Prolonged Cooling Interrupted The Bronze Age Cultures In Northeastern China 3500 Years Ago

The role of climatic change in the social transition in NE China during the Bronze Age is poorly understood due to the lack of reliable climate proxy records. Here we report a 3600-yr-long climate record based on branched glycerol dialkyl glycerol tetraether distributions in the Jinchuan peat core, Northeastern (NE) China. Our record shows a persistent cooling between ca.3.5-3.0 ka, which coincides with the societal transition from a settled to a mobile lifestyle. Comparing existing records suggests that this event represents a hemispherical-scale cooling probably driven by the prolonged El Nino conditions. The low temperatures caused unfavorable conditions for the agriculture-based society during the Lower Xiajiadian period and thus drove people to flee southward into the North China and Central China Plains, leading to a culturally desolated area that was gradually occupied by pastoralists in about 250 years. Our results highlight the need to consider the interplay of climatic dynamics with social upheaval in understanding the evolution of prehistorical civilization in NE Asia.