Then around 1300 A.D. things cooled drastically. This cold spell would last almost 500 years, a severe climate event known as the Little Ice Age. Millions died in famine as glaciers advanced all over the world. The plague returned. In Greenland, the Norse colony that had been established during the Medieval Warming froze and starved. Arctic pack ice descended south, pushing Inuit peoples to the shores of Scotland. People ice skated on the Thames; they walked from Staten Island to Manhattan over a frozen New York Harbor. The year 1816 was remembered as the year without a summer, with some portions of the Northern Hemisphere seeing snowfall in June.

But around 1850 the planet began to warm up yet again. Glaciers retreated. Temperatures rose.  This is the warming period which we are still enjoying today. And once again, the warmth brought bounty: The last 150 years have seen an explosion in life expectancy, population, and scientific progress like never before.

Of course, even before the appearance of humans, the earth alternated throughout its history between extremes of heat and cold: 700 million years ago the planet was covered entirely in ice; 55 million years ago, a swampy greenhouse.

Why?  What drives these ancient cycles? There are a lot of theories. The waxing and waning of solar output; cosmic rays and their role in cloud formation; the earth moving through plumes of galactic dust as it travels up and down through the arm of the Milky Way; plate tectonics redirecting the ocean currents; vulcanism.  Perhaps it is a combination of all of these things. Perhaps it is something as yet undiscovered. One thing for sure that it’s not: SUVs.

Why, then, do otherwise sensible people believe that we are both causing the current warming and that the warmth is a bad thing? To me it seems some grotesque combination of narcissism and self-loathing, a mentality that says at once “I am so important that my behavior is causing this” and “I am so inherently tainted that it must be bad.”

For these self-hating humans who want us to cut our carbs (carbons, not carbohydrates), I say relax and enjoy the warmth while it lasts.

Because it won’t.  No matter what we do, the ice and the cold and the dark will come again. That should be our worry.