[Illustrations, footnotes and references available in PDF version]
As presently constituted, earth’s atmosphere contains just slightly less than 400 ppm of the colorless and odorless gas we call carbon dioxide or CO2. That’s only four-hundredths of one percent. Consequently, even if the air’s CO2 concentration was tripled, carbon dioxide would still comprise only a little over one tenth of one percent of the air we breathe, which is far less than what wafted through earth’s atmosphere eons ago, when the planet was a virtual garden place. Nevertheless, a small increase in this minuscule amount of CO2 is frequently predicted to produce a suite of dire environmental consequences, including dangerous global warming, catastrophic sea level rise, reduced agricultural output, and the destruction of many natural ecosystems, as well as dramatic increases in extreme weather phenomena, such as droughts, floods and hurricanes.
As strange as it may seem, these frightening future scenarios are derived from a single source of information: the ever-evolving computer-driven climate models that presume to reduce the important physical, chemical and biological processes that combine to determine the state of earth’s climate into a set of mathematical equations out of which their forecasts are produced. But do we really know what all of those complex and interacting processes are? And even if we did — which we don’t — could we correctly reduce them into manageable computer code so as to produce reliable forecasts 50 or 100 years into the future?