Dec 26 2011

Mann’s Perjury To NAS Panel


Right before Christmas I finally purchased The Hockey Stick Illusion by A.W. Montford (a.k.a. owner of Bisop Hill blog), and I have to admit it has been both a fascinating read and a worthwhile investment in time. I have been able to accelerate my understanding of the interplay between The Hockey Team, the skeptics (led my McIntyre and McKitrick) and the mountain of email and data made public in Climategates 1  & 2.

I am just now nearing the halfway point after the intense march to, and repercussions from, the 2006 NAS ‘investigation’. I have a much deeper understanding of how the RE and R2 (also denoted as r2) verification debate became so intent. I will not be able to explain in a few lines what Montford did so skillfully in many chapters, but the point of this post is to show how the new Climategate emails uncover a blatant lie by one Michael Mann to the NAS panel. A panel that supposedly was an arm of a Congressional Committee investigating AGW theory and the battle over accuracy and correctness between the two camps.

A synopsis of the topic could be summarized as follows:

  • In Mann, Bradley, Hughes 1998 (denoted ‘MBH98′ and source of the infamous Hockey Stick graphic) the claim was made that the connection between modern temps and proxy reconstructions was statistically significant and showed today historically warmer than any period since Medieval times.
  • However, as McIntyre began his due diligence audit of the methods and data of MBH98 he noted a few problems, only one of which was how MBH98 relied on the rarely used and unwarranted statistical verification of RE instead of the traditional and more reliable R2 . In fact, most statisticians prefer to check multiple verification tests to prove their work is ‘robust’ and not just random correlations without any meaning. It turned out MBH98 admitted to using R2 as well, but did not report the value (i.e., was the math any good). This seemed very strange.
  • After much work McIntyre confirmed Mann had performed the R2 test, as had Amman & Wahl in their 2004 papers trying to confirm Mann’s Stick. But nowhere could he find the true values (or the ones ‘recreated’ by Wahl and Amman).
  • When Congress decided to investigate the mess, the NAS jumped in to try and protect the AGW claims and held hearings for Congress. It was at these hearings in 2006 that Mann’s Hockey Stick was shown to be pretty much broken. At that time Mann apparently testified (according to Montford’s book) that he had never computed R2.

Here is the passage from The Hockey Stick Illusion and McIntyre’s blog:

He [McIntyre] explained to the panel how Mann had reported in MBH98 that he had calculated the R2 for the Hockey Stick, but had withheld the fact that the results indicated his reconstruction was unreliable. McIntyre went on to demonstrate how the IPCC had later misrepresented the Hockey Stick as having significant ‘skill’. Having dramatically failed the verification R2 test, the confidence intervals for the Hockey Stick were, in the words of Hegerl, “from floor to ceiling”. In other words, you could have no confidence in the results at all.

This was a very damning set of accusations and one which promised some fireworks when Mann came to speak the following day. In the event though, absolutely nothing happened. John Christy, who was seen as the lone sceptic on the panel, asked Mann about his R2 score. Mann tried to evade the question by denouncing its usage in general, but Christy pressed him further, asking whether he had in fact calculated the figure. Mann’s reply was sharp and to McIntyre, at least, breathtaking:

We didn’t calculate it. That would be silly and incorrect reasoning.

Here is where Micheal Mann committed perjury to hide his mistakes. Mistakes that destroy the Hockey Stick and all claims today we are experiencing unprecedented warm climate conditions.We know his MBH98 stated they computed the numbers. But we also know the Hickey Team was working with Wahl and Amman on supporting Mann with Briffa and others. So what where they saying as this went down?

The truth comes from Eugene Wahl himself in a series of emails with Keith Briffa in June 2006, right after the NAS panel. It spans many emails, but let’s focus on email #5240:

Also, let me know if I can help on the issue of RE vs r^2. I could write a few brief sentences as something for you to look at if you would like. Wahl-Ammann show very clearly that there is objectively demonstrated skill at the low-frequency level of the verification period mean for all the MBH segments, although the earlier MBH segments do have really low r^2 values (indicating very little skill at the interannual level).

A low R2 value means there is no statistical significance. The ‘earlier MBH segments‘ are those reconstructions which compared the modern climate to the Medieval Warm Period (MWP). Thus the claim that the MWP is not as warm as today really had not statistical ‘skill’ (something I would also convey to Mann) – according to am brief moment of honesty by Wahl.

We later find out in Montford’s chronology of events that the Wahl-Amman papers never do support MBH98, and in fact confirm the low R2 values which Mann conveniently hid from scrutiny. All this proves the Hockey Stick is actually a crock of stick.

Mann lied many times to NAS. This is probably the most egregious one, to claim he never knew his claims were statistical garbage. No wonder he ran from McIntyre and McIntrick for so many years. They had caught him red handed, hiding the true math and the true results. And all the so called peer review in the world missed this until M&M stepped up and did the scientific process right.

Shame on all the rest for even pretending their PhDs convey upon them the title of ‘scientist’.

10 responses so far

10 Responses to “Mann’s Perjury To NAS Panel”

  1. Redteam says:

    Good review. It’s one thing to have a belief in something such as global warming and to use information that tends to prove your beliefs, but it’s a whole different matter to just completely lie about your results and the facts to prove that lie.

    Just today, I was tuned to the History Channel and the show was about Global warming. It started out with a statement about the climate today being warmer than it had ever been and the levels of CO2 being the highest it had ever been and stated that they had unequivocal proof of it. I changed channels. Why would any tv show put on such hogwash?

  2. [...] Mann’s Perjury To NAS Panel [...]

  3. WWS says:

    But… but… Micheal Mann was investigated by Penn State, and Penn State President Spanier personally stated that Mann had done nothing wrong and had lived up to all of Penn State’s ethical guidelines.

    Of course, this WAS the same Penn State President Spanier who was fired earlier this year for lying to the board and to the police, and for knowing all about Jerry Sandusky’s recreational activities for years.

    simple fact is, there ARE no rules for anyone who the university sees as a fountain of grants and/or donations. Follow the money, ‘cuz it makes all the rules. For a while.

    Sandusky, Mann… one’s been caught, one’s about to be.

  4. crosspatch says:

    Well, I believe everyone in the climate science field recognizes that the MBH paper is complete fantasy. Phil Jones is a contributing author of a paper that shows no such hockey stick in the Southern Hemisphere (South America) and quite clearly shows the MWP was a factor there as well and wasn’t a local phenomenon.

    This is discussed on the web here:

  5. MerlinOS2 says:

    Since this is all falling to pieces then by extension the finding of the IPCC should not be worth the paper they are written on.

    With that being the case it is well beyond time for SCOTUS to revisit the CO2 ruling that enabled the EPA to go on their regulation rampage.

  6. granitroc says:

    Okay, so what was the r2? This value will range between 0 and 1, with 0 being no correlation and 1 perfect correlation. In our work, we view correlations less than .7 as being meaningless. So what was it?

  7. crosspatch says:

    Part of the problem, too, is that something could have a low correlation and so have a low base weight but that weight is then multiplied by the area of the earth the reconstruction represents. So you can have something with low correlation and base weight that covers a huge area and so gets multiplied. That is, in fact, what happened:

    See the update to this posting at CA:

    This is specifically about MJ03

    Recall that Mann claimed to Bradley (and others) that the weighting in MJ03 was done “objectively” by their decadal correlations to the local temperature, and that the Yang composite had a “reasonable (r=0.22), but not great correlation” and thus it obtained a “moderate low weight”. What Mann “forgot” to tell is that the weight in MJ03 is calculated not only based on correlation but also on the area.

  8. Jessie says:

    Crosspatch @ 6.47pm

    Thanks for this overview and also those of the other posters.

    In Australia our federal census agency ABS (Australian Bureau of Statistics) has yet again changed the metadata for geographical classification.

    While not meaningful for studies using lat and long, it is meaningful for federal, state, local government analyses and thus funding grants.

    And we also have permutations of geography based on race (Indigenous), distance from nearest regional centre, population density, electoral etc.
    In the very northern regions (unpopulated but mining) these permutations are in spite of all weather airstrips these days, access to skype and 2-way satellite and much improved barge (shipping) access in the tropical north.

    My impression is that acquisition of PUBLIC funding based on spurious research is all important. I find this approach differs little to the public health studies that sought and supported regulatory change (legislative) driven by the EPA and the Unions.

  9. crosspatch says:

    If you are suddenly worried about race in your country’s bureaucracies, you must have elected a center-left government. There is no political faction more racist than the left and they are very Orwellian about it. They inject race into every possible thing and attempt on one hand to be a champion of minorities while on the other hand enacting policies to keep them dependent on government programs so they are never able to actually succeed on their own. So you pretend to be helping them but in reality you are making them dependent on your help forever by killing any work ethic and instilling a sense of entitlement.

    It is so sad, I wish people would wake up and realize they are being used.

  10. AJStrata says:


    I will look it up, but well below 0.2 (may have been below0.1!).