Tag Archives: divergence

Juckes and the Divergence Problem

Nov 8, 2006 – 11:12 AM

Juckes discusses the Divergence Problem as follows: Particular concerns have been raised about … the high latitude Eurasian trees (which have and anomalously low growth anomaly in the late 20th century — Tornetraesk, Fennoscandia, Yamal, Northern Urals in Table 1) No one has ever said that Yamal has an anomalously low growth anomaly in the […]

By Stephen McIntyre | Posted in Divergence, Jones et al 1998 | Also tagged | Comments (9)

Rutherford 2005 and the Divergence Problem

Jun 3, 2006 – 10:36 AM

Rutherford et al 2005 (the et al being half the Hockey Team: Mann, Bradley, Hughes, Briffa, Jones, Osborn) is a re-statement of the MBH98 network (flawed PCs and all) and the Briffa et al 2001 network using RegEM. I haven’t figured out exactly what the properties of the RegEM method are as compared to other […]

By Stephen McIntyre | Posted in Divergence, Statistics | Also tagged , | Comments (13)

Cook et al[2004]: More Cargo Cult?

Mar 14, 2006 – 3:09 PM

Reader Bart S. has argued that Cook et al [QSR 2004] disposed of the "Divergence Problem", the name applied at the NAS panel on March 2-3, 2006 for the problem that, if the proxies do not record late 20th century warming, how can we be sure that they recorded potential earlier warming in the MWP. […]

By Stephen McIntyre | Posted in Divergence, Multiproxy Studies, NAS Panel, Post-1980 Proxies | Also tagged | Comments (8)

D'Arrigo: Making Cherry Pie

Mar 7, 2006 – 5:09 PM

D’Arrigo presented their new study. I went over and introduced myself and said that I thought that their new study was much better than Osborn and Briffa and that it was too bad that they hadn’t received the same publicity. She said – Well, I guess that’s a compliment of sorts. I was trying to […]

By Stephen McIntyre | Posted in D'Arrigo 2006, Divergence, Jacoby, NAS Panel | Also tagged | Comments (61)

Upside-Down Quadratic Proxy Response

Oct 10, 2005 – 3:17 PM

David Stockwell has suggested a discussion of nonlinear responses of tree growth to temperature. I’ve summarized here some observations which I’ve seen about bristlecones, limber pine, cedars and spruce – all showing an upside-down U-shaped response to temperature. The implications of this type of relationship for the multiproxy project of attempting to reconstruct past temperatures […]

By Stephen McIntyre | Posted in bristlecones, Divergence, Post-1980 Proxies, Proxies | Also tagged , | Comments (85)

Post-1980 Proxies #1: Twisted Tree Heartrot Hill

Feb 15, 2005 – 10:13 PM

I get a lot of questions about post-1980 proxies and I find it a very interesting question. One would expect that 1998 – the "warmest" year of the millennium – and the 1990s – the "warmest decade" of the millennium would leave a loud signal in a valid proxy. I’m going to start discussing some […]

By Stephen McIntyre | Posted in Divergence, Post-1980 Proxies | Also tagged | Comments (11)