Effective radiative forcing from emissions of reactive gases and aerosols – a multi-model comparison

Abstract. This paper quantifies the pre-industrial (1850) to present-day (2014) effective radiative forcing (ERF) of anthropogenic emissions NOX, volatile organic compounds (VOCs; including CO), SO2, NH3, black carbon, and concentrations methane, N2O ozone-depleting halocarbons, using CMIP6 models. Concentration emission changes reactive species can cause multiple in composition radiatively active species: tropospheric ozone, stratospheric water vapour, secondary inorganic aerosol, methane. Where possible we break down ERFs from each emitted into contributions changes. The are calculated for models that participated AerChemMIP experiments as part project, where relevant model output was available. 1850 2014 multi-model mean (± standard deviations) −1.03 ± 0.37 W m−2 SO2 emissions, −0.25 0.09 carbon (OC), 0.15 0.17 (BC) −0.07 0.01 NH3. For combined aerosols (in piClim-aer experiment) it is −1.01 0.25 m−2. means well-mixed greenhouse gases (including any effects on ozone aerosol chemistry) 0.67 methane (CH4), 0.26 0.07 nitrous oxide (N2O) 0.12 0.2 halocarbons (HC). Emissions precursors nitrogen oxides (NOx), both together (O3) lead 0.14 0.13, 0.20 respectively. differences different reflect complexity their chemistry schemes, especially case captures increased production.