Supreme Court leaves in place two Biden administration environmental regulations

WASHINGTON — The Supreme Court left in place Friday two Biden administration environmental regulations aimed at reducing emissions of planet-warming methane and toxic mercury from coal-fired power plants.

The justices did not detail their reasoning in the orders, which came after a flurry of emergency applications to block the rules from industry groups and Republican-leaning states. There were no noted dissents.

The high court is still considering challenges to a third rule aimed at curbing planet-warming pollution from coal-fired power plants.

The industry had argued the Environmental Protection Agency overstepped its authority and set unattainable standards. The EPA said the regulations are squarely within its legal responsibilities.

The Supreme Court has shot down other environmental regulations in recent years, including a landmark decision that limited the EPA’s authority to regulate carbon dioxide emissions from power plants in 2022 and another that halted the agency’s air-pollution-fighting “good neighbor” rule.

The oil and gas industry is the largest emitter of methane, which is responsible for one-third of emissions of methane, a key contributor to climate change, the EPA said in court documents. A lower court previously refused to halt the regulation.

The EPA has said the mercury rule is needed to protect public health against pollutants that can affect the nervous system and kidneys as well as fetal development.