[emphasis added]

“It is because of this trend in these tree-ring data that we know does not represent temperature change that I only show this series up to 1960 in the WMO Statement.””

Then he makes critical remarks about arguments over statistical methods in Hockey Team papers etc. when he regards even the most basic methods as lacking rigorous analytical foundations:

http://thelukewarmersway.wordpress.com/2013/03/07/can-you-dig-it/comment-page-1/#comment-2454

Yet, it seems to me as an outsider that Bouldin is far too dismissive of differing levels of analysis. Yes, if his more fundamental criticisms were accepted (or even closely considered) then of course it follows that all methods and studies depending upon such fundamental issues must be on hold or re-scrutinized in light of his more fundamental critique. YET, as long as the entire field is proceeding as though such basics are established, it is hardly irrelevant for McIntyre and other climate auditors to scrutinize all the intermediate steps.

One of the reconstructions in 610b is the mislabeled sky-blue line (it should be BOS 2001), and is from Figure 4 in Briffa, K.R., et al., (2001) “Low-frequency temperature variations from a northern tree ring density network. J. Geophys. Res. (Atmospheres) 106, 2929-2941.

It’s also the same line as the truncated Briffa, et al., scaled 1856-1980, line in the first Figure in the head-post.

In IPCC Figure 6.10b, Briffa’s line is truncated at 1960, effectively hiding the same decline.

In 6.10b, it appears the IPCC didn’t use the “preferred reconstruction” in Briffa, 2001 Figure 4. Instead, they seem to have used one of the eight alternative reconstructions, specifically and likely the thin line that stands out with a slight inflection point at 1960.

Briffa, 2001 as it appears in IPCC Figure 6.10b has a slight provocative up-bend at 1960 that doesn’t seem to be in the “preferred reconstruction” of the original Figure 4. The felicitous terminal bend in 6.10b makes it seem like the line would rise if there were further data. But, of course, there are further data and it doesn’t rise.

Jonathan Overpeck was one of two Coordinating Lead Authors on AR4 CH6, and was also a co-author of the EOS article. Other cross-publishing personna are Tim Osborn and Keith Briffa, among AR4 CH6 contributing authors and lead authors, respectively.

So, institutionally, the IPCC/4AR is evidently guilty of the same lie of omission as the AGU/EOS.

He wrote the following in #4241:

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I first generated 1000 random time-series in Excel – I did not try and approximate the persistence structure in tree-ring data. The autocorrelation therefore of the time-series was close to zero, although it did vary between each time-series. Playing around therefore with the AR persistent structure of these time-series would make a difference. However, as these series are generally random white noise processes, I thought this would be a conservative test of any potential bias.

I then screened the time-series against NH mean annual temperatures and retained those series that correlated at the 90% C.L.

48 series passed this screening process.

Using three different methods, I developed a NH temperature reconstruction from these data:

1. simple mean of all 48 series after they had been normalised to their common period

2. Stepwise multiple regression

3. Principle component regression using a stepwise selection process.

The results are attached.

Interestingly, the averaging method produced the best results, although for each method there is a linear trend in the model residuals – perhaps an end-effect problem of over-fitting.

The reconstructions clearly show a ‘hockey-stick’ trend. I guess this is precisely the phenomenon that Macintyre has been going on about.

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