December 2009 – GHG Update: EPA Determines that Greenhouse Gases Threaten Public Health and Welfare

On December 7, 2009, the United States (U.S.) Environmental Protection Agency (EPA) announced that greenhouse gases (GHGs), including those released from on-road vehicles, threaten public health and welfare.

EPA Administrator, Lisa Jackson, signed two distinct findings regarding GHGs under section 202(a) of the Clean Air Act (CAA):

  • Endangerment Finding: The current and projected concentrations of the six key well-mixed greenhouse gases in the atmosphere threaten the public health and welfare of current and future generations.
    • carbon dioxide (CO2)
    • methane (CH4)
    • nitrous oxide (N2O)
    • hydrofluorocarbons (HFCs)
    • perfluorocarbons (PFCs)
    • sulfur hexafluoride (SF6)
  • Cause or Contribute Finding: The combined emissions of these well-mixed greenhouse gases from new motor vehicles and new motor vehicle engines contribute to the greenhouse gas pollution which threatens public health and welfare.


The EPA finding has no immediate regulatory effect, but it paves the way for proposed regulation on car and truck emissions. The findings will initially affect the automotive industry through increased improvement of efficiency. This action does not trigger Prevention of Significant Deterioration (PSD) or Title V permitting; however, the finalization of GHG emission standards for motor vehicles will trigger these programs. Additionally, EPA proposed a PSD and Title V GHG Tailoring Rule on September 30, 2009, to address large facilities that emit over 25,000 tons of GHGs per year.


Continue to track legislation and regulatory developments, and watch for EHS Support’s alerts to keep informed on updates. EHS Support will continue to follow regulation or legislation resulting from the EPA endangerment finding and keep you updated on important changes.

As a reminder, on October 30, 2009, EPA published the GHG Mandatory Reporting Rule, which becomes effective on December 29, 2009.  Affected facilities must begin collecting GHG emission data on January 1, 2010, with a report to be generated by March 31, 2011, for reporting year 2010. Companies can take a proactive approach and have EHS Support conduct a high level evaluation of your facility’s GHG emissions to determine if your company may be subject to permitting and reporting rules.

For more information about the EPA’s GHG findings or to request a high level evaluation of your facility’s GHG emissions, please contact Amy Bauer at 251-533-6949 or or Jessica Tierney at 412-779-1094 or

Background Information

EPA’s findings are in response to the 2007 U.S. Supreme Court decision that GHGs are part of the CAA definition of air pollutants. Administrator Jackson proposed the so-called GHG endangerment finding on April 17, 2009, and after receiving hundreds of thousands of public comments, issued the final findings. EPA’s endangerment finding was a result of determining that GHG concentrations in the atmosphere have increased due to human activities thus contributing to an increase in the earth’s temperature over the last 100 years (i.e., global warming).

EPA’s findings are a prerequisite to finalizing the EPA and Department of Transportation’s National Highway Safety Administration (NHTSA) jointly proposed GHG emission standards for light-duty vehicles on September 15, 2009. It was found that all on-road vehicles account for 4 percent of the total global GHG emissions compared to just over 23 percent of total U.S. GHG emissions. The agencies plan to dramatically reduce greenhouse gas emissions and improve fuel economy for new cars and trucks sold in the U.S. The combined EPA and NHTSA standards that make up this proposed National Program would apply to passenger cars, light-duty trucks, and medium-duty passenger vehicles, covering model years 2012 through 2016. They require these vehicles to meet an estimated combined average emissions level of 250 grams of carbon dioxide per mile, equivalent to 35.5 miles per gallon (MPG) if the automobile industry were to meet this CO2 level solely through fuel economy improvements.

President Obama, along with Administrator Jackson, has publicly stated that they support a legislative solution to the problem of climate change and Congress’ efforts to pass comprehensive climate legislation. However, it was critical that EPA fulfilled its obligation to respond to the 2007 U.S. Supreme Court ruling that determined that GHGs fit within the CAA definition of air pollutants.



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