Signal Nitrogen air pollution causes hundreds of thousands of avoidable deaths

Summary

Human activity disrupts the nitrogen and phosphorus cycles much as it has altered the carbon cycle. Excess nitrogen and phosphorus cause eutrophication and can create dead zones in fresh water and the sea. The main drivers are heavy fertilizer use and the growing of nitrogen-fixing crops, while nitrogen oxides from burning fossil fuels are another large source. Nitrogen-related air pollution causes hundreds of thousands of deaths every year that could have been avoided. The underlying driver is food demand, especially for livestock products that require feed crops and fertilizer, and the food system supplies about 70 percent of the nitrogen and 75 percent of the phosphorus entering surface waters. Today the nitrogen humans add to the biosphere exceeds all natural sources combined.