Global warming profoundly changes the spatial distribution of nitrogen use and losses in croplands

Abstract Maintaining food production while reducing agricultural nitrogen pollution is a grand challenge under the threats of global climate change, which has exerted negative impacts on agricultural sustainability. How global agricultural nitrogen use and loss respond to climate change on temporal and spatial scale is rarely understood. Here we show that climate change leads to small temporal but substantial spatial changes in cropland nitrogen use and losses across global regions based on historical data for the period 1961-2018 from 150 countries. Increases of yield, nitrogen surplus and nitrogen use efficiency (NUE) are identified in 24% of countries, while reductions are observed for the remaining 76% of countries, as a result of climate change in 2018. Changes of cropland area per capita of rural population (CAPRP) further intensify the variations of nitrogen use and pollution in global croplands. Yet, improving farmers’ practices with changes of CAPRP can facilitate climate change adaptation, by which global cropland NUE could be increased by one-third in 2100 compared to 2018 under future shared socioeconomic pathways. Our results would be of great significance to sustain global agriculture as well as eliminate national inequalities on food production and agricultural pollution control.