It’s interesting that the Hockey Team seems to be able to make spaghetti graphs of world temperature history when they can’t even arrive at a spaghetti graph for the Polar Urals. I posted up the difference between Briffa’s Yamal substitution and the updated Polar Urals ring widths. But before either one, there was Briffa’s Polar Urals temperature reconstruction – which I’ve discussed on many occasions (see Category – Jones et al 1998). Briffa’s Polar Urals reconstruction [Nature 1995] was widely applied in the multiproxy studies and even singled out in IPCC 1995. It stated that 1032 was the "coldest year of the millennium" and that the early 11th century was cold. It was instrumental in supporting the view that everything in the MWP was regional and inconsistent. So how does Briffa’s Polar Urals version compare with the recently disclosed version used in Esper et al ?
Well, the early 11th century is obviously not especially cold – quite the opposite. The correlation between the series is 0.11 (and between the 40-year smoothed version shown below is 0.07). Spaghetti for two, anyone?
Figure 1. Polar Urals. Top – temperature reconstruction from Briffa et al [Nature 1995]; bottom – ring width chronology from Esper et al , as provided in email from Science [Feb 2006].