Thursday, October 01, 2009
Since there were no thermometers available for most of the 1000 years that the temperature study covered, temperatures were estimated using proxy data, to wit: cores taken from larch trees that displayed the pattern of tree rings. It turns out that trees grow faster in warmer conditions, and so temperatures during the life of the tree can be estimated by analyzing whether the tree rings are close together (cooler) or farther apart (warmer).
It turns out that the dataset that was used to create the "hockey stick" was comprised of only 12 tree cores from a population of 252 cores known as the Yamal dataset. The dataset was being Bogarted for many years by Keith Briffa, a scientist at the Climate Research Unit (CRU) at the University of East Anglia (UK). Through dogged persistence and patience, McIntyre was able not only to finally obtain Briffa's data, but also data from other sets of tree cores that were taken from trees that were not far away from those in the Yamal dataset.
When those other datasets were used with the CRU methodology, the "hockey stick" went away!
Dear reader, since the whole anthropogenic global warming thing is based almost entirely on the MBH study, it just may be that global warming is a myth. Surprise, surprise!
If I were Mr. McIntyre, I might be considering hiring a bodyguard, because powerful people have a lot invested in stopping global warming.
If you are interested in this sort of thing, be sure to read Bishop Hill blog, which tells the story in lay terms.