Description: This minibrief describes the major hypothesis explaining why acid rain may be contributing to forest decline, along with the major arguments against this hypothesis. For additional information on acid rain and current legislation for pollutant emissions controls, see IB83016 -- Acid Rain: Current Issues, and IB83005 -- Clean Air Act: An Overview.

Description: After global warming became a concern in the mid-1950s, researchers proposed measuring deep ocean temperatures to reveal any significant trends in core ocean warming. Acoustic thermometry can detect changes in ocean temperature by receiving low-frequency sounds transmitted across an ocean basin because the speed of sound is proportional to water temperature. Acoustic Thermometry of Ocean Climate, or ATOC, is an international program involving 11 institutions in seven nations. It is designed as a 30-month "proof-of-concept" project to provide data on possible global climate change, with funding provided by the U.S. Department of Defense. A debate has arisen over ATOC's impact on marine mammals versus the benefits of better global warming information derived from ATOC. This report dicusses the ATOC program and related concerns.

Description: The Environmental Protection Agency (EPA) is currently engaged in a series of regulatory actions to address the transport of ozone pollution in the eastern United States. This report reviews this situation with respect to an EPA-proposed Ozone Transport Rule and other activities.

Description: The decisions by the Administrator of the Environmental Protection Agency (EPA) in 1997 to revise the National Ambient Air Quality Standards (NAAQS) for ozone and particulate matter refocused attention on the criteria and the process by which these decisions are made Tracing the steps of the decision pieces, this report identifies the statutory criteria established by the Congress and summarizes the administrative procedures the Agency follows in setting these standards and in reviewing them every 5 years.

Description: This report provides background information on federal emission standards for motor vehicles under the Clean Air Act and stricter standards originally developed to address the severity of air quality problems in California, explains the low emission standards and flexible compliance mechanisms to which states and manufacturers have voluntarily agreed under the National Low Emission Vehicle (LEV) Program, discusses the Environmental Protection Agency's (EPA) estimates of the program's air quality benefits and costs, and examines regulatory issues related to its implementation including sulfur levels in gasoline and the relative stringency of emission standards for light trucks.