The Supreme Court on Thursday ruled against an Environmental Protection Agency effort to regulate power plant emissions, dealing a blow to the Biden administration in one of the most significant climate cases decided by the high court in more than a decade. Chief Justice John Roberts wrote the opinion for a 6-3 majority. The court's three liberal justices dissented. At the center of the case was a question about whether the EPA had authority to curb carbon emissions from power plants. Simmering just below the surface was a deeper debate over how much authority all federal agencies have to issue regulations absent explicit authorization from Congress – an issue with far-reaching implications. Though not widely discussed during oral arguments earlier this year, the case arrived at the high court as scientists, U.S. military officials and the United Nations have warned about dire and imminent consequences from climate change. A report in April found that without immediate emission reductions, limiting global warming to 1.5 degrees Celsius – a key cutoff for curbing sea-level rise – is "beyond reach." 📸: Associated Press