Global warming alarmists are breathlessly filling the media with sensationalist reports of carbon dioxide levels approaching 400 parts per million (that’s 4 parts per 10,000, or a 0.0004 share of the atmosphere, versus 3 parts per million, or a 0.0003 share of the atmosphere, prior to the Industrial Revolution). The central message of alarmist global warming theory is that higher atmospheric carbon dioxide concentrations will cause catastrophic global warming. A real-world look at how global temperatures are responding to the rise in atmospheric carbon dioxide levels tells a different story. Although atmospheric carbon dioxide levels were much higher for much of the Earth’s history, 400 ppm is arguably the highest level in at least several hundred years and perhaps thousands of years. Global warming alarmists assert atmospheric carbon dioxide levels were approximately 280 ppm prior to the Industrial Revolution and up until the year 1900 or so, meaning atmospheric carbon dioxide levels...