The “Hockey-Stick” graph refers to the results of Dr. Michael Mann [see “NIPCC vs. IPCC” Fig. 20, pg. 22]. In 1998, he presented a summary of his analysis of “proxy” data of the past 1000 years, mostly tree-ring temperatures.
He showed a steady decline of temperatures of the Northern hemisphere, without the “cooling” of the Little Ice Age (LIA)], followed by a sharp temperature rise (the “blade” of the hockey-stick) in the 20th century.
The implication of his graph is obvious, but it is wrong in claiming that the copious emission of CO2 in the 20th century produced record warming in the decades before 1942.
Of course, the emission of CO2 grew after 1945, at the end of WWII; but the climate seemed to cool until about 1975. (Apparently, the climate did not respond to CO2, as expected from greenhouse theory.)
However, he halted the use of his proxy data at the end of the 1970s decade and cleverly added the instrumental data for the period 1978-1998 from surface thermometers, which showed a sharp rise seen by surface thermometers that proved to be a complete illusion (some went so far as to use the word “fake”); he managed to suppress his own contemporaneous proxy data for that interval and has never revealed them.
To do so would have removed the sharp rise (“the blade”) and ruined his “hockey-stick” graph.
In other words, the “hockey stick” is a fictitious construct that has been called “Mike’s Nature trick” by some, and has been “whitewashed” by the usual panels that were unaware of the background and implications.
The IPCC-Assessment Report-3 [2001] featured the “hockey stick” as the consequence as proof of human activity in the 20th century. Mann has since received many honors and lucrative government grants.
This, despite the brilliant and persistent efforts and publications by profs Ross McKitrick and Stephen McIntyre.
Starting in 2003, these two Canadian statisticians were the first to show the “shoddy” analysis by Mann of his own data.
They even demonstrated convincingly that an input of pure noise fed into the Mann algorithm would lead to a hockey stick [REF]. Gradually, their scholarly critiques convinced others.
But there are still many “warmistas” who believe that the 20th century was the warmest in the last 1000 years — despite strong observational evidence [REF] that the Medieval Warm Period (MWP) was warmer than the present.
And despite the existence of the well-known LIA (Little Ice Age), of about 1400-1850 A.D.
In fact, the proxy data for the second half of the 20th century are now available. They don’t show Mann’s sharp rise [REF; see also the tree-ring data of HTCS Fig. 16, pg. 46 and the ice-core data of NIPCC vs. IPCC Fig. 24, pg. 24.
Up until now, Mann has refused to reveal his own proxy data, which include the crucial interval 1978-1997. We are still waiting…
Read more at American Thinker
So just when will Al Gore give up his lifestyles of the Spoiled and Hypotcritical? and when will DiCaprio quit making movies go live as a hermit? not very likely these examples of the Do As I Say Not As I Do liberal spoiled brats
The hockey stick graph accomplished its purpose.
It also established a pattern. The liar gets the headlines.
Mike Mann is like having Bernie Madoff saying that he did not run a Ponzi scheme an he is allowed to keep the money, and no charges laid.
Many warmest who buy into the climate change fraud now realized that Michael Mann’s “Hockey-Stick” does not support their position. The fact that Mann has refused to reveal his own proxy data is extremely significant. Normally this is a guarantee that the author knows that his data doesn’t support his conclusion. When the study is done to support a political cause, it is assured that he knows this.
It seems to me that if recent ‘tree-ring’/temperature data doesn’t agree with recent ‘instrument’/temperature data – why should anyone rely on ‘tree-ring’ data from previous years/eras to determine ‘pre-instrument’ temperatures. Could it be argued that “Climate Change” is causing trees to generate annual rings in some modified pattern? Talk about a circular argument…..
I have thought the same, because tree growth is affected by things other than temperature. However, I’ve noticed that researchers include other proxy data from the same time period. It’s like detective work, if evidence is ignored or destroyed, the case is dismissed.
Is this proof that some climatologists are politically motivated? When tree ring data supported his thesis, he used it. When it didn’t agree, he substituted different information. It seems to me that scientists want to be right, while politicians want to win, facts be damned.
Substituting information is common with the so called scientists in the climate change movement. The main paper on ocean acidification selected 1988, the year the oceans had the highest pH (furthest from acid) as its starting point. This guaranteed that subsequent years would be closer to acid. But they had a problem. Their data previous to 1988 clearly showed that their theory was wrong. They easily solved that by substituting computer simulated data for the real world data.
AGW = Al Gore’s Wrong! Yes let’s be eco-friendly, not eco-stupid!!!
Please do not hold your breath while you wait. 😉