A decades-long drought interspersed with intense monsoons in the 14th and 15th centuries may have contributed to the fall of the Angkorean civilization, a new US research study suggests.
Brendan Buckley, a researcher at Columbia University, and his colleagues studied tree rings in the region, putting together a high-resolution record of periods of drought and moisture, and while it is not clear what exact role climate played in the fall of the empire, Buckley told VOA Khmer climate certainly played a part.
“We wanted to be careful not to make it sound like we were saying correlation equals causation,” Buckley said. “I mean there is plenty of evidence in our record, or in other records, where you know that drought doesn’t always lead to collapse, but what it does do if you have sustained drought is it certainly puts a stresser on societies when other factors are stressing them.”
The Angkorean empire had suffered a gradual decline in regional power and had not been maintaining its water systems for about a century, Buckley said.
But by studying tree rings, which can be a clear indicator of precipitation, Buckley and his team found a large drought in the middle of the 1300s that lasted nearly three decades. That was followed by a severe wet period, followed again by sharp drought in the early 1400s.
The opposing pressure of these weather patterns may have helped damage the empire’s infrastructure. The collapse of the empire coincided with this period.
Nearly all Angkorean archeology has been done with what is available above ground, on visually spectacular sites like the temples of Bayon or Angkor Wat, Buckley said, but no one has yet gone into the forest and looked underground. Another interesting question would be to look at the links between drought and disease outbreaks, he said.
The fall of Angkor is still the subject of much debate among researchers—including whether it collapsed at all or simply saw a slow migration of its people due to war, internal conflict or a change in religion.
Until now, climate change has not been widely discussed as a factor, but Cambodian historians and archaeologists told VOA Khmer the idea has at least some merit.
“When there is sustained flooding or drought, it affects the economy,” said Son Soubert, a member of Cambodia’s Constitutional Council and an archaeologist. “As you may know in Jewish history, in the Bible, during that time there was drought in Egypt, which negatively affected many people, especially Jewish. The climate may have affected Khmer society in that period. It’s important because it can also help explain the causes of the demise of Angkor. There was conclusion before that war was the only cause.”
To some researchers, war and conflict remain the main suspects in the empire’s fall.
“The major factor is the human factor,” said Michel Tranet, a Cambodian archaeologist who has worked extensively on Khmer temples and antiquities. “What I mean here is the cruelty of war.”
“Whenever there were wars between the Khmer and Siamese, Siamese troops were stronger and destroyed our nation, our heart, our soul and our great national structures, during which our great Angkor was abolished,” he said.
A religious shift, from Hindu to Buddhist, was another factor, he said, as was internal conflict between royal family members. He called climate change a small tree in a large forest.
“When we had internal conflicts, we were weak, and other nations attacked us, broke us apart,” he said.
Likewise, Ros Chantrabot, a Khmer historian and vice president of the Royal Academy of Cambodia, told VOA Khmer by phone that climate was a small contributing factor.
The invasions between neighboring regions were a main factor, starting with the expansion of Genghis Khan’s Mongol empire into China, he said. This pushed groups of ethnic Thais and Vietnamese into today’s Burma and the northern Khmer empire, leading to Angkor’s ultimate demise.