NOx gases represent some of
the most reactive gases produced from diesel combustion and other fossil fuels, but the emissions limits for nitrogen dioxide are regularly exceeded, especially in urban areas.
Consequently, the
most advanced climate models now require, in addition to concentrations or emissions of greenhouse
gases (CO2, CH4, N2O and halocarbons), emissions of
reactive gases and aerosol precursor compounds (SO2, NOx, VOC, BC, OC and NH3), to model atmospheric chemistry and interactions with the climate system.6 For
most variables, a sectoral differentiation would improve the quality of the calculations (e.g. from power plants and agricultural burning).
Most CM experiments based on RCPs will be driven by greenhouse
gas concentrations (Hibbard et al. 2007).8 Furthermore, many Earth system models do not contain a full atmospheric chemistry model, and thus require exogenous inputs of three - dimensional distributions for
reactive gases, oxidant fields, and aerosol loadings.