Fifteen state attorneys general petitioned a federal court in Washington on Thursday to block new US rules to curb carbon emissions from power plants, in the first of several expected legal challenges to the Obama administration measure.



States that oppose the Environmental Protection Agency’s (EPA) clean power plan filed for the stay in the US court of appeals for the DC circuit. The states asked for a ruling by 8 September, one year before they need to submit compliance plans to the EPA.

“This rule is the most far-reaching energy regulation in the nation’s history, and the EPA simply does not have the legal authority to carry it out,” West Virginia attorney general Patrick Morrisey said.

The Obama administration unveiled the final version of the clean power plan on 3 August. It aims to lower emissions from the country’s power plants by 32% below 2005 levels by 2030.

President Barack Obama called the rule the biggest action the US had taken to date to address climate change.

Under the proposal, each state needs to submit a plan to the EPA detailing how it intends to meet the target the agency set for it.

States, particularly those that have relied on coal for electricity, have argued the EPA has overstepped its regulatory authority.

“The Clean Air Act was never intended to be used to create this type of regulatory regime, and it flies in the face of the powers granted to states under the US constitution,” said Morrisey.

Alabama, Arkansas, Florida, Indiana, Kansas, Kentucky, Louisiana, Michigan, Nebraska, Ohio, Oklahoma, South Dakota, Wisconsin and Wyoming joined West Virginia in requesting the stay.

The EPA said the Clean Power Plan would withstand legal challenges because it was based on a “sound legal and technical foundation”.

“To ensure that the Clean Power Plan’s significant health benefits and progress against climate change are delivered to all Americans, EPA and the Department of Justice will vigorously defend it in court,” EPA spokeswoman Liz Purchia said.

Attorneys general for 15 other states, including New York, California, Illinois and Oregon, along with New York City and the District of Columbia, issued a statement supporting the EPA rules and saying they would oppose legal efforts to block their implementation.

The EPA has not yet filed the rule in the Federal Register, at which point parties can begin to formally file lawsuits.