Michael Mann’s 2008 Reconstruction
22 hours ago
Andy May
By Andy May
In my last post, it was suggested that Michael Mann’s 2008 reconstruction (Mann, et al., 2008) was similar to Moberg’s 2005 (Moberg, Sonechkin, Holmgren, Datsenko, & Karlen, 2005) and Christiansen’s 2011/2012 reconstructions. The claim was made by a commenter who calls himself “nyolci.†He presents a quote, in this comment, from Christiansen’s co-author: Fredrik Charpentier Ljungqvist:
“Our temperature reconstruction agrees well with the reconstructions by Moberg et al. (2005) and Mann et al. (2008) with regard to the amplitude of the variability as well as the timing of warm and cold periods, except for the period c. AD 300–800, despite significant differences in both data coverage and methodology.†(Ljungqvist, 2010).
A quick google search uncovers this quote in a paper by Ljungqvist in 2010 (Ljungqvist, 2010), one year before the critical reconstruction by Christiansen and Ljungqvist in 2011 (Christiansen & Ljungqvist, 2011) and two years before their 2012 paper (Christiansen & Ljungqvist, 2012). It turns out that Ljungqvist’s 2010 reconstruction is quite different than those he did with Christiansen over the next two years. All the reconstructions are of the Northern Hemisphere. Ljungqvist’s and Christiansen’s are of the extra-tropical (> 30°N) Northern Hemisphere and Moberg’s and Mann’s are supposed to be of the whole Northern Hemisphere, but the big differences lie in the methods used.
https://wattsupwiththat.com/2021/01/11/michael-manns-2008-reconstruction/
