The View From 1776
Monday, May 04, 2009
Correlation is not Cause
Much of the reported increase in global temperatures has occurred during the time that Al Gore became obsessed with the man-made greenhouse gases hypothesis. Is his obsession the cause of global warming?
Correlation (i.e., when two variables tend to fluctuate up or down at roughly the same time) does not imply cause and effect. Borrowing from Wikipedia, a couple of examples of false correlation illustrate the point.
The bigger the fire, the more fireman; therefore firemen cause fires.
In hot weather both ice cream sales and drownings increase, therefore ice cream causes drownings.
President Obama’s “green” legislation drive is akin to ordering a reduction in the number of firemen or prohibiting sale of ice cream. The President’s worship of the power of his mind to control God’s Creation will strangle American business with miles of new regulatory red tape and higher taxes. Everyone’s cost of living will increase significantly, with almost no effect upon global temperatures.
The hypothesis of man-made global warming rests upon the rough correlation in recent decades of temperature increases and rising amounts of CO2 detected in the atmosphere.
First, that correlation is much more limited when it is carried back into the 19th century, when coal-fired industrialization produced far more CO2 than today.
Second, even the UN’s socialist political group that controls interpretation of scientific climate study by its panel of experts (who do not agree with the UN’s summary of their work) now admits that the increases in global temperatures forecast in their earlier press releases are much overstated.
I am indebted to Frank Madarasz, who emailed the following two weblinks.
With regard to the very weak link between human action and global warming, read this letter posted in the Wall Street Journal.
For another example of false correlation read Shock: Global temperatures driven by US Postal Charges: The rise in global temperatures since 1880 closely correlates with increases in postal charges…