Consumption-driven intensification of regional inequality of diet-related nitrogen pollution in China

Reactive nitrogen (Nr) emissions from the food system are an increasing environmental pressure in China. However, production-based accounting fails to capture consumption-driven agricultural expansion and interregional pollution transfer. Here, we develop a consumption-based interprovincial trade-tracking model for 31 provinces and nine major food categories to quantify diet-related Nr emissions. We find that China's food consumption–related Nr emissions increased from 2985.9 Gg in 1980 to 6625.1 Gg in 2020, accompanied by a persistent rise in interprovincial inequality. Consumption-intensive provinces externalized environmental pressure through food inflows, while agricultural regions bore disproportionate emissions, resulting in a production–consumption mismatch. Structural decomposition analysis shows that mitigation gains of 1016.4 Gg from reduced emission intensity and trade restructuring (2010−2020) were offset by increases of 1393.7 Gg driven by population growth and dietary changes. Scenario simulations show that integrating dietary transition with gradient mitigation could reduce Nr emissions by 37.7% and interprovincial inequality by 21.7%. These findings highlight the need for coordinated cross-regional strategies for sustainable Nr governance. • Proposed the Concentration of Diet-related Nitrogen Emission Index. • Developed a consumption-based tracing model for diet-related Nr emissions. • Interprovincial inequality in diet-related Nr emissions has increased over 40 years. • Emission intensity and trade structure are key drivers of diet-related Nr mitigation. • Dietary transition with gradient mitigation reduces Nr emission inequality by 21.7%.