Sources of nitrogen oxides include:
- The combustion of fossil fuel and solid wastes
- Industrial and agricultural processes
Modern farmers use enormous volumes of nitrogen to fertilize their fields. This widespread application of nitrogen fertilizer generates nitrogen oxides.
They do not create positive feedback loops that increase their concentration in the atmosphere, unlike methane. Once humans stop creating artificial sources of nitrogen oxides, then these gases will balance themselves in our atmosphere.
Author: Brown, Nathan. A Cooler Climate, 2008.