As I’ve mentioned before, you have to really watch the pea under the thimble whenever Briffa is presenting a series. I showed before how the post-1960 decline in MXD reconstructions was simply excised from the record and carried forward into the IPCC spaghetti graph where the overlay of colors made the detection virtually impossible to […]
The continued negligence of the major journals in ensuring that paleoclimate authors archive data in accordance with journal policies is very frustrating and, as previously noted, has reared its ugly head once again with Osborn and Briffa. I have had little luck in the past with Science (except for the Kilimanjaro sample dO18 data) but […]
I’ve talked recently about the phenomenon of cherry picking tree ring chronologies with upticks in the small-subset (10-20) compilations used in typical Hockey Team multiproxy studies (e.g. Jones et al 1998; Crowley and Lowery 2000, etc., most recently Osborn and Briffa, 2006; and to a slight lesser extent D’Arrigo et al, 2006 (where there was […]
The Polar Urals temperature reconstruction (Briffa et al, 1995) has been a mainstay of multiproxy studies. More data was collected at this site in 1998 (russ176), but in the two new studies (Osborn and Briffa, 2006; D’Arrigo et al., 2006), they relate their site selection to the Polar Urals, but substitute the Yamal RCS series […]
There’s been a relatively lively discussion at realclimate here on O&B . I’ve got a couple of thoughts for now on (1) the independence of authors and (2) differences between datasets – two issues which I’ve frequently discussed.
D’Arrigo, Wilson and Jacoby [2006] represents state-of-the-art in dendrochronology and is hot off the press. It is unique among such studies in using a considerable amount of up-to-date data and is relatively candid about its results. I’ll try to discuss it in more detail. Here I want to pick up on one issue that featured […]
David Stockwell was intrigued by the seeming “robustness” of O&B results. There’s a reason for it: pretty much every one of the stereotyped Hockey Team proxies that are common to multiple studies are included in the O&B collation: bristlecones, Briffa’s re-processed series, Thompson’s Dunde and Guliya, Jacoby’s Mongolia. Pretty much every rascal has been gathered […]
Osborn and Briffa [2006] , published today in Science, cannot be considered as an “independent” validation of Hockey Stick climate theories, because it simply re-cycles 14 proxies, some of them very questionable, which have been repeatedly used in other “Hockey Team” studies, including, remarkably, 2 separate uses of the controversial bristlecone/foxtail tree ring data. Also […]
I’m finally trying to finalize my presentation on Jones et al [1998] for the US GCRP workshop in November, which is necessarily mostly about the Polar Urals and Tornetrask reconstructions. Bot MXD chronologies and RW chronologies are supposed to correlate to temperature. So an obvious quesiton is how do they correlate to eachother. I’ve plotted […]
I have obviously been very critical of the 11th century portion of the Polar Urals dataset used in Briffa et al. [1995], without which Jones et al [1998] does not have a cold 11th century (and which is a staple of other studies). It turns out that Schweingruber collected new subfossil samples for this site […]
Climate Audit 