Today, the US Supreme Court begins oral arguments in West Virginia v. EPA. This case will either reinforce the federal government's power to regulate greenhouse gas (GHG) emissions or punt that control to Congress, where passing climate legislation and limits on pollution is extremely difficult. The oral arguments, and the questions the nine Justices ask, may give a first impression of where the Court is likely to land when it issues its decision in May or June.

Why This Matters

At stake is the EPA's authority to regulate GHG emissions from existing coal- and gas-fired power plants under the landmark Clean Air Act. An eventual ruling restricting EPA authority could hobble the Administration's ability to curb the power sector's emissions, representing about a quarter of the country’s GHGs.

The case was brought before the Supreme Court by Republican-led states and headed by coal-producer West Virginia. Democratic-led states and major power companies, including Consolidated Edison Inc. (ED.N), Exelon Corporation (EXC.O), and PG&E Corporation (PCG.N), sided with Biden's Administration, as did the Edison Electric Institute, an investor-owned utility trade group. The utility industry believes regulatory certainty will help companies devise investment plans.

How the Court will rule is an unknown. A slightly less conservative majority in 2014 upheld the executive branch's authority to regulate major sources of GHG emissions like power plants and factories. But in 2016, it sent President Obama's Clean Power Plan back to regulators for reworking. Whichever way this Court rules, it will impact the future of climate action -- especially as President Biden prepares for a potential anti-climate Congress starting in 2023, leaving regulation his best option to effect change.

The Court in the News

The case comes before the Justices when the Court system is at the heart of climate action. And this year has already proven that the judicial branch matters. A recent court ruling sided with climate activists and sidelined an oil and gas auction. But before that, conservative jurists in another court effectively stopped the Administration from using one of its most potent tools in the climate fight, executive authority. Losing that authority would be a huge blow for the Biden Administration, which aims to decarbonize the US power sector by 2035.

Supreme Court Judges & Nominees

President Biden on Friday nominated federal appeals court Judge Ketanji Brown Jackson to the Supreme Court, making her the first Black woman selected to serve on the country's highest court. Jackson will, if confirmed, replace her mentor Justice Stephen Breyer, who is retiring. Still, in swapping Jackson for Breyer, the Court's ideological balance remains the same; a 6-3 conservative majority.

Eight years of the Bush Administration and four years of the Trump Administration, in particular, reshaped America's courts, especially the Supreme Court. Reliable conservative judges -- Alito (Bush II), Gorsuch (Trump), Kavanaugh (Trump), and Coney Barrett (Trump) -- have joined Clarence Thomas (Bush I) in the Court’s hard-right flank. Chief Justice Roberts (Bush II) is occasionally a moderating force, but rarely so when it comes to the environment.