Jeff Norman draws attention to Figure 1 in a new Mannian tirade, a variation of Mann’s stump speech in which he, as usual, tries to blame his own errors and tricks (the censored directory, verification r2 of 0, upside-down Mann, hide the decline) on right-wing interests. Amusingly, his new Figure 1 unapologetically splices proxy and instrumental data, an issue that ties to a central issue in Mann v National Review et al.

First, here is Figure 1, entitled “Hockey stick graph” of rising global temperatures. Sharp-eyed readers will notice that the Figure goes to 1998 or so, and that it grafts the instrumental record after 1902 onto the proxy record before 1901, with the grafting not mentioned in the caption.

Figure 1. Mann 2015 entitled: “Hockey stick graph” of rising global temperatures

Next, here is a blowup of Mann 2015 Figure 1, confirming that it is a graft of the MBH99 instrumental data from 1902 to 1998 (plotted in yellow) to the MBH99 proxy reconstruction prior to 1901.

Figure 2. Excerpt from Mann 2015 Figure 1, showing MBH99 proxy reconstruction (cyan) to 1901; MBH99 instrumental version from 1902-1998 (yellow.)

CA readers will also remember Mann’s famous and vituperative denial that any climate scientist had ever spliced proxy and instrumental data in one of the earliest and most cited Real Climate posts Myth vs. Fact Regarding the “Hockey Stick”. A Real Climate reader had observed:

Whatever the reason for the divergence, it would seem to suggest that the practice of grafting the thermometer record onto a proxy temperature record – as I believe was done in the case of the ‘hockey stick’ – is dubious to say the least.

To which, Mann responded with a vociferous denial that such grafting had ever occurred:

No researchers in this field have ever, to our knowledge, “grafted the thermometer record onto” any reconstrution. It is somewhat disappointing to find this specious claim (which we usually find originating from industry-funded climate disinformation websites) appearing in this forum… Often, as in the comparisons we show on this site, the instrumental record (which extends to present) is shown along with the reconstructions, and clearly distinguished from them (e.g. highlighted in red as here). – See more at: http://www.realclimate.org/index.php/archives/2004/12/myths-vs-fact-regarding-the-hockey-stick/#comment-345

When Climategate broke, the “trick” email obviously attracted much attention. The first explication of the trick email was Jean S’ Climate Audit post on November 20, 2009, a post which clearly demonstrated the grafting of instrumental and proxy data in the WMO 1999 diagram that was the subject of the trick email. Jean S also compared this technique to the splicing of instrumental and proxy data in construction of the smoothed MBH98 and MBH99 reconstructions, a technique that had been previously reverse engineered by UC here., but confirmed by the admission in the email that they had used “Mike’s Nature trick of adding in the real temps”. (In MBH98 and MBH99, Mann pared the hybrid smooth back to 1980, whereas the WMO1999 diagram continued the smooth to 1998). The effect of Mann’s hybrid smooth was that the smoothed reconstruction closed with a rhetorical uptick, rather than the downtick that would have resulted using the same smoothing technique on proxy data alone. Jean S acidly contrasted the hard evidence with Mann’s prior denial of ever splicing instrumental and proxy data.

The CA article prompted a Real Climate reader (citing http://www.climateaudit.org/?p=1553#comment-340175 and here

http://www.climateaudit.org/?p=7810#more-7810) to ask Mann about splicing (this was in the heat of Climategate and links to Climate Audit were temporarily not banned or tape delayed):

That leaves me with the simple question, “was the shape of a proxy record changed by including instrumental temperature record in in way that the proxy record was shifted from where it would have been in the 20th century?” Obviously, if the answer is yes, and this was bad science, then why was it done?

Even in the face of the Climate Audit demonstration two days earlier of splicing of proxy and instrumental data in the WMO 1999 diagram that had been the subject of the notorious email, Mann continued to deny that he and coauthors had ever grafted instrumental and proxy data into a single curve, the link below going to his original diatribe about “fossil fuel disinformation”:

The point that has been made a number of times is that the reconstruction (the raw annual values through 1980) has never been presented with the instrumental values (available after the end of the proxy record in 1980) as a single “grafted” curve by Mann and collaborators (here). Indeed, the instrumental values and proxy-reconstructed temperature values have always been demarcated and clearly labeled as distinct (e.g. in Mann et al ’98 and the extension back to AD 1000 in Mann et al ’99)

In the same inline comment, Mann opaquely conceded that instrumental and proxy data had been spliced in the smoothed Mann et al 1998, 1999 reconstructions:

In some earlier work though (Mann et al, 1999), the boundary condition for the smoothed curve (at 1980) was determined by padding with the mean of the subsequent data (taken from the instrumental record).

On November 24, 2009, in a press statement, one of Mann’s coauthors in the WMO 1999 graphic, Phil Jones of CRU, admitted the splicing in the WMO 1999 diagram, but Mann did not correct his previous denials.

Mann v Steyn

In the original Simberg article, under the word “data manipulation”, Simberg included a hyperlink to the Climate Audit article entitled “Mike’s Nature Trick”. Although lack of absolute malice almost certainly represents the easiest way of deciding Mann v National Review et al, in U.S. defamation law, opinions are protected if they are a supportable interpretation of disclosed facts. Hyperlinks are a recognized method of disclosing source facts. CEI argued (very convincingly in my opinion) that their use of the term “data manipulation” was a supportable interpretation of the facts set out in the hyperlinked Climate Audit post, Mike’s Nature Trick, and that these facts were “uncontested”. CEI included the Climate Audit post “Mike’s Nature Trick” as Exhibit 6(e) of the original CEI memorandum and is included in the joint attachments to the Appeals Court.

In response, Williams and Mann stated that the Climate Audit article preceded the NSF exoneration. (There is, however, no evidence in the NSF report that they considered the issues set out in the Climate Audit article. I have some thus far unreported documents that show directly that the Climate Audit post was not among the public documents considered by NSF or, for that matter, Penn State.)

Williams and Mann also argued that the assertion that there was “support in the articles hyperlinked to Mr. Simberg’s original post is simply without merit” and that “Mr. Simberg distorts the material he supposedly relies upon”. Williams and Mann conspicuously did not rebut or contest the “facts” set out in Exhibit 6(e), Mike’s Nature Trick, an analysis, which, to my knowledge, remains unrebutted to this day.

Is the term “data manipulation” a supportable interpretation of the splicing of instrumental and proxy data in the WMO 1999 diagram and the MBH98 and MBH99 smoothed reconstructions? Of course, it is.

In Mann’s most recent brief, Mann claimed that any criticism of his research as “misleading” was “demonstrably false” because Mann had supposedly “clearly labeled” both instrumental and reconstructed temperatures on a graphic – as though that were the only metric on which his research could be “misleading”. SKS has even attempted to re-frame Mike’s Nature trick as the technique of clearly labeling observations and estimates in a graphic – a standard and commonplace technique that existed long before Mann and one distinctly not observed in the WMO 1999 graphic. Or in the new Mann 2015 graphic, where instrumental and reconstructed temperatures are in slightly different shades of blue, but not labeled, let alone clearly labeled.

Most importantly, any suggestion that Dr. Mann’s research is misleading is demonstrably false. Dr. Mann’s hockey stick graph is clear regarding what it contains-both the instrumental and reconstructed temperatures are clearly labeled as such on the Hockey Stick Graph

Postscript

The splicing of instrumental and proxy data shown in the Mann 2015 is curiously similar to the splice in Al Gore’s Inconvenient Truth, as discussed at CA here.



