Sixteen states have filed motions to intervene in a challenge to greenhouse gas (GHG) regulation. Florida, Hawaii, Indiana, Kentucky, Louisiana, Mississippi, Nebraska, North Dakota, Oklahoma, South Carolina, South Dakota, and Utah filed a joint motion, while Alaska, Michigan, Minnesota, and Pennsylvania filed separate motions. Coalition For Responsible Regulation, Inc. v. EPA, No. 09-1322 (D.C. Cir. Filed 03/18/10). These states seek to join in a petition originally filed by Alabama, Texas and Virginia, which challenges an Environmental Protection Agency (EPA) final rule titled “Endangerment and Cause or Contribution Findings for Greenhouse Gases Under Section 202(a) of the Clean Air Act,” published at 74 Fed. Reg. 66,496 (12/15/09). The rule is a condition precedent for the regulation of GHG emissions from motor vehicles under the Clean Air Act.

Petitioners have alleged that the rule is “arbitrary and capricious” and that EPA failed to properly exercise its judgment by relying almost exclusively on reports from the Intergovernmental Panel on Climate Change in attributing climate change to GHG emissions. Fifteen other states, including Arizona, California and New York, have intervened in the case in support of EPA.