Global ammonia (NH₃) gas emissions to the atmosphere, without oceanic sources, was estimated at 44 million tons N-NH₃·y^-1, which is less than 57 million t N-NH₃·y^-1 returning to the earth’s surface with atmospheric depositions. It is generally maintained that the major sources of these emissions are agricultural activities, responsible for about 75% of emissions. Although in most inventories the non-agricultural sources are generally not considered, and only agriculture is blamed. The non-agricultural sources comprise human food consumption and waste, natural vegetation, wild animals, biomass and fuel burning, mobile sources, industry, and other technical activities.