Air Quality in Future Decades – Determining the Relative Impacts of Changes in Climate, Emissions, Global Atmospheric Composition, and Regional Land Use

In recent years, there has been a growing realization that regional-scale ozone (O3) air quality is influenced by processes occurring on global scales, such as the intercontinental transport of pollutants (Jacob et al., 1999; Fiore et al., 2002, 2003; Yienger et al., 2000) and the projected growth in global emissions that alter the chemical composition of the global troposphere (Prather and Ehhalt, 2001; Prather et al., 2003). However, little work has been performed to date to study the potential impacts of regional-scale climate change on near-surface air pollution. Climate change can influence the concentration and distribution of air pollutants through a variety of direct and indirect processes, including the modification of biogenic emissions, the change of chemical reaction rates, changes in mixedlayer heights that affect vertical mixing of pollutants, and modifications of synoptic flow patterns that govern pollutant transport. Another parameter affecting local and regional meteorology and air pollution is land use, and significant land use changes associated with continued urbanization are expected to occur over the same time scales as changes in regional climate.