The contributions of CO2 (a), N2O (b), CH4 (c), aerosols (d), O3 (e) and the net effect (f) (that is, sum of a – e) were derived in the GEOS-Chem-RRTMG model by calculating differences in all-sky top-of-atmosphere radiative forcing between CTRL_2019 and No_allNr experiments. The radiative forcing of aerosols is the sum of the direct radiative forcing contributed by ammonium, nitrate and sulfate aerosols. Numbers in parentheses represent the global area-weighted averages, whereas numbers in the brackets indicate the uncertainty ranges based on sensitivity experiments with GEOS-Chem-RRTMG using 1 standard deviation among NMIP2 ensembles as well as 30% uncertainty in OH and O3 concentrations (Supplementary Information Section 1.2). Note the Nr effects on global CO2, N2O and CH4 are assumed to be evenly distributed, so that the patterns of these three greenhouse gases are mostly determined by other forcing agents, including the distribution of clouds.
