Bottom Line on Regulating Greenhouse Gases Under The Clean Air Act

This fact sheet by the World Resources Institute explains the legal basis and potential mechanisms for the U.S. Environmental Protection Agency (EPA) to regulate greenhouse gas (GHG) emissions under the Clean Air Act following a 2007 Supreme Court ruling and a 2009 EPA endangerment finding.

• The U.S. Environmental Protection Agency (EPA) established the legal foundation for regulating greenhouse gases (GHGs) through two key findings in April 2009: an "endangerment finding" stating that GHG emissions threaten public health and welfare, and a "cause or contribute finding" specifically linking motor vehicle emissions to climate change.
• The EPA's authority to regulate GHGs stems from a April 2007 Supreme Court decision in Massachusetts v. EPA, which determined that greenhouse gases are classified as air pollutants under the Clean Air Act.
• Regulatory options for the EPA vary by source type: for mobile sources, the EPA generally issues emission performance standards (such as grams of CO2/mile); for stationary sources like factories and power plants, it may use performance standards, technology standards, or a cap-and-trade program.
• The document notes that the Clean Air Act's framework may limit the EPA's ability to implement a single, broad cap-and-trade program that covers diverse sources, such as petroleum refiners, importers, factories, and power plants simultaneously.
• Potential business impacts include increased production costs for manufacturers of regulated products, which may raise consumer prices, though these may be offset by lower operational costs due to reduced fuel or electricity use. Companies with superior GHG performance may gain a competitive advantage.

APA

World Resources Institute (n.d.). Bottom Line on Regulating Greenhouse Gases Under The Clean Air Act. https://www.wri.org/research/bottom-line-regulating-greenhouse-gases-under-clean-air-act

Chicago

World Resources Institute. Bottom Line on Regulating Greenhouse Gases Under The Clean Air Act. n.d. https://www.wri.org/research/bottom-line-regulating-greenhouse-gases-under-clean-air-act.

Wikipedia

{{cite report |author=World Resources Institute |title=Bottom Line on Regulating Greenhouse Gases Under The Clean Air Act |url=https://www.wri.org/research/bottom-line-regulating-greenhouse-gases-under-clean-air-act |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{worldresourcesinstitutendbottom, author = {{World Resources Institute}}, title = {{Bottom Line on Regulating Greenhouse Gases Under The Clean Air Act}}, institution = {World Resources Institute}, url = {https://www.wri.org/research/bottom-line-regulating-greenhouse-gases-under-clean-air-act}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }