Archive for 27 december, 2008

Documenting the global warming fraud – “Getting Rid” of the Medieval Warming Period

27 december, 2008

Documenting the global warming fraud

Thomas Lifson, December 25, 2008

Global warming theory represents one of the greatest scientific con games in history. The putative intellectual foundations are based on data manipulated to support the desired conclusion, and have been conclusively debunked.
Andrew G. Bostom pulls together a beginning history of the steps by which the theory was sold. Unscientific studies came to be embraced as conclusive, their debunkers targeted for abuse. The remarkable hockey stick graph and the effort to ”get rid” of the Medieval Warm Period (whose temperature rise dwarfs anything in the last century) are among the scandalous abuses of science covered here.

Those who want to marshal the evidence to induce skepticism in friends who fall for warmist propaganda should read and save this article. The science is explained lucidly, so that any serious reader can comprehend the issues. It is not a quick and light read, but it repays an investment of a few minutes of serious attention.


Se also my posts: Minus 60 C or not?,  More on the Blunder with NASA: s GISS Temperature data and the mess they haveThe world has never seen such freezing heat OR the Blunder with NASA: s GISS Temperature data,   Clinton-Gore behind the Global Warming!Global Warming Hysteria – Governments AND Media Together Close Down The DebateOverall temperature trend since 1979 for Antarctica is slightly negative.Don’t Panic! A Critique of Catastrophic Man-Made Global Warming Theory422 700 år av temperaturdata från Antarktis, Temperaturen för 130 000 år sedan och Temperature data – What it really means., GLOBAL TEMPERATURE TRENDS FROM 2500 B.C. TO 2008 A.D.,    Global Warming: Has the Climate Sensitivity Holy Grail Been Found?,  This is what the Global Warming Hysteria is all about – 0,03%!,  A Climate of Belief – The Story of Climate models!,  Study of Greenland Ice Finds Rapid Change in Past Climate,  NOAA Cherry Picking on Trend Analyses,  The Spatial Pattern and Mechanisms of Heat-Content Change in the North Atlantic,  Ytvattentemperaturen i Atlanten utanför Central Amerika de senaste 32 000 åren.,  Assessment of the reliability of climate predictions based on comparisons with historical time series,  Cold in the tropical troposphere but it should be warming if Global Warming ”theories” are correct!,  Average Day By Day Variations Of The Global And Hemispheric Average Lower Tropospheric Temperatures,  2 miljarder år av temperaturdata!Rewriting Temperature History – Time and Time Again!,  Has the IPCC inflated the feedback factor?Outstanding Job That Anthony Watts Has Done On Documenting The Immediate Environment Of Suface Temperature Monitoring Sites,  The wonderful benefits of CO2!,  När CO2 var som störst var temperaturen som lägst!

The UN Climate Change Numbers Hoax eller IPCC:s lögn!,  The Unscientific way of IPCC:s forecasts eller IPPC:s lögn del 2!The Great Global Warming Hoax

Andrew  Bostom’s post here:

Horse Hockey Climate Scientology: ”Getting Rid” of the Medieval Warming Period
December 25th, 2008 by Andrew Bostom

Hockey Stick Climate Scientologists Contemplating Their Work

U.S. Senate Committee on Environment & Public Works
Hearing Statements


Statement of Dr. David Deming

University of Oklahoma
College of Earth and Energy
Climate Change and the Media

Mr. Chairman, members of the Committee, and distinguished guests, thank you for inviting me to testify today. I am a geologist and geophysicist. I have a bachelor’s degree in geology from Indiana University, and a Ph.D in geophysics from the University of Utah. My field of specialization in geophysics is temperature and heat flow. In recent years, I have turned my studies to the history and philosophy of science. In 1995, I published a short paper in the academic journal Science. In that study, I reviewed how borehole temperature data recorded a warming of about one degree Celsius in North America over the last 100 to 150 years. The week the article appeared, I was contacted by a reporter for National Public Radio. He offered to interview me, but only if I would state that the warming was due to human activity. When I refused to do so, he hung up on me.

I had another interesting experience around the time my paper in Science was published. I received an astonishing email from a major researcher in the area of climate change. He said, ”We have to get rid of the Medieval Warm Period.”

The Medieval Warm Period (MWP)-a well-established phenomenon (see for example, Hubert H. Lamb’s Climate History and the Modern World, London, 1995, chapter 10, pp. 159-163)-dated from approximately 1000 to 1300 C.E., and comprised an interval during which global temperature conditions were warmer than those at present. The International Panel on Climate Change (IPCC), produced the graph below (Figure 1) in its Second Assessment Report from 1995/1996: the second millennial climate history includes the aforementioned MWP, as well as a subsequent Little Ice Age. As Professor Ross McKitrick notes (in ”What is the Hockey-Stick Debate About?”),

The late 20th century appears to be nothing special by comparison. It is easy to see why this graph was a problem for those pushing the global warming alarm. If the world could warm so much on such a short time scale as a result of natural causes, surely the 20th century climate change could simply be a natural effect as well. And the present climate change could hardly be considered unusually hazardous if even larger climate changes happened in the recent past, and we are simply fluctuating in the middle of what nature regularly dishes out?

David Holland, in his thorough 2007 analysis of the IPCC process, observes more pointedly,

 The extreme but frequently articulated view that, because of ”positive feedback”, a little further warming will lead to a ”tipping point”and ”runaway” global warming was clearly unfounded in comparison with historic higher temperatures from which the earth has previously ”recovered”. Since it is argued that present carbon dioxide levels are higher now than for several hundred thousand years, any previous higher temperatures in that period must mean that factors other than human-emitted carbon dioxide were responsible.

But facts are (supposed to be-see further discussion below) stubborn things. Huang et al (Huang, Shaopeng, Henry N. Pollack and Po Yu Shen (1997). ”Late Quaternary Temperature Changes Seen in Worldwide Continental Heat Flow Measurements.” Geophysical Research Letters 24: 1947-1950.) published a 1997 analysis of 6000 borehole records (boreholes drilled into the ground provide a vertical temperature profile that can be inverted to yield an estimate of the historical surface temperature sequence) from each continent, dating back 20,000 years. McKitrick, using data supplied by Huang, reproduced the portion of the graphic (see Figure 2) which highlights the interval from 1000 to 1990 C.E. He concludes,

The similarity to the IPCC’s 1995 graph is obvious. The world experienced a ”warm” interval in the medieval era that dwarfs 20th century changes. The present-day climate appears to be simply a recovery from the cold years of the ”Little Ice Age.”

                                                              Figure 1


                                                  Figure 2



Nevertheless, despite the publication of Huang et al’s findings in 1997, as summarized by McKitrick,

The next year, Nature published the first Mann hockey stick paper, commonly called ”MBH98.” (Mann, M.E., Bradley, R.S. and Hughes, M.K., 1998. Global-Scale Temperature Patterns and Climate Forcing Over the Past Six Centuries, Nature, 392, 779-787.) Mann et al. followed up in 1999 with a paper (Mann, M.E., Bradley, R.S. and Hughes, M.K., Northern Hemisphere Temperatures During the Past Millennium: Inferences, Uncertainties, and Limitations, Geophysical Research Letters, 26, 759-762, 1999.) in GRL (”MBH99”) extending their results from AD1400 back to AD1000.8 In early 2000 the IPCC released the first draft of the TAR. The hockey stick was the only paleoclimate reconstruction shown in the Summary, and was the only one in the whole report to be singled out for repeated presentation. The borehole data received a brief mention in Chapter 2 but the Huang et al. graph was not shown. A small graph of borehole data taken from another study and based on a smaller sample was shown, but it only showed a post-1500 segment, which, conveniently, trended upwards.

 As soon as the IPCC Report came out, the hockey stick version of climate history became canonical. Suddenly it was the ”consensus” view, and for the next few years it seemed that anyone publicly questioning the result was in for a ferocious reception.

Stephen McIntyre and Ross McKitrick (in McIntyre, Steven and Ross McKitrick, (2003). ”Corrections to the Mann et. al. (1998 ) Proxy Data Base and Northern Hemisphere Average Temperature Series.” Environment and Energy 14(6) pp. 751-771.) detailed meticulously the ”errors and defects” in the original Mann, Bradley, and Hughes paper (”MBH98”). Below, I have reprinted McIntyre and McKitrick’s conclusions followed by the hockey-stick graph of Mann et al (Figure 3) and the McIntyre/ McKitrick reconstruction (Figure 4) of the ”MBH98” graphic simply applying ”MBH98” statistical modeling procedures to an updated, correctly collated assembly of ”MBH98” proxy data.

 The MBH98 hockey stick-shaped Northern Hemispheric temperature index discussed here has been extremely influential in discussions of 20th century global warming. Together with a pre-1400 extension derived in Mann et. al. (1999) and a spliced instrumental temperature series, this index figured prominently in the IPCC Third Assessment Report (IPCC 2001) and numerous other publications. However, the dataset used to make this construction contained collation errors, unjustified truncation or extrapolation of source data, obsolete data, incorrect principal component calculations, geographical mislocations and other serious defects. These errors and defects substantially affect the temperature index.

 Although not all of the dataset could be audited, it was possible to prepare a data base with substantially improved quality control, by using the most recent data and collating it correctly, by avoiding arbitrary filling in or truncation of data and by computing principal components using standard algorithms. Without endorsing the MBH98 methodology or choice of source data, we were able to apply the MBH98 methodology to a database with improved quality control and found that their own method, carefully applied to their own intended source data, yielded a Northern Hemisphere temperature index in which the late 20th century is unexceptional compared to the preceding centuries, displaying neither unusually high mean values nor variability. More generally, the extent of errors and defects in the MBH98 data means that the indexes computed from it are unreliable and cannot be used for comparisons between the current climate and that of past centuries, including claims like ”temperatures in the latter half of the 20th century were unprecedented,” and ”even the warmer intervals in the reconstruction pale in comparison with mid-to-late 20th-century temperatures” (see press release accompanying Mann et al 1999) or that the 1990s was ”likely the warmest decade” and 1998 the ”warmest year” of the millennium (IPCC 2001).

                                                        Figure 3

2008-12-27-figure-3                                            Figure 4



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