Moisture variations during the first millennium CE and their linkage with social developments along the Silk Road in northwestern China

Moisture conditions, especially those that occur as multi-decadal anomalies, have profound impacts on society, in arid and semi-arid regions. However, the lack of high-resolution climate data for first millennium CE greatly limits our understanding how moisture variations influenced history. Here, we present an 1882-year (134–2015 CE) tree-ring chronology developed from Qilian juniper (Juniperus przewalskii Kom.) growing western Mountains, northwest China. The index correlates significantly with May–June self-calibrating Palmer Drought Severity Index (sc-PDSI) can be used to reconstruct since 241 CE. reconstruction reflects conditions at annual time scales over past two millennia. During period third eighth centuries, there were prominent interdecadal fluctuations, century late fifth being wettest driest periods during reconstruction, respectively. transition wet dry corresponded key events Chinese history, namely demise Western Jin Dynasty chaotic Southern Northern Dynasties. Thus, provides new evidence potential linkage between abnormal social changes ancient times.