The theory of man-made global warming rests on scientific evidence that the combustion of fossil fuels in the service of human energy needs has added high concentrations of carbon dioxide and methane and other heat-trapping greenhouse gases to the earth’s atmosphere. In the opinion of international scientists, global temperatures have risen significantly since the onset of the Industrial Revolution in the mid-1800s, when human activity became dependent on the use of coal, oil, and gas.

In fact, many researchers are convinced that human activity is responsible for the majority of the warming that has occurred over the past 150 years and practically all of the warming since the 1970s. A study of the climate of the last thousand years by Thomas J. Crowley, a geologist at Texas A&M University, found that “natural variability plays only a subsidiary role in...