In this comment on the Environmental Protection Agency's Advanced Notice of Proposed Rulemaking (ANPR) on greenhouse gas (GHG) regulation under the Clean Air Act (CAA), CEI identifies several compelling reasons why EPA should not issue a finding under CAA Section 202 that GHG emissions from new motor vehicles cause or contribute to dangerous "air pollution."

An endangerment finding would trigger a regulatory cascade throughout the Act, imposing potentially crushing burdens on regulated entities, environmental agencies, and the economy. Tens of thousands of previously unregulated buildings and facilities could face new regulation, monitoring, controls, and penalties under the Prevention of Significant Deterioration (PSD) pre-construction permitting program; hundreds of thousands could face pointless paperwork burdens under the Title V operating permits program; millions could face onerous yet inscrutable technology requirements under the Hazardous Air Pollutant (HAP) program. EPA could even be compelled to set GHG National Ambient Air Quality Standards (NAAQS) that an outright de-industrialization program would be insufficient to attain. In short, an endangerment finding could set the stage for horrible regulatory consequences no Congress would ever approve.

In addition, because of uncertainties regarding climate sensitivity and other scientific issues, it is not reasonable at this time to anticipate endangerment of public health and welfare from anthropogenic global warming. Therefore, EPA should decline to make an endangerment finding regarding GHG emissions from new motor vehicles.