States and industry groups challenging U.S. EPA's tailpipe rule on greenhouse gas emissions filed their opening briefs in federal court Friday.

It is one of three related cases in which opponents of the Obama administration's climate regulations are asking the U.S. Circuit Court of Appeals for the District of Columbia to invalidate four rules on legal grounds (Greenwire, March 23).

The tailpipe rule, which adopts new standards for car and light-truck emissions, pits several states against each other, with eight opposing the rule and 12 in support.

Car manufacturers support the rule, but it has still come under legal attack regardless because it helps provide the legal rationale for why the administration should also regulate other greenhouse gas emissions via the other rules it has approved.

The first of the two briefs filed Friday was by Texas Attorney General Greg Abbott (R) on behalf of the state challengers.

Abbott wrote that the rule should be invalidated under the Administrative Procedures Act "because EPA failed to consider the costs of compliance for stationary-source" greenhouse gas emitters, which, based on EPA's interpretation of the Clean Air Act "are necessarily regulated as a result of the tailpipe rule."

The second brief was filed by industry groups, including the Coalition for Responsible Regulation, the U.S. Chamber of Commerce and the National Association of Manufacturers.

Lead attorney Eric Groten of the Vinson & Elkins firm wrote that the rule should be invalidated on three grounds, including that it was the result of an "impermissible interpretation" of the Clean Air Act and the Massachusetts v. EPA Supreme Court ruling from 2007, in which the court said that carbon emissions could potentially be regulated via the statute.

EPA and its supporters are not required to file their briefs until September.

Click here to read the states' brief.

Click here to read the non-state petitioners' brief.