I’m going to do a detailed post on my diagnosis of the Marcott uptick, but before I do so, I want to comment on the reconstructions for NH and SH extratropics, neither of which have attracted sufficient notice though both are very remarkable. In a substantive sense, because orbital changes have different effects on NH and SH, the difference between NHX and SHX proxies is a source of substantive interest and is what ought to have been reported on.
In the running text, Marcott et al had emphasized that their reconstruction was “indistinguishable within uncertainty”. This was illustrated in their Figure 1E, which showed the Mann08 GLB and NH reconstructions (which of several versions is not denoted in the caption), Moberg 2005 (NH) and the Wahl-Ammann version of MBH98 (NH).
Our global temperature reconstruction for the past 1500 years is indistinguishable within uncertainty from the Mann et al. (2) reconstruction……
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