Future Air Pollution Levels and Climate Change: A Step Toward Realism
Guest Commentary
Joel Schwartz
Visiting Fellow
American Enterprise Institute
What happens to future air pollution if the climate warms? Efthimios Tagaris and colleagues (Tagaris et al., 2007) have come closer than anyone before them in providing a realistic answer to this question. They predict that between 2001 and 2050, mean summer 8-hour ozone levels over the U.S. will decline by 11% to 28%, depending on the region, with an average decline of 20%. Fine particulate matter (PM2.5) will decline by 9% to 32%, with an average decline of 23%.
Tagaris et al.’s results stand in marked contrast to previous studies, nearly all of which predict higher air pollution levels over the U.S. in the future (e.g., Knowlton et al. (2004), Mickley et al. (2004), and Sitch et al. (2007)).