Book Review: The Long Summer

The Long Summer: How Climate Changed Civilization, by Brian Fagan. Four out of five stars. Like most of Fagan’s works, this is an eminently readable overview of what we know from history and archaeology; in this case, about how climate affected civilizations across the globe over thousands of years. But the book tends to derail any time he comes near comparing things to the modern era; in particular, the strident tones whenever he brings up global warming. Given Fagan gives evidence in the text itself that Earth has been warmer in the past, you get the distinct impression he’s ignoring the evidence of his own research to spout the approved party line. Sad.

Most of the book, however, is very interesting climatic history, intriguing to anyone who’d like to put in some real-world reasons for a sudden advance or retreat of an Evil Empire in their fiction. For example, the Mount Tambora eruption of April 1815 killed at least 12,000 people directly, another 44,000 nearby through famine from ash-fall, and created clouds that led to 1816 becoming the “year without a summer”, ruining crops across the world. The bad weather also led to Mary Shelley writing Frankenstein. Any one of those ought to be enough reason to kick off a necromantic Army of Darkness.

Table I on page 13 ought to give you plenty of story-background ideas all on its own, comparing what happened when on the different continents, and pointing out that Europe didn’t have forests prior to about 12,000 BC. Before that, it was tundra. Like Siberia. Brr. Table II on p 98 goes from hunter-gatherers to the unification of Egypt.

The book covers great chunks of time; the last Ice Age, how the Americas were probably settled, how thinly Europe was populated at the time, and how many times farming and nomadism stopped and started various places based on how wet and how predictable the weather was. There’s enough detail given on everything from the earliest farming on the Nile to the agriculture of Tiwanaku in ancient Peru to give you a decent grasp of what climate was doing, and what humans were doing to adapt to it at any given time. Great stuff – until you hit the last chapter. *Wry* You’d think Fagan doesn’t like the modern era that allows him to make a living writing archaeology.

The really annoying things is that if you look at the book’s own collected data on the temperature of the planet over time, you can see Earth was significantly warmer than the present at about 7,000-8,000 years ago. And about 120,000 years ago, and 240,000 years ago, and 330,000 years ago. (Graphs p. 24-25, among others.) I defy anyone to say humans caused global warming then. And in fact Fagan proposes that those warming periods were all caused by Earth’s orbit shifting to get more sunlight. Yet the Holocene is supposed to be different because it’s ‘more stable and warmer over a longer period’.

…Except right from the Vostok ice core data you can see 1) it isn’t warmer than those peaks and 2) past peaks of temperature range about 10-25,000 years at a time. The Holocene is only 12,000 years old. Well within the range of past parameters.

I’m not saying Anthropogenic Global Warming isn’t possible. I’m saying that the degree of modern era warming we see falls within known past conditions.

AKA if someone suddenly filled the Dead Sea to the brim with ordinary salt water, and you tried to say this was “an unprecedented sea level”, I would point you right at the historical excavations showing its past sea level. And wait.

If Fagan had stuck to his original argument – that large civilizations are increasingly vulnerable to climatic shifts, and ours is the largest ever – it would have been a much stronger book. As it is, dragging in AGW and the associated Death and Disaster memes makes the book turn from arguing the evidence to arguing from emotion. I detest that.

I recommend reading the rest of the book, and skipping the epilogue.