On December 7, 2009, the U.S. EPA Administrator, Lisa Jackson, formally made two separate findings required to authorize the regulation of greenhouse gases under the Clean Air Act. Both findings pertain only to motor vehicles but set precedent for similar findings with respect to stationary sources. In the "Endangerment Finding" (proposed April 2009), EPA finds that the current and projected concentrations of the six key greenhouse gases -- carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6) -- in the atmosphere "threaten the public health and welfare of current and future generations." In the "Cause or Contribute Finding," EPA concludes that 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. Although these findings do not impose regulatory norms upon industry, they begin to lay the groundwork for future regulatory proposals affecting a wide range of stationary and mobile sources.
Find a more detailed analysis of the Agency's April 2009 proposal, click here.