Ancient Climate Catastrophe Drove Collapse of China's Largest Neolithic City

New research reveals that a severe global climate event 4,200 years ago, known as the 4.2-kiloyear event, led to the abandonment of China's largest Neolithic urban center, the Shijiahe culture. This period of widespread aridification paradoxically triggered massive flooding along the Yangtze River, rendering vast areas unsuitable for agriculture and settlement. The findings, published in the *National Science Review*, underscore how even advanced ancient civilizations were vulnerable to drastic environmental shifts.

Scientists investigated the long-debated decline of the Shijiahe culture, which thrived between 2,500 and 2,000 BCE, leaving behind sophisticated jade artifacts and pottery. While theories ranged from conflict to social collapse, the research team focused on environmental factors. They analyzed a stalagmite from Heshang Cave in the Yangtze Valley, which provided a natural record of thousands of years of rainfall data. High-precision measurements of the stalagmite's chemical layers allowed them to reconstruct ancient rainfall patterns, identifying significant periods of both low and high precipitation.

The analysis correlated extended high-rainfall periods with evidence of widespread flooding, wetland expansion, and a subsequent centuries-long population decline. Archaeological findings indicate that as Shijiahe city declined, its inhabitants migrated to higher ground. This historical event serves as a stark reminder of climate's profound impact on human societies, offering crucial context for contemporary climate change challenges. Modern extreme rainfall events are now surpassing the intensity of those that devastated the Shijiahe, posing significant tests for governments in managing water resources and agricultural stability to prevent similar societal disruptions.