Afforestation on Abandoned Croplands in China Has the Potential to Increase Carbon Sequestration by half

Afforestation of abandoned cropland represents a promising strategy for land-based climate change mitigation, particularly in regions where land resources for additional afforestation are limited. However, the carbon sequestration potential of such land remains largely unknown. Here, we assess the spatial distribution of abandoned cropland in China and its carbon sequestration potential through afforestation incentives, using 10,818 carbon empirical data derived from 298 peer-reviewed articles, multisource remote sensing data, and machine learning models. We identify 6.03 Mha of abandoned cropland in China that have been undergoing natural regeneration since the early 21st century. This land has the potential to sequester an additional 215.12–218.94 Tg of biomass carbon and 15.87–17.64 Tg of soil organic carbon (SOC) through afforestation by 2060, representing a 51.95–53.94% increase compared to natural regeneration alone. Our results further show that the carbon benefits from afforestation could offset 47.71–49.57% of government investments (approximately USD 16.254 billion) in abandoned cropland. Our findings highlight the significant potential of afforestation on abandoned cropland to support China’s carbon neutrality goals, while also offering a cost-benefit framework to guide land policy decisions.