The long-awaited (and long overdue) PAGES2K synthesis of 57 high-resolution ocean sediment series (OCEAN2K) was published a couple of weeks ago (see here here). Co-author Michael Evans’ announcement made the results sound like the latest and perhaps most dramatic Hockey Stick yet:
Kaufman and McKay recently and quietly issued an Arctic2K correction file at NOAA xls here that concedes yet another upside-down series previously pointed out to them at Climate Audit. Once again, they used information from Climate Audit without acknowledgement or credit (see NSF definition of plagiarism here).
Reflecting on then current scandals in psychology arising from non-replicable research, E. Wagenmakers, a prominent social psychologist, blamed many of the problems on “data torture”. Wagenmakers attributed many data torture problems on ex post selection of methods. In today’s post, I’ll show an extraordinary example of data torture in the PAGES2K Australasian reconstruction.
Wagenmakers on Data Torture
Nature’s policies on plagiarism state:
Duplicate publication, sometimes called self-plagiarism, occurs when an author reuses substantial parts of his or her own published work without providing the appropriate references.
Only two Gergis proxies (both tree ring) go back to the medieval period: Oroko Swamp, New Zealand and Mt Read, Tasmania, both from Ed Cook. Although claims of novelty have been made for the Gergis reconstruction, neither of these proxies is “new”, with both illustrated in AR4 and Mt Read being used as early as Mann et al 1998 and Jones et al 1998.
The calculation of the PAGES2K regional average contains a very odd procedure that thus far has escaped commentary. The centerpiece of the PAGES2K program was the calculation of regional reconstructions in deg C anomalies. Having done these calculations, most readers would presume that their area weighted average (deg C) would be the weighted average of these regional reconstructions already expressed in deg C.
The revised PAGES2K Arctic reconstruction used 56 proxies (down three from the original 59). Although McKay and Kaufman 2014 didn’t mention the elephant in the room changes in their reconstruction (as discussed at CA here here), they reported with some satisfaction that “decadal-scale variability in the revised [PAGES2K] reconstruction is quite similar to that determined by Kaufman et al.
The money quote in the PAGES2K abstract was that there wasn’t any worldwide Little Ice Age of Medieval Warm Period and that AD1971-2000 temperatures were the highest in nearly 1400 years, long before the Medieval Period:
There were no globally synchronous multi-decadal warm or cold intervals that define a worldwide Medieval Warm Period or Little Ice Age … during the period ad 1971–2000, the area-weighted average reconstructed temperature was higher than any other time in nearly 1,400 years.
PAGES2K (2013) unequivocally stated that the Arctic was “warmest during the 20th century”:
The Arctic was also warmest during the twentieth century, although warmer during 1941–1970 than 1971–2000 according to our reconstruction.
In today’s post, I’m going to discuss an important new 1000-year chronology from northern treeline spruce in Quebec (Gennaretti et al 2014, PNAS here). The chronology is interesting on multiple counts. This is the first Quebec northern treeline chronology to include the medieval warm period.
