Climate change denial is a major industry, lavishly financed by Exxon, the Koch brothers and others with a financial stake in the continued burning of fossil fuels. And exploiting variability is one of the key tricks of that industry’s trade. Applications range from the Fox News perennial — “It’s cold outside! Al Gore was wrong!” — to the constant claims that we’re experiencing global cooling, not warming, because it’s not as hot right now as it was a few years back.