Book excerpt: Although air quality has improved substantially in the U.S. in the 40 years of the EPA's Clean Air Act regulation, many issues remain unresolved. Recently, members of Congress from both parties have raised questions regarding the cost-effectiveness of, and authority for, EPA actions. This report focuses on three areas of likely interest to the 112th Congress: greenhouse gas regulations, emissions from power plants (including interstate pollution and mercury emissions), and air quality standards. Contents: Intro.; EPA's Greenhouse Gas Regulations; Legislation on Climate Change; Emissions from Power Plants; Clean Air Interstate Rule; Clean Air Mercury Rule; Air Quality Standards; Other Issues. Illustrations. This is a print on demand report.