El Nino’s effect on CO2 causes confusion about CO2’s role for climate change

The extraordinary claims about the relationship between temperature, CO2, and human activity made in Humlum et al. (2012) also makes me think of a Carl Sagan citation: “Extraordinary claims require extraordinary evidence”. I must say I’m disappointed by the reviewing process of Global Planetary Change and this is the second (Humlum et al., 2011) unpersuasive paper in that journal making such bold claims.

Earth shattering claims should meet rigorous evaluations. It would be useful for reviewers to google the authors of the papers, as some do have quite a track record of well-established mistakes (here and here and here and here).

In addition to failing the analytical set-up and the physics (which should have been picked up), they also provided some unusual citations, missed important works, and referred to questionable publications.

Furthermore, using the NOAA ESRL CO2 data, Humlum et al. could have sought advice with the data providers before submitting their paper (the ESRL is not mentioned in their acknowledgement, and I wonder if they would have a view on this analysis). Indeed, the ESRL encourages such quality checks according to the heading of the data file:

If the data are obtained for potential use in a publication or presentation, ESRL should be informed at the outset of the nature of this work. If the ESRL data are essential to the work, or if an important result or conclusion depends on the ESRL data, co-authorship may be appropriate. This should be discussed at an early stage in the work. Manuscripts using the ESRL data should be sent to ESRL for review before they are submitted for publication so we can insure that the quality and limitations of the data are accurately represented.

I also wonder what the affiliated universities think about Humlum et al.s work and their past record, and I think misguided work, as presented here, is not exactly good advertisement. Furthermore, they are also involved with an organisation called “klimarealistene” (with collaborations with the Heartland Institute), which claims that the IPCC has ‘cheated‘ in terms of the temperature data (which ironically, they themselves rely on in Humlum et al. (2012)) and produced the ‘famous hockey stick’ (The people thanked in the acknowledgement reads like who-is-who within “klimarealistene”).

A good thing is that Humlum et al. now have obliged themselves to share their data, results and methods by using the CO2 data from NOAA:

RECIPROCITY – Use of these data implies an agreement to reciprocate. Laboratories making similar measurements agree to make their own data available to the general public and to the scientific community in an equally complete and easily accessible form. Modelers are encouraged to make available to the community, upon request, their own tools used in the interpretation of the ESRL data, namely well documented model code, transport fields, and additional information necessary for other scientists to repeat the work and to run modified versions. Model availability includes collaborative support for new users of the models.

I’ve asked them to share their results, data and methods before, but so far with little success. My job as a climate scientist is to replicate results. Further progress may take place if we can go through the analysis together, test methods and data, and agree on which give robust answers and which don’t.

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References

  1. O. Humlum, K. Stordahl, and J. Solheim, "The phase relation between atmospheric carbon dioxide and global temperature", Global and Planetary Change, vol. 100, pp. 51-69, 2013. http://dx.doi.org/10.1016/j.gloplacha.2012.08.008
  2. O. Humlum, J. Solheim, and K. Stordahl, "Identifying natural contributions to late Holocene climate change", Global and Planetary Change, vol. 79, pp. 145-156, 2011. http://dx.doi.org/10.1016/j.gloplacha.2011.09.005

66 comments on this post.
  1. Jim Larsen:

    46 sbripman, that was the nicest thing I’ve ever seen posted on the internet. Your spouse is very lucky.

  2. R. Pardi:

    The problem with Humlum et al.’s paper starts right at the beginning with their hypothesis and methods. Rather than revealing the underlying trends in the (CO2 and temperature) data (their stated goal) their mathematical manipulations actually removed those trends. What their methods did reveal are secondary signals superimposed as those long-term trends of increasing CO2 and temperature. The phase relationships of the secondary signals – the gist of their further analyses – don’t necessarily tell you anything about the phase relationships of the underlying trends. Those secondary signals are, in fact, feedback signals, and, as such, the secondary temperature signal must always precede the CO2 signal. Because the limits of the period analyzed leave us out on an essentially linear (if you were able to successfully remove all the “noise”) “limb” of the modern CO2-temperature episode, it would not be possible to establish the phase relationship of the underlying signals – you would need to “see” either the starts or the peaks of the two signals to determine that phase relationship – exactly what has been done in the case of the paleo data.
    What is unfortunate is that there may well be something interesting lurking in the results of this type of analyses. If the peer-review process had worked properly in this case, the authors might have been challenged (admittedly not likely given their apparent prejudices) to defend their methods and, as such, may have come to see the basic flaw in their logic, remove their erroneous conclusions, explore the valid implications of their results and reveal something worthwhile about the Real Climate.

  3. Jim Larsen:

    I would like to see the graphs scaled at the estimated immediate response climate sensitivity rate. If Xppm rise in CO2 should result in YC increase, then it would be useful for them to be of the same visual size. I’m suspecting that if that were done, the CO2 curves would be much smaller. If so, then CO2 simply can’t drive temperature at these time scales, and the result is pre-ordained?

  4. Stuart:

    “Scientists here and elsewhere have stressed that regional results are wicked hard to predict.”

    “Science and geography is great combination to explain this issue.”

    As a non-climate scientist, I occasionally turn to turn to climate science literature to see what specific regional predictions are being made that may be relevant to my own line of work (fish systematics and zoogeography). Consequently, I have seen the sentiment expressed in the two preceding quotes appear often on this website.

    Although my limited reading of the primary climate science literture makes clear that there is a rich and abundant literature using time frequency and phase effects from climate relevant physical observations (ie temporal autocorrelation), I see much less use and detailed discussion of spatial autocorrelation among such contributions. While presumably the “difficulty” in making predictions is do at least in part to the well known phenomenon that slight change in boundary conditions can dramatically affect the magnitude and even direction of solutions to differential equations, this particular discussion prompts a more general question of exactly how do climate scientists attempt to statistically correct for obvious asymmetries in planetary regionality imposed on climate models by positional effects of highly irregular terrestrial and oceanic boundaries?

    Pointers to how climate scientists take into account spatial effects and specific results that demonstrate how statistical methods sensitive to and correcting for spatial effects have been used to address this issue would be appreciated. Perhaps a more roust discussion of spatial effects might well better elucidate cause and effect among measured variables on a regional, if not global scale.

  5. Jonathan Teller-Elsberg:

    As an academic note, I don’t like the NOAA ESRL policy statement you quote:

    “If the data are obtained for potential use in a publication or presentation, ESRL should be informed at the outset of the nature of this work. If the ESRL data are essential to the work, or if an important result or conclusion depends on the ESRL data, co-authorship may be appropriate. This should be discussed at an early stage in the work. Manuscripts using the ESRL data should be sent to ESRL for review before they are submitted for publication so we can insure that the quality and limitations of the data are accurately represented.”

    Data is data. I think it’s fine for ESRL to be listed as a coauthor if their data is essential to the paper, but I do not think it’s fine that they should act as gatekeepers for the use of their data in general–which they seek to do when they say they should review papers prior to submission. Is it a good idea for a researcher to get ESRL’s input on whether things are working out? Sure. But should the researcher be obligated to get ESRL’s input? No way.

    [Response: I agree. If data are online they are usable by anybody as long as they are properly cited. There are of course many mistakes that can be made and these can often be prevented by talking to the data originators, but pre-review and publication veto power are inappropriate. I’m a little surprised at this statement though – I know of nothing similar in other climate data repositories. – gavin]

  6. Rod:

    I’m surprised the Humlum paper wasn’t published in E&E. Surely that journal’s overdue for another corker.

  7. Steve Fish:

    Gavin:

    A question about your response to Jonathan Teller-Elsberg (30 Sep 2012 @ 8:03 PM). Is your concern about the NOAA ESRL policy due to the fact that they make their data available to all up front? For example, would you object if agreement to their policy was required prior to access to data in the first place, or do you think that any publicly funded original data source should release data unfettered immediately upon its collection?

    I favor the idea of free access, but don’t know what other important factors may be at play.

    Steve

    [Response: Not sure what you mean. I think it’s great that they make data available up-front and they should continue to do so. There is a quite widespread feeling among data originators that doing so will allow other people who don’t know what they are doing to mis-use it (and that certainly happens), which is why a policy statement like the one for ESRL was written. However, I think that is pretty much unenforceable and not sensible in the first case – people don’t have time to do the research that they want to do, let alone vet everyone else’s screw-ups. So the alternative is to simply let the data out into the wild and rely on the peer-review process (or post publication review process) to weed out the more dubious uses (and that mostly works out). – gavin]

  8. Steve Fish:

    Gavin (1 Oct 2012 @ 10:04 AM):

    Thanks.

    Steve

  9. Hank Roberts:

    > people who don’t know what they are doing to mis-use it

    Maintainers of web pages where data sets are publicly available could coordinate a moderated response to that.

    If maintainers would provide a recognizable consistent button — next to the data ‘download’ button — they could have _available_ to, as time allowed, accumulate references/links/comments on published (or blogged) claims that supposedly relied on the data set.

    Moderated so the septics wouldn’t use it for advertising.
    Basically — not saying _do_ a lot of work, but just do what “hypertext” was supposed to do for us, give one list of pointers right next to the source, “this data referenced in”
    ——

    Simpler:

    Does Google Scholar’s “cited by” button work for published data?

    It should.

    Maybe with a rating icon, for stuff not peer reviewed.

  10. Jim Larsen:

    “So the alternative is to simply let the data out into the wild and rely on the peer-review process (or post publication review process) to weed out the more dubious uses (and that mostly works out). – gavin]”

    Well, sure, assuming you don’t care about reality. Peer-reviewed = minor player. Watts can play with some data and he will have far more influence than any three peer-reviewed scientists.

    [Response: You can’t expect a few thousand scientists to act as policeman of truth for the whole world. The answer to bad information is better information – and that is the only sustainable long term strategy. – gavin]

  11. Ray Ladbury:

    Jim Larsen: “Peer-reviewed = minor player.”

    This is simply not true. Science is STILL the best guide to truth about nature–and truth eventually prevails. I would rather scientists go about generating science and allow laymen who care about science to inform idiots of their idiocy.

  12. t marvell:

    I wish someone would give a link to the full Humlum paper, such that people not in the field don’t have to pay $40.

    It looks like the well-known sitaution where temperature affects CO2 levels in the short term (several months), and CO2 affects temperature over the long term (years to decades). It’s possible to separate the effects statistically, and there is no doubt that the latter effect swamps the former.

  13. Hank Roberts:

    > The answer to bad information is better information

    We may fervently hope so.

    The alternative answer is the epitaph for democracies:

    “You can fool enough of the people enough of the time.”

  14. Unsettled Scientist:

    > I wish someone would give a link to the full Humlum paper, such that people not in the field don’t have to pay $40.

    Google (scholar) is your friend, just search for the title and grab the PDF.

    http://scholar.google.com

    Type in “The phase relation between atmospheric carbon dioxide and global temperature”

    Press Enter key.

    You ready for 37 pages of what everyone deems is a bad paper? Personally I’d spend my time reading the more important papers.

  15. Jim Larsen:

    Gavin said, “You can’t expect a few thousand scientists to act as policeman of truth ”

    Yep, I agree. This isn’t a fair fight, and scientists have been thrust into roles which are diametrically opposed to their chosen life paths. Asking a scientist to out-politician a politician is durn near futile and unfair to boot, but when the stakes are so high, you take your best shot, and if that slows the science a tad, then the question is which is more important. This blog is a grand example of your walking my talk.

    However, I think the window for scientists to help via “convincing the world” is about over, so I’m crying about spilt milk. The Arctic sea ice will continue to degrade, and Antarctica and Greenland are being closely monitored too. I’d guess we’re one US presidential election cycle from climate change being a core issue.

  16. t marvell:

    thank you Unsettled Scientist for the source, which I should have tried anyway.
    About reading the article – the journal Global and Planetary Change seems to be respectable and the paper was peer reviewed. At least it should be answered in a comparable way.