- 1The Hong Kong Polytechnic University, Faculty of Construction and Environment, Department of Civil and Environmental Engineering
- 2Environment Research Institute, Shandong University,Qingdao, China
- 3Luxembourg Institute of Science and Technology, Agro-environmental Systems Group, Environmental Sensing and Modelling (ENVISION unit), Belvaux, Luxembourg
- 4Joint International Research Laboratory of Atmospheric and Earth System Sciences, School of Atmospheric Sciences, Nanjing University, Nanjing, China
- 5Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Blas Cabrera, Spanish National Research Council (CSIC), Madrid, Spain
Soil microbial nitrous acid (HONO) production is an important source of atmospheric reactive nitrogen that affects air quality and climate. However, long-term global soil HONO emissions driven by climate change and fertilizer use have not been quantified. Here, we derive the global soil HONO emissions over the past four decades and evaluate their impacts on ozone (O3) and vegetation. Results show that climate change and the increased fertilizer use enhanced soil HONO emissions from 9.4 Tg N in 1980 to 11.5 Tg N in 2016. Chemistry-climate model simulations show that soil HONO emissions increased global surface O3 mixing ratios by 2.5% (up to 29%) and vegetation risk to O3, with increasing impact during 1980s-2016 in low-anthropogenic-emission regions. With future decreasing anthropogenic emissions, the soil HONO impact on air quality and vegetation is expected to increase. We thus recommend consideration of soil HONO emissions in strategies for mitigating global air pollution.
How to cite: Wang, Y., Li, Q., Treb, I., Wang, Y., Ren, C., Saiz-Lopez, A., Xue, L., and Wang, T.: Increasing soil nitrous acid emissions driven by climate and fertilization change aggravate global ozone pollution, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17830, https://doi.org/10.5194/egusphere-egu25-17830, 2025.
