WASHINGTON –In a challenge to the Environmental Protection Agency’s (EPA) authority to regulate greenhouse gases from industrial and automotive sources, the U.S. Court of Appeals in D.C. ruled that the EPA has the right to do so.

The EPA’s ability to regulate greenhouse gases was challenged in four lawsuits by U.S. states and industry groups. This verdict upholds the 2007 decision by the U.S. Supreme Court in Massachusetts vs. EPA that held greenhouse gases could be regulated as an air pollutant under the Clean Air Act.

According to the Court of Appeals’ written decision, it ruled specifically that the Endangerment Finding (i.e. where the EPA found that greenhouse gases could “reasonably be anticipated to endanger public health or welfare”) and Tailpipe Rule, which regulates vehicle emissions, are not “arbitrary or capricious.” The court also found that the EPA’s interpretation of the Clean Air Act provisions are “unambiguously” correct, and that none of the groups filing the lawsuits were successfully able to challenge the Timing and Tailoring rules that state that only the largest stationary sources of emissions would be subject to permitting requirements.

One argument that state and industry groups cited was that the National Highway Traffic Safety Administration’s (NHTSA) ability to regulate fuel economy gave the EPA the ability to defer regulating greenhouse gases at its discretion. The Court of Appeals sided with the Supreme Court’s decision, which rejected the contention that the EPA had the ability to defer regulation.

“Just as EPA lacks authority to refuse to regulate on the grounds of NHTSA’s regulatory authority, EPA cannot defer regulation on that basis,” the decision read.

In a press statement from the National Association of Manufacturers, the organization and its members said they object to the decision, with association President and CEO Jay Timmons describing the ruling as a “setback for businesses facing damaging regulations from the EPA.”

Timmons said the organization is considering further legal options on appeal.

By Greg Basich