Collapse of prehistoric cultures in central-eastern China linked to the El Niño-like states during the 4.2 ka event

The Huai River Basin, located in the transition zone between the Yangtze and Yellow River basins, plays a significant role in the integration and development of Neolithic cultures. Lack of precipitation reconstructions from the Huai River Basin limits our knowledge on patterns and mechanisms of precipitation in the East Asian monsoon (EAM) region during the 4.2 ka event, which also hinders our understanding of the relationship between Neolithic culture transitions and climate change. In this study, we report a pollen record from the Wufan profile in the upper Huai River Basin. Our record indicates a wetter climate condition during the 4.2 ka event, which is in contrast to the reconstructed dry conditions in northern China. We further integrated accurately dated precipitation records of the 4.2 ka event and found a significant “dry-wet-dry” precipitation pattern in the EAM region during this cooling period. Specifically, northern China was relatively dry, the Jianghuai region was relatively wet, and the southwestern region was relatively dry. This pattern was likely driven by El Niño-like conditions in the tropical Pacific. In addition, we discovered a close link between the collapse of Neolithic cultures and the increased precipitation in central-eastern China, which is likely dominated by the El Niño-like states in the tropical Pacific.