A Force That Has Shaped the History of the World

Does climate change directly influence the weather we experience? Until recently—for the past 40 years or so—that question has followed nearly every major hurricane or flood, every record snowfall or heat wave. In some people, it provokes instant denial, often political or economic, often rooted in prideful ignorance. But the question raises a genuine analytical issue: How do we determine the effect of incremental, global atmospheric change on locally transient weather systems? And how do we assess the effect that those systems—and the climate shifts underlying them—have had on human societies in the past? These are complicated questions. Now imagine trying to answer them throughout the whole of history, from the origin of our species to the day before yesterday. That’s the task the Oxford historian Peter Frankopan undertakes in The Earth Transformed: An Untold History.

Consider, for instance, what has come to be called the Little Ice Age, a period of sharply lower temperatures from (roughly) the 16th to the early 19th centuries. The term first appeared in 1939 in a report from the glaciers committee at the American Geophysical Union, and, as Frankopan notes, it “became popular with historians and general readers alike.” But was the Little