You can be forgiven if you didn’t know that we’re in the middle of an ice age right now, what with all the talk about global warming. But it’s true. We’re in what geologists call “the Quaternary glaciation,” an ice age that’s lasted for the past 2.5 million years.
Ice ages last a very long time, with periods of extreme cold punctuated by warmer periods, or interglacials. We’re in such an interglacial right now: The Holocene epoch began about 12,000 years ago. It’s best thought of as a brief respite from the most severe ravages of Quaternary ice.
So global warming actually began around 10,000 BC, when the ice sheets that had covered large portions of North America and Eurasia retreated to the poles. And what has happened since this (entirely natural) warming began? The Neolithic Revolution, the dawn of civilization and the expansion of human populations like never before.
In other words, homo sapiens, which existed in its more or less anatomically modern form for 100,000 to 200,000 years, began to flourish and thrive as a result of this most fortuitous warmth.
In short: Global warming is good for people.
If you don’t believe me, look at the temperature variations within the Holocene: The so-called Roman Warming coincided with the heights of classical civilization; then came a period of cooling which coincided with the social collapse of the Dark Ages.
Then there was the Medieval Warm Period, which coincided with the rise of monumental cathedrals in Europe and the settlement by Vikings in a lush Greenland, followed by the Little Ice Age (from roughly the 14th to the 19th centuries) — which saw widespread political upheavals, famine and disease.
Finally, there is the current warming trend of the last century and a half or so.
In each instance, the result is broadly the same: The warmer the Earth, the better it has been for people.
So let’s be thankful for the Holocene — civilization could never have arisen without it. And let’s be thankful we live in this especially warm period within the Holocene, which has seen human populations achieve measures of health and wealth unparalleled in all of history.
But let us also not be fooled — this blessed respite will someday end. The ice will return. It always has, it always will. And when it does, it will threaten all we have built, and indeed, our very existence.
Enviros often describe global warming as some kind of Hell on Earth. But Dante Alighieri, who taught us a thing or two about Hell, knew better. In Canto 34 of The Inferno, Dante and his guide Virgil descend to the ninth and lowest circle of Hell, and in the very center they find Satan who sits, not in a pit of fire — but frozen in a solid lake of ice.