As the climate warms, farm soils could release more nitrogen gases like ammonia and nitrogen oxides into the air. These gases help form fine particle air pollution, or PM₂.₅, which is harmful to human health. Our research used advanced computer models to predict how much more of these gases soils might emit in the future, and how that could affect air quality. We found that climate change alone could increase global agricultural ammonia emissions by 33% and nitrogen oxides by 12% by the end of the century. These extra emissions could raise PM₂.₅ levels significantly, especially in farming regions. In the United States, this could cause tens of millions more people to live in areas that exceed national air quality standards—even if other air pollutants like industrial emissions are reduced. These results show that climate change could make it harder to clean up air pollution, unless we account for how warming affects emissions from the land itself.