What Happened to Angkor?

Columbia tree-ring scientists journey to a remote forest in Cambodia to search for clues about the demise of a lost civilization.

by David J. Craig Published Spring 2011
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Partial histories

That discovery, published in the Proceedings of the National Academy of Sciences, has provided the most compelling evidence yet for a theory that most scholars, until now, have dismissed as overly speculative: that climate change contributed to Angkor’s collapse. Other, more subtle clues had been found before. A few years ago, Fletcher and his team of archaeologists unearthed evidence that Angkor’s main reservoir was retrofitted around the same time the city is thought to have collapsed, in the early 15th century, to be just half of its original size. The archaeologists hypothesized that this renovation was undertaken during a prolonged drought to ensure that water coming into the reservoir from a nearby river would accumulate rather than seep into a big, half-empty mud basin.

Buckley’s tree-ring research supports a theory that most scholars, until now, dismissed as overly speculative: that climate change led to Angkor’s collapse. / Photo by Andrew Nelson

“There are also accounts of drought in China and in India around this same time,” says Lieberman, the historian at Michigan. “It would stand to reason that Angkor might have had extreme weather, too.” This was a period when the Earth was undergoing a major climate shift, scientists believe, as it was transitioning from what’s commonly called the Medieval Warm Period into the Little Ice Age.

Few historians have considered climate change’s effects on Angkor, however. The standard explanation for Angkor’s demise, Lieberman says, is that its ruling elite simply abandoned the city when economic activity in Southeast Asia shifted southward toward coastal ports in the 14th century. Other scholars say that Angkor’s political structure disintegrated when Buddhism swept through the region in the 13th century, as Angkor’s rulers considered themselves earthly representations of Hindu gods.

Lieberman stands alone among prominent historians in that he has suggested for years that climate change hastened Angkor’s collapse. “The evidence that Angkor saw severe drought was rather circumstantial before Brendan generated this rainfall data, but I still thought it was the best prima facie explanation we had,”  he says. “Other historians haven’t looked at this issue closely, I think, in part because they don’t feel comfortable with their own understanding of the science. So, in the absence of any written accounts of drought or flooding near Angkor, they’ve preferred to focus on the types of phenomena they’re accustomed to writing about, which are the economic, political, and cultural factors.”

Now, with Buckley’s findings, Lieberman believes that historians are obligated to study how Angkor, as well as several other historic Southeast Asian civilizations, were affected by extreme weather. He points out that Buckley’s data reveal prolonged droughts also occurred between 1638 and 1641, just three years before peasant rebellions led to the fall of the Ming Dynasty, and between 1756 and 1768, around the same time that three kingdoms in what are now Vietnam, Myanmar, and Thailand all collapsed. In a forthcoming essay coauthored with Buckley, Lieberman exhorts fellow historians to examine why certain civilizations succumbed to these droughts while others survived. The answers might lie, they say, in the societies’ water-management strategies, the nature of their governments, and the diversification of their economies.

“For the first time,” Lieberman and Buckley write, “we have the data to make climate change a part of our regional narrative.”

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As a Columbia University alum and Cambodian-American, it was great to see scientists exploring Cambodia and studying about what may have happened to the city of Angkor. Never knew how much climate change can impact a country, society and significant period of time. Thanks for the read.

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