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Legal Update

US EPA Proposes to Find that Greenhouse Gases Threaten Public Health and Welfare

20 April 2009
Mayer Brown Legal Update
On April 17, 2009, the US Environmental Protection Agency (EPA) proposed “to find that greenhouse gases in the atmosphere endanger the public health and welfare of current and future generations.”  In addition, the Agency proposed to find that four greenhouse gases (GHGs) emitted from new motor vehicles and new motor vehicle engines contribute to that air pollution. 

EPA is issuing the proposed endangerment findings in response to the US Supreme Court’s April 2007 decision in Massachusetts v. EPA, 549 U.S. 497 (2007).  There, the Court held that EPA had improperly denied a petition seeking regulation of GHG emissions from new motor vehicles pursuant to Clean Air Act Section 202 and remanded the case for further administrative proceedings.

EPA now is proposing to make two distinct findings under Section 202.  Based on the existing scientific literature, including projected future effects on storm impacts, sea level, snowpack, crops, forest fires, ecosystems, heat mortality, and sickness, EPA would first conclude that the mix of six greenhouse gases—carbon dioxide, methane, nitrous oxide, perfluorocarbons, hydrofluorocarbons, and sulfur hexafluoride—constitutes “air pollution” that endangers public health and welfare.  The second finding would be that combined emissions from new motor vehicles and new motor vehicle engines of carbon dioxide, methane, nitrous oxide, and hydrofluorocarbons contribute to that air pollution.  In this regard, the proposal emphasizes that all on-road vehicles in the United States account for 24 percent of national GHG emissions and greater than 4 percent of worldwide emissions. 

EPA is planning to hold two public hearings on its proposal:  May 18, 2009, in Arlington, Virginia, and May 21, 2009, in Seattle, Washington.  Written comments will be due 60 days after the proposed findings appear in the Federal Register.

The background materials emphasize that the proposed findings, if finalized, would not impose any requirements.  Under Clean Air Act Section 202, however, EPA must prescribe motor vehicle standards once it makes the requisite findings.  Further, if finalized as drafted, the findings are likely to trigger other Clean Air Act provisions, leading to requirements for a variety of sources ranging from aircraft to ships to industrial facilities. 

Thus, the proposed findings may give EPA a platform for taking a variety of climate change-related actions.  Indeed, some observers have noted that the proposed endangerment findings inevitably will bring additional pressure on Congress and the affected industries to “come to the table” and seek an acceptable compromise in climate change legislation (already foreshadowed in the discussion draft of the American Clean Energy and Security Act that Representatives Henry Waxman and Edward Markey released on March 31, 2009). 

For more information about the proposed rule, or any other matter raised in this Client Alert, please contact , at +1 202 263 3301, or , at +1 202 263 3343.

Learn more about our Climate Change practice.

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