New Directions: Understanding interactions of air quality and climate change at regional scales

The estimates of the short-lived climate forcers’ (SLCFs) impacts and mitigation effects on the radiation balance have large uncertainty because the current global model set-ups and simulations contain simplified parameterizations and do not completely cover the full range of air quality-climate interactions (AQCI). Most AQCI studies to date used coarse grid models that cannot adequately resolve the highest SLCFs concentrations in the densest source regions and mesoscale circulations/processes (Anderson et al., 2003). Therefore, the radiative and vertical transport impacts and associated air quality issues in coarse grid models are likely to be under-represented at the regional and local scales. Since AQCI can be locally predominant due to the heterogeneity in emissions loading and process interactions, regional models capable of capturing AQCI are critically needed so that the cumulative effects on larger scale radiative forcing of the earth-atmosphere can be accurately assessed. Regional models include detailed physical, dynamical, and chemical formulations. However, the credibility of these models in properly simulating AQCI has not been critically assessed, a necessary step before they could be used more confidently for developing effective regulatory policies.