Using satellite imagery, this paper characterises the impacts of nitrogen oxide pollution on crop growth - a relationship which has remained poorly understood until now. Consistently negative impacts of nitrogen dioxide (NO2) on crop greenness (which is correlated with growth and yield) were found across five major agricultural regions. The authors estimate that crop yields could be increased by reducing nitrogen dioxide pollution.
Nitrogen oxides (NOx) are among the most widely emitted pollutants in the world, yet their impacts on agriculture remain poorly known. NOx can directly damage crop cells and indirectly affect growth by promoting ozone (O3) and aerosol formation. We use satellite measures of both crop greenness and NOx during 2018–2020 to evaluate crop impacts for five major agricultural regions. We find consistent negative associations between NO2 and greenness across regions and seasons. These effects are strongest in conditions where O3 formation is NOx limited but remain significant even in locations where this pathway is muted, suggesting a role for direct NOx damage. Using simple counterfactuals and leveraging published relationships between greenness and growth, we estimate that reducing NOx 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.
Lobell, D. B., Di Tomasso, S. and Burney, J. A. (2022). Globally ubiquitous negative effects of nitrogen dioxide on crop growth. Science Advances, 8(22).
Read the full paper here. See also the TABLE explainer Impacts of climatic and environmental change on food systems.