Timeline of EPA Actions on Greenhouse Gases

Following the 2007 Supreme Court ruling in Massachusetts v. EPA, the EPA established authority to regulate greenhouse gases (GHGs) under the Clean Air Act. This led to the 2009 Endangerment Finding and subsequent regulations targeting vehicle fuel economy and power plant emissions. Key initiatives include the Corporate Average Fuel Economy (CAFE) standards for light- and heavy-duty vehicles and the Clean Power Plan, which aims for a 30 percent reduction in the U.S. power sector's carbon emission rate by 2030 compared to 2005 levels.

• The 2007 Supreme Court case Massachusetts v. EPA established that greenhouse gases are air pollutants under the Clean Air Act, allowing the EPA to regulate them if they are found to be a danger to human health.
• The EPA's 2009 Endangerment Finding concluded that current and projected levels of six greenhouse gases threaten the health and welfare of current and future generations.
• The EPA and NHTSA implemented fuel efficiency and tailpipe emission standards for light-duty vehicles for model years 2012–2016, targeting 35.1 miles per gallon by 2016 and emissions under 250 grams of CO2 per mile. These standards were later extended through model year 2025 with a target of 54.5 miles per gallon.
• The Clean Power Plan, introduced in draft form in June 2014, targets a 30 percent reduction in the carbon emission rate of the U.S. power sector by 2030 relative to 2005 levels, utilizing four 'building blocks': improving heat efficiency, substituting lower emissions generation, installing zero emissions generation, and increasing end-use energy efficiency.
• The EPA established the first federal fuel efficiency and GHG emission standards for medium- and heavy-duty vehicles for model years 2014–2018, which is estimated to reduce CO2 pollution by 270 million metric tons over the vehicles' lifetimes.

APA

Collins, J. (2014). Timeline of EPA Actions on Greenhouse Gases. Environmental and Energy Study Institute. https://www.eesi.org/papers/view/fact-sheet-timeline-of-epa-actions-on-greenhouse-gases

Chicago

Collins, Jenifer. Timeline of EPA Actions on Greenhouse Gases. Environmental and Energy Study Institute, 2014. https://www.eesi.org/papers/view/fact-sheet-timeline-of-epa-actions-on-greenhouse-gases.

Wikipedia

{{cite report |last1=Collins |first1=Jenifer |title=Timeline of EPA Actions on Greenhouse Gases |publisher=Environmental and Energy Study Institute |date=23 September 2014 |url=https://www.eesi.org/papers/view/fact-sheet-timeline-of-epa-actions-on-greenhouse-gases |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{collins2014timeline, author = {Collins, Jenifer}, title = {{Timeline of EPA Actions on Greenhouse Gases}}, institution = {Environmental and Energy Study Institute}, year = {2014}, month = sep, url = {https://www.eesi.org/papers/view/fact-sheet-timeline-of-epa-actions-on-greenhouse-gases}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }