Climate Impacts on Air Pollution and the Related Health Impacts and Increased Control Costs (Invited Speaker)

Detailed air quality modeling was conducted to assess the impact of potential climate change on air quality in North America, and using those results, assess the potential health implications and control costs that would be required to overcome the “climate penalty.” Simulated future summers (i.e., 2049-2051) and annual (i.e., 2050) average regional O3 and PM2.5 concentrations over the US were compared with historic (i.e., 2000-2002 summers and all of 2001) levels to investigate the potential impacts of global climate change on regional air quality. Meteorological inputs to the CMAQ chemical transport model are developed by downscaling the GISS Global Climate Model simulations using an MM5-based regional climate model. Future-year emissions for North America are developed by growing the US EPA CAIR inventory, Mexican and Canadian emissions and by using the IMAGE model with the IPCC A1B emissions scenario that is also used in projecting future climate. In general, ozone levels are predicted to increase, particularly in and downwind of urban areas. Particulate matter responses were mixed. BenMap was employed to estimate the air pollution health outcomes at the county, state, and national level for 2050 caused by the effect of meteorology on future ozone and PM2.5 concentrations. Changes in health effects induced by PM2.5 dominate compared to those caused by ozone. PM2.5-induced premature mortality is about 15 times higher than due to ozone. Nationally the analysis suggests approximately 4,000 additional annual premature deaths due to climate change impacts on PM2.5 vs. 300 due to climate change-induced ozone changes. Overall, an annual cost of $9.3 billion is estimated for offsetting climate impacts on both regionally-averaged and urban air quality, and is largely driven by the controls needed to overcome ozone increases in a few urban areas.