New paper finds SE Asian climate was much more extreme from 14th through 18th centuries than the present

A paper published today in Quaternary Science Reviews reconstructs SE Asian climate over the past millennium and finds the climate was much more variable or "unstable" from the late 14th through 18th centuries in comparison to the rest of the past millennium, including the 20th century. The extended extreme droughts and floods that occurred during these portions of the Little Ice Age led to political upheaval and "great unrest."

According to the authors,

"We focus on Southeast Asia where an anomalous period of unstable climate coincided with the demise of the capital of the Khmer Empire at Angkor between the 14th and the 16th centuries, and we suggest that protracted periods of drought and deluge rain events, the latter of which damaged Angkor's extensive water management systems, may have been a significant factor in the subsequent transfer of the political capital away from Angkor. The late 16th and early 17th century experienced climate instability and the collapse of the Ming Dynasty in China under a period of drought, while Tonkin experienced floods and droughts throughout the 17th century. The 18th century was a period of great turmoil across Southeast Asia, when all of the region's polities saw great unrest and rapid realignment during one of the most extended periods of drought of the past millennium."

Monsoon extremes and society over the past millennium on mainland Southeast Asia

• Brendan M. Buckley^a, , , 
• Roland Fletcher^b, 
• Shi-Yu Simon Wang^c, 
• Brian Zottoli^d, 
• Christophe Pottier

Highlights

•

An analysis of climate variability over the past millennium for Southeast Asia.

•

Southeast Asian climate was unstable from the late 14th to early 15th century.

•

Archaeology shows alterations to water infrastructure to cope with drought.

•

LiDAR shows subsequent water damage to infrastructure that rendered it useless.

•

Similar impacts of drought and floods in Vietnam led to similar societal response.

---

Abstract

The early 21st century has seen vigorous scientific interest in the Asian monsoon and significant development of paleo-proxies of monsoon strength. These include the Monsoon Asian Drought Atlas – a 700-year, gridded reconstruction of hydroclimate derived from 327 tree ring records – and several long speleothem records from China and India. Similar progress has been made on the study of monsoon climate dynamics through re-analysis data products and General Circulation Model diagnostics. The story has emerged of a variable monsoon over the latter Holocene, with extended droughts and anomalously wet episodes that occasionally and profoundly influenced the course of human history. We focus on Southeast Asia where an anomalous period of unstable climate coincided with the demise of the capital of the Khmer Empire at Angkor between the 14th and the 16th centuries, and we suggest that protracted periods of drought and deluge rain events, the latter of which damaged Angkor's extensive water management systems, may have been a significant factor in the subsequent transfer of the political capital away from Angkor. The late 16th and early 17th century experienced climate instability and the collapse of the Ming Dynasty in China under a period of drought, while Tonkin experienced floods and droughts throughout the 17th century. The 18th century was a period of great turmoil across Southeast Asia, when all of the region's polities saw great unrest and rapid realignment during one of the most extended periods of drought of the past millennium. New paleo-proxy records and the incorporation of historical documentation will improve future analyses of the interaction between climate extremes, social behavior and the collapse or disruption of regional societies, a subject of increasing concern given the uncertainties surrounding projections for future climate.