The Contender writes: "@citizen, My argument is that scientists fall victim to group think sometimes."
"You are simply wrong about the facts you are claiming about the Hockey Stick. The observation remains that if all the proxies are just put into the standard processing methods, the traditional reconstruction of climate emerges including the Medieval Warm Period and the Little Ice Age. Only by massaging the data can the past climate events be made to vanish.'
MM claim that the main features of the Mann et al (1998–henceforth MBH98) reconstruction, including the “hockey stick” shape of the reconstruction, are artifacts of a) the centering convention used by MBH98 in their Principal Components Analysis (PCA) of the North American International Tree Ring Data Bank (‘ITRDB’) data, b) the use of 4 infilled missing annual values (AD 1400-1403) in one tree-ring series (the ‘St. Anne’ Northern Treeline series), and c) the infilling of missing values in some proxy data between 1972 and 1980. Each of these claims are demonstrated to be false below.
Numerous myths regarding the so-called "hockey stick" reconstruction of past temperatures, can be found on various non-peer reviewed websites, internet newsgroups and other non-scientific venues. The most widespread of these myths are debunked below:
MYTH #1: The "Hockey Stick" Reconstruction is based solely on two publications by climate scientist Michael Mann and colleagues (Mann et al, 1998;1999).
MYTH #2: Regional proxy evidence of warm or anomalous (wet or dry) conditions in past centuries contradicts the conclusion that late 20th century hemispheric mean warmth is anomalous in a long-term (multi-century to millennial) context.
MYTH #3: The "Hockey Stick" studies claim that the 20th century on the whole is the warmest period of the past 1000 years.
MYTH #4: Errors in the "Hockey Stick" undermine the conclusion that late 20th century hemispheric warmth is anomalous.
The claim by MM that the hockey stick pattern arises as an artifact of the PCA centering convention used by MBH98 is seen to be false on multiple levels.
- A statement from the EGU
- A Nature editorial
- A letter from US scientists (including leading members of the NAS, a Nobel Prize winner and two of us (ES, GS))
- A letter from the head of the National Academy of Sciences, and
- A commentary from Tom Crowley in EOS
- Other politicians, the House Committee on Science and Henry Waxman.
often cited to make the case for global warming— plucked McIntyre from obscurity and got him featured on the front page of the February 14, 2005, Wall Street Journal. The page-one story caught the attention of Rep. Joe Barton (R-TX), chair of the House Committee on Energy and Commerce. By late June, Barton was creating his own headlines by demanding that prominent researchers turn over the raw data from the hockey-stick analysis.
We discussed what would be required in an update of these millennial reconstructions a few months back and the main principles remain true now. You need proxies that are a) well-dated, b) have some fidelity to a climate variable of interest, c) have been calibrated to those variable(s), d) that are then composited together somehow, and e) that the composite has been validated against the instrumental record. ...
The fact that the very title of the report summary (“Nature, Not Human Activity, Rules the Climate“) itself poses–at best–a false dichotomy is not an auspicious start. The fact that the fonts and layout are identical to the real IPCC report is another indication that this isn’t quite on the level (and reminiscent of the infamous fake PNAS paper that accompanied the first ‘Oregon Petition’).
The letter he has written to the NY Times public editor, with its liberal sprinkling of his usual pomposity, has at its heart the following graph:
It is no secret that we have been unimpressed by the quality of reporting of climate science or late. From the insinuation that data were manipulated (for which there remains no evidence, primae facie or otherwise), to the suggestion that “climate skeptics” had somehow been kept from publishing in peer reviewed literature (how, we wonder, does Lindzen keep getting published?), to the blind repetition of false claims of major errors in the IPCC (when only a couple of actual errors – and none of them in the primary (Working Group 1) report – have been found), to the falsehood that climate data have not been readily available (yes, they have), the reporting has been more akin to the populist fearmongering of the McCarthy era than to the celebrated investigative journalism of Watergate.
That’s too bad, and not just because sensationalistic journalism may have done lasting damage to some institutions and individual scientists. More importantly, it has done damage to public understanding, quite the opposite of the rightful role of the free press in a democratic society.
1. A new study by Spielhagen and co-authors in Science reconstructs temperatures of North Atlantic source waters to the Arctic for the past two millennia, adding another very long-handled Hockey Stick to the ever-growing league.
Update 7/13/12: Further comment from Bob Ward of the Grantham Institute in Huffington Post UK “The World’s Most Visited Newspaper Website Continues to Regurgitate Nonsense from Climate Change ‘Sceptics’”
Update 7/14/12: Some additional context provided by this LiveScience article
...A response to the critics
- 'The hockey stick is broken' Coby Beck "How to Talk to a Climate Skeptic"
- The 'hockey stick' graph has been proven wrong Michael Le Page, "Climate Change: A guide for the perplexed"
- Myth vs. Fact Regarding the "Hockey Stick" Michael Mann, "Response to common contrarian arguments"
- What If … the "Hockey Stick" Were Wrong? Stefan Rahmstorf, "Response to common contrarian arguments"
- Dummies guide to the latest “Hockey Stick” controversy Gavin Schmidt and Caspar Amman "Response to common contrarian arguments"
- Hockey sticks: Round 27 RealClimate "Response to common contrarian arguments"
- Followup to the 'Hockeystick' Hearings RealClimate "Response to common contrarian arguments"
- Recent increase in global temperature Alan Thorpe, "Natural Environment Research Council Climate change challenge: Summary of the debate"
- Myth #9: Modern temperature increases are a direct result of the Earth’s climate exiting the Little Ice Age Brian Angliss, "Anti-global heating claims - a reasonably thorough debunking"
- "The Hockey Stick is broken. Michael Mann refuses to release his code & data." Logical Science, "Common Arguments from Global Warming Skeptics"
- NRC report on hockey stick released Tim Lambert, Deltoid, June 22, 2006
- The missing piece at the Wegman hearing RealClimate, 19 July 2006
- The Hockey Stick Controversy John P. Reisman, OSS Foundation - March 9, 2009