In The Climate Files, Fred Pearce wrote: When I phoned Jones on the day the emails were published online and asked him what he thought was behind it, he said” It’s about Yamal, I think”. Pearce continued (p 53): The word turns up in 100 separate emails, more than ‘hockey stick’ or any other totem [...]
At the close of Boulton’s April 9 interview with CRU, the only such interview relevant to the proxy reconstruction controversies that constitute 99% of the Climategate emails, Boulton asked CRU to comment on Ross McKitrick’s National Post op ed last October during Yamal. The response was given to Muir Russell on or after June 16 [...]
My submission to the UK Parliamentary Committee is here – this version excludes figures. Here is a pdf version with illustrations. In my situation – which is a little, shall we say, unique- it’s hard to figure out exactly where to start. So I tried to cover topics that I didn’t think anyone else would [...]
Addiction of paleoclimate reconstructions to particular proxies has been a longstanding concern at Climate Audit. One of the battleground issues has been the addiction to Briffa’s Yamal tree ring series, while the nearby update of Polar Urals (with a pronounced MWP) was disappeared. (See CA category.) Just before Climategate, we raised questions about the Yamal [...]
The Yamal reconstruction was introduced in Briffa 2000, a survey paper that did not include elementary information like core counts. As a result, users of the Briffa 2000 Yamal reconstruction (including Mann and Jones 2003, Moberg 2005, Hegerl 2007; D’Arrigo 2006, IPCC 2007, etc…) used it without any knowledge that the core counts did not [...]
As noted at CA last week, Briffa published a partial response to Yamal issues at the CRU website, one post discussing the impact of the Yamal chronology in various studies and another post discussing the Yamal chronology itself. For a response to Briffa’s online article on the impact of Yamal, I refer readers to last [...]
Reader Tom P observed: If Steve really wants to invalidate the Yamal chronology, he would have to find another set of cores that also gave good correlation with the instrument record, but indicated a previous climate comparable or warmer than that seen today. As bender observed, Tom P’s question here is a bit of a [...]
Now that we know the abysmally low replication of the modern portion of Briffa’s Yamal chronology (something previously unknown to specialists), I’ve been backtracking through some earlier documents to see how this may have impacted past studies. We’ve talked previously about how Briffa refused to provide measurement data to D’Arrigo et al 2006, resulting in [...]
Recently, after the posting of the Phil Trans B archive on Sept 8, 2009, I determined that the Yamal data set as used by Briffa is not more “highly replicated” than the Polar Urals data set and thus there is no basis for the preferential selection of the Yamal chronology over the Polar Urals chronology [...]
Briffa 2000 is one of the canonical “independent” reconstructions in the IPCC AR4 spaghetti graph, the Wikipedia spaghetti graph and similars. I’ve discussed it in the past, but I’m going to revisit this in light of the new information on Tornetrask and I’m going to run Brown’s inconsistency statistic on it. Briffa used 7 series: [...]
