Timeline of EPA Actions on Greenhouse Gases

This fact sheet provides a chronological timeline of the U.S. Environmental Protection Agency's (EPA) regulatory actions and associated court rulings regarding greenhouse gas (GHG) emissions from stationary and mobile sources between 2007 and 2014.

• The 2007 Supreme Court ruling in 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.
• In December 2009, the EPA issued an 'Endangerment Finding' stating that current and projected levels of six greenhouse gases threaten the health and welfare of current and future generations.
• The EPA and the National Highway Traffic Safety Administration (NHTSA) implemented fuel economy and GHG standards for light-duty vehicles, targeting 35.1 miles per gallon by model year 2016 and later extending standards to reach 54.5 miles per gallon by model year 2025.
• The EPA established the first federal 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.
• The Clean Power Plan, proposed in June 2014, aims to achieve a 30 percent reduction in the carbon emission rate from the U.S. power sector by 2030 compared to 2005 levels.
• The U.S. Supreme Court's 2014 ruling in Utility Air Regulatory Group v. EPA determined that the EPA cannot regulate a power plant based solely on its GHG emissions, which led to the striking down of the Tailoring Rule, though the EPA retains authority to regulate new power plants if they are regulated for other pollutants.
• President Obama's 2013 Climate Action Plan set a goal to reduce U.S. emissions to 17 percent below 2005 levels by 2020, focusing on cutting carbon pollution, preparing for climate impacts, and leading international efforts.

APA

Collins, J. (2014). Timeline of EPA Actions on Greenhouse Gases. Environmental and Energy Study Institute. https://www.eesi.org/files/FactSheet_EPA_timeline_092214.pdf

Chicago

Collins, Jenifer. Timeline of EPA Actions on Greenhouse Gases. Environmental and Energy Study Institute, 2014. https://www.eesi.org/files/FactSheet_EPA_timeline_092214.pdf.

Wikipedia

{{cite report |last1=Collins |first1=Jenifer |title=Timeline of EPA Actions on Greenhouse Gases |publisher=Environmental and Energy Study Institute |date=September 2014 |url=https://www.eesi.org/files/FactSheet_EPA_timeline_092214.pdf |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/files/FactSheet_EPA_timeline_092214.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }