The process of making NH3from atmospheric N2is energyintensive; current technologies in China have an efficiency averaging 51.3 gigajoule (GJ) t NH3-N −1 , compared with 43.7 GJ or 32.8 GJ t NH3-N −1 with more advanced or the best technologies worldwide (18). Adopting the superior technologies would lower the emission factor from 5.1 to 3.2 or 2.4 t CO2-eq t NH3-N−1.