Fig. 7: Time evolution of total anthropogenic NOx to CO emission ratios from 1970 to 2030.

Details of the inventories and scenarios are presented in Table 1 and see Supplementary Fig. 8 for the NOx and CO emissions separately. The COVID19 estimate is described in the method section. The ECLIPSEv6 used in Whaley, et al.101 are equivalent NOx and CO emissions to the GAINS methane emissions in Table 1. The stabilization period from 2000 to 2007 is indicated by grey shading.