Horizontal carbon compensation for cropland use: A policy tool for promoting the equitable utilization of cropland resources

Carbon compensation policies are widely recognized as effective emission reduction tools. As cropland carbon budgets gain importance in climate governance, balancing food production with emissions mitigation and carbon sequestration has become an urgent challenge. This study proposes a novel theoretical framework for horizontal carbon compensation for cropland use (HCCCU), which aims to promote equitable, efficient, and sustainable agricultural carbon governance in China. Using the city-level data, we analyze the spatiotemporal dynamics of cropland carbon budgets, evaluate the effects of regional disparities on compensation outcomes, and assess the feasibility and effectiveness of the mechanism of HCCCU. Our findings reveal a peak-then-decline trend in cropland emissions nationwide, while carbon sequestration has shown a steady growth trend. Southern regions exhibit higher emissions, particularly in major grain-producing areas, which serve as key emission hotspots. After adjusting for regional disparities, emission and sequestration allowances decreased in the south while increased in the northeast, reflecting significant spatial inequalities. The adjusted HCCCU demonstrates that major grain-producing areas are primary beneficiaries of compensation, with the cumulative compensation amount closely aligned with the estimated compensation needs. This equilibrium underscores the critical importance of accounting for regional disparities to ensure equity. Key contributors to compensation include Sichuan-Chongqing, North China, southeast coastal areas, and economically advanced cities, while the central part of northeastern, and northern border regions are identified as priority beneficiaries. Overall, this study offers a theoretical foundation and practical guidance for implementing the scheme of HCCCU, supporting regionally differentiated strategies for equitable emission reductions and sustainable cropland management.