Keith Briffa has a couple of posts today on Yamal – one discussing its impact in other multiproxy studies and the other on the Yamal chronology itself. His post on the Yamal chronology includes a careful consideration of various issues involved in the development of the Yamal chronology and is accompanied by an extensive archive […]
In a draft Corrigendum dated Oct 10, 2009 (most recently modified Oct 21, 2009), Kaufman gives what is obviously a warm and heartfelt shout-out in which they: thank those who have pointed out errors and have offered suggestions. More later today. [Note: see Sep 15 post here here for a preliminary assessment of Kaufman using […]
In examining the Briffa Yamal chronology, there has been a lot of emphasis (IMHO, correctly) placed on both the cherry-picking and the low core counts of the proxies which extend into recent times. However, the chronology also depends on the various methods used to adjust for various known biological effects and on the choices for […]
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 […]
In Andrew Revkin’s recent blog posting, he made the following observation about blogs, referring in particular to Climate Audit: What is novel about all of this is how the blog discussions have sidestepped the traditional process of peer review and publication, then review and publication of critiques, and counter-critiques, by which science normally does that […]
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 […]
One of the aspects of the Yamal discussion that is perhaps clearer to regular CA readers than to new readers is that Briffa’s Yamal chronology was very different from ring width chronologies previously reported in the area (including by Briffa itself.) Shortly after the publication of Osborn and Briffa 2006 and D’Arrigo et al 2006 […]
I was one of the more industrious reviewers for IPCC AR4. In my Review Comments, I made frequent reference to Yamal versus the Polar Urals Update, expressing concern about the rationale for using Yamal rather than Polar Urals, an issue that is once again in play. Keith Briffa was the section author and can be […]
Obviously, there has been considerable controversy over the past few days over the Yamal data. First, let’s observe the continued silence of field dendros on the dispute. None have stepped forward so far to support Briffa’s use of 10 cores in 1990 (and 5 in 1995). As others have observed, their silence is rapidly becoming […]
Climate Audit 
Yamal and IPCC AR4 Review Comments
I was one of the more industrious reviewers for IPCC AR4. In my Review Comments, I made frequent reference to Yamal versus the Polar Urals Update, expressing concern about the rationale for using Yamal rather than Polar Urals, an issue that is once again in play. Keith Briffa was the section author and can be […]