The term "hockey stick" was coined by the head of National Oceanic and Atmospheric Administration's (NOAA) Geophysical Fluid Dynamics Laboratory, Jerry Mahlman, to describe the pattern of historical temperatures in the northern hemisphere (it kind of looks like a hockey stick on its side). The chart, created by Professor Michael Mann of Penn State, shows relatively stable temperatures until around 100 year ago when we see a spike up. It is one of the key pieces of information used to prove that global warming is about to destroy the world.
To create most of the chart , climate change scientists had to use natural sources (as opposed to someone taking the temperature with a thermometer). Tree rings and ice core samples were used to measure the temperature levels, which are standard procedure. What isn't standard procedure is the revelation via the "stolen" CRU emails, that the tree samples were "cherry-picked to skew the study. You see, the famous Hockey stick is fudged. The scientists substituted a different kind of tree, who's rings would not show a medieval warming spell with temperatures much hotter than today. And it may be the cherry-picking of one kind of Siberian tree that Phil Jones of the CRU may have meant when he talked about using Dr. Mann's "trick" to adjust the data :
It is therefore vitally important that we should trust the methods by which these men have made their case. The supreme prize that they have been working for so long has been to establish that the world is warmer today than ever before in recorded history. To do this it has been necessary to eliminate a wealth of evidence that the world 1,000 years ago was, for entirely natural reasons, warmer than today (the so-called Medieval Warm Period).
The most celebrated attempt to demonstrate this was the "hockey stick" graph produced by Dr Mann in 1999, which instantly became the chief icon of the IPCC and the global warming lobby all over the world. But in 2003 a Canadian statistician, Steve McIntyre, with his colleague Professor Ross McKitrick, showed how the graph had been fabricated by a computer model that produced "hockey stick" graphs whatever random data were fed into it. A wholly unrepresentative sample of tree rings from bristlecone pines in the western USA had been made to stand as "proxies" to show that there was no Medieval Warm Period, and that late 20th-century temperatures had soared to unprecedented levels.
Although McIntyre's exposure of the "hockey stick" was upheld in 2006 by two expert panels commissioned by the US Congress, the small group of scientists at the top of the IPCC brushed this aside by pointing at a hugely influential series of graphs originating from the CRU, from Jones and Briffa. These appeared to confirm the rewriting of climate history in the "hockey stick", by using quite different tree ring data from Siberia. Briffa was put in charge of the key chapter of the IPCC's fourth report, in 2007, which dismissed all McIntyre's criticisms.
At the forefront of those who found suspicious the graphs based on tree rings from the Yamal peninsula in Siberia was McIntyre himself, not least because for years the CRU refused to disclose the data used to construct them. This breached a basic rule of scientific procedure. But last summer the Royal Society insisted on the rule being obeyed, and two months ago Briffa accordingly published on his website some of the data McIntyre had been after.
This was startling enough, as McIntyre demonstrated in an explosive series of posts on his Climate Audit blog, because it showed that the CRU studies were based on cherry-picking hundreds of Siberian samples only to leave those that showed the picture that was wanted. Other studies based on similar data had clearly shown the Medieval Warm Period as hotter than today. Indeed only the evidence from one tree, YADO61, seemed to show a "hockey stick" pattern, and it was this, in light of the extraordinary reverence given to the CRU's studies, which led McIntyre to dub it "the most influential tree in the world".This may turn out to be Dr. Mann's famous "trick" talked about in Phil Jones email released two weeks ago. It wasn't about manipulating numbers, it was all about changing the trees:
The most quoted remark in those emails has been one from Prof Jones in 1999, reporting that he had used "Mike [Mann]'s Nature trick of adding in the real temps" to "Keith's" graph, in order to "hide the decline". Invariably this has been quoted out of context. Its true significance, we can now see, is that what they intended to hide was the awkward fact that, apart from that one tree, the Yamal data showed temperatures not having risen in the late 20th century but declining. What Jones suggested, emulating Mann's procedure for the "hockey stick" (originally published in Nature), was that tree-ring data after 1960 should be eliminated, and substituted – without explanation – with a line based on the quite different data of measured global temperatures, to convey that temperatures after 1960 had shot up.
A further devastating blow has now been dealt to the CRU graphs by an expert contributor to McIntyre's Climate Audit, known only as "Lucy Skywalker". She has cross-checked with the actual temperature records for that part of Siberia, showing that in the past 50 years temperatures have not risen at all.
In other words, what has become arguably the most influential set of evidence used to support the case that the world faces unprecedented global warming, developed, copied and promoted hundreds of times, has now been as definitively kicked into touch as was Mann's "hockey stick" before it. Yet it is on a blind acceptance of this kind of evidence that 16,500 politicians, officials, scientists and environmental activists will be gathering in Copenhagen to discuss measures which, if adopted, would require us all in the West to cut back on our carbon dioxide emissions by anything up to 80 per cent, utterly transforming the world economy.None of this has been reported by the Mainstream Media, who are single minded promoting the progressive agenda. Then there are those college scientists getting rich off of government grants,who trade in their scientific ethics and pile on to the supposed global warming consensus without bothering to investigate any of the glaring scientific discrepancies and procedural flaws. Over the coming few years, as the costs of global warming policies mount and the evidence of a crisis continues to collapse, perhaps one day they will be allowed to tie their shoes without first getting permission from the likes of Professors Mann and Jones.