Ahh McLean, you’ve done it again

John McLean, the guy who kept guiding Andrew Bolt off cliffs, has this time taken Bob Carter and Chris de Freitas with him. As tamino explains, they say that recent warming trends can be attributed to natural variation, but their analysis removed the trend from the data. See also McLean’s defence and Robert Grumbine’s lucid post. James Annan exposes another error – they fit a step function to that data and conclude that there is step in the data merely because there is a step in the fitted step function. John Lott made the same mistake in his “more guns, less crime” argument, as I showed here.

McLean et al needs to be added to the list of the worst climate papers published in proper journals.

Comments

  1. #1 Oakden Wolf
    July 29, 2009

    I commented that this paper needs a quick takedown; fortunately it’s being promised.

    Watershed: the McLean, de Freitas, and Carter paper

    Others are indicating the same general tenor:

    McLean, de Freitas, Carter paper update

  2. #2 John Surname
    July 29, 2009

    “…their analysis” you mean. *[Yes. Tim]*

  3. #3 Billy Bob Hall
    July 29, 2009

    Well summarized Oakden Wolf

    ‘Watershed: the McLean, de Freitas, and Carter paper’.

    Let’s see what happens next. Can I have some popcorn too ? :-)

  4. #4 John Cook
    July 29, 2009

    Getting on the McLean bashing bandwagon, I’ve just posted a
    Skeptical Science take on McLean’s El Nino paper plus a look at other peer reviewed papers on El Nino and the temperature record.

  5. #5 Dave Andrews
    July 29, 2009

    If the Mclean et al paper is as bad as you say, how did it manage to get published in a reputable Journal and what does this say about the quality of peer review in the field of climate change?

  6. #6 sod
    July 29, 2009

    If the Mclean et al paper is as bad as you say, how did it manage to get published in a reputable Journal and what does this say about the quality of peer review in the field of climate change?

    if the quality of peer review is as bad as you assume, what does this say about all those denialist papers that can t even pass it?

    apart from that, the worst claims based on this paper were not made in the paper itself, but in the press release, in statements by the authors and in the denialist blogosphere/media.

    a typical denialist approach: misrepresent weak findings in peer reviewed papers to support wild denialist theories, without any supporting evidence in the paper.

    there are several good explanations on the web, that could explain how this assortment of wild errors could slip through peer review. but we ll have to wait a little, to confirm them.

    meanwhile the authors have already retreated from the majority of their wild claims, and it will be interesting to see how the paper handles the errors.

  7. #7 Robert Grumbine
    July 29, 2009

    @5
    To quote my wife, “It’s peer review, not God review.”

    She’s not a scientist, but that elementary aspect of peer review process did not escape her. See the article for more about peer review (written by a scientist).

    Actually, though, I think it speaks to a different matter. And a pretty good example. Namely, there is a constant whinge that papers ‘critical of the consensus’ don’t get published. Obviously, one did. Had it been claiming to support the consensus, instead of disagreeing, it would have been bounced on sight. It was obviously terribly flawed. It’s about the best that McLean and co. can do in their ‘criticism’ of the consensus, but … whew.

  8. #8 Billy Bob Hall
    July 29, 2009

    All a bit quiet here on this one my ‘warmist’ friends ? Has McLean et al ‘taken the wind out of your sails’ with this paper ?
    Or was it me the last couple of days on the Piers thing ? ;-)
    Oh, just kidding guys.. no need to get upset :-)

  9. #9 Nils Ross
    July 29, 2009

    On the subject of criticising papers that pass peer review, denialists should know that scientists do this a lot. Peer review doesn’t catch everything, new data becomes available, better models are proposed, and so forth. The only requirement for such criticism is that it be well grounded in reason, and, where possible, cite evidence.

    This is the crux of scientists’ objections to typical denialist criticisms: they are (exclusively to date, in this debate) based on false premises, and often simultaneously follow flawed logic to arrive at their conclusions.

    Almost every person on the planet would heave a sigh of relief if someone could present convincing evidence that the AGW model was flawed (provided that evidence also suggested a sensible replacement model for the effects of CO2, methane, etc on climate), scientists included. The point is being pushed because it’s what the evidence suggests, and no one has been able to show any different.

  10. #10 Bernard J.
    July 30, 2009

    BBH trolls:

    All a bit quiet here on this one my ‘warmist’ friends ? Has McLean et al ‘taken the wind out of your sails’ with this paper ?

    Obviously the boy hasn’t followed any links, or he would know that [Tamino at Open Mind](http://tamino.wordpress.com/2009/07/24/old-news/), [Robert Grumbine](http://moregrumbinescience.blogspot.com/2009/07/how-not-to-analyze-climate-data.html), [Real Climate](http://www.realclimate.org/index.php/archives/2009/07/friday-round-up-3/), [John Cook at Skeptical Science](http://www.skepticalscience.com/Global-warming-and-the-El-Nino-Southern-Oscillation.html), amongst others, have well and truly gutted the McLean et al nonsense.

    There is chatter all over the Interweb regarding this paper, but it is flattering to the rest of us here that BBH thinks that the quietness on Deltoid regarding McLean et al indicates that the climatology world has not responded. However, BBH is wrong.

    Dave Andrews thinks that he has cornered a flaw in the peer review process of science:

    If the Mclean et al paper is as bad as you say, how did it manage to get published in a reputable Journal and what does this say about the quality of peer review in the field of climate change?

    but he doesn’t seem to realise that the journal in question, J. Geophys. Res., has [past form](http://www.nzherald.co.nz/climate-change/news/article.cfm?c_id=26&objectid=3516830) in letting the occasional poor-quality paper through. There must be many in the field wondering if the current fiasco indicates a lingering effect of de Freitas’ former editorial influence.

    It’s hardly cause for a critique of all climatological peer review, and if Dave Andrews thinks otherwise, he should expand here on his reasoning, post haste.

  11. #11 Donald Oats
    July 30, 2009

    The paper presents an argument constructed from some simple statistics. The conclusion makes a few waffley remarks. A reviewer may decide that they don’t agree with the argument or its conclusions, but it is worth publication anyway.

    After publication, other scientists read it and pull the argument apart to see just how well the argument holds up. There will be some disagreement about which parts are weak and which parts are robust, but generally scientists will reach a consensus, one that they are each led to by the logical analysis they’ve done on the paper’s argument and data.

    And then a few scientists submit response articles or letters in which they criticise or support the argument of the paper.

    That’s science in motion.

    The fact that this paper of Carter et al was published is interesting because it demonstrates that scientists who do not accept AGW as a theory may posit alternatives in the mainstream scientific media – this is in stark contrast to claims of censorship so often levelled at the mainstream scientific media. So; are these three authors now a part of the club of scientists, who argue about AGW, so they can get grants to do more of the same? Surely they are, if they are publishing in the mainstream scientific media.

    Science in motion…

    What will be interesting is to see if a) a heck of a good demolition of the paper is itself published (soon?) in the scientific literature; and, b) journalists latch onto this response article with the same vigour as they did to the three amigos article.

  12. #12 Mark
    July 30, 2009

    > The paper presents an argument constructed from some simple statistics. The conclusion makes a few waffley remarks. A reviewer may decide that they don’t agree with the argument or its conclusions, but it is worth publication anyway

    Remember, they will sell more copies of their journal too.

    Which is nice…

    PS Billy, where were you on the DMCA takedown thread? Cat got your tongue there?

  13. #13 Billy Bob Hall
    July 30, 2009

    No worries Mark, I have not been following this one, but I will now that you think it’s important. (Sorry I cannot keep up…some of us have work to do too you know…. ;-))

  14. #14 Mark
    July 30, 2009

    > Sorry I cannot keep up…some of us have work to do too you know…. ;-))

    > Posted by: Billy Bob Hall

    That’s OK: Phillip Morris WANTS you to post denialist crud, so don’t mind you doing it during work time there.

  15. #15 Barton Paul Levenson
    July 30, 2009

    Billy Bob writes:

    All a bit quiet here on this one my ‘warmist’ friends ? Has McLean et al ‘taken the wind out of your sails’ with this paper ?

    Not even remotely. The paper is worthless and never should have been published. They compared their SOI informtion to the first time derivative of the temperature anomalies–which wiped out the trend! Their conclusion that it is the sun and ocean cycles which drive global warming and not CO2 are therefore completely unjustified. They’re essentially saying, “If you take out the trend, there’s no relation between carbon dioxide and the trend.” Duh.

    More here:

    http://tamino.wordpress.com/2009/07/24/old-news/

  16. #16 cohenite
    July 30, 2009

    Yes, yes a very competent man is Tamino and he has laid bare the terrible statistical deficiencies of poor McLean, Carter and de Freitas. Back in the real world the very pertinent issue of a cumulative SOI/ENSO effect on temperature trend remains; a good treatment of this issue is here;

    http://wattsupwiththat.com/2009/07/27/why-regression-analysis-fails-to-capture-the-aftereffects-of-el-nino-events/#more-9594

    Any of you genuises care to definitively state that SOI/ENSO has no effect on trend at all.

  17. #17 sod
    July 30, 2009

    Any of you genuises care to definitively state that SOI/ENSO has no effect on trend at all.

    Enso obviously has a massive effect on the short term “climate trends” that you folks prefer.

    in the long run, the Enso effect is obviously zero. real new energy has to be added, to change the long term trend. Enso is just moving energy around. it does not generate new additional energy.

    the Tisdale article you linked to, is extremely unconvincing. it does not tell us, what mechanism increases Enso activity, and where the energy comes from. a funny but useless analysis.

    better stick to cosmic ray. they could, at least in theory, change the long term global temperature.

  18. #18 Mark
    July 30, 2009

    “Any of you genuises care to definitively state that SOI/ENSO has no effect on trend at all.

    Posted by: cohenite”

    As sod says: prove to us that ENSO introduce new energy into the system that wasn’t there before.

    If you can’t, it’s not a climate trend. It’s a modifier of climate.

    Rather like walking up steps: each step goes up and along. But the along bit isn’t the trend. The trend is upward. The bit that goes up isn’t the trend. The trend is forward. If this were not so, the steps would not be “steps” but “a path” or “a ladder”.

    So where is the force on the climate that produces a trend from ENSO?

    If there isn’t one, then ENSO has no effect on the climate TREND.

    But, maybe you’re not a doofus as you appear but secretly a genius and answering that will be easy for you.

    Go ahead.

  19. #19 Mark
    July 30, 2009

    > They compared their SOI informtion to the first time derivative of the temperature anomalies–which wiped out the trend!

    It wipes out any trend more than one year’s worth.

    I.e. if the trend is 2C per century, this method will see only 0.02C change.

    0.02 << 2

  20. #20 John Mashey
    July 30, 2009

    Peer review: again, I point at how to learn about science, whose Great Wall analogy I’d extend by saying:

    a) When extending the Wall, there’s always dust thrown up at the leading where the construction is going on. That’s normal science, although it sometimes verges on non-science (or fuzzy-science) or something, when onlookers over-interpret an early paper.

    b) Those operating the anti-science Smog Machine (h/t DeSmogBlog) try to obscure the Wall from onlookers.

    Someone doing pseudoscience or anti-science may attempt to establish a brick elsewhere that invalidates the whole Wall, either for that purpose or to promote their own idea.

    It may well be pulverized within a day or two. The worse the paper is, the less likely that a professional will take the time to write a serious refutation and get it published, which is not guaranteed anyway, as such papers are often “not interesting”.

    But anti-science will cite the brick forever…l.

  21. #21 Deep Climate
    July 30, 2009

    This Canadian perspective may be of interest.

    http://deepclimate.org/2009/07/30/is-enso-responsible-for-recent-global-warming-no/

    Here’s the concluding summary:

    * The McLean, de Freitas and Carter paper presented unsubstantiated conclusions that are contradicted by a cursory analysis of the very data presented.
    * There is widespread agreement among climate scientists that this paper should not have passed review and should not have been accepted for publication.
    * The authors actively participated in a deceptive public relations campaign that trumpeted and exaggerated the paper’s claims, a campaign that even substituted a press release headline for the true title of the paper.
    * The authors permitted an egregious breach of copyright in the dissemination of the paper in its published form at the New Zealand Climate Science Coalition website.

    What more is needed to prod the AGU and the Journal of Geophysical Research to do the right thing? The paper should be withdrawn, and the editor responsible disciplined. Now.

    In explanation of the third point (for those who won’t wade through the whole post):

    http://deepclimate.files.wordpress.com/2009/07/icsc-july-26-short-2.jpg

    That’s right – according to the International Climate Science Coalition website, the title of the paper was – wait for it:

    “Nature not Man responsible for recent global warming”.

    Well, that’s one way to sneak a preferred title past reviewers.

    By the way, I found a longer quote from John McLean in the Australian version of the press release, than made it into the original NZCSC/Climate Depot “presser”. He actually claims that climate scientists just need to properly model ENSO, and then the need for “human” influence will disappear (full quote in the post)!

  22. #22 cohenite
    July 30, 2009

    So I can put down sod and Mark as no shows for the SOI/ENSO creates a trend view. The zero energy/ shuffling deck-chairs explanation for the no trend over the “longer” period seems to have at least one large gap; variation in cloud cover; that is, was there reduced cloud cover post 1976 so as to allow increased insolation over the Eastern Pacific, the source of the upwelling cessation [see Palle et al, Pavlakis et al]; the higher SSTs will transfer heat to the atmosphere but OHC increased during this period; AGW says the increase in OHC is due to back radiation from increased CO2 concentrations and relies on TOA radiative imbalance; but even if there was TOA imbalance for LW, increased SW warming the ocean through cloud decrease could also do the trick of increasing OHC as heat was transferred from the ocean to the atmosphere; that is, it is not a zero-sum game.

    The key is the 1998 reversion of the upwelling and the PDO phase shift. CO2 was still increasing but a contrary condition to the 1976 event has occured during that CO2 increase; how can CO2 produce one result and more CO2 produce an opposite result?

  23. #23 James Haughton
    July 30, 2009

    I think we should consider this paper not as a scientific publication but as part of a debating strategy.
    Certainly Carter (don’t know about the others) is smart enough to know that “Global warming stopped in 1998″ is going to stop working as an excuse as soon as the next El Nino hits; which is likely to be this year. So he needs a fallback position.
    Therefore, he’s going to go from denying El Nino exists to claiming that all Global Warming is solely due to El Nino, which will enable him to get past the “hotter than 1998″ problem.
    As demonstrated by the witless Anthony Cox (Cohenite) above and his Mclean & Quirk hobgoblins, ENSO will be for the next 11 years what 1998 has been for the last 11; the standard talking point. Denialists will claim that until climate models model every last detail of ENSO, they are unreliable, that if you take every single El Nino year out of the record then it isn’t hot after all, et cetera ad nauseum.

  24. #24 cohenite
    July 30, 2009

    So witty James is a third taker; but Carter et al did not say all global warming is due to El Nino, rather not all global warming is due to AGW.

  25. #25 Mark
    July 30, 2009

    > but Carter et al did not say all global warming is due to El Nino, rather not all global warming is due to AGW.

    > Posted by: cohenite

    And since the IPCC WG reports have a chapter on attribution, they haven’t said it is all due to AGW either.

    So why did a paper have to get written just to say something that isn’t disputed?

  26. #26 cohenite
    July 30, 2009

    Well Mark, the devil’s in the detail. IPCC gives a decadal temperature senstivity of 0.14C per decade including feedbacks; there is a host of contrary papers around which suggest something like 0.07C per decade is more realistic; that is equivalent to IPCC’s no-feedback position; and consistent with the upper range of temperature increase over the 20thC.

  27. #27 John Surname
    July 30, 2009

    I forced Tim to edit his post and admit he was wrong! Wait until Tim Blair hears about this!!1!

  28. #28 MAB
    July 30, 2009

    cohenite, When observing water heating one notices that it starts to roll energetically with new visible currents. Did the rolling cause the heating or vice versa?

  29. #29 Observa
    July 30, 2009

    Mark,
    >So why did a paper have to get written just to say something that isn’t disputed?

    Mark, the paper needed to get written so, we could see the gross misunderstanding of the authors (and their advisors) and to help to disern the skeptics from the psudo-skeptic who defend the author’s unsuportable claims.

  30. #30 cohenite
    July 30, 2009

    And does the rolling distribute heat?

  31. #31 Nathan
    July 30, 2009

    Cohenite,

    ” there is a host of contrary papers around which suggest something like 0.07C per decade is more realistic; that is equivalent to IPCC’s no-feedback position; and consistent with the upper range of temperature increase over the 20thC.”

    So what? Just because they exist doesn’t make them right.

    Hey, have you given up on Miskowlzi (or however you spell his name) yet?

  32. #32 Janet
    July 30, 2009
  33. #33 cohenite
    July 30, 2009

    Is that an anti-consensus position you’re espousing Nathan?

    Miskolczi? There are some developments I gather Nathan, which will go some way to rectifying the issues with A_A = E_D and his tau. You’ll be the first I’ll let know when I find out.

  34. #34 pough
    July 31, 2009

    There are some developments I gather Nathan

    Funkiest clause I’ve seen in a good long while. Say it out loud. Experience it. That’s stream of unconsciousness beat poetry, that is. That’s fevered dream.

  35. #35 Nathan
    July 31, 2009

    Cohenite,

    You cling to your Misko-love… It’s kind of cute. And I’d love to hear all about it…

  36. #36 Mark
    July 31, 2009

    > there is a host of contrary papers around which suggest something like 0.07C per decade is more realistic;
    > Posted by: cohenite

    But there are a greater host of papers that say that much more than 0.07C is vastly more likely.

    Or please explain why those contrary papers are right and the other papers are wrong. After all, they are all still “papers around that suggest”.

    And what does a guess of 0.07C/decade have to do with:

    > but Carter et al did not say all global warming is due to El Nino, rather not all global warming is due to AGW.

    ?

    Which isn’t disputed and was, apparently, for you so important about the paper that this was quoted rather than a different value for temperature sensitivity to CO?

  37. #37 cohenite
    July 31, 2009

    The “guess” of 0.07C per decade is, as I said, the actual 20thC increase in temperature and the IPCC no-feedback estimate for ^T(CO2); McLean et al have given their estimate of how much this trend is due to cumulative SOI; their statistics have been found wanting; since you say there is no dispute that AGW is not responsible for all of the ^T what % of ^T do you attribute to AGW and SOI/ENSO?

  38. #38 Billy Bob Hall
    July 31, 2009

    Sorry to pull the ‘plug on your nice warm bath’ there James Haughton (#23), but my prediction on next El Nino is not next year. It’s more likely to be in ~4-5 years time. El Nino generally coincide with peak sun-spot numbers.
    http://ggweather.com/enso/years.htm
    http://www.astro.ucla.edu/~obs/150_data.html#spotplots
    We are in a particularly quiet low number period right now. Cycle 24 has been very slow to start up.
    Space weather reports today the sun is ‘blank’ again… no sun-spots. (http://www.spaceweather.com/)

  39. #39 Mark
    July 31, 2009

    “The “guess” of 0.07C per decade is, as I said, the actual 20thC increase in temperature”

    And a toss of a coin produces a head. This doesn’t mean the coin produces only heads when tossed.

    The *GUESS* is that that 0.07 is the actual trend, not a result of the trend modified by unreliable random noise on top.

  40. #40 Janet Akerman
    July 31, 2009

    Billy Bob,

    Near record temperatures despite a La Nina and Solar minima? How could that be?

  41. #41 Nick Stokes
    July 31, 2009

    I noticed that the teenage wunderkind of skeptics, Kristen Byrne, a couple of years ago neatly anticipated this unoriginal thesis of McLean et al. I think it was a school project:

    I will demonstrate that a negative trend in the El Nino Southern Oscillation (more and stronger La Ninas) from 1945 to 1975 and a positive trend in the ENSO from 1975 to present (more and stronger El Ninos) correlates better with global temperature changes than greenhouse theory. Thus, ENSO is probably the largest contributor to global warming in the past 30 years.

  42. #42 cohenite
    July 31, 2009

    Sign him up Nick.

  43. #43 Billy Bob Hall
    July 31, 2009

    No worries Nick, note I said ‘tend’…. If I said I drove from Sydeny to Melb and I said “I tended to stick to the speed limit’, would it also still be possible that I would not perhaps exactly be able to predict my time of arrival in Melb.
    You guys are just too damn sophisticated sometimes… why not try a bit of Occams Razor now and then ? If climate Science was so predictable, then perhaps there would be a ‘General Theory of Climate’. But there ain’t. And so you cannot predict how many ‘eighths’ cloud cover there will be over Adelaide in 7 days time – for example.
    And which ‘record temperatures’ are you referring to – not those right now I hope ! ;-)

  44. #44 Mark
    July 31, 2009

    “If climate Science was so predictable, then perhaps there would be a ‘General Theory of Climate’.”

    There is. It is quite complicated and spreads over several hundred papers.

    The IPCC report is a synthesis of the results of applying the general theory of climate.

  45. #45 Mark
    July 31, 2009

    > And does the rolling distribute heat?

    > Posted by: cohenite

    Same way if you run the hot and cold tap at the same time for a bath.

    You swirl the cold and warm water together and the peak temperature becomes the average temperature which is colder.

  46. #46 Barton Paul Levenson
    July 31, 2009

    cohenite writes:

    Any of you genuises care to definitively state that SOI/ENSO has no effect on trend at all.

    The “O” stands for “Oscillation,” cohenite. That means it goes up and down–not steadily up.

  47. #47 cohenite
    July 31, 2009

    “The “O” stands for “Oscillation,” cohenite. That means it goes up and down–not steadily up.”

    Agreed; it’s the extrapolation from that to trend neutrality which is problematic; but anyway I’ll put you down as another who thinks that SOI/ENSO has no bearing on temperature trend.

  48. #48 MarkG
    July 31, 2009

    >Agreed; it’s the extrapolation from that to trend neutrality which is problematic; but anyway I’ll put you down as another who thinks that SOI/ENSO has no bearing on temperature trend.

    You should probably include most scientists in that group. If you wish to argue that ENSO actually causes global warming you are first going to have to consider a longer timescale than the last 100 years. ENSO has probably been operating for a very long time. Perhaps even geological timescales. Certainly at least the past few thousand years…now think about these small temperature increase ever few years over that period. It adds up.

    Simply put: If ENSO caused warming the seas would have already boiled away.

  49. #49 Mark
    August 1, 2009

    > Agreed; it’s the extrapolation from that to trend neutrality which is problematic;

    > Posted by: cohenite

    No, the trend doesn’t exist.

    If there were a trend to it, there would have to be energy produced by it (force expressed expends energy).

    And you still avoid showing there’s an energy source in ENSO.

    I’ll put you down as one of those idiots who think they know science.

  50. #50 Barton Paul Levenson
    August 1, 2009

    cohenite writes:

    I’ll put you down as another who thinks that SOI/ENSO has no bearing on temperature trend.

    Here’s why I think so, cohenite. Haven’t done ENSO yet, but when I compare SOI to Hadley Centre CRU temperature anomalies for 1866-2008, I get r = -0.25, which means r^2 = 0.06.

    If I then regress SOI on year for that period (N = 143, remember, a nice big set of data), I find that the t-statistic on the trend is -1.5, which is statistically insignificant. The t-statistic on temperature anomaly for the same period, however, is 15.3, which is well beyond the 99.9% significance level.

    So it looks like SOI accounts for a bit of the up-and-down variation (about 1/17th of it), but none of the trend. See?

  51. #51 Nick Stokes
    August 1, 2009

    The SOI, at least the BoM version, can’t have a prolonged trend. It’s the barometric pressure difference between Darwin and Tahiti. Two tropical places can’t have a sustained pressure difference, since the air would just move to equilibrate. Of course, it can take several months, but not decades.

  52. #52 cohenite
    August 1, 2009

    Thanks Barton, but I’ll stick with the post 1950 period since that was covered in the McLean paper and it is the crucial period for professor Raupach;

    http://www.smh.com.au/opinion/climate-change-poised-to-feed-on-itself-20090731-e4gi.html?page=-1

    In any event I don’t think your analysis captures the idea of a cumulative SOI but I’ll get back to you.

    Nick, the way you describe it the SOI is just like breathing; and we know that breathing has only one trend.

  53. #53 Bernard J.
    August 1, 2009

    Cohenite.

    Interpolating from you logic, if ENSO is driving global temperature trends, then it must be the gearbox in my car that powers the vehicle, and not the engine.

    Just think, there are a couple of hundred extra kilograms plonked in the front that don’t need to be there…

  54. #54 Mark
    August 1, 2009

    > Nick, the way you describe it the SOI is just like breathing; and we know that breathing has only one trend.

    Only in???

  55. #55 Deep Climate
    August 1, 2009

    Cohenite,
    Let’s stick to the subject at hand. McLean et al have claimed that a shift in ENSO is “responsible for recent global warming”, as their first press release put it. They claim that “trends” in temperature and SOI are “similar” and that SOI can account for any trends “that might exist”, even though they “didn’t look” for them.

    These claims are manifestly false when one examines the actual data. Will you at least admit that?

    See:
    http://deepclimate.org/2009/07/30/is-enso-responsible-for-recent-global-warming-no/

    http://deepclimate.org/2009/07/30/is-enso-responsible-for-recent-global-warming-no/#comment-250

  56. #56 cohenite
    August 1, 2009

    BJ, you must drive one of those new-fangled hybrids.

    DC; the McLean paper has a statistical issue in supporting its thesis; some back-up is forth-coming; in the meantime perhaps you and BJ may care to cast your expertise over this;

    http://arxiv.org/abs/0907.1650

  57. #57 Janet Akerman
    August 1, 2009

    >” the McLean paper has a statistical issue in supporting its thesis”

    “*a statistical issue*, that’s a polite euphemism for they didn’t understand what their statistics meant, and that they made unsupportable claims based on their failure to understand the statistical transformations they had used.

  58. #58 dhogaza
    August 2, 2009

    “a statistical issue, that’s a polite euphemism for they didn’t understand what their statistics meant, and that they made unsupportable claims based on their failure to understand the statistical transformations they had used.

    Actually, if you parse their words carefully, you’ll see that they *do* understand what their statistics meant, but they also realize that it’s easily to use their results to mislead people.

    Carter himself:

    The McLean et al. paper supports earlier understanding of the effects of ENSO and volcanic eruptions on the climate system, and shows that much of the variance in the global temperature record can be explained by changes in ENSO 7 months prior. That fact leaves no room for a major influence from human carbon dioxide emissions, and cannot simply be shrugged of.

    The paper does not address trends as such (which Real Climate and similar websites often appear to be obsessed by).

    This: “leaves no room for a major influence from human carbon dioxide emissions” clearly refers to variability around the trend (be it down, flat, or up, though we know, of course we know it is up).

    Yet Carter cheerfully quote-mines himself, in a sense, in his public statements, allowing it to be understood he’s talking about trend, not variability.

    The comment about RC being obsessed by trend is … rather amazing … given that *trend* is the entire f—ing point and the entire f—ing concern regarding AGW (the W not standing for “variability”).

    This man is dishonest, but he’s not so stupid as to misunderstand what their paper shows. It shows something that can easily be misunderstood, especially when he (and apparently, his co-authors) cheerfully aid in the misunderstanding.

  59. #59 dhogaza
    August 2, 2009

    So, while in the quote from Carter I posted above (taken from e-mail he sent to someone in response to a direct question), in which he clearly states that the statement regarding ENSO vs. CO2-driven warming is about variability, here’s what he’s said in public:

    “The close relationship between ENSO and global temperature, as described in the paper, leaves little room for any warming driven by human carbon dioxide emissions. The available data indicate that future global temperatures will continue to change primarily in response to ENSO cycling, volcanic activity and solar changes.”

    These people know *exactly* what they’re up to.

  60. #60 cohenite
    August 2, 2009

    dhogaza angry person; angry person knows what evil lurks in the heart of man; angry person is the Shadow.

    Variability vs trend; the trend since 1850 has been up despite the usual ups and downs; the LIA ended in 1850 and natural variation was the trend for at least the first 50 and arguably the first 100 years after the LIA ended. In any event 1950 is the key period for AGW, according to Professor Raupach;

    http://www.smh.com.au/opinion/climate-change-poised-to-feed-on-itself-20090731-e4gi.html?page=-1

    But natural variation hasn’t ceased regardless of whether AGW has started to kick in; McLean et al had right idea; to isolate natural factors; their % contribution for SOI must have some legs despite their removal of other potential trend factors; there are 2 reasons why natural variability must be the bulk of the 0.14C per decade upward trend since 1960; the first is that the trend from 1910-1944 is equivalent to the trend from 1976-1998; if natural variation was the trend before AGW properly kicked in [ie before 1950] then the trend produced by natural variation must still be happening [unless you want to go down the Meehl golden path to pixie-land]; secondly, 1976 and 1998 are crucial variation points or breaks as David Stockwell’s break paper shows, with strong correlation with major oceanographic events. This shows that the trend pre and post 1998 has a major natural variation component; it’s a matter of putting a % to that natural variation component of the trend for this period since 1950 but the natural % will be the dominant one.

    The conclusion is that AGW’s contribution to trend is either less than touted by the likes of Raupach or non-existent if there are other yet to be revealed natural factors making up the remainder of the trend after the known natural factors have been isolated.

  61. #61 dhogaza
    August 2, 2009

    But natural variation hasn’t ceased regardless of whether AGW has started to kick in; McLean et al had right idea; to isolate natural factors; their % contribution for SOI must have some legs despite their removal of other potential trend factors

    They didn’t “remove other potential trend factors”. They mathematically removed the trend.

    Don’t be dense. They even agree with this statement, when talking to scientifically knowledgeable types.

    They only lie about it when talking to the press, etc, as Carter did in my quote above.

    Why not get angry at people who blatantly lie about something as important as this issue?

    And … if they had anything *substantial* … why do they have to lie?

    The conclusion is that AGW’s contribution to trend is either less than touted by the likes of Raupach or non-existent if there are other yet to be revealed natural factors making up the remainder of the trend after the known natural factors have been isolated.

    Let’s imagine that you’re right, and there is no AGW contribution to trend.

    It doesn’t change the facts about McLean et al:

    1. The paper doesn’t address trend, but variability

    2. Therefore the paper supports neither the contrarian position that there is no AGW contribution to trend, or the science position that yes, there is.

    3. Therefore the paper supports neither the contrarian position that there is a natural contribution to trend, or the science position that there is a natural contribution to trend (see what ‘doesn’t address questions about trend” gets you?)

    4. Therefore Carter’s statement that “”The close relationship between ENSO and global temperature, as described in the paper, leaves little room for any warming driven by human carbon dioxide emissions.” is a flat-out lie.

  62. #62 dhogaza
    August 2, 2009

    their % contribution for SOI must have some legs despite their removal of other potential trend factors

    Actually, I’ll concede this, since the paper doesn’t address trend, it shows a 0% contribution to trend by the SOI/ENSO phenomena. You can give that hypothesis all the legs you want …

  63. #63 Nathan
    August 2, 2009

    So Cohenite, is it better to be angry or stupid? How could you possibly believe that ENSO can produce a ‘trend’. It’s very stupid. You have to have an energy source or storage system.

    Why don’t you do some research on paleoclimate. Senstivity must be high to satisfy early climates. Jeepers, we have discussed this with you at length, but you refuse to learn. You are letting your ideology influence your understanding. You are dumb as a box of hammers.

    Go back and worship your Misko-god and his Chief Eunuch David Stockwell…

  64. #64 Bernard J.
    August 2, 2009

    Cohenite.

    So you are still gabbling on about ‘breaks’?

    Try this exercise: take [these data](http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.txt), calculate the resiuals of the annual temperature anomalies, and plot a histogram of the total number of residuals in each of bins of, say, 0.05C width.

    Have a look at the distribution (analyis it for Gaussian fit, if you like), and ask yourself what the shape of the spread means in terms of ‘breaks’, whether positive or negative.

    And whilst you’re at it, ask yourself what the apparent trimodal distribution implies… It’s rather curious actually, and if you interpret it correctly you’ll realise that it blows your desire to establish a ‘natural’ ENSO ‘forcing’ completely out of the water.

    Perhaps I’ll tell you in a day or so, but in the mean time I want to see you actually do some statistical grunt-work yourself.

  65. #65 Mark Byrne
    August 3, 2009

    cohenite writes:
    >“the trend from 1910-1944 is equivalent to the trend from 1976-1998”

    Cohenite, the current rate of [warming is faster](http://bravenewclimate.com/2009/05/18/climate-denial-crock/#comment-15766) than the 1910 to 1940s period. And this warming is faster despite a greater drag (greater than the pre WWII) from dimming produced by aerosol emissions.

  66. #66 Martin Vermeer
    August 3, 2009

    Bernard J., that’s cruelty to animals… and cohenite babbles so much more fluently when he doesn’t have to understand the multi-syllable words he strings together. Don’t go and spoil a good act.

  67. #67 Bernard J.
    August 3, 2009

    Apologies for cross-threading, but for those who normally escue Tim Curtin’s febrile pseudoscience, [this one](http://scienceblogs.com/deltoid/2009/03/tim_curtin_thread.php#comment-1812128) is a beauty that you may just want to read. He’s correlating Mauna Loa temperature with the CO2 levels taken there… et voila!

    That is why McLean et al are on the money, as cohenite understands, and Bernard J does not, there is NO trend between CO2 and temperatures anywhwere except airports and under the air con. vents that Hansen and HadleyCRUT place their trust in.

    Call the gentlemen with the big butterfly nets.

  68. #68 cohenite
    August 3, 2009

    BJ’s histogram; a histogram is like a very primitive Chow Test BJ; do one on the data that “Chief Eunuch David Stockwell” [charming Nathan] uses in his break paper; you’ll find the Gaussian Fit quite satisfactory; if it hadn’t been what would have been the point of doing the Chow?

    You guys remind me of “The Big Bang Theory”.

  69. #69 Mark
    August 3, 2009

    > BJ’s histogram; a histogram is like a very primitive Chow Test

    No, I think you’ll find it is much more like a histogram.

    And remember: correlation is not causation. Where is the causation for your theory?

    You remind me of an idiot. Oh, you *are* an idiot. That’d be why…

  70. #70 Barton Paul Levenson
    August 3, 2009

    cohenite writes:

    You guys remind me of “The Big Bang Theory”.

    As cohenite gets his climatology from people like McLean and Miskolczi, he probably gets his cosmology from people like Eric Lerner and Tom van Flandern.

  71. #71 sod
    August 3, 2009

    BJ’s histogram; a histogram is like a very primitive Chow Test

    cohenite, your obsession with chow-tests is getting weirder and weirder. has your wife come back home?

    http://scienceblogs.com/deltoid/2009/05/whoosh.php#comment-1664738

    My wife usually does my stats and she isn’t home right now.

    again: that a test discovers a step in some data does NOT excuse you from explaining that step and from looking at significant long time periods in climate science.

    the article that you keep citing does NEITHER of this. case closed.

  72. #72 Bernard J.
    August 3, 2009

    Cohenite.

    A histogram is a histogram, and not a Chow test. But others have already pointed this out.

    Do you not understand why I asked you to construct the histogram? In fact, have you even looked at the histogram?

  73. #73 MAB
    August 3, 2009

    Cohnite,

    Did you *”find the Gaussian Fit quite satisfactory”* then? Are you able to answer that?

  74. #74 cohenite
    August 3, 2009

    Why don’t you say something sensible MAB, instead of playing puerile piddling games? The Australian data is a perfect Gaussian fit and if you bother looking at Figure 1(a) from David’s paper that is what you would expect; the global data has a slight positive bias and that is reflected in Figure 2 for both the full data (a) and the truncated set (b).

  75. #75 Mark
    August 3, 2009

    > The Australian data is a perfect Gaussian fit

    TO WHAT???

  76. #76 Bernard J.
    August 3, 2009

    Cohenite.

    You haven’t looked at [the data](http://scienceblogs.com/deltoid/2009/07/ahh_mclean_youve_done_it_again.php#comment-1812111), have you? If you had, your comments would have a decidedly different focus.

    Seriously, take a gander at it. Remember, you speak of ENSO and global temperature ‘trends’ – look at the data, and tell us what it shows…

  77. #77 cohenite
    August 3, 2009

    TO WHAT??? A histogram is useful for showing the underlying distribution of the temperature data and whether there has been a change in the trend; the issue is whether a Gaussian spread of the frequencies would indicate that there was a change or break in the trend; well, would it?

    BJ; I have looked at the data; you tell me where David’s Chow analysis falls down and why you don’t think a conclusion of a break in 1976-8 and 1997-8 is justified.

  78. #78 MarkG
    August 3, 2009

    This thread seems to have tapered off, but if you scroll up to our local denialist expert (Billy Bob) at #38 you’ll get his confident prediction:

    >Sorry to pull the ‘plug on your nice warm bath’ there James Haughton (#23), but my prediction on next El Nino is not next year. It’s more likely to be in ~4-5 years time. El Nino generally coincide with peak sun-spot numbers.

    Meanwhile back in the real world, the 2009/10 El Nino has started [NOAA press release].

  79. #79 Michael
    August 3, 2009

    Ah, cohers is back. Priceless.

    Hey cohers, how is your titanic struggle with these numbers ((2, 4, 6, 3, 1, 5) and (7, 12, 8, 10, 11, 9)) going??

    For any one who missed it, BJ set cohers this simple data problem 2 months ago –
    http://scienceblogs.com/deltoid/2009/05/whoosh.php#comment-1664460

    Still no answer. So, despite his inability to analyse such a simple set of numbers, cohers can see ENSO in the temp trends. What a clever lad.

  80. #80 MAB
    August 3, 2009

    cohenite writes:
    >The Australian data is a perfect Gaussian fit and if you bother looking at Figure 1(a) from David’s paper that is what you would expect; the global data has a slight positive bias…

    Yes a Gaussian fit and a positive bias it is what you would expect from a warming climate. [As predicted]( http://www.grida.no/publications/other/ipcc_tar/?src=/climate/ipcc_tar/wg1/088.htm) by models.

  81. #81 Bernard J.
    August 3, 2009

    Sheesh Cohenite, you seem to be emphatically determined to give others the impression that you’re a thickie when it comes to commenting, off your own bat, on statistical and graphical issues.

    Can you really not see what the histogram implies? Or are you just afraid to embarrass yourself by actually attempting a comment?

    I’ll give you another prompt – subtract the linear trend from the anomalies and then see what you end up with…

  82. #82 Michael
    August 3, 2009

    Bernard, it’s rather unfair of you to pick on poor cohers – it’s like a Pee Wee Herman vs. M. Ali fight.

  83. #83 cohenite
    August 3, 2009

    My answer, Michael, was to present the David Stockwell paper on breaks/steps in 1976-78 and 1997-8; I had originally come onto this congenial site with the McLean/Quirk break paper and was castigated for the poor stats in that paper; well I’ve come back with some more statistical analysis of the break concept by Dr Stockwell and still the concept is lampooned; the breaks are undeniable but of course the argument now is that they are unexplained [see silly sod's comment somewhere], which is untrue; the breaks are well correlated with empirically verified oceanographic events and PDO phase shifts. I would have thought that would have been interesting to all you pure minded scientific types who Raupach praises in the gang of 15 letter. Ha!

  84. #84 Michael
    August 4, 2009

    A long-winded way of saying that you still haven’t done it.

  85. #85 MAB
    August 4, 2009

    cohenite wrties:
    >1976 and 1998 are crucial variation points or breaks as David Stockwell’s break paper shows, with strong correlation with major oceanographic events. This shows that the trend pre and post 1998 has a major natural variation component”

    Bollocks, it shows ocean cycles drive warming just like it shows the rolling water is the a source of heat for kettle on a fire.

  86. #86 Mark
    August 4, 2009

    > BJ; I have looked at the data; you tell me where David’s Chow analysis falls down and why you don’t think a conclusion of a break in 1976-8 and 1997-8 is justified.

    > Posted by: cohenite

    You’re the one who brought up the Chow test.

    Eat your own dogfood first.

  87. #87 Michael
    August 4, 2009

    chowing….dogfood….all very appropriate given that cohenite’s posts are mostly word-salad.

  88. #88 Bernard J.
    August 4, 2009

    Cohenite.

    Can you, or indeed David Stockwell, show that Stockwell has accounted for all variables that might impact upon climatic temperature trend?

    Remember, at the most fundamental level a Chow test determines whether the coefficients derived for one ‘set’ of data are statistically equivalent to the coefficients derived for another ‘set’ (for generally arbitrary ‘sets’). This whole ‘structural break’ jingo is an artificial, economic approach, and is hardly transportable to a climate context.

    In order to empoy a Chow legitimately, one must include all of the variables that might influence the trajectory, and once one starts to include more than several variables the chance of discerning a true ‘break’ (even where such is a valid concept), drops rather rapidly. Stockwell leaves out a whole suite of possible variables, and in doing so his application of a Chow to the variables he does include is rather like cherry picking…

    Oo, and the concept of “[post hoc](http://en.wikipedia.org/wiki/Post-hoc_analysis)” seems to have been ignored too, but I guess that that is part and parcel for a cherry pick.

    This is to leave aside the fact that Stockwell does not in any way adequately describe how ‘breaks’ might be discerned from oscillations, the latter which are already anticipated by current climatological modellings. Heck, Tamino shows how oscillations are quite easily discerned from the trajectories – have you bothered to consider his material?

    Which reminds me – when do you intend to comment upon the nature of the very simple plot of anomaly distributions, and of the implications (and there are several) of the trajectory of the anomalies once the linear trend is subtracted? Ockham’s razor seems to have been left on the counter whilst you employ a butter knife to dissect the underlying statistical realities…

    One should always walk before one runs, and I haven’t seen you take a single step yet.

  89. #89 Nick Stokes
    August 4, 2009

    I agree with scepticism about the Chow test in this context. All it tells you is that a broken line (with a nominated breakpoint) fits better than an unbroken one. That just says something about the linear fit – it isn’t good affirmative evidence for the existence of the breakpoint. If you apply the analysis to an exponential curve with added noise, at some point a Chow test will tell you that a broken line fits better. Of course, an exponential would have fit even better, but that wasn’t in the universe of curves that you were considering.

  90. #90 Bernard J.
    August 4, 2009

    Cohenite.

    How is your collection of the answers to some of the [earlier questions](http://scienceblogs.com/deltoid/2009/07/ahh_mclean_youve_done_it_again.php#comment-1814622) going?

    There are a number of peculiarities in the data that are begging to be addressed…

    Nick has pre-empted my next comment, which was about the fact that an exponential or a sigmoid fit could be argued to be more appropriate than a linear one, but perhaps you would care to discuss, in addition to the previous questions, why inferring a ‘structural break’ in an oscillatory phenomenon, in order to explain temperature rise, is more appropriate to consider than is a non-linear fit to CO2 forcing.

    Climate science is breathlessly awaiting!

  91. #91 cohenite
    August 5, 2009

    BJ; “why inferring a ‘structural break’ in an oscillatory phenomenon, in order to explain temperature rise, is more appropriate to consider than is a non-linear fit to CO2 forcing.”

    So you’re saying that CO2 forcing is non-linear on ^T after all the natural variables are removed? That is, as Nick says, an exponential curve is a better fit? A couple of questions; what would the exponential curve look like; would it be asymptopic against the x or y axis? And why do you assume the break does not reflect that forcing as well as natural factors? According to AGW CO2 forcing cannot be equal or the same on either side of the break [because on the top side there would be more of it] but in combination with the natural factors it may be. Finally it is a bit rich to demand that David include “all the variables that may affect the trajectory” when no AGW model does so.

  92. #92 Bernard J.
    August 5, 2009

    Cohenite, you are a sad, sad case.

    Answering questions with questions might work for a divorce lawyer, but it does not demonstrate to those here that you are actually capable of performing your own satisfactory statistical analysis.

    Nevertheless I will enter the fray, because I am garnering a modicum of satisfaction at your wriggling.

    So you’re saying that CO2 forcing is non-linear on ^T after all the natural variables are removed? That is, as Nick says, an exponential curve is a better fit?

    No, I am not “saying that CO2 forcing is non-linear on ^T after all the natural variables are removed”. I am saying that it may well be, and in fact could reasonably be expected to be so, but without a comprehensive inclusion and analysis of all of the relevant impinging parameters it is difficult to be certain.

    An exponential curve may be a better fit, but only for a certain period of time, because one would not expect even a runaway greenhouse response to continue to adhere to such a trajectory for long. Oo, does that mean that there would be a structural break…?

    Depending on the stage of CO2 addition to the atmosphere a logarithmic trend might be apparent – as might a sigmoid (and more likely over a greater length of time) or a power function. Heck, when the day comes it might even turn out to follow a (gasp!) polynomial fit, although probably not of the sort that is so beloved of a certain [Jon
    Jenkins](http://scienceblogs.com/deltoid/2009/01/sixth-degree_polynomial_fits_j.php).

    The thing is, without a justifiable a priori reason for selecting a particular trajectory, any statistical analysis should be the most parsimonious possible. To this end a linear fit fills the bill, and a linear fit indicates a significant warming: less parsimonious trendlines would only increase the improbability that a warming trend is just a random event.

    what would the exponential curve look like; would it be asymptopic against the x or y axis?

    You can throw the terms around cohenite, but you obviously don’t don’t why doing so made you look silly.

    Even so, I know what you were probably trying to say, so the answer, trivial as it is, is that the final trajectory of warming will be asymptotic to a (y) value of temperature greater than the contemporary global mean.

    And why do you assume the break does not reflect that forcing as well as natural factors?

    Ockham’s razor.

    Finally it is a bit rich to demand that David include “all the variables that may affect the trajectory” when no AGW model does so.

    All I would expect is that Stockwell include all of the variables that climatologists model. If he did this, his test for unequal coefficients would fall over in a heap, for the reason I explained [earlier](http://scienceblogs.com/deltoid/2009/07/ahh_mclean_youve_done_it_again.php#comment-1814622) – every additional variable decreases the power of the test to statistically detect differences in the regression coefficients.

    And note that I do not speak of a “Chow test to ‘detect’ structural breaks”. This is pretty much a bogus phrase, without a paragraph of fine print following that explains exactly what such a test actually does.

    And there is still no sign that you have even contemplated starting your homework. As [sod asked](http://scienceblogs.com/deltoid/2009/07/ahh_mclean_youve_done_it_again.php#comment-1812283): is your wife not home yet?

  93. #93 cohenite
    August 5, 2009

    “No, I am not “saying that CO2 forcing is non-linear on ^T after all the natural variables are removed”. I am saying that it may well be, and in fact could reasonably be expected to be so,”

    Goodnight BJ.

  94. #94 Mark
    August 5, 2009

    > I am saying that it may well be, and in fact could reasonably be expected to be so,”

    > Posted by: cohenite

    Why are you saying it, though.

    All the purpose of saying that seems to be is to deny AGW. No other reason for it. No proof given that it is a likely proposition (or even an unlikely one).

  95. #95 Janet Akerman
    August 5, 2009

    Goodnight cohenite, sweet dreams.

  96. #96 MAB
    August 5, 2009

    But Mark, we know it is not denying AGW, nor is it in conflict with the dire assessments if BAU continues through the coming decades.

  97. #97 Bernard J.
    August 5, 2009

    Goodnight BJ.

    What, waving the white flag again? C’mon Cohenite, you can do better than that.

    Oh, and nice selective, lawyer-style quoting. You managed to omit emphases, and also a half of a sentence, and totally change the tenor of my comment.

    It might serve well in a divorce case, but it ain’t how scientists reference their sources.

    How’s the homework progressing?

  98. #98 Bernard J.
    August 5, 2009

    Cohenite.

    It strikes me that you might be struggling because you may be considering data only from the middle of the 20th century, onward.

    Compare Stockwell’s timeframe with the entire dataset, and see if this helps you in your musings.

  99. #99 Mark
    August 5, 2009

    > But Mark, we know it is not denying AGW, nor is it in conflict with the dire assessments if BAU continues through the coming decades.

    > Posted by: MAB

    It’s denying the science is right. Therefore the scientists are wrong. Therefore AGW is wrong.

  100. #100 cohenite
    August 5, 2009

    Good morning BJ; one final comment as Mark and MAB are degenerating; the data in David’s break paper is, in both the BoM and HadCRU3GL series, from 1910 to current; this was the primary complaint about the McLean/Quirk paper; that they only used data from 1950.

    Has anyone read David’s paper; besides Nick?