- Banned
- #81
Of course they do Matt they used the same data sets and the same methodologies. Which, when tested, gave a hockey stick NO MATTER WHAT NUMBERS YOU ENTERED INTO THE ALGORITHM.
That's not science dude.
The 'meme' that feeding noise into Mann's process produces hockey sticks HAS BEEN LONG AGO REFUTED (May 2005). When you repeat this nonsense, you make yourself look... well... ignorant.
From Wikipedia: The Hockey Stick Controversy
Principal components analysis methodology
In their renewed criticism, McIntyre & McKitrick 2005 (MM05) reported a technical statistical error in the Mann, Bradley & Hughes 1998 (MBH98) method, which they said would produce hockey stick shapes from random data. This claim was given widespread publicity and political spin, enabling the George W. Bush administration to assert that the 1997 Kyoto Protocol was discredited. Scientists found that the issues raised by McIntyre and McKitrick were minor and did not affect the main conclusions of MBH98 or Mann, Bradley & Hughes 1999.[77][116] Reconstructions using different statistical methods had produced similar "hockey stick" graphs. Mann himself had already stopped using the criticised statistical method in 2001, when he changed over to the RegEM climate field reconstruction method.[123]
The available climate proxy records were not spaced evenly over the northern hemisphere: some areas were covered by closely spaced networks with numerous tree-ring proxies, but in many areas only sparse proxy temperature records were available, such as lake sediments, ice cores or corals. To achieve balance, the MBH 1998 (and 1999) studies represented each dense network by using principal component analysis (PCA) to find the leading patterns of variation (PC1, PC2, PC3 etc.) ranked by the percentage of variation they explained. To establish how many significant principal components should be kept so that the patterns put together characterized the original dataset, they used an objective selection rule procedure which involved creating randomised surrogate datasets with the same characteristics and treating them with exactly the same conventions as the original data.[124] The temperature records were of various lengths, the shortest being the instrumental record from 1902 to 1980, and their convention centered data over this modern calibration period.[125] The selection rule found two significant patterns for the North American tree ring network (NOAMER); PC1 emphasized high altitude tree ring data from the Western U.S. showing a cooler period followed by 20th century warming, PC2 emphasised lower elevation tree ring series showing less of a 20th-century trend. This is an acceptable convention, the more conventional method of centering data over the whole period of the study (from 1400 to 1980) produces a very similar outcome but changes the order of PCs and requires more PCs to produce a valid result. Mann did not use the PCA step after 2001, his subsequent reconstructions used the RegEM Climate Field Reconstruction technique incorporating all available individual proxy records instead of replacing groups of records with principal components;[126] tests have shown that the results are nearly identical.[127]
The McIntyre and McKitrick analysis called the PCA centering over the 1902–1980 modern period "an unusual data transformation which strongly affects the resulting PCs". When they centered NOAMER data over the whole 1400–1980 period, this changed the order of principal components so that the warming pattern of high altitude tree ring data was demoted from PC1 to PC4.[120] Instead of recalculating the objective selection rule which increased the number of significant PCs from two to five, they only kept PC1 and PC2. This removed the significant 20th century warming pattern of PC4, discarding data that produced the "hockey stick" shape.[128][129] They said that "In the controversial 15th century period, the MBH98 method effectively selects only one species (bristlecone pine) into the critical North American PC1",[120] but subsequent investigation showed that the "hockey stick" shape remained with the correct selection rule, even when bristlecone pine proxies were removed.[129]
Their MMO5 paper said that the MBH98 (1902–1980 centering) "method, when tested on persistent red noise, nearly always produces a hockey stick shaped first principal component (PC1)", by picking out "series that randomly 'trend' up or down during the ending sub-segment of the series".[120] Though modern centering produces a small bias in this way, the MM05 methods exaggerated the effect.[125] Tests of the MBH98 methodology on pseudoproxies formed with noise varying from red noise to white noise found that this effect caused only very small differences which were within the uncertainty range and had no significance for the final reconstruction.[130] Red noise for surrogate datasets should have the characteristics of natural variation, but the statistical method used by McIntyre and McKitrick produced "persistent red noise" based on 20th century warming trends which showed inflated long term swings, and overstated the tendency of the MBH98 method to produce hockey stick shapes. Their use of this persistent red noise invalidated their claim that "the MBH98 15th century reconstruction lacks statistical significance", and there was also a data handling error in the MM05 method. Studies using appropriate red noise found that MBH98 passed the threshold for statistical skill, but the MMO5 reconstructions failed verification tests.[125][129][131]
To demonstrate that that some simulations using their persistent red noise "bore a quite remarkable similarity to the actual MBH98 temperature reconstruction", McIntyre and McKitrick produced illustrations for comparison.[120] Figure 4.4 of the Wegman Report showed 12 of these pre-selected simulations. It called this "One of the most compelling illustrations that McIntyre and McKitrick have produced", and said that the "MBH98 algorithm found ‘hockey stick’ trend in each of the independent replications".[132] McIntyre and McKitrick's code selected 100 simulations with the highest "hockey stick index" from the 10,000 simulations they had carried out, and their illustrations were taken from this pre-selected 1%.[133]
Publicity
In a public relations campaign two weeks before the McIntyre and McKitrick paper was published, the Canadian National Post for 27 January carried a front page article alleging that "A pivotal global warming study central to the Kyoto Protocol contains serious flaws caused by a computer programming glitch and other faulty methodology, according to new Canadian research." It reprinted in two parts a long article by Marcel Crok which had appeared in Natuurwetenschap & Techniek under the heading "Proof that mankind causes climate change is refuted, Kyoto protocol based on flawed statistics" and the assertion that the MBH99 finding of exceptional late 20th century warmth was "the central pillar of the Kyoto Protocol", despite the protocol having been adopted in December 1997, before either of the MBH papers had been published. The Bush administration had already decided to disregard the Kyoto Protocol which was to come into effect later that month, and this enabled them to say that the protocol was discredited.[134]
McIntyre & McKitrick 2005 (MM05) was published in Geophysical Research Letters on 12 February 2005. They also published an extended critique in Energy & Environment responding to criticism of their 2003 paper and alleging that other reconstructions were not independent as there was "much overlapping" of authors.[135] Two days later, a lead article in the Wall Street Journal said that McIntyre's new paper was "circulating inside energy companies and government agencies. Canada's environment ministry has ordered a review", and though McIntyre did not take strong position on whether or not fossil-fuel use was causing global warming, "He just says he has found a flaw in a main leg supporting the global-warming consensus, the consensus that led to an international initiative taking effect this week: Kyoto."[136]
Technical issues were discussed in RealClimate on 18 February in a blog entry by Gavin Schmidt and Caspar Ammann,[137] and in a BBC News interview Schmidt said that by using a different convention but not altering subsequent steps in the analysis accordingly, McIntyre and McKitrick had removed significant data which would have given the same result as the MBH papers.[138]
On on 4 April 2005, McKitrick gave a presentation to the Asia-Pacific Economic Cooperation Study Centre outlining the arguments of MM05, alleging that the TAR had given undue prominence given to the hockey stick graph, and discussing publicity given to the TAR conclusions in Canada. He said that "In the 1995 Second Assessment Report of the IPCC, there was no hockey stick. Instead the millennial climate history contained a MWP and a subsequent Little Ice Age, as shown as in Figure 3." The figure, headed "World Climate History according to IPCC in 1995", resembled the schematic 7.1(c) from IPCC 1990, and corrections to refer to IPCC 1990 were made on 22 July 2005.[139]
At the end of April Science published a reconstruction by J. Oerlemans based on glacier length records from different parts of the world, and found consistent independent evidence for the period from 1600 to 1990 supporting other reconstructions regarding magnitude and timing of global warming.[140] In May the University Corporation for Atmospheric Research advised media about a detailed analysis by Eugene Wahl and Caspar Ammann, first presented at the American Geophysical Union’s December 2004 meeting in San Francisco, which used their own code to replicate the MBH results, and found the MBH method to be robust even with modifications. Their work contradicted the claims by McIntyre and McKitrick about high 15th century global temperatures and allegations of methodological bias towards a hockey stick outcomes, and they concluded that the criticisms of the hockey stick graph were groundless.[141]
Your source is Wikipedia - obvious bullshit, in other words. Also, all the article says is that a couple of cult members claim McIntyre's results are incorrect. There's no evidence to support their claims. Many such attempts have been made, and McIntyre has shot them all down.
Of course. What COULD I have been thinking? Hmm... maybe it was that no one outside Soon, Bailunas, Legate (and actually support from those three is iffy) and the ever-impressive Senator Inhofe view MM as valid. That'd be more than 97% in opposition and supporting Mann. And if you think McIntyre has refuted Wahl and Ahmann, I'm sure you'll have no problem pulling that up for us. And more importantly, some widespread acceptance of his arguments.
The obvious problem here is that I almost automatically assume the view of the 97% to be correct where you automatically assume it to not only be wrong, but to be intentionally false.
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