In its most significant climate change action since the US Supreme Court's landmark Massachusetts v. EPA decision, EPA has published anAdvance Notice of Proposed Rulemaking (ANPR) seeking comprehensive feedback on how EPA should regulate greenhouse gas (GHG) emissions. The July 11, 2008 ANPR explains that resolution of the specific issue identified by the Supreme Court – whether GHG emissions from mobile sources "endanger public health or welfare" – may well have a significant ripple effect by triggering many other Clean Air Act obligations that use similar tests. It also includes highly critical comments by several federal agencies that question the threshold viability of regulating GHGs under the Clean Air Act.

Recognizing that any "endangerment" decision would have far-reaching consequences, EPA is soliciting comments from the regulated community and others to generate a foundation for making critical decisions regarding who should be subject to GHG regulation, when regulatory obligations should accrue and what requirements should be imposed. Among many other key issues, EPA has requested comments regarding:

  • Which obligations necessarily follow an endangerment finding?
  • Which GHGs should be regulated and in what manner?
  • What level of regulation is warranted?
  • Which regulatory approach maximizes EPA's ability to consider costs?
  • Is a cap-and-trade approach legal and feasible under the Clean Air Act?
  • Which sources and industries should be subject to regulation?
  • Whether regulation should be economy-wide or sector-based?
  • How will GHG regulation affect permitting obligations?

This ANPR presents a unique opportunity for the regulated community to shape EPA's fundamental approach to climate change regulation under the Clean Air Act. Interested parties from all perspectives are invited to submit creative solutions to the many statutory and regulatory hurdles facing EPA. The most effective advocates in this process can proactively alter the nature and timing of climate change obligations. Climate change advocacy is forging new alliances within and across traditional industry groups to advocate for common interests relating to the GHG implications of different fuel types and efficiency improvements. The legal component of an effective ANPR comment is critical because recent Court decisions striking down EPA's Clean Air Interstate Rule (CAIR) and maximum achievable control technology (MACT) innovations reveal that solutions in this complex area must be grounded in EPA's statutory authority to survive judicial review.