Global air emission inventories for anthropogenic sources of NOx, NH3 and N2O in 1990

Abstract

Global emission inventories with 1° × 1° resolution were compiled for nitrogen oxides (NO + NO 2 , together denoted as NO x ), ammonia (NH 3 ) and nitrous oxide (N 2 O) emissions. For NO x the estimated global anthropogenic emission for 1990 is about 31 million ton N year −1 . The major anthropogenic sources identified include fossil fuel combustion (70%, of which the major sources are road transport and power plants) and biomass burning (20%). Natural sources contribute about 19 million ton N year −1 , mainly lightning and soil processes. For NH 3 the estimated global emission for 1990 is about 54 million ton N year −1 . The major sources identified include excreta from domestic animals and wild animals, use of synthetic N fertilisers, oceans and biomass burning. About half of the global emission comes from Asia, and about 70% is related to food production. For N 2 O the major sources considered include fertilised arable land, animal excreta, soils under natural vegetation, oceans, and biomass burning. The global source of N 2 O is about 15 million ton N 2 O–N year −1 of which about 30% is related to food production. All three inventories are available on a sectoral basis on a 1° × 1° grid for input to global atmospheric models and on a regional/country basis for policy analysis.