This study investigates the impact of human land use on soil organic carbon (SOC) debt over the past 12,000 years. Using a machine learning model and a global compilation of SOC data, the researchers estimated that agricultural activities have led to a global SOC loss of 133 Pg C in the top 2 meters of soil. The model's performance was validated against paired plot studies, and it showed that grazing and cropland were major contributors to SOC loss. The analysis identified hotspots of SOC loss in major cropping regions and semiarid grazing lands, suggesting these areas as targets for SOC restoration efforts. The study also found that while some regions, particularly those with naturally infertile soils, experienced little to no SOC loss, others, especially in arid and semi-arid regions, showed significant losses. The findings highlight the importance of targeted restoration efforts and the need for more comprehensive soil profile data to improve models of SOC dynamics.This study investigates the impact of human land use on soil organic carbon (SOC) debt over the past 12,000 years. Using a machine learning model and a global compilation of SOC data, the researchers estimated that agricultural activities have led to a global SOC loss of 133 Pg C in the top 2 meters of soil. The model's performance was validated against paired plot studies, and it showed that grazing and cropland were major contributors to SOC loss. The analysis identified hotspots of SOC loss in major cropping regions and semiarid grazing lands, suggesting these areas as targets for SOC restoration efforts. The study also found that while some regions, particularly those with naturally infertile soils, experienced little to no SOC loss, others, especially in arid and semi-arid regions, showed significant losses. The findings highlight the importance of targeted restoration efforts and the need for more comprehensive soil profile data to improve models of SOC dynamics.