Normally when we read about climate change in the press, the stories center around the affect that human technology and carbon emissions have on the planet’s climate. So, we get doom and gloom, handwringing and finger-pointing stories like this one yesterday at Al Jazeera.
What we tend to read less about is the manner in which climate conditions shape us. To wit, there’s a new study out by tree-ring scientists at Columbia University that suggests that the medieval warming period contributed significantly to the rise and fall of the Mongol Empire:
Pederson and Hessl analyzed 17 trees to chart a yearly record of rainfall back to 658 AD. They saw that from 1211-1230—the exact time of the Mongols’ rise—central Mongolia saw one of its wettest periods ever. That time also was unusually warm, as shown by a 2001 paper from other Lamont researchers. Pederson and Hessl reasoned that the clement weather could have brought an unusual boom in grass production—and thus a boom in camels, yaks, cattle, sheep and other livestock that have always comprised the country’s main wealth. A glut of war horses–each Mongol cavalryman was said to have five or more—could have enabled fighters to travel like never before, along with a mobile meat supply. “The weather may literally have supplied the Mongols with the horsepower they needed to do what they did,” says Pederson. He stresses that the idea is still based on only a small sample, and more data is needed to draw firm conclusions. Pederson, Hessl and an interdisciplinary team including Mongolian scientists are now exploring the hypothesis, with a $1.4 million grants from the National Geographic Society and the U.S. National Science Foundation. The work will include not only further analyses of tree rings, but lake sediments, historical documents and other sources.
The idea that shifting climate can influence civilizations has gained traction in recent years. For instance, Lamont scientists in 2010, a team including Lamont tree-ring specialists showed that the 14th-century Angkor civilization of Cambodia and later kingdoms rose and fell based on rainfall, although other factors were almost certainly involved. The Mongols could have suffered a climatic setback, too: a cold snap in 1260-1266 and subsequent return to more normal weather in Mongolia appears to coincide with the decline of Karakorum, whose heyday lasted only 30 years. The empire soon fragmented. Today, barely anything of Karakorum remains but a giant stone turtle that once marked one of its corners.
These days, given the state of our technological development in the contemporary West, it is easy to lose sight of the ways that these commonplace natural cycles—a kind of fate—helped shape the fortunes of empires.
But not so long ago, Montesquieu in his Spirit of the Laws speculated that climate was a important factor not only to the economies of various political societies, but also to their mores, laws, religion, and customs. He urged his students, our Founders among them, to take climate into account when legislating.
Columbia’s study seems to suggest Montesquieu reasoned well, and it is a good reminder to us when reading the history of battles, wars, and nations not to lose sight of the ways that chance and climate might be taken advantage of or might affect their outcome.
What are your thoughts?