The USA’s legislators are still embroiled in legal conflicts about who, if anyone, has the authority to set national standards to control the emissions that are causing climate change.

The Supreme Court was due to hear arguments on 28 February in a dispute, which has rumbled on for years, that could restrict or even eliminate the US Environmental Protection Agency’s authority to control air pollution, potentially shredding president Biden’s plans to halve greenhouse emissions in the USA by the end of the decade.

Members of the US Supreme Court’s conservative majority have voiced skepticism over whether Congress had authorised the EPA to decide ‘major political and economic questions’.

The outcome could also have repercussions that stretch well beyond air pollution, restricting the ability of federal agencies to regulate health care, workplace safety, telecommunications, the financial sector and more.

At issue is a lack of a federal regulation that governs emissions from power plants, after the Supreme Court put Barack Obama’s Clean Power Plan, his chief strategy to fight climate change, on hold. The Biden administration has yet to issue its own legislation.

The case involves claims by 19 mostly Republican-led coal producing states and coal companies that the EPA does not have the legal power to issue sweeping new policies governing power plants and are challenging the agency’s ability to issue sweeping, new clean power policies. The question to be decided therefore is whether Congress must give the EPA specific authority to make new rules limiting carbon emissions nationwide.

“They [the Supreme Court] could handcuff the federal government’s ability to affordably reduce greenhouse gases from power plants,” said Michael Oppenheimer, a professor of geosciences and international affairs at Princeton university.