Introduction
When life first appeared on our planet, whether by chance or designs, it was possible only because the climate was friendly; it was neither too hot nor too cold. The atmosphere, containing water vapor, carbon dioxide, and other components, acted like the glass panels of a greenhouse, letting the sun's heat in but preventing some of it from escaping, thus warming the planet. If it were not for this greenhouse effect, temperatures at the earth's surface would be far colder than they are, and life as we know it could not exist. Global warming has become an issue of concern because of the perception that increasing greenhouse gases will cause the earth to warm so fast that nature (and humankind) may not be able to adapt to the rapid change. The atmosphere has always acted as a warming blanket around the earth. It is not the warmth of this blanket but the possibility of an abrupt or extreme temperature change that is causing some scientists concern. The popular view of global warming—the "myth"—has developed over the past decade because of predictions of computer climate models. This view has been presented in books by authors such as Al Gore, Stephen Schneider, Isaac Asimov, and Paul Ehrlich, and it has been advanced by the media and in school classrooms. Environmental organizations have taken up the cause and demanded political action. At times the reaction to this view reaches a feverish pitch, generating hysteria.
Carbon dioxide, generally believed to be the most important greenhouse gas and climate modifier, is today the centerpiece of a heated political and scientific debate. In its most polarized form, one side maintains that C [O.sub.2] is the principal driver of climate, and the sequence of events is "higher C [O.sub.2] equals global warming equals climate.......
