The U.S. Supreme Court restricted the Environmental Protection Agency’s authority to curb greenhouse gases from power plants, siding with coal-mining companies and Republican-led states in a blow to President Biden’s climate-change agenda.

The 6-3 ruling interpreting the U.S. Clean Air Act is likely to keep the administration from imposing the wide-ranging emissions-cutting plan the EPA tried to put in place when Obama was president. It limits the agency’s available tools amid increasing criticiszm from climate alarmists.

The majority said that, while the EPA can regulate power plant emissions, the agency cannot shift power generation away from fossil-fuel plants to cleaner sources, as Obama’s Clean Power Plan sought to do. Writing for the court, Chief Justice John Roberts said Congress needs to speak more explicitly to give an agency that much power.

“A decision of such magnitude and consequence rests with Congress itself, or an agency acting pursuant to a clear delegation from that representative body,” Roberts wrote.

The court’s three Democratic-appointed justices -- Stephen Breyer, Sonia Sotomayor and Elena Kagan -- dissented.

The ruling casts fresh doubt on Biden’s pledge to reduce U.S. emissions in half by the end of decade and his goal of a carbon-free electric grid by 2035. Hitting those targets will be impossible without regulations to stifle greenhouse gases from oil wells, automobiles and power plants, as well as tax incentives designed to spur clean energy.