The resulting atmospheric chemistry of the enhanced soil nitrous acid emissions has aggravated global ozone pollution in the last decades.

Soil microbial nitrous acid (HONO) production is an important source of atmospheric reactive nitrogen that affects air quality and climate. In this work, we propose that climate change (through changing soil temperature and soil water content) and the increased fertilizer use have enhanced soil HONO emissions since the 1980s. Model simulations suggest that the resulting atmospheric chemistry of increased soil HONO emissions has contributed to aggravate tropospheric ozone pollution at a global scale, although with marked regional differences. From these results, we suggest the need for more efficient use of fertilizers in agriculture and recommend consideration of soil HONO emissions in strategies for mitigating global ozone pollution. Yanan Wang, Quinyi Li, Yurun Wang, Chuanhua Ren, Alfonso Saiz-Lopez, Likun Xue and Tao Wang. Increasing soil nitrous acid emissions driven by climate and fertilization change aggravate global ozono pollution. Nature Communications: https://www.nature.com/articles/s41467-025-57161-6