Greenhouse gas emissions from global production and use of nitrogen synthetic fertilisers in agriculture

Abstract The global agri-food system relies on synthetic nitrogen (N) fertilisation to increase crop yields, yet the use of synthetic N fertiliser is unsustainable. In this study we estimate global greenhouse (GHG) emissions due to synthetic N fertiliser manufacture, transportation, and field use in agricultural systems. By developing the largest field-level dataset available on N 2 O soil emissions we estimate national, regional and global N 2 O direct emission factors (EFs), while we retrieve from the literature the EFs for indirect N 2 O soil emissions, and for N fertiliser manufacturing and transportation. We find that the synthetic N fertiliser supply chain was responsible for estimated emissions of 1.13…