano, like Mt. Rainier.–eric]

    Comment by M — 4 Aug 2011 @ 9:41 PM

  29. 9:
    Volcanoes represent a recycling of the silicate carbonate cycle. Silicate rock (I think these are of volcanic origin) weather into quartz and carbonate, absorbing CO2 in the process. When the carbonates are subducted and heat up enough the reaction revereses. This in combination with the sensitivity of erosion rate to global temperature over geologic timescales is the proposed thermostat that has keep the earth livable over billions of years.

    Comment by Thomas — 4 Aug 2011 @ 9:47 PM

  30. “TV screen images of erupting and exploding volcanoes spewing forth emissions are typically spectacular, awesome, and vividly suggestive of huge additions of gas to the atmosphere. By comparison, the smokestack and exhaust pipe venting of anthropogenic emissions is comparatively unexciting, unimpressive, and commonplace.”
    In cognitive psychology, this is known as the “availability heuristic”, first empirically studied by Tversky and Kahneman: .

    Comment by Vincent — 5 Aug 2011 @ 12:54 AM

  31. For a discussion elsewhere, in response to such a volcano claim, I did a ballpark calculation of how much stuff was put out by Pinatubo.

    It looked to be a bit less than human CO2 emissions, but that was everything sent up by Pinatubo combined. Everyone here should know where most of that stuff ended up: On the ground within sight of the volcano, it’s not like rocks stay in the atmosphere for very long.

    Comment by Rick Pikul — 5 Aug 2011 @ 1:00 AM

  32. That should be “annual human CO2 emissions”.

    Comment by Rick Pikul — 5 Aug 2011 @ 1:02 AM

  33. You may wish to read this article on Volcanic CO2

    Comment by janama — 5 Aug 2011 @ 1:17 AM

  34. Good post, and hopefully, it will clear up some common misconceptions.

    Comment by E.L. — 5 Aug 2011 @ 1:21 AM

  35. ** Yes we are aware that CO2 is colorless and that the plumes in the figures are mostly steam. – Eds.
    Steam is also colorless. The clouds in both cases are mainly fine droplets of liquid water

    [Response: Water vapour is indeed colourless, and indeed, these plumes are made up of droplets of liquid water. But steam colloquially can refer to both. – gavin]

    Comment by Nick Rouse — 5 Aug 2011 @ 3:06 AM

  36. (I don’t know if this should be posted in this thread or the current Open Variations thread)
    This infamous E&E paper;
    (consider the publication in E&E and the site location where posted, as both are highly biased with intent)
    claims that there is no lag between the NH and the SH with respect to CO2 concentrations, and therefore concludes (incorrectly I might add) that atmospheric CO2 concentrations can’t be anthropogenic in origin.
    However, anyone can go to the Scripps CO2 site;
    And download the entire MLO and SPO monthly datasets (two flask datasets, one each for SPO and MLO), and one atmospheric air in situ dataset (MLO) (NOTE: I’m using the last column of data from these three files (seasonally adjusted filled)).
    These are the two sites where direct CO2 measurements have the longest records (March 1961 to February 2011 (flask based comparison, 50 years of record) or March 1958 to February 2011 (flask vs air in situ, 53 years of record).
    I get the following results when plotting SPO vs MLO (no lag), SPO = 0.961*MLO +11.6 (spo (flask) vs mlo (air in situ)), R^2 = 0.99953 (autocorrelation)

    I get the following results when plotting SPO vs MLO (no lag), SPO = 0.962*MLO +11.2 (spo (flask) vs mlo (flask)), R^2 = 0.99933 (autocorrelation)

    Note the close agreement between these two results, one with flasks and one with two different measurement systems, the coefficients and constants, as well as the very high R^2 (yes, there is bound to be a lot of autocorrelation regardless), and note that the linear coefficients are less than one.

    Now I forward lag SPO relative to MLO by N months (forward lagging brings a later part of the SPO monthly time series in line with the untouched MLO time series), forcing the lagged plot through zero at the origin, and lag until N yields a slope of the line of approximately one (cross-correlation).

    I get the following results when plotting SPO vs MLO (N = 16 month lag), SPO = 0.999895*MLO (spo (flask) vs mlo (air in situ)), R^2 = 0.99897 (cross-correlation). (the linear coefficient is slightly less than 1, thus lag is actually somewhat greater than N = 16).

    I get the following results when plotting SPO vs MLO (N = 17 month lag), SPO = 1.00016*MLO (spo (flask) vs mlo (flask)), R^2 = 0.99888 (cross-correlation). (the linear coefficient is slightly greater than 1, thus lag is actually somewhat less than N = 17).

    NOTE: I did this aboot a year ago and updated the spreadsheet today with the annual Scripps update for 2011 that was released a few months ago.

    Anyways, tha lag in SPO relative to MLO is quite obvious and unambiguous, consistent with the majority of anthropogenic CO2 emissions being sourced predominantly from the NH, thus one would expect a significant lag in CO2 concentrations at the SPO versus all other higher latitude CO2 measurement sites.

    Therefore, the author of this infamous E&E paper does not know what all they are even talking aboot.

    Comment by EFS_Junior — 5 Aug 2011 @ 6:08 AM

  37. #2 (Slioch)
    I have searched through the BGS publication you mention (Hards, 2005) 3 or 4 times in the past. It reports various estimates by others for various aggregates of volcano types, but I have never found a place where it lays out a global volcanic CO2 emission estimate of it brings them together into a global estimate. Its 0.3-Gt/y estimate is for terrestrial (i.e., subaerial) volcanic degassing only, and this is at least a factor of 2 greater than other subaerial estimates. Further, it is taken from the subaerial volcanic CO2 emission estimate of 0.3 Gt/y by Morner and Etiope (2002), which is an assumed estimate rather than an empirical estimate, as I point out in my supplement. It was obtained by first assuming (dubiously) a plume CO2 output of 0.25 Gt/y for 500 historically active subaerial volcanoes—a lot of CO2 output for a group of volcanoes that are presently mostly inactive (each one would be emitting about 20% of what a very active volcano like Kilauea in Hawaii emits each year); next, it is assumed that the diffusive flux of CO2 from the volcano flanks is 20 percent of this value to get an additional 0.05 Gt/y. Until these assumptions (particularly the first one!) are verified, this estimate is highly speculative and suspect. Neither Morner nor Etioipe have subsequently published measurements supporting either of these assumptions. This estimate was published in Global and Planetary Change, not exactly a mainline journal for volcanology, petrology, and high-temperature geochemistry, which is probably how it survived the review process.
    #6 (wili)
    No, non-CO2 GHGs are not included. The 35 Gt includes CO2 from fossil fuel combustion, land use changes, cement production, and waste gas flaring. This information is stated in the figure caption along with reference and URL sources (sorry, probably not the best choice for it).
    If you click on the graph in comment #1 and magnify it so you can read the y-axis label and caption, you will see it is not about total accumulated anthropogenic CO2 emissions. As noted by #12 (Jaime), it shows the anthropogenic CO2 multiplier (ACM)—defined in the paper as the ratio of anthropogenic to volcanic CO2—over time rising gradually from 1900 to 1950 and then rapidly to the present. The figure shows anthropogenic CO2 is increasingly dominant over volcanic CO2.
    #13 (Hans), #19 (Jim)
    Interesting discussions. A volcanic analogy to the anthropogenic “addition” may be a period of accelerating volcanism during plate tectonic reorganization or breakup of supercontinents.
    #14 (Hansi)
    Excellent critical comment. I’ll remember this!
    #15 (Dikran)
    The estimates for global submarine volcanic CO2 were the earliest global scale estimates to be made, thanks to isotope and tracer techniques that made this possible for the submarine environment. There are some words in the supplement about techniques that allow estimates of submarine volcanic CO2 without needing to count submarine volcanoes or measure gases from individual volcanoes. For example, much of the work has been done on glass samples from dredged lavas coupled with He isotope fluxes for the oceans. I think Plimer understands this (or at least could understand it), but he typically makes diverting commentary about all the many uncounted volcanoes on the seafloor—nearly all of which are extinct, but he never points that out.
    #17 (Ian)
    The gas emitted by erupting volcanoes is typically about 90 percent water vapor (mole basis).
    #18 (Tamino)
    Thank you for the link. I look forward to reading the comments. Do you think Plimer is the source of the Pinatubo quote? I’ve been looking for evidence that clearly ties it to him. Do you have anything?
    Thanks for all your comments.

    Comment by Terry Gerlach — 5 Aug 2011 @ 6:19 AM

  38. If I understand it correctly, Plimer has been making a slightly more subtle argument than “volcanoes produce more CO2 than human activity”. His argument is that one volcanic eruption could produce more CO2 than the amount we’ve *avoided emitting* by instituting emissions reduction measures… and for all I know, that could be true. It’s certainly not as obviously false as the “volcanoes produce more CO2 than human activity” claim, but it is without a doubt intended to mislead and to be misinterpreted (wilfully or otherwise) as minimising the significance of human emissions. It’s also entirely irrelevant to the issue of emissions reductions, for a couple of the reasons already raised here, plus other reasons.

    Comment by Icarus — 5 Aug 2011 @ 6:57 AM

  39. The end is near.

    CO2 follows warmth.

    [Response: Well done. You have discovered the positive carbon-cycle feedback. Now think about what happens when you put human CO2 in the air, which warms the planet and which then releases more CO2 into the air and ….. The end may indeed be a bit nearer. – gavin]

    Comment by Dave — 5 Aug 2011 @ 8:33 AM

  40. janama @33, why on earth would we disregard what the US Geological Survey and the British Geological Survey say about volcanic CO2 and instead accept the pseudo-paper published by a petroleum geologist on his website?

    That’s right, Timothy Casey’s lively hood depends on the petroleum industry.

    But let’s assume for a moment that he’s correct that CO2 emissions from volcanic activity is larger than thought. Let’s assume it’s double the estimates. It would still amount to less than 2% as much annually as from burning fossil carbon fuels.

    Please, get a clue.

    Comment by Jim Eager — 5 Aug 2011 @ 8:53 AM

  41. 26

    Fast forwarding geological time to advertise eschatology is not limited to televangelists seeking to cash in on the end times before the end of the fiscal year.

    Environmental PR firms can photoshop the apocalypse as well as anybody in the business.

    Comment by Russell — 5 Aug 2011 @ 9:04 AM

  42. I’m mildly addicted to Russell’s writing, a brilliant conservative unwilling to mess with the truth (and a witness for the existence of same), otherwise I would have used this time elsewhere. (If he reads this, I do not expect him to return the favor; that’s OK by me.) Daniel Curewitz (@5) also makes a good point – volcano had less effect than not flying planes. I remember at the time of the post about Glory somebody linked to the satellite site, and I fossicked around, finding highest CO2 emissions somewhere in the neighborhood of Greenland, 298 at the time. I know data over time and space is different from point sources, but it was interesting nonetheless.

    Definitely check out Earth 2100; at the time somebody mentioned the “look” was Soviet era graphics which was against it. I wish Podesta and his institute and some other good people would find better PR. As time trickles through our lives, leaving us in progressively worse case, oil is being given a makeover – love your oil and gas, smart molecules – which to my eye is very effective (likewise with coal, but this is recent). On every level, fakery does a better job of promoting its mischief than those who know what they are talking about outside the political position.

    Comment by Susan Anderson — 5 Aug 2011 @ 9:26 AM

  43. Any thoughts on the Salby talk/paper being touted elsewhere?

    Comment by Mike — 5 Aug 2011 @ 10:10 AM

  44. Mike, wrong topic, asked and answered.

    The very same question has been repeatedly posted around the site, off topic — likely by people who try to bump it up in search results.

    When that happens, often it gets ignored after a while.

    There’s a way to avoid being confused with those copypastebotpeople, though.

    You do know how to use the Search tool.

    Try it. White rectangle, upper right corner of every page.

    Click the option for Site Search and type “salby” into the white space.

    See? Easy.

    Comment by Hank Roberts — 5 Aug 2011 @ 11:18 AM

  45. Terry Gerlach @37 “A volcanic analogy to the anthropogenic “addition” may be a period of accelerating volcanism during plate tectonic reorganization or breakup of supercontinents.”

    Yes, something that I often point out when discussing the interaction of CO2 and temperature, particularly the slow build up in CO2 and temperature at the end of the Paleocene as the Indian subcontinent moved northward, forcing the subduction of the shallow carbonate-rich seabed between it and Asia, which triggered the PETM on the way to the peak of that warming in the early Eocene.

    But I also point out the subsequent long, slow draw down of both CO2 and temperature as the resulting uplift of the Himalaya and Tibetan plateau led to accelerated silicate weathering, both excellent examples where the change in CO2 clearly preceded the change in temperature.

    Comment by Jim Eager — 5 Aug 2011 @ 11:18 AM

  46. #43 Any thoughts on the Salby talk/paper being touted elsewhere?

    Hm, no.

    So far, all we have is an audio podcast, no slides even. Go figure.

    Typical denier MO though, circle j**k fantasies litter the denial-o-sphere, waiting for jolly old St. Nick.

    The paper will appear at some future date TBD, perhaps E&E, or some other obscure 3rd tier publication totally unrelated to climate science.

    You will also get to buy the book BEFORE the paper is published though, with hints of inclusion of some of this proported “bombshell” of a revelation.

    In the good old days (three days before The Day After Tomorrow), we got the PR just slightly ahead (by a few days) of the peer reviewed paper, now we’ve had the BEST pre-pre-pre announcements, and now this pre-pre-pre-pre-pre-pre- …, ad infinitum ad nauseum.


    Comment by EFS_Junior — 5 Aug 2011 @ 11:39 AM

  47. Re # 38. Your remark is interesting, but I have a question:

    Plimer has been making a slightly more subtle argument,

    I wonder if he has ever withdrawn the less subtle versions such as the one in #25 ?

    He doesn’t usually make an argument. Unless he has reformed recently, he has a whole encylopedia of them, which can be used one at a time or all together in a gish gallup.

    Comment by Geoff Wexler — 5 Aug 2011 @ 11:55 AM

  48. @ janama — 5 Aug 2011 @ 1:17 AM

    Don’t you think it’s too much of a coincidence that Casey’s “1000 potentially active subaerial volcanoes worldwide” have been hypothetically increasing their emissions, starting around 1850, precisely matching the rate of anthropogenic fossil fuel emissions? Something that has never happened in the last 400000 years, according to the Vostok CO2 record.

    Casey is also wrong in his assertion that volcanic CO2 is indistinguishable from fossil fuel emissions. Concentrations and isotope ratios of carbon, nitrogen and sulfur in ocean-floor basalts SARAI et. al 1984 found “The isotopic ratios of indigenous carbon and nitrogen are in very narrow ranges, -6.2 [per mil; symbol didn’t paste] relative to PDB and +0.2 & 0.6460 relative to atmospheric nitrogen, respectively.”
    This is less negative than the atmospheric ratio, which declined from -7.6 in 1980 to -8.2 in 2008. The Mid Ocean Ridge is the largest volcanic structure on earth, 65,000 miles long. Its erupted basalt created the ocean floor, average age ~70 million years, thickness ~2km, area ~1.8e8 km^2. The volume is therefore 3.6e8 km^3, and the eruption rate is ~5km^3 per year. The is equivalent to one Mount Pinatubo every 2 years – Pinatubo was the largest eruption since Novarupta in 1912, and caused no measurable change in atmospheric carbon isotope ratios. FÜRI ET AL.: CARBON RELEASE AT THE COSTA RICA FORE ARC
    “We estimate that the carbon flux (CO2 plus methane) through submarine fluid venting at the outer fore arc is 8.0 × 105 g C km−1 yr−1, which is virtually negligible compared to the total sedimentary carbon input to the margin, …the implication is that most of the carbon being subducted in Costa Rica must be transferred to the (deeper) mantle, i.e., beyond the depth of arc magma generation.”

    The ocean ridge carbon has the wrong isotope ratio to account for atmospheric CO2 rise. Plate margin subduction zone volcanism removes more carbon than it emits. Even if you accept Casey’s glorified guesswork that Toba emitted 494 Mt of carbon, that is a small fraction (<2%) of the 26 Gt of carbon from fossil fuels and other human activities. We can't possibly be missing 50 Toba scale eruptions per year, (or 500 Tambora scale eruptions). Pinatubo didn't even make Casey's scale, and most of us noticed that eruption and its effect on climate.

    Comment by Brian Dodge — 5 Aug 2011 @ 1:40 PM

  49. Hiding a smirk, I’m afraid to say both opinions on the source of CO2 are wrong here. Apparently, in the current WUWT article,
    a Prof. Salby ‘proves’ the current CO2 rise is due to Warming, i.e. the old ‘800 year’ lag. (and therefore AGW must be hoax)

    Comment by Clippo (UK) — 5 Aug 2011 @ 1:45 PM

  50. Clippo, you are late to the party and in the wrong thread.

    Comment by Jim Eager — 5 Aug 2011 @ 2:18 PM

  51. I am confused here. I here that volcanos cool the planet due to sending dust in to the upper atmosphere, and a really big eruption could send us in to something like a nuclear winter. Now they are warming agents. Which is it?

    Comment by DP — 5 Aug 2011 @ 5:33 PM

  52. Not a Wikipedia fan, however, this looks an interesting limk to my previous comment:

    Comment by Titus — 6 Aug 2011 @ 12:41 AM

  53. re:- #50, Jim eager

    I apologise for being late to the party but I didn’t see EFS_juniors reference to Salby before I posted. As for the wrong thread, Que?, – this is about CO2 emissions & recent rises is it not?
    (and my opening words, “Hiding a smirk” meant that I consider Salby’s opinions a load of rubbish).

    Comment by Clippo (UK) — 6 Aug 2011 @ 8:31 AM

  54. Re Jim Eager

    Further apologies, I have now just discovered this was discussed in Unforced Variations – I simply don’t have time to read every post in every thread.

    Comment by Clippo (UK) — 6 Aug 2011 @ 8:36 AM

  55. My answer to the CO2 from volcanoes (as a non scientist, who can’t answer with authority on the “science” the denialists bring up) is:

    “Then we have to REALLY reduce our GHG emissions a lot more, because you never know when a reall big volcano is going to emit CO2, and we just can’t have our human emissions added on to that, or it would be very bad for us. We can’t stop those volcanos (or the sun from shining, or the cosmic rays, etc), but be can and really must reduce our own GHG emissions, and even more so now that you’ve brought up these other contributions to global warming that are beyond our control.”

    And as for #49 and “warming causes CO2 [and CH4] emissions from nature” — similar answer:

    “Now that’s really scary, that warming releases GHGs, which, of course, does not disprove that GHG cause warming (which is well known), so in that case we REALLY have to reduce our GHGs way down, more than what everyone’s saying, because we just can have a situation in which the little warming we cause then causes release of GHGs from nature, causing more warming, causing more release, causing …. total doom. We just can’t have that!”

    P.S. I’ve read that volcanoes (near massive coal formations), the Siberian traps, probably played a role in triggering the end-Permian great warming 251 mya that killed off more than 90% of life on earth…but I think over a much longer period than our human spewing of GHGs into the atmosphere. Also, that the great warming caused hydrogen sulfide formation and release, nearly wiping out what little life remained. And I think recently I read that the warming of ? 200 mya led to vast methane release which killed off a lot of life.

    What are we doing playing with matches in a dynamite storeroom?

    Comment by Lynn Vincentnathan — 6 Aug 2011 @ 8:38 AM

  56. Thanks Slioch and Terry for the clarifications.

    Anyone have an accurate, sourced figures for CO2 equivalent anthropogenic annual emissions–that is a figure for all GHGs humans are directly responsible for emitting?

    Comment by wili — 6 Aug 2011 @ 10:02 AM

  57. > Titus
    > Not a Wikipedia fan …

    You need to specify the day you refer to, as edit-war-prone climate-related articles change a lot.

    Peiser’s long been calling attention to catastrophes as possibilities affecting climate; arguments occur about the details of events.

    Comment by Hank Roberts — 6 Aug 2011 @ 10:49 AM

  58. PS for Titus, down at the very bottom of that Wikipedia page, it points to:

    “retrievals fortatv” says the ReCaptcha oracle.

    Comment by Hank Roberts — 6 Aug 2011 @ 10:52 AM

  59. The language probably works for the readers of a publication like EOS, but if you get a chance to make the same points in a publication for the general public, I’d advise against talking about “orders of magnitude.” Most people don’t really know what an order of magnitude actually means, any more than they get exponential notation.

    The terminology that throws people is not always obvious. Experienced journalists always talk about the eighteen hundreds instead of the 19th Century, for example, but it took me a while to realize why.

    Comment by Jim Harrison — 6 Aug 2011 @ 11:57 AM

  60. For wili, who asks for help, wondering if anyone knows

    First result of the search:

    AR4 SYR Synthesis Report – 2.1 Emissions of long-lived GHGs
    (a) Global annual emissions of anthropogenic GHGs from 1970 to 2004. … Carbon dioxide-equivalent (CO2-eq) emissions and concentrations …

    Comment by Hank Roberts — 6 Aug 2011 @ 12:08 PM

  61. “climate skeptic literature” — there are skeptics of climate?!

    Comment by Farmer — 6 Aug 2011 @ 12:45 PM

  62. #37 Terry Gerlach

    Thanks for those comments on the BGS article.
    I had rather taken it that the 0.3 GtCO2/year does include the submarine contribution, and is a rough summation of the contributions given in Fig.2, rather than the reference to 300 Mt/year on page 1, but, like you, I don’t find it at all clear.

    [Fig. 2 gives 66-97 Mt CO2/year for mid-ocean ridges, 80-132 Mt CO2/year for hotspots and 66-135 Mt CO2/year for subduction related volcanism, but the text mentions that Morner and Etiope (2002) consider that hydrothermal alteration of the newly erupted lavas at mid-ocean ridges absorbs as much CO2 as the eruptions emit, so that the net atmospheric emissions of CO2 from that source are close to zero.]

    However, at the level of general take-home message the BGS article does agree that volcanoes are emitting to the atmosphere less than 1% of the CO2 that humans are producing, and that is the main message that needs to be got across.

    Comment by Slioch — 6 Aug 2011 @ 12:50 PM

  63. A simple question, but one I’ve not found the answer to in my searches: has the North Pole itself been ice-free yet? I know an endurance swimmer swam very near the ice pole in 2007, but has the pole itself yet been free of ice. I ask because of the symbolism attached to the north pole.

    Comment by John Mayer — 6 Aug 2011 @ 3:01 PM

  64. @55: See . Also:

    The EIA says coal-burning added 13,394 MT CO2 (= 3,653 MT C) in 2009.

    And the CDIAC estimates coal-burning added 3,392 MT C in 2009.

    The EIA says oil-burning added 10,888 MT CO2 (= 2,969 MT C) in 2009.

    And the CDIAC estimates liquid-fuel burning (mostly oil?) added 3,019 MT C in 2009.

    The EIA says natural gas-burning added 6,032 MT CO2 (= 1,645 MT C) in 2009.

    And the CDIAC estimates natural-gas burning added 1,553 MT C in 2009.

    By EIA figures, we added ~8,267 MT C in 2009 solely from burning fossil fuels. And by CIADC estimates, it’s 7,964 MT. CIADC also estimates cement manufacture at 381 MT and gas flaring at 54 MT. Neither figure includes emissions from land-use changes or feedbacks.

    You could SWAG land-use change and feedback figures, then cross-check the results with CO2’s airborne fraction, but since that number seems to vary a great deal year-to-year, I’m not sure what it would mean.

    CAPTCHA: suspi rainee

    Comment by Meow — 6 Aug 2011 @ 3:29 PM

  65. That’s all well and good – we humans are much better in CO2ing our air than good old volcanoes are. But the other side is at least as interesting: their emission of light-reflecting matter like sulfur and ashes and so forth.
    I would be interested in whether these balance volcanic CO2 more or less.

    Comment by Dominik Lenné — 6 Aug 2011 @ 3:33 PM

  66. #63 Domimik Lenne

    Balance? No. see fig.a under “Effective Forcings Employed in Current Climate Simulations” here:
    The “stratospheric aerosols”, grey line, are the volcanic aerosols of which you speak. They are short-lived and intense, increased CO2 is slow, relentless and long-lasting.

    Comment by Slioch — 6 Aug 2011 @ 6:03 PM

  67. > Dominik Lenné
    asks whether
    > [volcanic] sulfur and ashes … balance volcanic CO2

    Briefly, for a year or two; see paleo records from before humans came along.

    A large volcanic eruption can produce a year or several years of cooling.
    Sulfate and ash fall out of the atmosphere over a few years’ time.

    Any pulse of CO2 persists in the atmosphere far longer.

    Comment by Hank Roberts — 6 Aug 2011 @ 6:30 PM

  68. Dominik Lenné @ 63, the occasional major eruption has a distinct cooling effect (look up :the year without a summer) but this is part of the normal background noise, superimposed on the trend but a trend is still a trend.

    note the graphs (scroll down to see them all)

    Comment by Pete Dunkelberg — 6 Aug 2011 @ 7:01 PM

  69. Those gray down-spikes are due to volcanoes.

    Comment by Pete Dunkelberg — 6 Aug 2011 @ 7:10 PM

  70. Dominic Lenne #63 The aerosol cooling effect you describe lasts for 1-3 years or so, and reduces temperature considerably more than the volcanic CO2 raises it.

    Comment by One Anonymous Bloke — 6 Aug 2011 @ 8:32 PM

  71. #54–

    Nicely done, Lynn, and much to the point, really.

    Comment by Kevin McKinney — 6 Aug 2011 @ 10:33 PM

  72. On the topic in #63 – #68, please also see Solomon et al.:

    “Several independent data sets show that stratospheric aerosols increased in abundance since 2000. Near-global satellite aerosol data imply a negative radiative forcing due to stratospheric aerosol changes over this period of about –0.1 W/m2, reducing the recent global warming that would otherwise have occurred. Observations from earlier periods are limited but suggest an additional negative radiative forcing of about –0.1 W/m2 from 1960 to 1990.”


    Science DOI: 10.1126/science.1206027

    From Science’s RSS descriptive tag for this article: “A thickened stratospheric haze has been counteracting global warming, but it won’t last”

    (Posted by a non-scientist who’s merely trying to stay current with your conversation; thanks).

    Comment by Pete Helseth — 7 Aug 2011 @ 7:07 AM

  73. #72, that paper has reminded me of this one:

    “it has been unclear why global surface temperatures did not rise between 1998 and 2008. We find that this hiatus in warming coincides with a period of little increase in the sum of anthropogenic and natural forcings. Declining solar insolation as part of a normal eleven-year cycle, and a cyclical change from an El Nino to a La Nina dominate our measure of anthropogenic effects because rapid growth in short-lived sulfur emissions partially offsets rising greenhouse gas concentrations”

    Kaufmann et al 2011

    Reported by BBC as “Global warming lull down to China’s coal growth “.

    [Response: The trouble with that paper is that it addresses a non-question. See e.g. Richard Black’s commentary here: for why claiming ‘no warming since 1998’ is just silly. See also Stoat’s amusing take on this.–eric]

    Comment by Jesús R. — 7 Aug 2011 @ 4:05 PM

  74. Thanks for your answer, Eric. I perfectly understand that we cannot statistically say that there’s any pause in the warming trend (especially since the Kaufmann et al paper just focus on surface temperatures). However, regardless of that, I think that these two papers estimate that there is a slight slowdown in net antrhopogenic radiative forcing:

    The Kaufmann paper says:
    “Because of the resultant increase in anthropogenic sulfur emissions, there is a 0.06 W∕m2 (absolute) increase in their cooling effect since 2002 (Fig. 1). This increase partly reverses a period of declining sulfur emissions that had a warming effect of 0.19 W∕m2 between 1990 and 2002.

    The increase in sulfur emissions slows the increase in radiative forcing due to rising greenhouse gas concentrations (Fig. 1). Net anthropogenic forcing rises 0.13 W∕m2 between 2002 and 2007, which is smaller than the 0.24 W∕m2 rise between 1997 and 2002.”

    And the Solomon et al paper mentioned in #72 estimate “a negative radiative forcing due to stratospheric aerosol changes over this period of about –0.1 W/m2“.

    So I think that, regardless of what statistics tell us about recent trends, both papers are pointing to a somewhat relevant role of sulfur emissions in slowing recent net antrhopogenic forcing, which I think is something new, and therefore, potentially interesting. I say “potentially” because I don’t know whether this new stuff is relevant (should this trend in sulfur emissions continue, I don’t really know whether it would have any relevant impact on warming projections).

    [Response: Yup, fair enough. My objection was to the silliness of the way Kaufmann and others introduce their work, not to the details of the work itself, which seems fine. –eric]

    Comment by Jesús R. — 8 Aug 2011 @ 5:07 AM

  75. This caught my eye in Comment 26:
    Plimer states: “Over the past 250 years, humans have added just one part of CO2 in 10,000 to the atmosphere. One volcanic cough can do this in a day.”

    For the mathematically challenged, thats 10 parts per 100,000 and 100 parts per million…just about what humans have added over the course of the past 250 years during the industrial revolution if you accept, as I do, the per-industrial atmospheric concentration of CO2 at ~280 ppm.

    The problem with Plimer’s assertion is that even if the volcanic gas released was 100% CO2 and was treated as a supercritical fluid prior to release from the crust, from a sufficiently large vent, the supersonic velocities needed to be attained (and the local impacts associated with such a supersonic jet) defy physics, at least on the scale of a single day.

    Talk about fire and ice. The ice storm, not to mention the dry ice storm, would be of an unprecedented nature…think large scale CO2 fire extinguisher. Add to that the huge dead zone because of local anoxic conditions. That CO2 does not instantly and uniformly distribute itself through the vertical column of air nor across the spatial surface area of the planet.

    As an offhand remark, its a way to dismiss human impact or to give some “credibility” to the idea that conditions have been like this before. But I doubt Plimer can point to any single event in the recent geological past that has had this effect.

    And my question to anyone who takes this line that it not only can happen but has happened before is this: “How did the 7 billion people living on the planet fare the last time this happened?”

    Comment by Gsaun039 — 8 Aug 2011 @ 12:36 PM

  76. John Mayer #63,

    IMHO this question should also be posted in the ‘Unforced Variations’ thread, but I’ll attempt a layman’s answer. (Any scientists please feel free to correct me.)

    On the micro scale (up to a few hectares, perhaps??), there would almost certainly have been occasions when there was a lead or polynya open at the North Pole.

    On the macro scale, I suspect the answer is ‘No’.

    Comment by ozajh — 8 Aug 2011 @ 8:10 PM

  77. Errrr, that was ‘No’ as in ‘not in the last few thousand years’.

    Comment by ozajh — 8 Aug 2011 @ 8:13 PM

  78. #59 (Jim)
    Thank you for the suggestions and advice.

    #62 (Slioch)
    In fact, there are offsets for all of global volcanic CO2 emissions (not just the mid-oceanic ridge source) because the long-term carbon cycle is well balanced. Over a thousands-of-years timescale, all volcanic CO2 emissions are offset by silicate weathering and alteration of continental and oceanic crust, carbonate deposition, and organic carbon burial. So there is no net buildup of climate-forcing CO2 in the atmosphere from volcanoes, provided long-term carbon cycle balance is maintained.

    This is Hans’s point (#13) that, in this context, volcanic CO2 emissions have “no meaning.” But climate skeptics could argue that over shorter timescales the carbon cycle may not be well balanced and volcanic CO2 may dominate anthropogenic emissions. For this reason, I prefer to simply sum up volcanic CO2 emissions and confront them with the numbers to underscore that the probability of volcanic CO2 dominating anthropogenic CO2 year after year for during the past century is very small, even without considering offsetting carbon cycle processes.

    Terry Gerlach

    Comment by Terry Gerlach — 9 Aug 2011 @ 2:30 PM

  79. I remember watching documentary years ago about the Permian Die off called “The Day the Earth Nearly Died” (link below). The title is a bit misleading in that; it took a bit longer than a day. It starts off looking at an asteroid as the cause of the die off but moves on to the Siberian Traps.

    This Documentary had a Scientist, Paul Wignall, go to Iceland and look at the rocks from the Permian period and he found that global warming had taken approximately 40 thousand years of co2 releases from the volcanos of the Siberian Traps to lift global temperatures 4 to 5 degrees c. He went on to say that was enough to warm the oceans and allow methane hydrates to evaporate and release from the oceans to push it up another 5 degrees to kill nearly everything (total of about 80,000 years).

    My understanding of the Siberian Traps volcanos leads me to believe that they were releasing far more co2 (100,000 gigatons of carbon) than we do (8 gigatons annually) and for it to take 40,000 years of that kind of a release to lift global temperatures 4-5c means, well, we couldn’t possibly repeat that trick with our current release levels.

    What was a bit unclear is from the documentary is when his timeline starts, at the beginning of the Siberian event, middle, end; he doesn’t say.

    Anyway, it comes down to this, it took 40,000 years to raise the temperature 4-5 c at co2 release level epically larger than ours. I just don’t see how the IPCC could figure we would raise temperatures 1c in 100 years with our current release levels.

    Video embedded on this page:


    Comment by Clif Westin — 9 Aug 2011 @ 6:57 PM

  80. Possible dumb question (from possibly dumb reader – me)

    The EOS piece talks a lot about estimates. I guess that is not surprising as some of these things are pretty hard to measure.

    My question is: how reliable are the estimates?

    What are they based on? How do you estimate the CO2 from a volcano? From every volcano? Do we even know how many undersea volcanoes exist?

    How do we estimate human CO2 emissions?

    These are not rhetorical questions. I would really like to know.

    Comment by Michael J — 9 Aug 2011 @ 7:43 PM

  81. Human CO2 emissions are estimated from direct measurement of incre3asing concentration and C13 / C12 comparisons, and from knowing how much carbon we burn.

    Volcanic CO2 is reliably estimated to be a tiny fraction of this from the fact that if were anywhere near as high as CO2 produced by the carbon we burn, much 100 times as much as very dense types say, we would have been cooked before we ever evolved. We exist therefore volcanic CO2 is low.

    Oh, and for volcanic CO2 to have been similar to ours throughout earth’s history, the atmosphere would need to be far heavier than it is and the seas would be acid.

    Comment by Pete Dunkelberg — 9 Aug 2011 @ 10:12 PM

  82. #80 … estimates … estimates … estimate … estimate …

    Do you, a priori, have a basic problem with estimates? Other than repetition of said word?

    For CO2 estimates, see, for example, the IEA;

    or the EPA (for USA);

    If you don’t trust those estimates, I’d suggest that you make up your own estimates, and get your estimates published in E&E. I estimate, with p = 1.0, that E&E would gladly publish your made up estimates.

    Comment by EFS_Junior — 9 Aug 2011 @ 10:31 PM

  83. #82 (and #81)

    I don’t distrust the estimates, but I don’t (yet) know if I can trust them. If they are reliable, then that probably means they were computed from some reliable data using a reliable algorithm. I would like to know what data and what algorithm.

    e.g. We might say
    – Americans consumed ‘n’ litres of gasoline last year
    – Each ‘n’ litres of gasoline produces ‘n’ Kg of CO2
    – Therefore we know that ‘n’ Kg of CO2 was produced.

    Repeat for every major source of CO2, in every country, and we can make a pretty good estimate of human-produced CO2.

    Now that was just speculation. The actual method might be quite different. But I would like to know how we come up with the estimates for human and volcanic CO2 emissions.

    [Response: The back-of-the-envelope suggestion you make is of course done all the time to check on whether the more complete results done by someone else pass the ‘sniff test’ of reliability. Try it. The data are not hard to find. You’ll discover it is impossible for the essential point — that people completely overwhelm volcanoes — to be wrong. After that, it is just details (does it really matter if volcanoes contribute .1% vs. .2%?). And of course, that’s not even including the ancillary data (isotope ratios, etc. etc.).–eric]

    Comment by Michael J — 10 Aug 2011 @ 12:46 AM

  84. #82 – By the way, who is E&E?

    [Response: Energy and Environment, a not-actually-peer-reviewed journal.–eric]

    Comment by Michael J — 10 Aug 2011 @ 12:49 AM

  85. Hi Eric

    I don’t really have the time to redo the calculations. Truth be told, nor the inclination. Certainly to do it the way I suggested above would (I suspect) take a great deal of time, tracking down all the CO2 sources and their world-wide usage.

    The EOS article mentioned in the original post quotes a bunch of CO2 estimates to illustrate why human CO2 dwarfs Volcanic CO2. If the estimates are reliable, then the author has a very strong argument.

    The numbers are just quoted without any source info (unless I missed it). Now that may be because everybody (except me) already knows that they’re reliable. However for my own assurance, I would love to see a paper or article explaining how the estimates are produced — thus giving me confidence that they are reliable.

    Sorry if I’m repeating myself, but I’m just trying to follow this through. :-)

    Comment by Michael J — 10 Aug 2011 @ 2:12 AM

  86. #83

    First, RTFM!

    That means read the effin’ paper and supplimentary materials that are the subject of this thread, there are references to the relevant CO2 estimates for anthropogenic and volcanic emissions, how those estimates were made, etceteras.

    Second, one pillar of the scientific method is falsification, that means you will need to put up or shut up, by means of citing from the well respected peer reviewed climate science literature, that directly counter, with evidence, the numbers cited here for CO2 emissions from volcanic and anthropogenic sources.

    Third, I provided links to the IEA and EPA, methodologies and uncertainties are explicitly covered in both of those reference locations, see also, for instance, this IEA workshop titled “IEA Energy Statistics Co-operation”;

    Fourth, do your own research and then publish your own results in the well respected peer reviewed climate science literature (NOTE: E&E is most definitely NOT in that group).


    Comment by EFS_Junior — 10 Aug 2011 @ 4:44 AM

  87. I think it is worth quoting the other part of the Gerlach paper about marine volcano emissions of CO2. Current estimates of total ocean basalt production are about 3 square km per year. if CO2 emissions from under the ocean were to match fossil fuel CO2 emissions, the CO2 emissions would be the same as the total mass of basalt production. This is clearly wrong–way too much CO2.

    It might be possible to argue that the volcanic CO2 emissions vary by a factor of two or so, but that is still ~100 times less than humans.

    Comment by Mitch Lyle — 10 Aug 2011 @ 6:22 AM

  88. #86 – EFS_Junior

    I’ve clearly said something that you find offensive and I apologise for that. My intention was not to cause any harm.

    1. RTFM
    I did read the paper which was quite short. It contained many estimates, but no information about how they were arrived at.
    I didn’t read the supplemental material. (My bad).
    I’ve just read that now. It mentions CO2/3He ratios for estimating volcanic CO2. I will investigate further and try to find an explanation of how that works, if nobody here can tell me.

    2. Falsification
    I haven’t proposed any new information so it would be impossible for me to propose falsifying anything. That makes no sense.

    3. IEA and EPA
    I did quickly read the links you gave me and did not spot anything helpful. If you know they contain the information on how to compute CO2 estimates, could you please point out where?
    The new link from your last comment was a bit more helpful. It has some conversion factors for burning fossil fuels, g(CO2) per kWh. Unfortunately I still don’t know how to estimate the kWh of all the different fuel types, world-wide.

    4. Publishing
    I have no research, I am just trying to understand Mr Gerlach’s research. (Should that be Dr Gerlach?)

    I do not understand why you are so hostile to somebody asking questions. You act like I am asserting that Mr Gerlach is wrong. I am doing no such thing. I’m just trying to understand it better.

    It may be that everybody here is so familiar with CO2 emission estimates that my question seems foolish — but for me it is a valid question.

    Comment by Michael J — 10 Aug 2011 @ 9:01 AM

  89. #88 – Michael J
    In the EPA report, the methodological details are given in the “Annex” sections at the bottom. The last one, Annex 7, which is all about quantifying the uncertainty in the estimates, might be of particular interest to you.

    Comment by jkga — 10 Aug 2011 @ 10:16 AM

  90. Re #88 — understandable response to #86. Shrug off the nonsense and keep looking for the truth. It is clear you will need to do some homework (perhaps much some consider remedial, but so be it – we all start at the bottom). It may be a few years worth given the time you may have available for it, and how far you may have to go, but time well worth investing. I know from an analogous experience: I transitioned by personal interest a few years ago from a long career in physical science to medical science with interest in glucose monitoring. It ended up requiring 3 years attending scientific conferences with MDs and clinicians using words, terms and concepts I had never heard of or considered and biochemical names and process so long and complex they seemed barely comprehensible. My investment has provided me at least two things of great value: (1) I now do (at least what I my colleagues consider) significant development in that field and (2) what I learned has changed my whole attitude toward food, behavior and lifestyle. I learned what diabetes is on a personal level from testimony of those who live with Type 1 and desperately want a cure. I learned how Type 2 diabetes develops from inattention to diet, lifestyle and behavior. I learned what a terrible life changer it is to have to inject oneself with insulin daily and to prick one’s finger every few hours just to make sure you stay alive. Analogies to global climate change aside, my point of all this is simply that spending a few years studying climate science and understanding its underpinnings, its methodologies (physics and math) and its impact on our collective and individual lives and future is well worth the investment and will likely change how you view and value your life and lifestyle and of those around you.

    Comment by JG_in_SoCal — 10 Aug 2011 @ 10:39 AM

  91. Michael J, annual world-wide production figures for coal, oil and natural gas are readily available. The stuff isn’t stockpiled for a rainy day, it pretty much all gets burned in the year it’s produced, so annual consumption figures pretty well match annual production figures. Although undoubtedly not precise, they will not be off by much, certainly no where even near by an order of magnitude (factor of 10). Converting those figures into emitted CO2 based on the carbon content of each fuel is therefore a simple multiplication exercise and people do indeed make that calculation. So, calculating annual emissions of CO2 from the burning of fossil fuels is pretty straightforward. Add to that the measured proportional decline in atmospheric O2 (molecular oxygen) in lock step with the increase in CO2 and it is abundantly clear that the increase is the result of the combustion of carbon.

    Volcanic emissions of CO2, on the other hand, are far less constrained and thus less exact, but are still clearly two orders of magnitude smaller (a factor of 100). They are based on physical sampling of the gasses in actual eruption clouds (most of which by far is good-old H2O), magma and rock samples, and samples of deep sea rock and water in extrusion zones. As Mitch said, even if off by a factor of 2, or even 4, volcanic emissions would still be two orders of magnitude (factor of 100) lower than human emissions.

    It really is a slam-dunk.

    Comment by Jim Eager — 10 Aug 2011 @ 11:49 AM

  92. @88 etc.: A very rough estimate of anthro emissions from fossil fuel burning takes a few hours. You can find figures on estimated production, consumption, and emissions from major fossil fuels here. To get from the consumption to emissions figures, you need to do things like estimate what proportion of the fuel in question is eventually burned and how much of it is carbon. This is not always straightforward. For example, you need to know whether the consumption figure for coal is of raw coal, washed coal, or washed and dried coal. It makes a big difference, because raw coal can contain ~13% moisture and 12% “ash” (clay, etc.). Similarly for natural gas, which isn’t all CH4, and whose industry-standard measure (“cubic feet” — ha!) needs to be converted into something useful, like moles of carbon.

    I haven’t tried a back-of-the-envelope calculation for anthro CO2 emissions from land-use changes, which has got to be much more difficult than for fossil fuel burning. You could examine how the IPCC estimated total anthro CO2 emissions, which has cites to all its sources.

    As to source reliability, you can at least cross-check multiple sources (for example, this is an alternative to EIA’s coal stats). You could also estimate coal production by examining shippers’ stats (e.g., railroad and surface ship), and consumption by examining electric utility and steel producer stats.

    CAPTCHA: W-algebra urpfork

    Comment by Meow — 10 Aug 2011 @ 12:11 PM

  93. #89, 90 and 91 – Thanks for taking the time to make constructive replies. You have given me quite a bit to digest. I don’t want to recompute every estimate, just to get a better feel for how the estimates are computed so I have a bit of confidence.

    If you look ’round the internet there are many people quoting estimates of CO2 and of many other things. Clearly they’re not all right. :-)

    Anyway, I’ve got some work to do.

    Comment by Michael J — 10 Aug 2011 @ 3:23 PM

  94. In reference to comment 79 on Permian rocks in Iceland.
    Iceland is very young, in geological terms. The oldest parts (according to are just listed as over 3 million years old.
    The Permian Extinction was over 200 million years ago.
    Iceland is definitely not the place to look for evidence of the Permian extinction.

    Comment by Randy Ross — 10 Aug 2011 @ 3:41 PM

  95. > just listed as over 3 million years old.

    Looking into that, it says “older than 3 million years” in the caption here:

    The focus of the article Randy Ross quotes is on the volcanic rock that formed what we now call Iceland, not on the ocean sediments around it:
    “… the age of Iceland’s rocks and lava flows depend on their position on the island. Because of the sea-floor spreading, in the Northwest and in the East of Iceland rocks are older than along the Mid-Atlantic ridge which is situated in the middle. …”

    Elsewhere on the subject, I found

    “Paul Wignall from the University of Leeds in the UK examined the marine fossil record in Iceland from the Permian era.”

    I’d guess the confusion is because the marine sediments predate the relatively recent volcanos that form what we now call Iceland.

    Comment by Hank Roberts — 10 Aug 2011 @ 3:52 PM

  96. @Michael J
    For all countries under the Kyoto Protocol there is a very strict reporting system with a lot of international reviews for each country.
    The yearly report for my country has more then 700 pages – I don’t think, you would like to read this ;).
    The greatest part of the emissions of CO2 is calculated from fossile fuels with conversion factors. But there are a lot of other emissions (eg. land use change, production of lime, use of solvents, incineration of waste) of CO2 and the other gases. You get not only sums but also emissions for different sources (traffic, households, industry…).

    Most fuels are standardized (you don’t want to buy fuel, that gives you less energy then what you paid for), so the conversion factor for a specific product is precisly known. The numbers are cross-checked with other methods (eg. energy needed to heat houses, energy per produced ton of steel, kms driven by cars and trucks).

    Under the Kyoto Protocol you can be quite sure, that no country will report to much CO2, because it will have to pay for the excess.

    Comment by indri — 10 Aug 2011 @ 4:14 PM

  97. @ Michael J
    (and for what it is worth): I just did a 5 minute calculation – went to Wikipedia, found that world energy consumption is 5 TW (power) of which 85% is from carbon-based fuels (from graphs), which translates to ~ 40,000 Tw-hrs (energy; need hrs per year). Using a shortcut etimate I know in my head 33 KWhrs in 1 gallon gasoline (I own a Leaf!). Since within a factor of 2 or 3 carbon-based fuels are fairly equal when it comes to CO2 production and 1 gallon of gasoline produces about 20 lbs of CO2 (thank you Google), I calculate a human emission of 10^10 tons/yr (within a factor of 2 or 3). I then Googled volcanic CO2 production and got 2 x 10^8 tons/yr. So, to an order of magnitude (factor of 3 or so AND assuming I’ve done my arithmetic correctly) Human:natural = 100:2. Natural CO2 is only ~ 2% of the yearly production, which I believe is in line with what the more detailed calcualtions provide. It took longer to write up this text than to do the calculation. But, little mater since I’ve got some experience in such matters – you should consider the simple process by which I found the data and arrived at the result … and that I compared that result with more rigorous calculations. My conclusion is that the inferences drawn from rigorous calculations are worth considering. You now might want to study a bit about the CO2 iosoptic anomaly perspective to see what that says about how the ocean and biosphere transpire CO2. This task will bring you another step into realm of the complexity and wonder of our atmosphere.

    Comment by JG_in_SoCal — 10 Aug 2011 @ 5:42 PM

  98. #79 (Clif Westin)
    I watched your video and skimmed through the transcript (thanks for providing these). Both sources say that Paul Wignall did his fieldwork in Greenland, not Iceland (as your post states). This unfortunate error misled Randy Ross and Hank Roberts to make ‘false alarm’ posts (#94 and #95).

    The video does correlate the mass extinction at the end of the Permian with the 40,000 years of intermittent continental flood basalts eruptions from volcanism in the Siberian Traps. This much is mainly fact. Then, Wignall infers that CO2 released from the basalts increased atmospheric CO2 sufficiently to cause a 4-5 degree C temperature rise and trigger the breakdown of methane hydrates——a positive feedback effect that supposedly added another 5 degrees to the temperature rise and enhanced the extinction to include an impressive 95 percent of all living species. This is not mainly fact; it is mainly interpretation. It will serve as a useful working hypothesis for future research to confirm or disprove, but it is not yet an established fact, as far as I know. Your post, however, seems to assume that the inferred CO2 release from the basalts did in fact cause a 4-5 degree C temperature rise. I don’t think that was established at the time the video was made. Perhaps you know of subsequent studies that established it.

    Here’s what I would like to know: You say, “My understanding of the Siberian Traps volcanoes leads me to believe that they were releasing far more CO2 (100,000 gigatons of carbon) than we do…” Is this 100,000 gigatons total carbon for the entire 40,000 years, or is it an average per year estimate of 100,000 Gt carbon? The video makes no mention of a 100,000-Gt carbon release from the basalts of the Siberian Traps. So, where does this number come from? Is it from a published study? If so, please give the reference. If it is your number, how did you arrive at it? How much basalt was involved and what was its weight-percent pre-degassing CO2 content?

    Comment by Terry Gerlach — 10 Aug 2011 @ 7:59 PM

  99. #94 Yup, sorry, misprint, it was Greenland. ” Wignall suspected all the explanations for the extinction had been based on insufficient data. He also knew there was one place he might find more: Greenland. It’s a country known to contain Permian rock, but always considered too difficult to explore. In the late 1990s he took a gamble and flew out there.”

    Any thoughts on his findings?

    Comment by Clif Westin — 10 Aug 2011 @ 8:01 PM

  100. #98 Q: Is this 100,000 gigatons total carbon for the entire 40,000 years, or is it an average per year estimate of 100,000 Gt carbon? The video makes no mention of a 100,000-Gt carbon release from the basalts of the Siberian Traps. So, where does this number come from? Is it from a published study? If so, please give the reference. If it is your number, how did you arrive at it? How much basalt was involved and what was its weight-percent pre-degassing CO2 content?”

    I went looking to find out how much was released and found a couple of sources that gave me a number. I, too, don’t know the duration, I’m asking. Here’s one place I found it (obviously not definitive, and not the original sites, you can never find them when you need them) They might reference a source in there. (in my best Dr. McCoy “I’m an engineer darn it, not a climate scientist!) The amount of basalt is stated as roughly the size of the US and about 8 miles thick (if memory serves and from other sources)…so, a lot? I would suggest reaching out to Wignall, he’s at Leeds isn’t he?

    Comment by Clif Westin — 10 Aug 2011 @ 8:22 PM

  101. Form my post #79 Sorry for my misprint, I apologize to all who went on a wild goose chase.

    Comment by Clif Westin — 10 Aug 2011 @ 8:25 PM

  102. I found this review paper from 2009; it cites the Svensmark, together with other work. They are talking about annual emissions from the volcanoes of around .03 GT/yr, as compared with current emissions of about 7 GT/yr.

    Comment by Kevin McKinney — 10 Aug 2011 @ 10:23 PM

  103. Is it only me or do other people find it deeply disturbing that this debate is still stuck in a mire of misinformation? Two and three decades on and still on this same roundabout of refuting blatant lies and misinformation.

    Comment by Ken Fabos — 11 Aug 2011 @ 2:31 AM

  104. The volcano source of current CO2 has always been nonsense, as badly proposed by anti-climate change goons of geology. If average volcano activity is a major contributor to the rapid rise of CO2 in the last century, then the onus is on them to explain why all life on earth has not already been smothered in a green-house effect, during earlier increased volcanic activity periods. If volanos actually did contribute more signficantly, but not quite enough to smother all life on earth, then additional human contributions are even more deadly. Since we are all here, a mechanism to remove atmosphere CO2 faster might also be required to balance extra volcano output. Extra volcanic output would also mean an increased need to restrict human industrial output even more than previously thought. Its just as well that volcano contribution is tiny compared to human activities.

    Comment by Michael Rynn — 11 Aug 2011 @ 4:53 AM

  105. Clif Westin #100: Your link says “In all, the volcano may have belched as much as 100,000 gigatons of carbon into the air …” so that’s either 2.5GT/year if we use the 40,000 year number, or 0.5GT per year if we use the 200,000 year number in the article. In either case, substantially less annually than our 8GT/year infusion.

    Comment by Jan Rooth — 11 Aug 2011 @ 3:26 PM

  106. And note … the source of that carbon was not the volcano itself, but fossil carbon burned in the lava flows.

    Comment by Jan Rooth — 11 Aug 2011 @ 3:28 PM

  107. Jan Rooth #105: Yup, could very well be. I was asking for some milestones in there too. All in all, there’s an event that could have lead to a massive global warming event that killed off most life on the plant. So there’s something to look at and potentially model if all the variable can be determined. That timeline is key I would suspect. Probably be best to get a hold of Dr. Wignall, he’s at Leeds. I assume he has more work and data then was presented in the documentary, I’d like to know more about this event, because that outcome, which has happened once, can tell us a lot about what’s about to happen and, specifically, when if we can get enough level of detail.

    Comment by Clif Westin — 11 Aug 2011 @ 10:10 PM

  108. For Clif Westin:

    Start here:
    Put in some likely search terms from your sources you’ve mentioned above.
    You’ll find quite a few models have some relevance to your question.
    Note you can limit the start year of the period searched, which lets you leave out older papers that may be less useful.

    Comment by Hank Roberts — 12 Aug 2011 @ 12:26 AM

  109. #103–

    It’s not just you. This is deeply dispiriting–but like I keep saying, despair is not adaptive.

    Comment by Kevin McKinney — 12 Aug 2011 @ 8:43 AM

  110. #104–ah, but that’s their point: since, obviously, life wasn’t smothered by all that (mythical) CO2, that must mean that the physics that says that’s what should have happened ‘must’ be wrong.

    ‘Course, since it’s all counter-factual in the first place. . .

    Comment by Kevin McKinney — 12 Aug 2011 @ 8:45 AM

  111. “ that was published in the journal Nature in 1997 that looked at the connection between the change in the rate of sea level rise and volcanic activity in the Mediterranean for the past 80,000 years and found that when sea level rose quickly, more volcanic eruptions occurred, increasing by a whopping 300 percent.”

    Comment by prokaryotes — 13 Aug 2011 @ 10:57 PM

  112. When is it predicted that oceans will stop absorbing CO2? How hot will it have to get? Or will increased atmospheric concentrations always drive CO2 into rather than out of the water?

    Could future volcanic eruptions play a role in these dynamics?

    (reCaptcha sadyocc John)

    Comment by wili — 15 Aug 2011 @ 10:27 PM

  113. Re wili, i wonder too, and found this recent item…

    Climate change reducing ocean’s carbon dioxide uptake

    In a new analysis published online July 10 in Nature Geoscience, McKinley and her colleagues identify a likely source of many of those inconsistencies and provide some of the first observational evidence that climate change is negatively impacting the ocean carbon sink.

    “The ocean is taking up less carbon because of the warming caused by the carbon in the atmosphere,” says McKinley, an assistant professor of atmospheric and oceanic sciences and a member of the Center for Climatic Research in the Nelson Institute for Environmental Studies.

    Comment by prokaryotes — 15 Aug 2011 @ 11:51 PM

  114. Thank, pro. There seem to be (at least) two factors here:
    the increase in temperature reducing the amount of CO2 the water can absorb, and
    the increase in concentration of CO2 in the water (at whatever temp)

    What I am wondering now is whether there is a saturation point at which water will absorb no more CO2 no matter how high the CO2 concentration is in the atmosphere above it (and at whatever temperature you want to choose).

    And how much can we depend on overturn to take some of this CO2 saturated water down into the depths?

    Comment by wili — 16 Aug 2011 @ 11:41 AM

  115. > wondering if there is a saturation point ….

    Not soon enough to matter to us at the rate we’re changing it.
    Each previous great extinction has reached some stopping point eventually.

    Perhaps you’ve heard this phrase?
    “Death is nature’s way of telling you to slow down.”

    Comment by Hank Roberts — 16 Aug 2011 @ 12:46 PM

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