Broken Hockey Stick! (Global Warming Scam Busted)

Still Waiting for Warming ^ | Oct 29, 2003 | John Daly

[Dan Evans]

Broken Hockey Stick!   (29 Oct 03) In a stunning scientific paper just published in Energy and Environment, the infamous `Hockey Stick' as developed by Mann, Bradley and Hughes in 1998 has been comprehensively discredited - using the same data sources and even methodology used by the Hockey Stick's original authors. According to McIntyre and McKitrick [Energy & Environment ref]; " The data set of proxies of past climate used in Mann, Bradley and Hughes (1998, “MBH98” hereafter) for the estimation of temperatures from 1400 to 1980 contains collation errors, unjustifiable truncation or extrapolation of source data, obsolete data, geographical location errors, incorrect calculation of principal components and other quality control defects. We detail these errors and defects. We then apply MBH98 methodology to the construction of a Northern Hemisphere average temperature index for the 1400-1980 period, using corrected and updated source data. The major finding is that the values in the early 15th century exceed any values in the 20th century. The particular “hockey stick” shape derived in the MBH98 proxy construction – a temperature index that decreases slightly between the early 15th century and early 20th century and then increases dramatically up to 1980 — is primarily an artefact of poor data handling, obsolete data and incorrect calculation of principal components." On this website, the Hockey Stick's conclusions about past climates were challenged (see `The Hockey Stick: A New Low in Climate Science') on the basis of direct comparison with numerous other scientific studies which found that late 20th century climate was in no way remarkable when compared with previous `pre-greenhouse' centuries, especially the warmer Medieval period. However, McIntyre and McKitrick have challenged the `Hockey Stick' on its own turf by subjecting it to an `audit’, using the same data and assumptions, and developing a temperature reconstruction from similar principles.  It was a classic replication exercise, so necessary in science.  The result is shown below - The McIntyre-McKitrick reconstruction (blue) shows earlier climates to be warmer than the late 20th century, a conclusion supported by numerous other scientific studies, whereas the `Hockey Stick’ denies this reality.  It seems that through a combination of tabulation errors, truncating data series for no valid reason, and `bridging gaps’ in data with little more than guesses, the `Hockey Stick' authors created a thoroughly false picture of past climates, which was instantly embraced as policy by the UN-IPCC and the greenhouse industry it leads.  It became influential in convincing pro-Green policy-makers like former US vice-president Al Gore, that late 20th century climatic warmth  was without precedent in human history.  Not only did the `Hockey Stick' fly in the face of a mountain of evidence from other sciences which contradicts its conclusions, but thanks to McIntyre and McKitrick, we now know that the Hockey Stick is internally flawed as well, since its own data sources, properly read, do not support its conclusions either. This raises the question of the scientific bona fides of climate science itself.  McIntyre and McKitrick have exposed fundamental scientific flaws in an influential scientific paper which was fully peer reviewed by `experts' from the greenhouse industry and published in a top journal.   Their audit of the databases and statistical processes which lay behind the `Hockey Stick’ called for first-order statistical skills above all else, and it is here that they have exposed the incompetence which lay behind the original `Hockey Stick' concept.  There have been many other instances of deeply flawed science being given an uncritical green light for publication by reviewers from this science, but the question must now be asked whether their pretensions to scientific status can be justified by their performance.  Energy and Environment is one journal that has stood up for free debate on this and other issues of public importance, and is to be commended for publishing this long-awaited and damning critique of the `Hockey Stick'.  To facilitate public debate, the journal has taken the unusual step of making the full McIntyre-McKitrick paper freely available online. Download the full .pdf of the McIntyre-McKitrick `Hockey Stick' critique here

[palmer]

As for McIntyre and McKitrick, it doesn't look to me like they did the amount of checking and double-checking that they should have done before going to the presses with a major announcement of apparent "bad science" on the part of Mann et al.

Now we have two authorities stating that it is bad science (Wegman and Jolliffe), as was obvious to most unbiased scientists from the beginning (that includes M&M).

It is interesting that you were much more open minded and skeptical 5 years ago. What changed?

[<1/1,000,000th%]

Great post!

[cogitator]

It is interesting that you were much more open minded and skeptical 5 years ago. What changed?

Intriguing that the quote was about the old M&M paper.

The short answer would be: more data. A longer answer would go into the types of data: a lot of phenological indicators (as I've noted) -- quite a few things in the most recent IPCC report that might have gone unnoticed by those just reading the summary for policymakers -- some pithy comments by Frank Wentz I discovered by accident -- the summer sea ice trend -- and there's more, a lot more. I don't have three hours to write it all down.

I'd be curious to know what you think I was more skeptical about. I've felt that I always was consistent on increasing atmospheric CO2 concentrations causing warming, and hewing to a mid-range (2-3 C) projected global temperature increase by 2100. I credited the hockey stick critics with doing necessary work to address discrepancies in that line of research, while always seeing the paleoclimate research as only contributing to, and not defining, knowledge of how the modern climate is changing. Mann and Co. coming out with another paper that reignites the sound and fury is a distraction, because it creates emphasis on sidebar questions like "was the MWP actually warmer or only just as warm as now?" and "if it warmed up in the past naturally, then there's no proof that the warming now is non-natural, is there?" (Pardon me while I choke.)

As this discussion has progressed, I've become increasingly dismayed by the constant barrage of inaccurate, incorrect, and repetitively reiterated discredited and misunderstood arguments trotted out by the increasingly vocal skeptics, which are accepted credulously by those who view climate change solely as a political issue. My dismay has certainly affected my tone.

[palmer]

In your post above you appear to not have made up your mind and were skeptical about Mann’s claims. Today you just dismissed the MWP with a red herring counterargument and Mann’s continued attempts to localize the MWP to Greenland have gained your tacit approval (is Mann the distraction or Mann’s critics?) Mostly it’s your tone that has change partly from the continued repetition of old arguments, and partly from the hardening of your position in general. You were quite successful in countering Mars is warming and numerous other arguments made countless times. Now you have the impression that the denialists are switching arguments (a claim made over and over on RC), when you are only looking at the Rush Limbaugh arguments. The truth is that the skeptics and the AGW proponents have both stayed more or less consistent over the last decade but their idealogues have varied wildly (Mann’s changes in tactics being a perfect example).

[cogitator]

I think you're making interpretations of things I didn't say. I did say the following:

However, given that there are independent analyses of climate proxy data that show the same general patterns as the Mann et al. papers,

and

The argument is that his data analyses reduced the apparent scope and intensity of the Medieval Warm Period warmth and the Little Ice Age cold.

So was I skeptical about Mann's claims? I guess the central claim then was that this period was the warmest in 1000 (2000?) years, globally. Whether or not I was skeptical at the time (I don't remember how skeptical I was or whether I really concerned myself with that particular claim), I was unsurprised when it turned out that there wasn't very good data allowing any quantitative comparisons going back more than 400 years -- hence you can't say that the MWP was warmer than now or vice versa, you can just say now and then were both clearly warm periods.

So now the question might be posed: what about the most recent paper (i.e., Mann et al. 2008)? If I read Climate Audit correctly -- and I haven't bothered with the new paper -- then there's only a "skillful" reconstruction back to 1500, so any results before that are not "skillful". If that's true, then I would think any direct quantitative comparisons are still kinda stupid.

And I will note, as I know I've done numerous times before, that it's not the actual value of the temperature that's as important as the rate of change. Looking at the paleoclimate record solely as an indicator of when abrupt climate changes happened and not concentrating on absolute temperatures, it is clear that times of maximum ecosystem disruption occurred at the times of most rapid climate change. (Unsurprising.) Knowing what I purport to know (and what I think I know) about the current climate indicates that we are on the verge of a very rapid climate change. And I know what that means for ecosystems.

So what about Mann? In summary, he got hired to do a job. He's doing that job by continuing to publish in the field that the university which hired him expected him to publish in. Unfortunately, the controversy that has dogged his earlier efforts has made him a lightning rod, and any further criticism that sticks (and some of it might) will serve as a further example to those who are aleardy convinced of it that the whole scientific understanding of global warming is unsound.

And since I know that's utterly idiotic, there's no point in my pursuing the arcania of centered or non-centered PCA. This is a sideshow. The main show is going on under the big tent.

[palmer]

there's no point in my pursuing the arcania of centered or non-centered PCA

It's not just arcania of centered or non-centered PCA. It's Briffa's Yamal series Think we'll see corrections to the dozens of papers using the series?

[palmer]

If anyone clicks into this thread wondering why it has been resurrected yet again, it's because this time instead of naive (at best) and incorrect application of statistical techniques to automatically select hockey-stick shaped "temperature" proxies (some of which are clearly preipitation proxies and some may be CO2 proxies), we have a clear and undeniable case of proxy selection based on nothing more than human selection bias (or at best for some of the faulty reconstructions, they blindly followed the biased scientists out of misplaced trust).

In red above subset of data used to create the hockey stick used as part of dozens of other hockey stick papers. In black, the full set of data known to the researcher.

[editor-surveyor]

Environmentalist lies ping!

[editor-surveyor]

"But I've seen the junk produced by the creationist crowd by taking selected pieces of fact and extrapolating fiction from it."

You must have creationists confused with evolutionists:

- Piltdown man.

- Nebraska man.

- Feathered chinese dinosaurs.

You psuedo-science groupies will stop at nothing!

[editor-surveyor]

The confusion is in your mind, as usual.

Have you ever seen a global warming fraud that you didn’t love?

[editor-surveyor]

The site is blocking down-loads.

[GOPJ]

If Global Warming is totally discredited - what scam will liberals come up with next?

It has to be something a drama queen would love.

It has to give liberals power to force middle class citizens.

It must cause the United States to give extra money to Africa.

And it has to give power to democrats and the so-called "intellectuals" on college campuses...

Anyone?

[airborne]

...broken hockey stick...?

[airborne]

Swine flu.

Pandemic = complete government control/police state

[GOPJ]

It's a good guess - problem is in pandemic people die - or get better.

For liberals this has to be something that's mildly plausible - enough to trick most of the people for a while. And long term. It has to be costly and have enough buildup time for Hollywood idiots to jump on the bandwagon and do "fund raisers"...

A pandemic's too quick.

[Victoria Delsoul]

Lol, the phony enviro-wackos were caught lying? What a surprise!

[cogitator]

Have you ever seen a global warming fraud that you didn’t love?

I'm not aware that I'm in love with any global warming frauds. If you're going to call something a fraud, you'll have to justify what and why.

[cogitator]

Think we'll see corrections to the dozens of papers using the series?

Yes, if they are necessary. Now, the reason I say yes is that the large-scale process of scientific peer-review, i.e., publishing new analyses, is ponderously self-correcting. If the time-series was used (or constructed) erroneously, and this bears out under scrutiny, then there will be new analyses that update and improve the old incorrect analyses.

Be that as it may, McIntyre has a specialty. I think he's doing a good job of keeping the practitioners on their toes and accelerating some necessary introspection. If he's finding errors that need to be corrected, I hope to h*ll they are corrected, ASAP.

Quoting Robert Procter: "The tobacco industry started responding particularly in the 1950s with propaganda. That’s when they started their doubt campaign—the manufacturing of doubt, the manufacturing of ignorance. It was really rather new, certainly on the scale at which they pursued it. It was a new way of using science as an instrument of deception. And that’s become important recently. Franchised down into the global warming issue are the same techniques. Demanding ever-greater precision, invoking doubt, questioning the physical methods. Raising alternate possibilities. The whole realm of smoke screens and distractions."

Now, I am not quoting Procter to indicate that legitimate scientific concerns about data accuracy, interpretational bias, methodological misapplication, experimental cross-checking, instrumental calibration (et cetera, et cetera, et cetera) should not be entertained. They should be; and as I said, science is ponderously self-correcting, it takes time to move a heavy weight if a heavy weight needs to be moved. What I am saying is that the "throw everything against the wall without applying cognitive or quality filters to see if anything sticks", just to create a perception of doubt, IS disreputable.

[SierraWasp]

By George! I think you’ve gotit!!!

[palmer]

Good statement. As I see it, there are three issues that need to be resolved. The first was the subject of this thread, the statistics that included an approx 1900 center for PCA causing the effect that any set of red noise time series would produce a hockey stick. I think that has been beaten to death. Second is the whether the data represents temperature. I think the key is that the ability of proxies to represent temperature is not a constant. Third is public access to all the data. There was data that was ignored and data that was discarded, but all of it needs to be made available.