Minimizing cropland GHG emissions while maintaining nutrient surplus within planetary boundaries in China

Navigating the trade-offs between food production and environmental sustainability has become increasingly challenging in the context of accelerating climate change in China. A key question is whether the highly heterogeneous spatial patterns of greenhouse gas emissions (GHG) and nitrogen (N) and phosphorus (P) surpluses across croplands can be mitigated to remain within county-level planetary boundaries while maintaining sustainable food production. This study aims to minimize cropland GHG emissions in China through an integrated strategy that combines improved management, optimized cropland redistribution, and dietary shifts, while keeping N and P surpluses within county-level planetary boundaries and ensuring sustained food production. We downscaled the planetary boundaries for GHG emissions and nutrient surpluses to county level based on population and cropland, and freshwater resources allocations. Then, we evaluated the mitigation potential of improved management (informed by the national farm survey), crop redistribution (using linear programming), and dietary shifts (50 % Dietary Guidelines for Chinese Residents (2016)), both individually and in combination. Our results demonstrate that the integrated strategy could reduce GHG emissions, N surplus, P surplus, and arable land area by 55 %, 62 %, 67 %, and 54 %, respectively, compared with the current status. Furthermore, this strategy would enable approximately 53 % of China’s counties to remain within the planetary boundaries for GHG emissions as well as N and P surpluses, which accounts for around 60 % of the total adjusted sowing area. The mitigation potential exhibits pronounced spatial heterogeneity, with Southeast China and the Yangtze River Basin experiencing the greatest reductions. However, even under the integrated strategy, 932 counties still exceed the planetary boundaries for P surplus, underscoring persistent challenges. Despite socio-economic and cultural constraints, achieving synergistic reductions in environmental impacts and remaining within multiple planetary boundaries at the county scale holds significant promise. This study provides a practical and scalable pathway for mitigating agricultural environmental pressures while supporting sustainable production, particularly in smallholder-dominated systems. The insights offer valuable guidance for other developing countries, such as India and African nations, seeking to reconcile rising food demand with the need to remain within Earth’s safe operating space.