Urban heat and air pollution - An emerging role for planners in the climate change debate

This article presents empirical evidence linking recent fluctuations in regional temperatures to enhanced ozone formation within the country's 50 largest metropolitan regions. The results of an analysis of regional climate and ozone formation during the 1990s indicate that annual violations of the national ozone standard were more strongly associated with regional temperatures than with the emissions of regulated ozone precursors from mobile and stationary sources. Based on the results of this analysis, I argue that the air quality management strategies outlined in the Clean Air Act may be insufficient to control ozone formation due to ongoing and unanticipated changes in global and regional climate. I further argue that the emergence of urban heat as a significant air "pollutant" demands a strategic response from the field of urban planning. The article concludes with a discussion of the linkages between urban form and regional temperature and outlines a set of design strategies that have proven successful in mitigating urban heat production.