Table 1. Gaseous emission process altered by reactive nitrogen, climate forcing elements, process of warming/cooling and their overall impacts.

Gaseous emission process altered by reactive N	Climate forcing element	Process of warming/cooling	Overall impacts
1. N2O	N2O	Emitted from agricultural soils	Warming
2. NOx → ozone and CH4	Ozone, CH4	NOx perturbs the chemical production and destruction of the greenhouse gases ozone and CH4.	Cooling
3. NOx → aerosol	Nitrate, ammonium aerosol	NOx can enhance the formation of light-scattering aerosols.	Cooling
4. NH3 → aerosol	Nitrate, ammonium aerosol	NH3 enhances the formation of light-scattering aerosols.	Cooling
5. N fertilizer → CO2 flux	CO2	On croplands, nitrogen from fertilizer and manure may enhance the storage of CO2.	Cooling
6. N fertilizer → CH4 flux	CH4	On croplands, N from fertilizer and manure may perturb uptake and emission of CH4.	Warming

Source: Modified from Pinder et al.¹⁸.