Air Quality in a Changing Climate

Once, in the not so distant past, smoke belching from urban factories and plants was viewed as a symbol of a prosperous, growing economy with abundant jobs. However, awareness of the downside of such pollution spawned the environmental movement of the 1960s, culminating in the Clean Air Act Amendment of 1970. This landmark legislation provided the regulatory mandates and legal tools that stimulated innovative technological efficiencies. Remarkably, over the next 40 years, emissions were brought down by more than two-thirds, even as productivity improved. Today, the absence of sooty urban air and the presence of clear vistas are the visible hallmarks of successful air pollution policies. Indeed, in the past two decades, the percentage of people who view the threat of air pollution with " a great deal of concern " has been reduced by 25% (Jones 2010). Even the Office of Management and Budget (2007) noted that air pollution regulations have yielded substantial benefits to the U.S. economy—providing $3 to $17 for every $1 spent over the previous 10 years on implementation of air rules. Ironically, about 127 million Americans still live in counties where air pollution levels exceed one or more of the six National Ambient Air Standards (NAAQS), and politicians still debate whether the health-based regulation of air quality is hurting the economy and stymieing job growth despite evidence to the contrary. For example, in March 2011, a U.S. Environmental Protection Agency (EPA)-commissioned study ordered by Congress reported that air policy benefits from 1990 to 2020 exceeded $2 trillion, and 160,000 deaths were prevented in just 1 year (U.S. EPA 2011). Another study has estimated that capital investment in air pollution controls on the U.S. power generation sector will create 638,000 construction, installation, and other professional jobs between 2010 and 2015 (Heintz et al. 2011). Clearly, air pollution regulation continues to have important implications for public health and environmental welfare, as well as the health of the economy. To be sure, these critical policy decisions need to be made on a foundation of sound and innovative science. The question remains: What is left to do regarding air pollution control, and can we further advance our understanding of air pollution risk and find ways to sustainably protect health and the environment? In this regard, a few broad questions do come to mind: What innovative technologies and strategies can be developed, at reasonable cost, to further reduce air pollution …