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3 September 2008 at 10:04 am #3508
From BBC website:Quote:A new study by climate scientists behind the controversial 1998 "hockey stick" graph suggests their earlier analysis was broadly correct.
Michael Mann’s team analysed data for the last 2,000 years, and concluded that Northern Hemisphere temperatures now are "anomalously warm".
Different analytical methods give the same result, they report in Proceedings of the National Academy of Sciences.
The 1998 hockey stick was a totem of debates over man-made global warming.
The graph – indicating that Northern Hemisphere temperatures had been roughly constant for 1,000 years (the "shaft" of the stick) before turning abruptly upwards in the industrial age – featured prominently in the Intergovernmental Panel on Climate Change’s (IPCC) 2001 assessment.
In their latest study, Dr Mann’s group collated more than 1,200 proxy records – the majority from the Northern Hemisphere – and used different statistical methods to analyse their cumulative message.
"We used two different methods that are quite complementary in the assumptions they make about data, so that provides a test of the sensitivity of data to the methods used," he told BBC News.
"We also made use of a far wider network of proxy data than previously available.
"Ten years ago, the availability of data became quite sparse by the time you got back to 1,000 AD, and what we had then was weighted towards tree-ring data; but now you can go back 1,300 years without using tree-ring data at all and still get a verifiable conclusion."
Both analytical methods produced graphs similar to the original hockey stick, though starting further back in time. The "shaft" now extends back to about 700 AD.
The same basic pattern emerged when tree-ring data – whose reliability has been questioned – was excluded from the analysis.21 December 2009 at 2:42 am #4673Anonymous
You must be well invested in the carbon credit buss21 December 2009 at 1:46 pm #4670
Ah, if only I was well invested in something, anything!12 February 2010 at 2:11 am #4679
Deep Climate has lengthy investigation re shenanigans involving two people who have attempted to discredit the Hockey Stick. Begins:Quote:
The well-timed release of the stolen CRU emails (a.k.a. Climategate) did much to enhance public awareness of self-appointed climate science auditor Steve McIntyre and his long-time co-author and promoter, economist Ross McKitrick. Indeed, the pair has finally recieved widespread coverage in their native Canada with a spate of mainstream profiles full of fawning admiration from the CanWest newspaper chain, McLean’s magazine and the Toronto Star. That’s on top of new interest from the likes of Associated Press and CNN, along with coverage from the usual biased sources like Fox News and the Wall Street Journal.
Those stories tell the tale of a humble retired mining executive (McIntyre), whose analysis of the “hockey stick” temperature reconstruction got the attention of economist Ross McKitrick, and eventually shook all of climate science to its core. Of course, the reporters seem blissfully unaware that McIntyre and McKitrick have published exactly one – that’s right, uno – peer-reviewed article in a scientific journal. (Besides the pair’s 2005 GRL article, Ross McKitrick’s misleading list of so-called “peer-reviewed science journal articles” also includes two pieces in the contrarian social science journal Energy and Environment, a comment letter to PNAS and a pair of replies to comments on the GRL article!)
Even worse, the writers appear to have relied on McIntyre himself to supply the context of his improbable rise (always a dodgy proposition where McIntyre is concerned). But McIntyre’s thin publication record suggests that his prominence has less to do with any compelling scientific analysis, and much more to do with astute promotion. And, indeed, the McIntyre-McKitrick saga turns out to have the usual supporting cast of anti-science propaganda: two notorious right-wing think tanks (the Competitive Enterprise Institute and the George Marshall Institute) and a deft fossil-fuel company funded PR veteran operating behind the scenes (none other than Tom Harris of APCO Worldwide).
Steve McIntyre and Ross McKitrick, part 1: In the beginning
Part 2 is here:
Steve McIntyre and Ross McKitrick, part 2: The story behind the Barton-Whitfield investigation and the Wegman Panel
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