Health Hazards of Greenhouse Gases: Pollutants and the Clean Air Act

It's official: greenhouses gases not only contribute to global warming but also cause air pollution that presents a danger to human health, the EPA announced today. The move could open the door for greenhouse gases like carbon dioxide to be considered "pollutants", and for their emission to be regulated under the federal Clean Air Act. 

Today's Findings. The Proposed Endangerment Finding released by the EPA today declares that "In both magnitude and probability, climate change is an enormous problem. The greenhouse gases that are responsible for it endanger public health and welfare within the meaning of the Clean Air Act."

The EPA's conclusions come after "rigorous, peer-reviewed scientific analysis of six gases -- carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride -- that have been the subject of intensive analysis by scientists around the world," according to an EPA News Release. 

What It Could Mean. Currently, greenhouse gases like carbon dioxide are not considered "pollutants" under the Clean Air Act. If today's proposed EPA findings become final, all emission of greenhouse gases could be regulated under strict and uniform federal standards. This means that vehicle manufacturers, factories, and other emitters of greenhouse gases would need to comply with rules created based on the EPA's Clean Air Act authority.

Not surprisingly, today's announcement from the EPA was applauded by environmentalists but was met with some concern from those in affected industries (A Reuters article carries an interesting collection of reaction quotes). 

What is the Clean Air Act? The Clean Air Act is a federal law that defines the EPA's responsibilities for protecting and improving the nation's air quality. Congress created the Clean Air Act in 1963, significantly strengthened it in 1970, and then expanded it even further in 1990, when the EPA was given broad authority to "implement and enforce regulations reducing air pollutant emissions." (Learn more about the Clean Air Act from the EPA).

• News Release: EPA Finds Greenhouse Gases Pose Threat to Public Health, Welfare (EPA.gov)
• Proposed Endangerment and Cause or Contribute Findings for Greenhouse Gases Under the Clean Air Act (EPA.gov)
• Reuters: EPA Says CO2 Emissions Endanger Human Health
• N.Y. Times: EPA to Clear the Way for Regulation of Warming Gases
• The Plain English Guide to the Clean Air Act (EPA.gov)
• Text of the Clean Air Act (EPA.gov)