As you all recall, the NAS panel let MBH off rather lightly in respect to disclosure and the House Energy and Commerce Committee couldn’t be bothered. So all in all, MBH dodged a bullet and you’d think that they’d have been wise enough to leave well enough alone. But no. In today’s Nature, Mann, Bradley and Hughes send an astonishing letter, in effect re-opening disclosure issues after everyone else had got bored with it. MBH write:
Your News story “Academy affirms hockey-stick graph”à (Nature 441, 1032; 2006) states that the US National Academy of Sciences (NAS) panel “concluded that systematic uncertainties in climate records from before 1600 were not communicated as clearly as they could have been”. This conclusion is not stated in the NAS report itself, but formed part of the remarks made by Gerald North, the NAS committee chair, at the press conference announcing the report.
The name of our paper is “Northern Hemisphere temperatures during the past millennium: inferences, uncertainties, and limitations” (Geophys. Res. Lett. 26, 759-762; 1999). In the abstract, we state: “We focus not just on the reconstructions, but on the uncertainties therein, and important caveats” and note that “expanded uncertainties prevent decisive conclusions for the period prior to AD 1400″. We conclude by stating: “more widespread high-resolution data are needed before more confident conclusions can be reached.” It is hard to imagine how much more explicit we could have been about the uncertainties in the reconstruction; indeed, that was the point of the article!
The subsequent confusion about uncertainties was the result of poor communication by others, who used our temperature reconstruction without the reservations that we had stated clearly.
Well, readers of this site can doubtless think of many ways in which they could have been more "explicit about the uncertainties".
Some of the "poor communication by others" is conveniently documented at Mann’s website for MBH98 and MBH99, he lists various press clippings. Not all the links still work, but some do. Contemporary examples of poor communications victimizing MBH include:
USA Today is one example of "poor communication by others", saying:
The latest reconstruction supports earlier theories that temperatures in medieval times were relatively warm, but "even the warmer intervals in the reconstruction pale in comparison with mid-to-late 20th-century temperatures," said Hughes.
And, of course, the CBC:
Researchers at the University of Massachusetts say the 1990s were the warmest decade of the millennium, and 1998 was the warmest year of the decade.
I’m sure that MBH took every conceivable step to try to redress these "poor communications by others" and were frustrated when their efforts to ensure uncertainties were emphasized by these publications were rebuffed.
The victimization was not just in the press, but even their own colleagues victimized poor MBH. At CRU, Phil Jones – and I’m sure they felt certain that they could rely on Phil – let them down by saying atthe CRU website:
Analyses of over 400 proxy climate series (from trees, corals, ice cores and historical records) show that the 1990s is the warmest decade of the millennium and the 20th century the warmest century.
No wonder they feel let down. But one of the worst offenders in victimizing poor MBH was the University of Massachusetts press office, which issued news releases for both MBH98 and MBH99, ( obviously over the vehement protests of Mann et al), claiming that "advanced statistical techniques" were used. The MBH98 news release stated:
Climatologists at the University of Massachusetts have reconstructed the global temperature over the past 600 years, determining that three recent years, 1997, 1995, and 1990, were the warmest years since at least AD 1400. …
The researchers were able to estimate temperatures over more than half the surface of the globe, pinpointing average yearly temperatures in the northern hemisphere to within a fraction of a degree, going back to AD 1400. The study places in a new context long-standing controversy over the relative roles of human and natural changes in the climate of past centuries, according to Mann….
Advanced statistical techniques were used to translate the proxy information into surface temperature patterns, so that past centuries could be compared with the 20th century.
The MBH99 news release stated:
1998 Was Warmest Year of Millennium, UMass Amherst Climate Researchers Report
March 3, 1999
AMHERST, Mass. – Researchers at the University of Massachusetts who study global warming have released a report strongly suggesting that the 1990s were the warmest decade of the millennium, with 1998 the warmest year so far. …
"Temperatures in the latter half of the 20th century were unprecedented," said Bradley. …
Using proxy information gathered by scientists around the world during the past few decades, the team used sophisticated computer analysis and statistics to reconstruct yearly temperatures and their statistical uncertainties, going back to the year AD 1000…
FAQ for MBH99 can be retrieved from the Wayback Machine here.
How frustrating it must have been for Mann et al do be so frequently victimized by "poor communications by others" – even by their own university press office – with themselves helpless to do anything about it. It must have taken great personal fortitude and courage to survive such adversity.