Suppose a friend or your broker came to you with performance
charts on two popular stocks, one called Wonderful Widgets, the
other called Terrific Thimbles. Their share price over time is
shown at the right. In which of the two stocks would you
invest?
Suppose a friend or your broker came to you with performance charts on two popular stocks, one called Wonderful Widgets, the other called Terrific Thimbles. Their share price over time is shown at the right. In which of the two stocks would you invest?
It is a loaded question. By choosing one or the other, you would be weighing in, not on the next hot stock, but on the raging discussion over global warming.
Oklahoma Senator James Inhofe, Chairman of the Senate Environment and Public Works Committee, took to the podium of the U.S. Senate on Sept. 25 to lay out the case for discipline and measured response to the chorus of calls for immediate action from scientists and politicians in the area of global warming. His speech outlined much of the empirical evidence that tends to refute the raucous claims of imminent disaster seen daily in the popular media.
The heart of the global warming evidence lies in the validity and interpretation of the two graphs shown. These are actual graphs used to describe the average temperature of our planet over the last 1,000 years. Wonderful Widgets is the graph used for the last century and more to document average temperature of the earth from A.D. 1000 to the present time. This graph showing the trend in average temperature for the period in question as issued in 1990 by the U.N. Governmental Panel on Climate Change. On the left-middle of Wonderful Widgets we see the Medieval warm period followed by the Little Ice Age on the middle right. Both of these periods have been reaffirmed by the National Academy of Sciences. Can you observe in the graph of Wonderful Widgets enough of an upward trend toward the right – increasing share price – to make you invest your treasure? Or do you conclude that the graph has no real pattern and you should leave your money in the bank?
Terrific Thimbles is a computer generated graph published in the magazines Nature and Geophysical Research Letters in 1998 and 1999 respectively by Michael Mann of the University of Virginia, Ray Bradley of the University of Massachusetts, and Malcolm Hughes of the University of Arizona. The data represents the same 1000 years as does Wonderful Widgets and shows the earth’s temperature taking into account other data such as tree rings, ice cores, etc. The shape of the graph in the Terrific Thimbles chart and its “hockey stick” shape have become the smoking gun of the global warming alarmists. Constant exposure by the scientific and environmental communities and the press has caused the Mann graph to become a symbol of man’s effect on global climate.
The Mann graph has been challenged not only by climatologists but also by statisticians. The statistical challenge to the Mann graph comes from his method of handling the data collected. Two Canadian scientists, Stephen McIntyre and Ross McKitrick, examined in detail the statistical method used by Mann. They not only found that Mann had not used a standard method called principal component analysis, but had used a method that emphasizes data that looks like the hockey stick in Terrific Thimbles, and suppresses data that does not resemble the hockey stick. To prove their assertion, McIntyre and McKitrick generated random data using what is called a Monte Carlo program. This technique of statistical estimation is well known to scientists and engineers. In my electrical engineering work I have myself used this proven technique. When this totally random data was fed through Mann’s temperature estimation program, amazingly the hockey stick appeared! This analysis has been repeated by other groups of statisticians.
So would you invest in Terrific Thimbles? I certainly would and that is just the point. Prior to the Mann graph, the public was not buying into the alarmists’ story on warming. Since 1999, funds have become much more readily available for investigations of climate phenomenon. Lawmakers in California have bought into the greenhouse gas frenzy. But the frenzy should not be confused with solid science and statistical analysis. Stay tuned.
Al Kelsch is a Hollister resident who writes a weekly column for the Free Lance that runs on Saturdays. Contact him at [email protected]
