The central argument of global warming alarmists is that the past 40 years of human economic activities have added huge new quantities of carbon dioxide to the earth's atmosphere – notably from the burning of fossil fuels such as oil and coal – resulting in a small, but perceptible increase in its temperature. This increase, they warn, is bound to have big and largely negative consequences for life in general, and human life in particular, over the next few decades. Among these – depending on the computer model adopted and the amount of warming it forecasts – are everything from...