The purpose of this chapter is to provide knowledge to the reader regarding the regulation of air pollutants and the public policy aspects of air quality management. The reader is introduced to the common-law principles applicable to air pollution-related litigation; the limitations of civil litigation in abating air pollution problems; and the principles, advantages, and limitations of cost-benefit, air quality management, emission standards, and economics-based air pollution control strategies. This chapter also provides a history of air pollution regulation in the United States; an understanding of the major provisions of the 1970, 1977, and1990 Clean Air Act (CAA) Amendments; and their roles in achieving clean air goals. Various aspects of air quality management are described in detail, including the relationship between air quality criteria, air quality control regions (AQCRs), state implementation plans (SIPs), and air quality standards (NAAQS); the concept, history, and regulatory requirements of prevention of significant deterioration (PSD) programs; the differences among, and the applicability of, reasonably available control technology (RACT), best available control technology (BACT), and maximum achievable control technology (MACT); the differences between pollutants regulated under air quality standards, new source performance standards, and toxic/hazardous pollutant standards; acidic deposition control requirements under the 1990 CAA Amendments and how these requirements were achieved; regulatory efforts to control upper atmosphere ozone-destroying chemicals; and motor vehicle emission control requirements. This latest revision provides a more in-depth look at the difference between emission standards for criteria pollutants and emission standards for greenhouse gases and includes a history of the regulation of motor vehicle emissions and the more recent greenhouse gas emission standards and CAFE standards. This chapter concludes with a summary of many of the public policy issues that face regulators relative to global climate change, tropospheric ozone, particulate matter, new source review, and motor vehicle emissions.