Climate variability has been a constant long before human beings inhabited this earth. Of course, carbon dioxide is a greenhouse gas that can trap energy. But so is water vapor, and its levels are far harder to track because its amount and distribution are not constant across the earth’s surface. Most crucially, observed cyclical patterns of temperature change do not correlate with slow but steady increases in carbon dioxide. Recent work by climate scientists Richard Lindzen and others shows that during the so-called Holocene period (roughly covering the last 11,000 years), there was a negative correlation between temperatures and carbon dioxide concentrations—strongly suggesting that carbon dioxide levels cannot be the main driver of temperature changes. It should, therefore, come as no surprise that recent climate models that have predicted sharp temperature increases have consistently run “hot,