Supreme Court Lets Biden Plans on Mercury and Methane Move Forward

The Supreme Court said on Friday that it would not stop the Biden administration from enforcing rules to reduce emissions of two pollutants: mercury, a hazardous neurotoxin, and methane, a potent greenhouse gas.

The court’s brief orders did not give reasons, which is typical when the justices act on emergency applications. There were no noted dissents.

The orders followed recent decisions limiting the Environmental Protection Agency’s authority to address climate change, water pollution and air pollution that drifts across state lines.

The case concerning mercury began in the spring after the Biden administration moved to tighten emissions standards for hazardous air pollutants from coal-fired power plants.

Under the new guidelines, operators of the plants must, among other things, continuously monitor for some toxins and face stricter limits on a type of coal called lignite, the lowest grade of coal. Power plants have up to three years to comply, with a fourth year available if needed.

Republican attorneys general and industry groups filed suit to block the regulations and asked a federal appeals court to temporarily block the rules from going into effect while their suit was pending. The court denied the request and set an expedited schedule for hearing the case.