The Tipping Point

Posted: February 24, 2011 by tallbloke in solar system dynamics

This is a partial repost from Climate Etc including the intro and two responses. See the original for the full monty.


"A spurious piece of nonsense built on bad data selection methods, selective data deletion and rubbish stats" -Tallbloke-

Hiding the Decline

by Judith Curry

To date, I’ve kept Climate Etc.  a “tree ring free zone,” since the issues surrounding the hockey stick are a black hole for conflict and pretty much a tar baby, IMO.  Further, paleoproxies are outside the arena of my personal research expertise, and I find my eyes glaze over when I start reading about bristlecones, etc.  However, two things this week have changed my mind, and I have decided to take on one aspect of this issue: the infamous “hide the decline.



You have gone significantly over the line with this post. Accusations of dishonesty are way beyond a difference of opinion on how a graph should be displayed.

If you thought that a single, smoothed graph of estimates of paleo-temperature told the whole story of paleo-climate reconstructions is far more a failing at your end than it is the authors involved. How can a single graph say everything that can possibly be said?

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.

Problems with modern divergence – which only applies to the Briffa et al curve in any case – are issues to be dealt with in the technical literature, as they still are.

The quote from the emails on the ‘dilution of the message’ was related to a completely different issue – the fact that Briffa et al’s initial reconstruction did not have very much centennial variability at all (the version of the graph that was being discussed is here: ). You are being misled if you think that is related.

One can have a difference of opinion in how to present a graph, and that depends entirely on what point you want to make. If you want to make a point about multi-decadal temperature changes in the past, it makes sense to include estimates of those temperatures and the uncertainties. It doesn’t make much sense to include annual estimates, or seasonal estimates, or parts of the curve that the originators think doesn’t reflect actual temperatures (for whatever reason). The only issue is to ensure that the graph is sufficiently documented so that these choices are clear (which in the WMO report they were not sufficiently so, but were fine in the IPCC graphs).

But to ascribe a difference of opinion to dishonesty is to remove yourself from any sensible discussion on the topic. Perhaps if I was to find a graph in one of your papers which I thought didn’t show some aspect of the data I was interested in, and then accuse you of dishonesty? Would you react well to that? This is exactly the same.

How can you claim to be building bridges, when you are so busy burning them?

  • Gavin, the field does not need any more summary graphs of this nature. They have done an enormous disservice to climate science and its credibility. Continuing to defend these kinds of graphs is beyond anything I can understand. Leaving out that data and putting a “likely” confidence level on conclusions from that data is bad science, anyway you slice it. If you don’t like dishonest, try misguided and pseudoscience. There is no way this is defensible scientific practice. I really hope we don’t see any more of these kinds of graphs, in the AR5 or elsewhere. I’ve tiptoed around this one long enough, I’m calling it like I see it.

So there we have it. The tipping point. We have seen the outcome of the point that the Team wanted to make with their particular ‘style’ of graph presentation. It has been the ruination of good climate science and the skewing of the perception of public, press and policy makers alike. Followed by their derision and disbelief following the revelations in the emails which must not be named.

There is so much wrong with the Hockey Stick : Hide the Decline graph. It has been comprehensively dealt with by many analyses and published papers. Yet still the Team play politics and pretend there is no case to answer to. Instead they attempt to undermine the credibility of the people who have politely proved to them that they are wrong. This is why, finally, harsh words like dishonesty get used.

Considering the false accusations and ridicule the Team has meted out, Gavin doth protest too much.

“Gone significantly over the line”? The Team can’t plot where the line is using the data handling techniques they defend, that’s for sure.

  1. Zeke the Sneak says:

    “If you thought that a single, smoothed graph of estimates of paleo-temperature told the whole story of paleo-climate reconstructions is far more a failing at your end than it is the authors involved. How can a single graph say everything that can possibly be said?”

    Now he tells us, aaafter frightening school children, Hollywood actresses, and rock stars with the appearance of runaway, unprecedented temperatures. They might like to know that it was just “a failing at their end, that they thought the paleo-temp records told the whole story”!

  2. Joe Lalonde says:


    The main theme that Gavin and his like minded brethren keep imposing is that we should all listen to them and believe them 100% as they are the experts that should not be questioned. They are above having their science or views questioned.

  3. Will this graph survive the Landscheidt Minimum?

  4. tallbloke says:

    “They are above having their science or views questioned.”

    Joe, the mainstream scientists would deny that, and say that anyone is free to rebut their papers in the literature. However as we know from the climategate emails, the journals and the peer reviewers they use are biased towards the pro AGW position. This has maintained a pretty effective stranglehold on the science for years, with a few notable exceptions.

  5. Joe Lalonde says:


    Question is: Who do you go to to dispute scientific points?
    Who do you go to to show new work that is beyond the current box that has been created?
    Who would be the expert in a field never explored?

    Certainly not the current publishing establishments.

  6. tallbloke says:

    Joe, see Miles Mathis’ thread.

  7. Joe Lalonde says:


    Re-read it a second time.

    So the answer is no place.

    I guess I’ll just pass it down to my grandson and hope time will erase the current regime in power.

  8. As professor Khabibulo Abdusamatov said, when asked by Ria Novosti about “global warming”: “It´s Hollywood science”

  9. tallbloke says:

    Martin Lewitt says:
    February 24, 2011 at 3:16 am


    “Since the aerosals alone would create a cooling trend, and the anthropogenic emission of GHG’s create the main warming trend, the aerosals couldn’t be responsible for warming, despite the uncertainty in trend that you mention.”

    Variation in aerosol forcing can create a cooling or warming trend depending on whether they are increasing or decreasing respectively. CO2 forcing which is proportional to the log of its concentration could not have caused the mid-century cooling nor the relatively steep upward temperature trend of the 80s and 90s. The uncertainty in aerosol forcing was particularly helpful to the climate models in “matching” the 20th century climate despite significant disagreement among them on climate sensitivity. But this helpful little buddy, could easily have performed a similar role for solar, and possibly could have handled the task of matching the 20th century warming without any variation in solar or CO2.

    Recall that in the 20th century the proportion of energy from petroleum was increasing, the 50s, 60s, and 70s saw the boom and decline in use of leaded gasoline, and it also saw the peak of acid and then significant reduction of acid raid due to sulfate aerosols. Notice that the IPCC groups aerosols with CO2 in anthropogenic forcings, and discounts natural forcings alone as being able to explain the recent part of the warming. Well if you group things a little differently, the solar grand maximum could explain the 20th century warming, with the same kind of aerosol curve fitting that helped CO2 forcing. The uncertainty in aerosol forcing also served as good cover for the model inability to reproduce the observed multi-decadal climate modes were in phases that help explain both the mid-century cooling and the acceleration of warming in the 70s, 80s and 90s.

    Where does the reality probably lie? Most of the warming since the little ice age is due to solar, which plateaued at a grand maximum for the last 60 years of the 20th century. CO2 probably contributed about 30% of the warming since 1950. Aerosols and climate modes and volcanoes sculptured the details of the temperature curve. Any greater contribution from CO2 requires net positive feedbacks to CO2 forcing that act in decadal time frames without crossing climate tipping points, for which is there is no model independent evidence. We need a longer sample of high quality data, better models subjected to perhaps a couple decades of less accommodating peer review. A really interesting couple solar cycles would help increase our understanding and may be arriving just in time. With these we might reach a scientific consensus rather than an ideologically imposed one.

    Those of us who love science really want to know and understand, we don’t trust those that want to cover up and withhold the evidence rather than follow it, and who want to express confidence where they should acknowledge uncertainty. We don’t trust them because they aren’t like us, they don’t love science, they aren’t sharing our quest to know and understand. The climategate revelations were shocking, cathartic and really, really sad and disappointing. I cried, and still tear up if I think about them very much. Don’t let them tell you that everybody is two faced when they get behind closed doors, because everybody isn’t, but those who tell you that almost certainly are. Climategate is sad, not just because of what those people were doing to the science, but also because of what they are missing. If you have ever been at the whiteboard at M.I.T. or Caltech or our national or corporate laboratories with the very best minds, you know what I mean. It is refreshing, cleansing, challenging and enlightening. Did the authors of the climategate emails sound like they wanted to be challenged and enlightened or did they sound like they had an agenda?

    Know the thirst. Follow the evidence. Let the chips fall where they may. Welcome to the quest!

  10. Roger Andrews says:

    I spent many years in the mining industry reviewing and verifying assay data bases (gold, silver, copper, etc.) The basic approach was to take every 20th sample and send it off to a different assay lab for a check assay. If the check assays came back within +/-5% of the original assays the original assays were accepted and if they didn’t they weren’t. Standard operating practice.

    The Hockey Stick is an analogous situation. The original assays are the tree-ring proxies and the check assays are the instrumental temperature records. And how well do they compare? Not worth a damn. The differences are more than large enough to prove that tree ring series – or at least the ones MBH were using – were NOT reliable temperature proxies. The MBH study should have died stillborn as soon as this was discovered.

    But it didn’t. Why? Because the Hockey Stick showed exactly what the powers-that-be wanted to see – no more MWP, LIA gone, nothing left but AGW. It was so obviously correct in every detail that the science didn’t even need to be checked. It was, in short, a complete breakdown of the peer review process.

    In fact I think it’s questionable whether ANY proxy temperature reconstruction would pass an objective peer review process. Why? Because proxy records are all over the map. (Click on the link below for a demonstration. It should be good for a laugh if nothing else.)

    Click to access making-holocene-spaghetti-sauce-by-proxy.pdf

  11. Richard says:

    A wicked thought has occured to me (and off topic to boot so I’ll understand if it does not get past moderation 🙂 ).

    What if we were to rename the IPPC Scenario 3 as ‘Carbon Dixoide does not influence the Climate in any meaningful way’. I realise that this is a rather harsh paraphrase, but surely defensible.

    Then all is needed is to track how close Global temperatures are to Scenario C (with appropriate confidence intervals) to decide on Glabal warming/Cooling.

    [edit] Like it. 🙂

  12. Richard says:

    Carbon Dioxide. Carbon Dixoide is a new compond!

    [edit] Some people get so tired of typing those words they get tired I guess.

  13. tallbloke says:

    People have asked why mainstream scientists are keeping silent on these issues. As a scientist who has largely kept silent, at least in public, I have more sympathy for silence than most people here. It’s not for the obvious reason, that speaking out leads to immediate attacks, not just from Gavin and friends, but also from some of the more excitable commentators here. Far more importantly most scientists are reluctant to speak out on topics which are not their field. We tend to trust our colleagues, perhaps unreasonably so, and are also well aware that most scientific questions are considerably more complex than outsiders think, and that it is entirely possible that we have missed some subtle but critical point.

    However, “hide the decline” is an entirely different matter. This is not a complicated technical matter on which reasonable people can disagree: it is a straightforward and blatant breach of the fundamental principles of honesty and self-criticism that lie at the heart of all true science. The significance of the divergence problem is immediately obvious, and seeking to hide it is quite simply wrong. The recent public statements by supposed leaders of UK science, declaring that hiding the decline is standard scientific practice are on a par with declarations that black is white and up is down. I don’t know who they think they are speaking for, but they certainly aren’t speaking for me.

    I have watched Judy Curry with considerable interest since she first went public on her doubts about some aspects of climate science, an area where she is far more qualified than I am to have an opinion. Her latest post has clearly kicked up a remarkable furore, but she was right to make it. The decision to hide the decline, and the dogged refusal to admit that this was an error, has endangered the credibility of the whole of climate science. If the rot is not stopped then the credibility of the whole of science will eventually come into question.

    Judy’s decision to try to call a halt to this mess before it’s too late is brave and good. So please cut her some slack; she has more than enough problems to deal with at the moment.

    If you’re wondering who I am, then you can find me at the Physics Department at Oxford University.

    Jonathan Jones

  14. Tenuc says:

    The fact the the temperature reduction seen in the post ’60(ish) tree ring data is in conflict with the thermometer temperature record makes the hockey stick graphs a complete reductio ad absurdum. It is clear that the tree ring data used cannot be trusted and it is perhaps no surprise that the scale of the MWP and LIA seemed to disappear.

    Without facts, assumption rules the day and science itself becomes corrupted as politicians, and their masters, use the confusion to tighten their stranglehold on the freedoms of the electorate.

  15. P.G. Sharrow says:

    The trees are just dumb plants, they do not lie. Liers lie even when they don’t have to. The trees say that they are living in declining growing conditions. SO! One lame paper leads to the next. Armchair scientists that don’t do real research can make big mistakes and don’t even know it. I once spent several weeks inventing and engineering a device based on a typo mistake in a chemistry book. 😦 should have done more work on research. At least I did not build it! and I still have an unpatented device that went with it. 😎 pg