Sunday, January 10th 2010, 12:50 PM EST
SEPP SCIENCE EDITORIAL #2-2010 (Jan 9, 2010)
By S. Fred Singer, President, Science and Environmental Policy Project
[Note: This is the fourth of a series of mini-editorials on the “junk science” influencing the global warming issue. Other topics will include the IPCC’s Assessment Report 4, the UN Environmental Program, and some individuals heavily involved in these matters.]
Junk Science #4: IPCC’s Third Assessment Report [IPCC-TAR, 2001]
In line with what seems to be an IPCC plan of claiming increasing confidence in AGW (anthropogenic global warming) with each successive report, the Summary of IPCC Third Assessment Report [IPCC-TAR, 2001] promised new information to support a conclusion of AGW. This new information turned out to be the “Hockeystick,” a dramatic graph that showed temperatures since 1000 AD steadily decreasing – until, suddenly, here was a huge warming in the 20th century. No trace of the Medieval Warm Period (MWP) and the Little Ice Age (LIA), so clearly shown in earlier IPCC reports and supported by both physical and historic data. [See figure in the pdf version]
Please see the figure in the Adobe version
The hockeystick (HS) graph was based on the ‘multi-proxy’ (mainly using tree-ring data) analysis of Mann, Bradley, and Hughes (MBH) [Nature 1998]. Strangely, there was little challenge from the paleo-climate community, perhaps because the statistical method used to combine different kinds of proxy data was not familiar. Soon and Baliunas published a paper (with great difficulty) that contradicted MBH but they were shouted down. As I related (in Science Editorial #1-2010), I questioned Mann as to why his proxy analysis did not go beyond 1980. And Steve McIntyre and Ross McKitrick (MM), in Energy & Environment 2003, found many irregularities in the data that MBH had assembled.
But it was only later that MM and Wegman et.al. discovered fatal errors in MBH’s statistical methodology and in their tree-ring calibration. A convincing demonstration of this was that even random data treated with Mann’s methodology would always yield a HS. While I consider it likely that Mann was not fully aware of his statistical problems in 1998, when he first published his analysis, any subsequent use of the HS to support AGW certainly borders on fraud.
The National Academy of Sciences undertook to investigate the HS controversy and produced an ambivalent report that was used by some to ‘whitewash’ MBH. It mildly criticized the MBH analysis but confusingly claimed that the 20th century was the warmest in the past 400 years – without mentioning that the 16th century was near the depth of the LIA. A Congressional investigation (headed by Rep. Joe Barton) pulled no punches and condemned not only the HS analysis but also the clique of scientists that protected it from legitimate criticism by withholding information, misusing the peer-review process, and even pressuring editors of scientific journals to turn down dissenting papers. The ClimateGate e-mails have served to confirm what had been known or suspected.
A final word: The IPCC-TAR’s case for AGW rested on the claim that the 20th century was ‘unusual’ in the past 1000 years. But it was not. See, for example, the paper by Craig Loehle [E&E 2007], who did not use tree-ring data and showed a MWP substantially warmer than the 20th century. (For other examples, see the NIPCC Summary report.) Besides, there is nothing magic about 1000 years; there are many periods in the Holocene that are even warmer than the MWP.
Click PDF download to read FULL report by Ken Haapala