Just when you think that you’ve heard of all the possible problems with tree rings, the newest issue comes from “positive” and “negative” responders to temperature within the same site. These issues are discussed in a number of articles by various post-docs associated with Jacoby and D’Arrigo with the latter as co-authors. So in fairness […]
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 […]
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’ve been working away at our reply to Ammann and Wahl so I’m a little behind in blogging. One of our readers drew my attention to a discussion in the New York Times involving our favorite bristlecone pines. Kammerer et al. [J. Im. Gen. 2006] report the extension of human lifespan to 969 years following […]
Many Americans of a certain age will recall an American radio commentator, called Paul Harvey, who ran ironic commentaries entitled "The End of the Story". They were short segments leading you to expect one answer and Harvey’s closing comment explaining what happened would reverse the field altogether. I once heard a commentary on dendrochronology, in […]
A while ago, I discussed the very interesting study by Naurzbaev et al [2004] (co-author Hughes), which calculated growth curves at 34 larch sites in a meridional transect from 55 to 72 N (at a longitude of about 90-100E) and 23 larch sites along an altitudinal transect from 1120 to 2350 m around Tuva (~ […]
I’ve been re-visiting the various multiproxy studies with respect to scale and variability. In addition, as you know, one of my interests in these multiproxy studies is the non-robustness of MWP-modern levels to a very few non-independent proxies, used in multiple studies – in particular: bristlecones, Polar Urals and Thompson’s Himalayan dO18 series – each […]
I will write up some notes on the U.S. Climate Change Science Workshop, but I’d like to post up some information on a couple of interesting reports in the past few days on archaeological discoveries in a receding glacier on a high Swiss pass towards Italy, sent in by a reader. Glacier retreat in the […]
The Quelccaya glacier is at a similar latitude to Kilimanjaro and is also receding. It’s a logical point of comparison. Core 1 is 163.6 m deep (Summit Core- 154.8 m) and is attributed a start date of 470 AD (Summit Core: 744 AD). Annual dust layers are a guide to dating in the upper portions. […]
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 […]
Climate Audit 