Human Impacts Overwhelmed Hydroclimate Control of Soil Erosion in China 5,000 Years Ago.

Deforestation and intensive land use have accelerated soil erosion, reshaped topography, and altered carbon reservoirs for thousands of years. The timing, scope, and magnitude of long‐term anthropogenic soil erosion across China are especially important to understand the global scale of this process. Here, sediment accumulation rates (SARs) from 191 sediment archives are found to be temporally correlated with monsoon intensity during 6–40 ka BP, indicating that hydroclimate was the main driver of soil erosion in this time interval. The rapid increase in SARs after ca. 5 ka BP is decoupled from persistently weakened hydroclimate but instead follows the trend of increasing population and related agricultural activities in China, implying a change in the primary controlling factor since then. Early human activities in China therefore appear to have had profound implications on Earth's surface at a continental scale. Plain Language Summary: The key agency in modulating Earth's surface environment and carbon reservoirs includes the hydroclimate and anthropogenic factors. However, their effect on the magnitude and drivers of long‐term soil erosion across China is not well understood yet. Here changes in sediment accumulation rates were applied as a proxy for soil erosion. The results showed a direct linkage between soil erosion proxy and Chinese population for ca. 5,000 years, suggesting that hydroclimate controlled soil erosion before the mid‐Holocene, but human impacts overwhelmed afterward and started to control soil erosion ca. 5,000 years ago in China. The timing was about 1,000 years earlier than the global average, highlighting the inter‐continental differences and extending our view of long‐term human‐environment interactions. Key Points: Hydroclimate controlled soil erosion before the mid‐Holocene in ChinaDirect linkages between sediment accumulation rates and Chinese population were detected across ChinaHuman impacts started to control soil erosion in China 5,000 years ago, at least 1,000 years earlier than the global average [ABSTRACT FROM AUTHOR]