We examined the impact of future climate change on regional air pollution meteorology in the United States by conducting a transient climate change (1950-2052) simulation in a general circulation model (GCM) of the Goddard Institute of Space Studies (GISS). We included in the GCM two tracers of anthropogenic pollution, combustion carbon monoxide (COt) and black carbon (BCt). Sources of both tracers and the loss frequency of COt were held constant in time, while wet deposition of BCt responded to the changing climate. Our results show that the severity and duration of summertime regional pollution episodes in the midwestern and northeastern United States increase significantly relative to present. Pollutant concentrations during these episodes increase by 5-10% and the mean episode duration increases from 2 to 3-4 days. These increases appear to be driven by a decline in the frequency of mid-latitude cyclones tracking across southern Canada. The cold fronts associated with these cyclones are known to provide the main mechanism for ventilation of the midwestern and northeastern United States.