Fig. 4. Impact of changing spatial distribution of fertilisation as well as climate warming on N₂O emissions from 1940 to 2020.

a The average change in annual N₂O emissions due to the shifting spatial distribution of fertiliser N inputs, calculated using the 1940 spatial distribution of fertilisation scaled to the 2020 total fertilisation quantity as a baseline, and comparing this to the actual modelled 2020 emissions. b The average change in annual N₂O emissions due to climate warming and the temperature dependency of N₂O production, found by calculating 2020 emissions with and without the impact of warming on EFs since 1940. c The proportion of anthropogenic N inputs from fertilisation, deposition and fixation in 1940, 1980 and 2020 accounted for within bins defined according to the EF for N₂O. 20 bins were used; 19 were distributed evenly between the parameter minimum and the mean + 3 standard deviations; the highest bin was for all data >mean + 3 standard deviations. Maps generated with Cartopy (Met Office, 2015,¹³²).