Tag Archives: Keith Briffa

How to be a climate science auditor, part 2: The forgotten climategate emails

In this installment, I’ll look at another technique in the climate auditor’s toolbox, namely selective quotation. Once again, our example case study will involve accusations by Steve McIntyre concerning the use of paleoclimatologist Keith Briffa’s tree-ring based reconstruction in a key figure from the IPCC Third Assessment Report.

Arguing from a cherrypicked selection of quotes from the “Climategate” emails, McIntyre has claimed that IPCC authors Chris Folland and Michael Mann pressured Briffa to submit a reconstruction that would not “dilute the message” by showing “inconsistency” with multi-proxy reconstructions from Mann and Briffa’s CRU colleague Phil Jones. Briffa “hastily re-calculated his reconstruction”, sending one with a supposedly larger post-1960 decline before. According to McIntyre, Mann resolved this new “conundrum” and simply “chopped off the inconvenient portion of the Briffa tree-ring data”.

But a review of the emails – including some that have never been quoted before – clearly contradicts McIntyre’s version of events:

  • Jones and Briffa were concerned that Mann had an outdated version of the Briffa reconstruction, and both urged the adoption of the newer “low frequency” one, more appropriate for comparison with other multi-century reconstructions.
  • Far from pressuring Briffa to change his reconstruction right away, Mann questioned whether an immediate change was required, or even possible, and counselled waiting for the next revision.
  • CRU colleague Tim Osborn advised Mann that he and Briffa “usually stopped” the “low frequency” reconstruction in 1960, and went one better in his later “resend” to Mann, by explicitly removing the post-1960 data.

I’ll also show how McIntyre has changed his narrative along the way , in an effort to prove that the true “context” of the famous “trick” to “hide the decline” is somehow an indictment of the IPCC. (Speaking of which, be sure to take the poll at the end about McIntyre’s next move). But first, once again, here is the cause of all the fuss, namely Figure 2-21 from Chapter 2 of the IPCC Third Assessment Report – Working Group I: The Scientific Basis (2001).

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How to be a climate auditor, part 1: Pretty pictures

Do you have what it takes to be a climate auditor? Try the following fun test and find out. And at the same time, you can’t help but learn something about the fine art of argumentation from charts as practiced by the master himself, Steve McIntyre, and refined in his most devoted media outlet, the U.K. based Mail on Sunday.

Here is the chart that is held to epitomize the “trick” to “hide the decline”: figure 2-21 from the IPCC ‘s Third Assessment Report, showing key temperature reconstructions.

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McClimategate continues: Yet another false accusation from McIntyre and McKitrick

How do they get away with it? That’s the inevitable question as I examine one of the most specious – and despicable  – “climategate” allegations from contrarians, namely the oft-repeated claim that climate scientists at East Anglia University’s Climate Research Unit inappropriately adjusted certain tree-ring temperature proxy data to provide a better match with instrumental temperature record.

In an extraordinary interview with FoxNews in December of last year, economist Ross McKitrick alleged that scientists were “faking the match” between proxy and temperature data. McKitrick averred this was “not being honest with the reader” and even invoked a comparison to  falsified experimental medical research.  Stephen McIntyre of  ClimateAudit recently claimed that the “artificial correction” seemed “to have entered the CRU toolkit” (in his submission to the U.K. parliamentary committee examining  allegations arising from stolen CRU emails, no less).

Yet a close examination of the computer code and ensuing research bears out the key contention of the firm rebuttals from East Anglia University, as well as CRU scientist Tim Osborn, namely that the specific adjustments in question were for private exploration only and never incorporated into CRU scientists’ subsequent published research temperature reconstructions. So, once again, McIntyre and McKitrick have made odious and unfounded accusations, based on non-existent evidence. They should withdraw these specious allegations immediately.

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McIntyre provides fodder for skeptics

[This post was updated on December 12 to provide additional context that strengthens the original analysis – see below for details.]

This so-called Climategate is really getting out of hand, isn’t it?

Steve McIntyre has published allegations – twice now – that an internal IPCC authors’ debate about the inclusion of Briffa’s tree-ring reconstruction in a key figure from the 2001 WG1 Third Assesement Report was driven by concern about the post-1960 “decline” in tree-ring widths, a decline that showed a marked divergence with the instrumental tempertaure record.

The Climategate Letters show clearly that the relevant context is the IPCC Lead Authors’ meeting in Tanzania in September 1999 at which the decline in the Briffa reconstruction was perceived by IPCC as “diluting the message”, as a “problem”, as a “potential distraction/detraction”. [Emphasis added]

McIntyre even claims that lead author Michael Mann worried that showing the series with this decline would give “fodder” to “skeptics”.

But even a cursory examination of the emails in question shows that the discussion was really about other aspects of the reconstruction, specifically obvious discrepancies between Briffa’s reconstruction and the other two under consideration over the major part of the reconstruction’s length. Thus, once again, McIntyre’s speculations are shown to be utterly without foundation.

Even worse, McIntyre left out intervening sentences within the actual proffered quotes in what appears to be an unsophisticated attempt to mislead.

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Briffa teaches, but will McIntyre ever learn?

Recently we’ve discussed several aspects of the raging controversy around climate blogger Steve McIntyre and dendrochronologist Keith Briffa and the supposed destruction (once again) of the “hockey stick” temperature graph.

A few commentators have suggested that more attention should be paid to  McIntyre’s actual “analysis” of Briffa’s Yamal tree-ring chronology, and less to his outrageous accusations (not to mention all the inconvenient evidence that those accusations were completely without foundation).

Now that Keith Briffa has delivered his promised detailed response in an article co-written with Thomas Melvin, it is a good time to do just that. Here, then, is a review of the various problems I and others have pointed out in comments here and elsewhere over the past while, along with highlights from Briffa’s response.

First, here is the abstract of Briffa’s article .

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Let the backpedalling begin

KHantemirovRM Fig 5 zoomThe latest battle over the “hockey stick” has taken quite a turn, one that may finally lay to rest all the  absurd claims of its demise made by contrarians (not to mention apparently libelous accusations of scientific malfeasance). In previous posts, we discussed climate blogger Steve McIntyre’s scurrilous accusations of “cherrypicking” against UK dendrochronolgist Keith Briffa, and summarized a a quick technical critique of McIntyre’s work by a dendrchronologist known as Delayed Oscillator.

Now comes new evidence that McIntyre’s accusations were completely false. And not only that, one of the Russian researchers who actually control the raw tree-ring data that McIntyre was mistakenly hounding Briffa for, has apparently confirmed that utilization of  a newer more complete Yamal data set has no substantial effect  on Briffa’s Yamal temperature reconstruction.

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“Delayed Oscillator” on divergence

Anyone who has blogged, or even just hangs around blogs more than they should, is familiar with the “pingback”. You know, it’s that automatically generated comment that signals that another blog has referred to a particular post. Yesterday, I got this “pingback” from a blogger called Delayed Oscillator (or “delayed.oscillator” as it is formatted there) and decided to follow it up.

And am I ever glad I did. DO (pronounced Dee-Oh), as I will call this blogger (I hope that’s OK!) has brought a welcome expert perspective to the discussion of the Steve McIntyre-Keith Briffa controversy, said by certain economists and business section editors to expose the global warming sham once and for all. In a two-part series of posts, DO shows why it “ain’t necessarily so” (to say the least).

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