Globally ubiquitous negative effects of nitrogen dioxide on crop growth

Nitrogen oxides (NO(x)) are among the most widely emitted pollutants in the world, yet their impacts on agriculture remain poorly known. NO(x) can directly damage crop cells and indirectly affect growth by promoting ozone (O(3)) and aerosol formation. We use satellite measures of both crop greenness and NO(x) during 2018–2020 to evaluate crop impacts for five major agricultural regions. We find consistent negative associations between NO(2) and greenness across regions and seasons. These effects are strongest in conditions where O(3) formation is NO(x) limited but remain significant even in locations where this pathway is muted, suggesting a role for direct NO(x) damage. Using simple counterfactuals and leveraging published relationships between greenness and growth, we estimate that reducing NO(x) levels to the current fifth percentile in each region would raise yields by ~25% for winter crops in China, ~15% for summer crops in China, and up to 10% in other regions.