On Monday, December 7, the U.S. Environmental Protection Agency (“EPA”) formally determined that greenhouse gases endanger public health and welfare. This endangerment finding is a direct response to the Supreme Court’s 2007 decision in Massachusetts v. EPA, which held that greenhouse gases are pollutants covered by the Clean Air Act and ordered the agency to determine whether or not emissions of greenhouse gases from motor vehicles cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare.
EPA’s endangerment finding for greenhouse gases marks the first in a series of steps that the agency is poised to take in order to regulate greenhouse gas emissions. The endangerment finding itself triggers the regulation of emissions from motor vehicles; specifically, it allows the EPA to finalize greenhouse gas emission standards for light-duty vehicles, which were proposed on September 15, 2009. After these vehicle standards are finalized and promulgated, greenhouse gases will be considered to be “regulated pollutants” that are also subject to permitting requirements under the Clean Air Act’s Prevention of Significant Deterioration (“PSD”) program for stationary sources. In order to make such regulation practicable, the EPA has proposed a “tailoring rule” to exempt from PSD requirements sources that emit fewer than 25,000 tons of carbon dioxide per year. Environmental organizations and others have questioned whether EPA has the legal authority to create a higher threshold for greenhouse gases than presently applies to other pollutants.
The endangerment finding for greenhouse gases, along with the regulations it will engender, are likely to be challenged in court. Even if these actions do not survive judicial scrutiny, they represent a concerted effort to regulate greenhouse gases beyond mere reporting requirements. Notably, the specter of complex greenhouse gas regulation by the EPA may increase the sense of urgency in Congress to forge legislation that will offer a comprehensive, coherent, and cost-effective approach to the problems posed by climate change.
