Volcanic climate impacts can act as ultimate and proximate causes of Chinese dynastic collapse

Chaochao Gao,Richard Breen,Alexander R Stine,Yuqing Pan,John A Matthews,Francis Ludlow,Michael Sigl,Brianán Nolan,Alan Robock

doi:10.1038/s43247-021-00284-7

Abstract

State or societal collapses are often described as featuring rapid reductions in socioeconomic complexity, population loss or displacement, and/or political discontinuity, with climate thought to contribute mainly by disrupting a society’s agroecological base. Here we use a state-of-the-art multi-ice-core reconstruction of explosive volcanism, representing the dominant global external driver of severe short-term climatic change, to reveal a systematic association between eruptions and dynastic collapse across two millennia of Chinese history. We next employ a 1,062-year reconstruction of Chinese warfare as a proxy for political and socioeconomic stress to reveal the dynamic role of volcanic climatic shocks in collapse. We find that smaller shocks may act as the ultimate cause of collapse at times of high pre-existing stress, whereas larger shocks may act with greater independence as proximate causes without substantial observed pre-existing stress. We further show that post-collapse warfare tends to diminish rapidly, such that collapse itself may act as an evolved adaptation tied to the influential “mandate of heaven” concept in which successive dynasties could claim legitimacy as divinely sanctioned mandate holders, facilitating a more rapid restoration of social order.

Highlights

State or societal collapses are often described as featuring rapid reductions in socioeconomic complexity, population loss or displacement, and/or political discontinuity, with climate thought to contribute mainly by disrupting a society’s agroecological base
To establish whether a systematic association exists between explosive volcanism and dynastic collapse during the first two millennia CE, comprising the great majority of China’s Imperial
It accommodates an understanding that societies are unlikely to respond mechanistically to climatic shocks

Summary

Introduction

State or societal collapses are often described as featuring rapid reductions in socioeconomic complexity, population loss or displacement, and/or political discontinuity, with climate thought to contribute mainly by disrupting a society’s agroecological base. Because sophisticated agronomy was critical to sustain successive populous Chinese dynasties, abrupt climatic change and extreme weather held the potential to deeply perturb their political, economic and demographic functioning[3,38], providing multiple pathways by which volcanically induced climatic shocks might promote or contribute to collapse These pathways may have been amplified or otherwise mediated in complex ways by the influential concept of the “Mandate of Heaven,” in which contemporaries associated the perceived quality and moral authority of a dynasty’s rule with the clemency of weather and related agricultural fortunes[39,40,41]. To establish whether a systematic association exists between explosive volcanism and dynastic collapse during the first two millennia CE, comprising the great majority of China’s Imperial

Methods

Results

Conclusion