Climate response to projected changes in short‐lived species under an A1B scenario from 2000–2050 in the GISS climate model

摘要: [1] We investigate the climate forcing from and response to projected changes in short-lived species methane under an A1B scenario 2000-2050 GISS model. We present a meta-analysis of new simulations full evolution gas aerosol other existing experiments with variations same The comparison highlights importance several physical processes determining radiative forcing, especially effect change on stratosphere-troposphere exchange, heterogeneous sulfate-nitrate-dust chemistry, oxidation natural emissions. However, impact these fairly uncertain effects is substantially less than difference between alternative emission scenarios for all species. net global mean annual average direct .02 W/m2 or our projections, as substantial positive ozone largely offset by negative forcing. Since reductions also lead reduced indirect effect, surface temperature warms ∼0.07°C 2030 ∼0.13°C 2050, adding 19% 17%, respectively, warming induced long-lived greenhouse gases. Regional forcings are large, up 3.8 W/m2. ensemble-mean shows little regional correlation spatial pattern however, suggesting that oceanic atmospheric mixing generally overwhelms even large localized forcings. Exceptions polar regions, where aerosols may induce seasonal changes.