Winter-spring drought in Yunnan since the early 19th century and its impact on social governance in China's southwestern border regions

Climate change and variability have been demonstrated in interdisciplinary scholarship to, in some cases, have played a noteworthy role in a number of aspects of human history. Many studies in the climate-history nexus concern East Asia, but comparatively few concern the southwestern border areas of China. Although adverse climatic conditions have had profound environmental and socio-economic impacts in this vast region, their effects on societal changes in the past remain poorly understood. Here, we present a consistent picture of the environment and socio-economic impacts of drought in the southwestern border areas of China. To this end, we developed a new precipitation reconstruction for the central Yunnan region over the 1814-2022 period. This reconstruction was used to evaluate the duration and severity of droughts. Additionally, we explored the relationship between extremely low precipitation and the outbreak of specific plague epidemics. Our findings reveal the presence of persistent drought conditions, which presumably contributed to economic and societal instability preceding the Du Wenxiu Uprising (1856-1873), particularly impacting regions reliant on arable and pastoral agriculture. Large-scale peasant uprisings, concurring in time with drought, occurred in the mid-19th century against the backdrop of the repressive tax policies of the late Qing Dynasty. During the period 1814-1900, outbreaks of plague occurred more frequently two to three years after the onset of drought in Yunnan, and ongoing armed conflicts favored the spread of the disease. In conclusion, our reconstruction not only underscores the occurrence of recurrent multi-year drought conditions in the region but also suggests a potential key role for climate variability in shaping the socio-economic dynamics of this ecologically fragile area during the 19th century.