The Supreme Court issued an order stating that while it would not yet decide whether to block the Environmental Protection Agency’s (“EPA”) smog rule from being effective, it would hear oral arguments on the matter during the upcoming February session. The oral arguments will include four related disputes over whether the EPA can implement a plan to reduce cross-state pollution amid legal challenges.

The Supreme Court also said that proponents and opponents of this rule should be prepared for arguments about whether the rule’s emissions controls are reasonable. The subject rule seeks to control emissions of smog-forming nitrogen oxides from power plants and other industrial facilities in upwind states, so pollution from the states with the polluting facilities do not harm their upwind neighbors, hence it is known as the “good neighbor” rule. When the EPA enacted the rule, it noted the public health benefits of cutting pollution, saying it expected to prevent 1,300 premature deaths in 2026.

In October 2023, Republican attorneys general, as well as industrial and utility groups, asked the Supreme Ocurt to halt the rule after a federal appeals court declined to do so. In their legal brief, they argued that the rule would “irreparably” harm their industries and citizens because they would have to spend money to comply with the mandate, which they view as unlawful.  They went on to argue that the rule would undermine their ability to generate electricity, which would destabilize the state power grid(s).

While it is too early to tell how the Court will ultimately rule, the conservative-majority court has recently moved to curtail the EPA’s authority on other regulations concerning climate and water.