A credit system to solve agricultural nitrogen pollution

'Commentary' paper. Increasing amounts of nitrogen fertilizer have been used in agriculture during the last decades to boost food production for the increasing global human population. The marked increase in reactive nitrogen use has also contributed to severe nitrogen pollution and multiple impacts on human and ecosystems' health. Nitrogen is an important precursor to air pollution (e.g., fine particulate matter, near-surface ozone), water pollution (algal blooms, nitrate contamination), biodiversity loss (nitrogen deposition and eutrophication), soil acidification (ammonium fertilizer use), and global warming (nitrous oxide). Agricultural nitrogen pollution has decreased in some high-income countries, such as those in the European Union (EU), during the last decades, but the remaining nitrogen pollution still causes serious damage. The societal cost of nitrogen pollution by agriculture in the EU has been estimated to range from €35 to €230 billion per year and this cost appears to be greater than the farm profits from nitrogen fertilizer use, which range from €20 to €80 billion per year. Socioeconomic trade-offs between farmers and society need to be introduced to decrease nitrogen pollution.