New Light on “Hide the Decline”

In today’s post, I’m going to discuss a previously undiscussed example of “Hide the Decline”, one that precedes Briffa and Osborn (Science 1999), the earliest example discussed so far. CRU did not report it in their submission to Muir Russell.

Jones et al 1999 (Rev Geophys) was published in May 1999, the same month as Briffa and Osborn (Science 1999). However, the latter was a comment with a shorter peer review process, placing Jones et al 1999 at least several months earlier in the queue. Its section 5.6 discussed proxy reconstructions, with its Figure 6 being a spaghetti graph, consisting of the same elements as the later IPCC TAR spaghetti graph: CRU plus the Mann, Jones and Briffa reconstructions. In this case, they used the Briffa et al 1998 (Nature) reconstruction – IPCC TAR used the then unpublished version from Briffa et al 2001. The Briffa series has been truncated in the mid-20th century.


Original Caption: Figure 6. Northern Hemisphere temperature reconstructions from paleoclimatic sources. The three series are Mann et al. [1998, 1999] (thick), Briffa et al. [1998] (medium) and Jones et al. [1998] (thin). All three annually resolved reconstructions have been smoothed with a 50-year Gaussian filter. The fourth (thickest) line is the short annual instrumental record also smoothed in a similar manner. All series are plotted as departures from the 1961–1990 average.

The following graph is an emulation of Jones et al 1999 Figure 6, applying the adjustments (re-scaling and re-centering) of Tim Osborn’s March 1999 program osborn-tree5/pl_mannbriffajones.prom showing the Briffa version in orange. The versions plotted here clearly match the ones in the Jones et al 1999 figure – except for the deletion of Briffa values from 1960 or so on.


Caption: Emulation of Jones et al 199 Figure 6.

CRU Submission to Muir Russell
In their submission to Muir Russell (page 38), CRU described the “hide the decline” methodology used in IPCC and most other publications (as opposed to the WMO splice) as follows:

(b) Depict the reconstruction over the period for which it can be considered to be a reliable estimate of past temperature variations (typically we have curtailed it in 1960, considering the post-1960 data to be a poor representation of temperature) and overlay separately the appropriate instrumental temperature observations.

They purported to justify the deletion of adverse data (“hide the decline”) as follows:

Presentation type (b) has typically been selected for publications whose purpose is to convey the available range of evidence for past temperature variations. In this situation, it is arguably reasonable to show only data that are considered to provide some information about temperature variations. In the same way that the early parts of a reconstruction might not be shown if they were considered to be unreliable (due, for example, to unacceptably low replication), the post-1960 values are also excluded. This avoids the presentation of values that are known to be unrepresentative of the real temperatures. Of course, the recent divergence in these data will be less clear if post-1960s values are excluded and that represents a potential disadvantage of this exclusion if this divergence is important for assessing confidence in the earlier reconstructed values. Section 1.2 outlines various situations where this is or is not a concern. If this is a concern, then to avoid the exclusion of the recent period resulting in an overly confident impression being given of the accuracy to which past temperatures can be reconstructed, we include appropriate caveats and references to the articles where the limitations are explored in greater detail. Examples of this type of presentation include Plate 3 of Briffa et al. (2001); Figure 2A of Jones et al. (2001); Figure 8 of Briffa et al. (2004); Figure 6.10b of Jansen et al. (2007); and Figure 5b of Hegerl et al. (2007).

The Muir Russell “inquiry”, with their typical negligence, failed to address this “explanation”, which, in Graham Stringer’s words, is “difficult to parody”. Obviously the divergence is “less clear” if the adverse data is deleted.

CRU stated that “If this is a concern, then to avoid the exclusion of the recent period resulting in an overly confident impression being given of the accuracy to which past temperatures can be reconstructed, we include appropriate caveats and references to the articles where the limitations are explored in greater detail.”

This assertion is a fabrication. In virtually all cases in “presentation (b)” style, they included no caveats whatever. To date, I have not identified a single publication in which they explicitly state that they have deleted post-1960 data and why. In some cases, the caption says that the Briffa data is from 1402-1960, but in such cases, there is no explicit statement that data was deleted and why. In other cases, there is not even a hint that the data has been chopped back to 1960.

Jones et al 1999

Jones et al 1999 is a pernicious example where there is not even a hint that data has been deleted. Worse, the running commentary all too often depends on the deletion of the adverse data.

Over the last few years, a number of compilations of proxy evidence have been assembled following the pioneering work of Bradley and Jones [1993]. In Figure 6 we show three recent reconstructions of Northern Hemisphere temperature for part of the last millennium. The reconstructions are all of different seasons (annual [Mann et al., 1998, 1999] and two definitions of summer [Briffa et al., 1998; Jones et al., 1998]). The short instrumental record on an annual basis is superimposed.

Agreement with the annual instrumental record is poorest during the nineteenth century, partly because of the different seasons (summer in two of the series) used. The instrumental record also rises considerably in the last 2 decades, and this cannot be seen in the multiproxy series because they end before the early 1980s, as some of the proxy records were collected during these years. The most striking feature of the multiproxy averages is the warming over the twentieth century, for both its magnitude and duration. The twentieth century is the warmest of the millennium and the warming during it is unprecedented (see also discussion by Mann et al. [1998, 1999] and Jones et al. [1998]). The four recent years 1990, 1995, 1997, and 1998, the warmest in the instrumental
series, are the warmest since 1400 and probably since 1000. The end of the recent El Nin˜o event (such events tend to warmer temperatures globally) and the greater likelihood of La Nin˜a (which tends to lead to cooler temperatures) as opposed to El Nin˜o conditions during 1999 and 2000 means that 1998 will likely be the warmest year of the millennium. The coolest year of the last 1000 years, based on these proxy records, was 1601.

Neither the caption nor the running text gives any hint that the reconstruction of Briffa et al 1998 (Nature) has been deleted after 1960. Yes, the article cites Briffa et al 1998 – which reports the decline – but Jones et al 1999 contains no “caveats” about the decline or about the deletion of data.

Important comments in the running text on Figure 6 also depend on the deletion of the decline. For example, Jones et al state: “Agreement with the annual instrumental record is poorest during the nineteenth century.” Actually, the worst agreement is between the Briffa decline and the late 20th century temperature increase – but that’s been hidden.

Jones et al say: “The instrumental record also rises considerably in the last 2 decades, and this cannot be seen in the multiproxy series because they end before the early 1980s, as some of the proxy records were collected during these years.” Again, this is completely misleading. The Briffa multiproxy series do not end before the early 1980s because of they were collected during those years, but because the post-1960 was deleted.

Jones et al say: “The most striking feature of the multiproxy averages is the warming over the twentieth century, for both its magnitude and duration.” Again, this statement depends entirely on the deletion of the decline. If the Briffa series were shown, the inconsistency of the Briffa reconstruction with the 20th century temperature history becomes the most striking feature of the graphic – calling the validity of the reconstructions into play.

New Light

In my opinion, locating the earliest known example of “hide the decline’ in Jones et al 1999 (Rev Geophys) places hide the decline in a remarkable new light. I think that it’s fair to say that most of us have assumed that “hide the decline” originated with Mann or Briffa. However, it seems to me that this new evidence suggests that the lead author of Jones et al 1999, Phil Jones himself, may have been responsible for CRU’s decision to hide the decline in the spaghetti graph comparisons – initially Jones et al 1999 Figure 6, later, as we all know, IPCC TAR Fig 2.20.

To my knowledge, “hide the decline”, as a technique, was used in every subsequent spaghetti graph using the Briffa reconstruction except one – the Zero Order Draft of IPCC TAR presented to the Lead Authors in Arusha in September 1999. This spaghetti graph – which didn’t hide the decline – went over like a lead balloon with IPCC – thus the busy emails of September 1999, which I’ve previously discussed. The IPCC spaghetti graph in its First Order Draft (October 1999) adopted a hide-the-decline strategy modeled on the techniques “pioneered” in Jones et al 1999 and Briffa and Osborn 1999 (though Mann varied the method somewhat.)

In preparing my emulation of Jones et al 1999, I used the adjustment parameters of Osborn’s program pl_mannbriffajones of March 1999, almost contemporary with the preparation of Jones et al 1999. When one does a cross-chronology of the Climategate programs, there is some further interesting information on the genesis of “hide the decline” that I’ll discuss in another post.

Update Mar 23:
Here is an updated emulation of the Jones et al 1999 spaghetti graph, showing that the hide-the-decline is effective in 1950 (rather than 1960) and that the source information is the 4th column (NHD2) in the Briffa et al 1998 archive.

Figure 2. Excerpt from Jones et al 1999 with annotation.


58 Comments

  1. Paul Penrose
    Posted Mar 15, 2011 at 11:48 AM | Permalink

    Keep digging Steve, we’ll drain this swamp eventually.

  2. Hu McCulloch
    Posted Mar 15, 2011 at 12:18 PM | Permalink

    Steve —
    In your emulation, you have the orange Briffa series running almost to 2000 and flat after 1980. Shouldn’t it end in 1980, even if unsmoothed? How are you and Jones smoothing the ends of the series?

    Laying a ruler on the 1950 ticks on Jones’s Fig. 6, it appears that the Briffa series ends right in 1950, and not in 1960 as in later versions.

    Apparent typo:

    The Briffa multiproxy series do not end before the early 1980s because of they were collected during those years, but because the post-1960 was deleted.

    Shouldn’t this be, “before the early 1980s because they were not collected during those years…?


    Steve – the Briffa recon goes to 1994. It is built from the Schweingruber series which were collected in the early 1990s. I’ve done end-padding with the mean of the last half-period of the smooth – standard CRU smoothing.

    • artwest
      Posted Mar 15, 2011 at 1:04 PM | Permalink

      Steve-
      I think that Hu was drawing your attention to a typo but but because he made a wrong guess at what you meant it threw you off noticing the typo.

      i.e.

      “The Briffa multiproxy series do not end before the early 1980s because of they were collected during those years, but because the post-1960 was deleted.”

      The sentence as it stands doesn’t make sense, particularly the “of” in relation to the “but”. Looks like there are words wrong/missing.

  3. Jeff Norman
    Posted Mar 15, 2011 at 12:21 PM | Permalink

    Interesting. Does referring to it as “Mike’s trick” suggest that Jones kind of knew that it was not a good thing?

    Steve – not everything is Mann’s fault. I think it was more that CRU had their own trick to hide the decline – I was going to include a discussion of funct_decline in this post, but it is deferred for now. Mann’s trick was a little different and Jones decided to use it (or what he thought it was), rather than the CRU trick in the WMO graphic.

    • Hu McCulloch
      Posted Mar 15, 2011 at 12:48 PM | Permalink

      Jeff — These are two different “tricks.”

      In what might now be called “Phil’s RG Trick”, the portion of the proxy data that doesn’t fit the instrumental data is simply deleted.

      In “Mike’s Nature Trick,” what purports to be a smoothed version of the proxy data is apparently constructed by splicing the instrumental data onto the end of the proxy data before smoothing.

      And finally, in what might be called “Phil’s Grand WMO Trick,” both tricks are used at once, along with along with Mannian double flip (“minimum roughness”) endpegging, to create the impression of a really close fit to the instrumental data, plus a dramatically high end value.

      Steve: looking at the code remnants, it looks to me like there’s more to the CRU trick than simple deletion. Remember the “Briffa bodge” with Tornetrask. At first glance, funct_decline looks like the Briffa bodge.

  4. MikeN
    Posted Mar 15, 2011 at 1:00 PM | Permalink

    This brings up what Phil Jones meant by hide the decline.
    Is it ‘I’ve used Mike’s Nature trick… to hide the decline’
    or ‘I’ve cut off Briffa at 1960 to hide the decline’?

  5. Layman Lurker
    Posted Mar 15, 2011 at 1:10 PM | Permalink

    Steve, besides the Figure 6 truncation, the Briffa values in your emulation also mismatch Jones figure 6 by a negative offset. Dollars to doughnuts this is the same offset that Mann used to align Briffa series in the TAR graph. Eyeballing it looks to me like Jones must have devised a method to re-align the Briffa series after truncation rather than use the ‘suspect’ 1961-90 declining data.

  6. J Bowers
    Posted Mar 15, 2011 at 1:53 PM | Permalink

    It;s pretty simple. Why you guys don’t just get it from the horse’s mouth I really can’t understand.

    Skip to 21:17

    Transcript:

    Phil Jones — The [World Meteorological] organisation wanted a relatively simple diagram for their particular audience. What we started off doing was the three series with the instrumental temperatures on the end, clearly differentiated from the tree ring series, but they thought that was too complicated to explain to their audience. So, so what we did was just to add them on and bring them up to the present. And, as I say, this was a World Meteorological Organisation statement. It had hardly any coverage in the media at the time, and had virtually no coverage for the next ten years, until the release of the emails.

    Paul Nurse — So why do you think so much fuss was made about the emails and this graph, rather than the peer reviewed science?

    Phil Jones — I think it’s that the number of climate change sceptics, or doubters, deniers, whatever you want to call them, just wanted to use these emails for their own purposes to cast doubt on the basic science. The basic science is in the peer reviewed literature, and I wish more people would read that than read the emails.

    • Posted Mar 15, 2011 at 4:53 PM | Permalink

      Re: J Bowers (Mar 15 13:53),

      Bowers, you don’t seem to be tracking here.

      Steve is showing another Jones “hide the decline” in Jones et al 1999 (Rev Geophys). Nothing to do with the better-known WMO pub, but it does tend to show a pattern… Do pay attention.

      This rather complicates your (and The Teams’) defense of the indefensible, doesn’t it?

      Best, Pete Tillman

      • stephen richards
        Posted Mar 16, 2011 at 4:27 AM | Permalink

        Peter

        I think you missed the tone of Bowers comment.

    • nanny_govt_sucks
      Posted Mar 15, 2011 at 11:58 PM | Permalink

      snip – relate to Jones et al 1999

    • DEEBEE
      Posted Mar 16, 2011 at 5:55 AM | Permalink

      Nurse loses all credibility as a scientist and a journalist, if he can sit there without seeing the obvious scientific problem. And also the communication to the public problem. Jones’ explanation seems to be like John N-G’s attitude that scientist have to (trick / hide / fool pick your word) the public for its own good.

    • Duster
      Posted Mar 16, 2011 at 1:57 PM | Permalink

      Actually, “simplifying” the presentation reflects either a remarkable degree of contempt for their audience – not bright enough – understand what they see – or an even more remarkable doubt about the robusticity of their results.

    • Timothy Sorenson
      Posted Mar 16, 2011 at 4:47 PM | Permalink

      In the video it seems that Jones is saying that ‘They created the graph for the World Metero. Soc.’ because what they had FIRST created was TOO complicated. SO: it should be clear that ANY publication prior to the World Met. Soc graph he is referring to: was/is the complicated one. When was the first appearance of the graph he is referring to (in the video), (a meeting? a presentation?) and when did he submit his first graph for publication. The citation:Rev Geophys pub. May 1999 seems to require a much earlier submission date than a talk given for the WMS talking about Climate in 1999, as the title in the graph shown in the video clip shows. Jone clearly indicates the GRAPH WAS CREATED FOR the WMS audience. Seems there may be another little white lie creeping in.

  7. Posted Mar 15, 2011 at 1:57 PM | Permalink

    “New Light” indeed.

    “Liar, liar, pants on fire” comes to mind.

    As always, thanks for your patient digging and reconstructions.

    Cheers — Pete Tillman

    “When men are most sure and arrogant they are commonly most mistaken, giving views to passion without that proper deliberation which alone can secure them from the grossest absurdities.” — David Hume.

  8. William Larson
    Posted Mar 15, 2011 at 2:01 PM | Permalink

    And what all this scurrilous gamesmanship by Jones does is give the impression that those recons are certainly reliable as indicators of past temps, because look how closely the proxies agree with the modern thermometer record. They give one the impression then–the thrust of the message–that the shaft of Hockey Stick is truly quite straight; DON’T “hide the decline” here and suddenly, “Whoa, how can one possibly say that the recent warming was/is ‘unprecedented’? For all we know, those proxy recons are just a mishmash of noise.” Always have to keep your eyes on the “take-home message”. From this posting I am especially impressed with the efforts Jones has gone to to promote his take-home message–looks to me that THAT is the “pioneering work of…Jones…”

  9. Fred
    Posted Mar 15, 2011 at 2:19 PM | Permalink

    Dr. Roger Muller speaks on the topic.

    http://rogerpielkejr.blogspot.com/

    The blink comparator at about 3:50 is good.

    “I now have a list of people who’s papers I won’t read anymore”

  10. Fred
    Posted Mar 15, 2011 at 2:21 PM | Permalink

    the real link . .

    http://rogerpielkejr.blogspot.com/2011/03/hide-decline-in-5-minutes.html

  11. Craig Loehle
    Posted Mar 15, 2011 at 2:44 PM | Permalink

    To get their nice smooth graphs, how did they do endpoint padding (which I find a simply astonishing practice)? Did they mirror past data, or add the instrumental to the end before smoothing?

    • Craig Loehle
      Posted Mar 15, 2011 at 2:50 PM | Permalink

      Sorry, should read before posting…Briffa bodge…
      The transcript above from Jones and Nurse is priceless, where they don’t seem to grasp how deceptive it is to do what they did to the data. To alter graph because you “know” what the data should look like is post-normal science at its best, like making up numbers in the millions for homeless people or for those dying from climate change.

      • J Bowers
        Posted Mar 15, 2011 at 3:07 PM | Permalink

        So it wasn’t intentional deception, but just as Jones describes?

        • Posted Mar 15, 2011 at 3:23 PM | Permalink

          Re: J Bowers (Mar 15 15:07),

          :So it wasn’t intentional deception, but just as Jones describes?

          So, what difference does it make. Are you familiar with
          http://en.wikipedia.org/wiki/Confirmation_bias ?

          As per Feynman, the easiest person to fool is yourself…

        • J Bowers
          Posted Mar 15, 2011 at 3:37 PM | Permalink

          Ever heard of Okkam’s Razor?

        • RomanM
          Posted Mar 15, 2011 at 4:08 PM | Permalink

          Yes. What does that have to do with anything?

        • J Bowers
          Posted Mar 15, 2011 at 4:57 PM | Permalink

          Well, let’s see. Jones’ explanation is pretty straightforward, takes seconds, and simply makes a lot of sense. His detractors’ convoluted “detective” workings out have been going on for almost a year and a half now and still require ESP. What’s to add?

        • RomanM
          Posted Mar 15, 2011 at 5:47 PM | Permalink

          Wow, “Jones’ explanation is pretty straightforward, takes seconds, and simply makes a lot of sense.” Really? And you think that you understand Occam’s razor?

          From Wikipedia:

          Occam’s razor (or Ockham’s razor[1]), often expressed in Latin as the lex parsimoniae, translating to law of parsimony, law of economy or law of succinctness, is a principle that generally recommends selecting the competing hypothesis that makes the fewest new assumptions, when the hypotheses are equal in other respects.[2] For instance, they must both sufficiently explain available data in the first place.

          Now, let’s see. Jones claims that the proxies were tracking temperatures just fine until 1960, and then they just lost it (for an unknown cause according to the explanation he gives in the video). That explains the data.

          However, I would posit that the proxies never tracked the temperatures in the first place because they were just noise. That also explains the data. But, I don’t have to assume an unknown cause to account for the divergence.

          So which would Occam choose? If I thought you understood the science, I would suggest that you decide, but clearly you don’t have the ESP. Let me give you a hint. There is a reason for validation procedures and that is to give some indication that the proxies are not a bucket of random noise and chopping the tail off of the reconstruction pretty much violates any assumption that the proxy is useful for the purpose. Hiding this fact as Jones did with his trick is not doing science.

        • StuartR
          Posted Mar 15, 2011 at 6:43 PM | Permalink

          Explanations can always be easy, make sense, and be quick to divulge; and also be totally wrong. That is because it depends on the level of knowledge you had, or wanted, before you started to hear the explanation.

          I think you have an incorrect understanding of what Occams’razor means. I think Occams’razor talks more about how to approach each next step, and Occams’razor could even be applied at each step in a chain of a few steps that are spread over a year and a half and can be followed in the archives here without requiring ESP :)

        • Craig Loehle
          Posted Mar 15, 2011 at 3:42 PM | Permalink

          Just because they believed the story they told themselves about the data does not mean dropping parts of it (or tacking on instrumental or bodges before smoothing) is ok or scientific. Believing the story only means they could pass a lie detector test about trying to deceive, it doesn’t mean we were not deceived. Ponzi schemes sometimes start because the fund manager is so sure he will hit it big soon and is justified robbing peter to pay paul…but it is still wrong.

        • J Bowers
          Posted Mar 15, 2011 at 3:51 PM | Permalink

          But can’t that apply both ways? What makes you so immune?

        • Craig Loehle
          Posted Mar 15, 2011 at 4:20 PM | Permalink

          Of course everyone is at risk from believing what they believe, this is why science has standards–you only drop outliers if you can prove something went wrong, not just because you don’t like those data points. You show all the data. Maybe you want to take meds where the company hid the patients who died, but I don’t.

        • J Bowers
          Posted Mar 15, 2011 at 4:38 PM | Permalink

          But this is in the published papers. Why such the focus on what was essentially a graphic which was specifically requested by the WMO to be dumbed down? Why wasn’t everyone on this like a rash when it was first done?

          Steve; – Please do not divert this thread into the WMO graph. Try to focus on the fresh points.

        • J Bowers
          Posted Mar 15, 2011 at 5:01 PM | Permalink

          So publish a paper. What’s the big deal if it’s so certain?

        • Peter
          Posted Mar 16, 2011 at 11:47 AM | Permalink

          > So publish a paper. What’s the big deal if it’s so certain?

          ENOUGH ALREADY!! Removing data, or reducing its weight without explaination and especially with an explaination that its not following expected patterns is utterly and incontrovertably wrong. In every discipline where lives/money etc. depend on these kinds of analysis, such practices would land you in jail and/or kill people. If you did it in school or University you’d get an F or possibly kicked out. It is quite simply utterly indefensible and as far as I’m concerned anybody who defends it, or fails to chastise it carries no weight in any current or future arguments they engage in.

        • Gord Richens
          Posted Mar 16, 2011 at 4:25 PM | Permalink

          “If you did it in school or University you’d get an F or possibly kicked out.”
          Hmm.

        • Larry
          Posted Mar 22, 2011 at 10:34 AM | Permalink

          Though probably not from UEA, which hadn’t quite made it into the Russell Group last time I checked.

        • BillyBob
          Posted Mar 16, 2011 at 12:42 PM | Permalink

          Certainty: Briffa’s tree ring data post-1960 is NOT a proxy for temperature — by the Teams own admission.

          Almost Certainty: Briffa’s tree ring data pre-1960 is NOT a proxy for temperature — by deduction.

        • Eric Anderson
          Posted Mar 15, 2011 at 4:24 PM | Permalink

          Yes, yes, it can happen both ways. Who said they were immune? Do you have a specific example in mind or other place you are going with this?

        • Micky Corbett
          Posted Mar 16, 2011 at 5:34 PM | Permalink

          Without trying to put words or ideas in anyone’s mouth, I think you touch on exactly what happened here Craig, in that there was already a confirmation bias.

          Basically if I were to speculate, it looks like Briffa was assumed to be “wrong” because 3 other proxies were showing the increase in temperature. So rather than get into the complexities, the series is truncated assuming that something is affecting that series in the latter 20th century.

          What didn’t happen and is now coming back to bite them, was anyone asking themselves, “wait a minute, how sure are we of anything with these proxies? I mean how big are the samples, where do the trees come from? Can temperature estimates really be gleaned from the data?”

          In that scenario you don’t trust anything so you look for confidence with characterisation instead of just statistics.

          And as you rightly point out, it might be understandable but it is still wrong and not scientific.

          And to tell you the truth that’s all I would like these guys to say. That they messed up and we shouldn’t have done what we then subsequently did. Then let’s see what we can do from here.

      • Geoff Sherrington
        Posted Mar 15, 2011 at 7:29 PM | Permalink

        In the video from J Bowers above, Jones tells Nurse he provides data reasonably. This is the man who wrote to Warwick Hughes (I paraphrase here) “Why should I make the data available to you, when your aim is to try and find something wrong with it.” 21 Feb 2005.

  12. kramer
    Posted Mar 15, 2011 at 3:34 PM | Permalink

    I think Steve missed his calling… he probably should have been a detective.

  13. Posted Mar 15, 2011 at 3:36 PM | Permalink

    The fall of mann was not the original sin, apparently. For those that haven’t seen it, Sir David King, while government chief scientist in the UK, was not above hiding the decline and inventing 1000 years of temperature measurements: http://www.bishop-hill.net/blog/2011/3/13/more-splicing-more-hiding-the-decline.html

  14. pax
    Posted Mar 15, 2011 at 6:25 PM | Permalink

    I wonder when I stop to get really angry when I read about this stuff.

    J Bowers, I assume you’re joking.

  15. Geoff Sherrington
    Posted Mar 15, 2011 at 8:05 PM | Permalink

    Let’s concentrate on the orange curve in the lower graph, the Briffa emulation (typo 199). This has essentially a flat and level response from years 1400 to 1900, with noise. We’ll asssume for this note that the instrumental record used for calibration and graphics starts at about 1900.

    The illustrated 1400 to 1900 period can be flat basically because

    (a) there was no significant change in proxy measurements; or
    (b) the past temperature did relate validly to the proxy and the temperature was constant; or
    (c) there is no known relation between proxy and temperature; or
    (d) there is a mathematical error in the calibration with instrumental (assuming the latter to be adequate), that had a perverse effect on reconstruction; or
    (e) the graph was a cartoon representation drawn by hand or a graphics program for illustrative purposes unstated.

    In any event, it does not matter much except for the ongoing confusion. There is only so much value in presenting a flat and level response on most graphs, that value usually being to exclude possibilities that there is something interesting.

    The case for (e) has evidence within the broader community. See, for example, the full emails from which these snippets are taken.

    1123513957.txt – an email that ends with “Take you pick, Peck.”

    1167752455.txt – ends “….The IPCC Scientific Assessment (Cambridge Univ. Press, Cambridge, 1990).But I had nothing to do with that one!
    So, that’s how a crude fax from Jack Eddy became the definitive IPCC record on the last millennium!
    Happy New Year to everyone
    Ray”

    1169653761.txt – ends “Kevin,
    I have attached updated versions of the diagrams so that you can see
    where the 2006 bars and dots should be moved to.
    John”

    Sir Paul Nurse, you do indeed need to move some sectors of science closer to the data sharing standards you note with the Human Genome project. This has been the most fundamental message from Steve from the beginning.

    You also need to note the harm you can cause by a blanket RS endorsement of a weak position.

  16. Charles Bourbaki
    Posted Mar 15, 2011 at 8:29 PM | Permalink

    Pax – no, J Bowers is not joking. He has no scientific qualifications whatsoever (admitted on a blog, but can’t find the reference), but does have an extreme antipathy towards our host.

    As demonstrated by his 92 out of 962 comments in New Statesman’s 50 People who Matter 2010.

    92 of them unfavourable.

  17. stumpy
    Posted Mar 16, 2011 at 2:47 AM | Permalink

    “This avoids the presentation of values that are known to be unrepresentative of the real temperatures” Jones

    If he “knows” what the temperatures really were than why bother with the graph? Just tell us what you “know” they should have been and throw out the observed data / proxies

    Either the proxy data is right and theres been no warming since 1960 in some proxie reconstructions, or they have little skill as proxies – please pick one, dont swap and splice bits to paint a picture of what you “know” it should be (like you know what is should be pre-1880 anyways) – this is whats called “fudging data” and its not science!

  18. David Holland
    Posted Mar 16, 2011 at 4:21 AM | Permalink

    The final two sentences in this quotation from page 44 of Fred Pearce’s “The Climate Files”, which I have have made bold, tell us how long the “hockey team” has been working on this business.

    That contrast between the Urals and Yamal has come back to haunt Briffa. Some sceptics say he has more recently favoured the Yamal tree ring data over his Ural proxies because they fit the hockey stick shape. We will explore that issue in the next chapter. But when I interviewed him back in the 1990s, Briffa revelled in the diversity of tree ring chronologies. Such superficial agendas as hockey sticks were nor for true tree ring aficionados.
    At the same time that Briffa was developing his temperature proxies based on tree rings other analysts were producing other kinds of proxy climale data. They were based on the size of glaciers and air bubbles trapped in ice, the isotope imprint left in coral reefs, the types of seeds in lake sediment and the temperature. of water at different depths in deep boreholes.
    Tim Barnett of the Scripps Institution of Oceanography, part of the University of California, San Diego, joined Phil Jones to form a small group within the IPCC to mine this data for signs of global warming. They planned to summarise the research in the panel’s next assessment, due in 2001. They had an agenda. “What we hope is that the current patterns of temperature change prove distinctive, quite different from the patterns of natural variability in the past,” Barnett told me in 1996. Even then they were looking for a hockey stick.

  19. David Holland
    Posted Mar 16, 2011 at 4:28 AM | Permalink

    Sorry, I screwed up that link!

  20. pete m
    Posted Mar 16, 2011 at 6:43 AM | Permalink

    Gavin said at Judith”S place:

    “Summary graphs are by their very nature, summaries. The graphs you pick out were summaries of various estimates of what paleo-temperature estimates from the literature were. It is therefore not surprising that they show only the reconstructions where the authors had confidence that the reconstructions were actually of the temperatures.”

    This seems to be an example of truncation of data BEFORE any literature discussion of the concerns anyone could possibly have with Briffa 98.

    lol @ confidence for 1400 reconstruction but not 1960 reconstruction – pull the other one Gavin.

  21. Alexander K
    Posted Mar 16, 2011 at 8:19 AM | Permalink

    Steve, more great Sherlocking on your part, great to follow.
    Deebee, J Bower is one of G Monbiot’s Grauniad CiF faithful who strayed from the garden of reason long ago. His usual tactic is to demand links, but he’s being a little more circumspect here than he usually is. Ignore him if he irritates you; I see his maunderings as quite sad.

  22. Posted Mar 16, 2011 at 9:12 AM | Permalink

    Steve’s description of Jones et al’s statement “this cannot be seen in the multiproxy series because they end before the early 1980s” as misleading seems rather generous. I would describe it as untrue, since Briffa et al 1998 say
    “Two hemispheric mean timeseries were constructed from these data, covering the period 1400–1994″.

    For info, here is the caveat in Briffa et al 1998:

    We note that after 1960, there is a reduction in the decadal-timescale correspondence between the instrumental temperature records and the density series, possibly reflecting some large-scale anthropogenic influence causing the densities to decline.

    It is particularly interesting that this caveat was put in a Letter to Nature (and repeated in the methods section) where space is tight, but not mentioned in the 27-page Jones et al review article.

    In general it would help to give the full reference of the paper or a link. It is
    Surface air temperature and its changes over the past 150 years
    Jones, PD, New, M., Parker, DE, Martin, S. and Rigor, IG
    Reviews of Geophysics 37(2) 173-199 (1999).
    You can find it on the web by googling the title.

    • Posted Mar 16, 2011 at 9:14 AM | Permalink

      For example here

    • oneuniverse
      Posted Mar 16, 2011 at 12:01 PM | Permalink

      That single-sentence caveat in Briffa ea. 1999 refers to Briffa ea. 1998*, the abstract of which contains (my emphasis) :

      During the second half of the twentieth century, the decadal-scale trends in wood density and summer temperatures have increasingly diverged as wood density has progressively fallen. The cause of this increasing insensitivity of wood density to temperature changes is not known, but if it is not taken into account in dendroclimatic reconstructions, past temperatures could be overestimated.

      The paper has a paragraph discussing possible explanations for the divergence :

      [..] The reason for this increasingly apparent and widespread phenomenon is not known but any one, or a combination, of several factors might be involved.

      The positive linear thermal response of the trees may break down above some absolute threshold, perhaps with lower soil moisture exerting increasing stress at a number of sites. However, the fidelity of the long-term growth response to the relatively high temperatures in the middle part of the century would imply the need for a concomitant lowering of soil moisture levels over very widespread areas during recent decades. There is little evidence that this has occurred in the regions represented by these trees. Also the maintenance of high positive interannual temperature correlations during recent decades, argues against a simple soil-moisture-related explanation of the reducing tree growth. However, more subtle changes in precipitation or temperature seasonality, such as the documented move to warmer springs, and associated earlier snow melt mean that it would be unwise to dismiss summer drought sensitivity too readily. Other factors such as increasing competition with other plants and increasing insect herbivory could play a role, but the apparent widespread synchroneity of the phenomenon suggests a hemispheric-scale influence. Higher UV-B levels or decreased solar radiation receipts (increased optical depth) may be involved, but attempting to isolate such effects will be problematic in the presence of increasing atmospheric CO2 concentrations and increasing amounts of acidic deposition and tropospheric ozone, all of which, along with climate variability, are likely to influence tree growth.

      The divergent data only seems to have been deleted or hidden when the proxies underestimated the temperatures – in contrast, the Yamal and NA strip-bark series, for example, which have extreme 20th C increases beyond the temp record, have proved very popular amongst Team researchers.

      *: Briffa, K. R. et al. “Reduced sensitivity of recent tree-growth to temperature at high northern latitudes.” Nature 391, 678–682 (1998)

  23. David Jay
    Posted Mar 16, 2011 at 3:57 PM | Permalink

    Steve, you continue to amaze – your unrelenting pursuit (I have been a CA reader for more than 3 years) of climate research “anomolies” personifies Winston Churchill’s famous speech to the Harrow School in 1941:

    “Never give in–never, never, never, never, in nothing great or small, large or petty, never give in except to convictions of honour and good sense. Never yield to force; never yield to the apparently overwhelming might of the enemy.”

    …sorry if this is too gratuitous, but it is heartfelt.

  24. Posted Mar 16, 2011 at 8:24 PM | Permalink

    “Almost Certainty: Briffa’s tree ring data pre-1960 is NOT a proxy for temperature — by deduction.”

    Except by accident.

  25. Publius
    Posted Mar 17, 2011 at 10:43 AM | Permalink

    “In this situation, it is arguably reasonable to show only data that are considered to provide some information about temperature variations.”

    Rule 1:
    Beware of adverb pile-up, e.g., “arguably reasonable” means… get ready for finagling.

    Rule 2:
    Beware of “show only data that”, translates as “we have selected those data that make the case we want to make.”

    Rule 3:
    Watch out for the cue: “some information,” in which the word “information” does not mean information in the rigorous sense that Shannon meant it (i.e., independent of context); rather it means “it supplies a trend that we believe is correct.”

  26. Hu McCulloch
    Posted Mar 17, 2011 at 3:07 PM | Permalink

    Likewise (see my comment on the next post on Briffa and Osborne, Science 1999), if RG has any scientific pretensions, it will be retracting this article for deceptive graphics.

  27. Hu McCulloch
    Posted Mar 17, 2011 at 5:40 PM | Permalink

    The versions plotted here clearly match the ones in the Jones et al 1999 figure – except for the deletion of Briffa values from 1960 or so on.

    Actually, your Briffa series is a little lower, and hence closer to the Mann series, throughout. But apart from centering, it appears to be the same series, except for the suppressed final 3+ decades.

  28. Steve McIntyre
    Posted Mar 24, 2011 at 10:01 PM | Permalink

    I’ve updated the emulation graphic using a technique of overprinting digital data on the original graphic that I’ve just learned in the past few days. I’ve made an animated sequence to illustrate it better.

    This shows clearly that the hide-the-decline here is effective in 1950 (rather than 1960) and that the source information is the 4th column (NHD2) in the Briffa et al 1998 archive.

12 Trackbacks

  1. By News Roundup 15 March 2011 on Mar 15, 2011 at 1:05 PM

    [...] New Light on Hide the Decline Steve McIntyre, Climate Audit, 15 March 2011 [...]

  2. By Hide the Decline: Sciencemag « Climate Audit on Mar 17, 2011 at 11:34 AM

    [...] Climate Audit by Steve McIntyre Skip to content Hockey Stick StudiesStatistics and RContact Steve McProxy DataCA blog setupFAQ 2005Station DataHigh-Resolution Ocean SedimentsSubscribe to CAEconometric ReferencesBlog Rules and Road MapGridded DataTip JarAboutCA Assistant « New Light on “Hide the Decline” [...]

  3. [...] 1998 was the “warmest year” of the millennium. Jones et al 1999, discussed recently here, contained a different spaghetti [...]

  4. [...] [...]

  5. [...] recently re-visited an article in Science (Briffa and Osborn 1999), that, together with Jones et al 1999 (Rev Geophys), [...]

  6. [...] recently re-visited an article in Science (Briffa and Osborn 1999), that, together with Jones et al 1999 (Rev Geophys), [...]

  7. [...] la curva de Man (al famoso palo de hockey) está masajeada. Lean a Steve McIntyre y sabrán más: 1, 2 y [...]

  8. By New Light on ?Hide the Decline? « Bee Auditor on Mar 23, 2011 at 10:30 AM

    [...] Source: http://climateaudit.org/2011/03/15/new-light-on-hide-the-decline/ [...]

  9. By Hide the Decline – igen | The Climate Scam on Mar 25, 2011 at 6:11 PM

    [...] här, här och [...]

  10. By Cooler Heads Digest 18 March 2011 on Mar 29, 2011 at 9:03 AM

    [...] New Light on Hide the Decline Steve McIntyre, Climate Audit, 15 March 2011 [...]

  11. [...] warmth of recent decades. To give the hockey stick its alarming looking blade, MBH had to “hide the decline.”  In contrast, the Esper team found no divergence between instrumental data [...]

  12. [...] The researchers argue that “X-ray densitometry” enables a more accurate reconstruction of climate history than does analyzing the width of tree rings – the principal data used by MBH. For example, MBH found a “divergence,” starting in 1960, between a decline in Northern Hemisphere temperatures, as reconstructed from tree ring data, and the increase in Northern Hemisphere temperatures, as measured by thermometers and other heat sensing instruments. The divergence raises the question of how MBH can be so sure the Medieval Warm Period was tiny or non-existent when their proxy data fail to reflect the instrument-measured warmth of recent decades. To give the hockey stick its alarming looking blade, MBH had to “hide the decline.”   [...]

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