A global high‐resolution emission inventory for ammonia

TLDR

Ammonia emissions are expected to rise with projected global population growth and increased food production. A 1° × 1° global inventory of ammonia sources was compiled, providing detailed spatial data for atmospheric modeling. The 1990 estimate of 54 Tg N yr⁻¹ is dominated by domestic animal excreta (21.6 Tg N yr⁻¹) and synthetic fertilizer use (9.0 Tg N yr⁻¹), which together account for about 70 % of emissions, roughly half of which originate in Asia, with regional uncertainties of 25 % globally and higher locally.

Abstract

A global emissions inventory for ammonia (NH 3 ) has been compiled for the main known sources on a 1° × 1° grid, suitable for input to global atmospheric models. The estimated global emission for 1990 is about 54 Tg N yr −1 . The major sources identified include excreta from domestic animals (21.6 Tg N yr −1 ) and wild animals (0.1 Tg N yr −1 ), use of synthetic N fertilizers (9.0 Tg N yr −1 ), oceans (8.2 Tg N yr −1 ), biomass burning (5.9 Tg N yr −1 ), crops (3.6 Tg N yr −1 ), human population and pets (2.6 Tg N yr −1 ), soils under natural vegetation (2.4 Tg N yr −1 ), industrial processes (0.2 Tg N yr −1 ), and fossil fuels (0.1 Tg N yr −1 ). About half of the global emission comes from Asia, and about 70% is related to food production. The regions with highest emission rates are located in Europe, the Indian subcontinent, and China, reflecting the patterns of animal densities and type and intensity of synthetic fertilizer use. The overall uncertainty in the global emission estimate is 25%, while the uncertainty in regional emissions is much greater. As the global human population will show considerable growth in the coming decades, food production and associated NH 3 emissions are likely to increase as well.