The Supreme Court's 6-3 decision in West Virginia v. EPA may not be the worst outcome environmental advocates feared, but it is a major blow to the Biden administration's efforts to reduce the severity of human-caused global warming.

• In repeatedly questioning the scope of the EPA's authority from Congress and using the term "administrative state," the conservative justices may also be inviting future challenges to rules imposed by other agencies beyond the EPA.

• "Administrative state" is court-speak for the sprawling federal bureaucracy and the rules such agencies impose.
• President Biden called it a "devastating decision" and said he "will not relent in using my lawful authorities to protect public health and tackle the climate crisis."

The backstory: Under former President Obama, the EPA had devised a program, known as the Clean Power Plan, to help decarbonize the power sector, which is the second-largest source of emissions.

• These regulations looked at the power sector broadly, rather than regulating each power plant one by one, smokestack by smokestack.
• In today's ruling, the majority of the court found that Congress did not intend to delegate to the EPA the creation of what was in effect a national pollution reduction system, which Congress itself had repeatedly declined to authorize.

Zoom in: The EPA sought to move the power sector as a whole away from emissions-intensive, coal-fired power plants and toward natural gas and renewable energy technologies.

• The majority opinion, written by Chief Justice John Roberts and joined by the five other conservative members of the court, invokes the so-called major questions doctrine in scrutinizing whether the EPA was given the authority under the Clean Air Act to impose rules of great national economic and political significance.

What they're saying: Biden said his administration "will continue using lawful executive authority, including the EPA’s legally upheld authorities, to keep our air clean, protect public health, and tackle the climate crisis."

• He also said the administration will work with states and cities to pass their own climate initiatives and will push for new legislation from Congress.
• In the dissenting opinion, Justice Elena Kagan took the majority to task for purporting to know how much authority Congress intended to give to the EPA and "rewriting the text" of the Clean Air Act.
• "And let’s say the obvious: The stakes here are high. Yet the Court today prevents congressionally authorized agency action to curb power plants’ carbon dioxide emissions."

Yes, but: While environmental advocates have much to criticize in the outcome of this case, it is noteworthy that the majority opinion did not challenge the EPA's authority to regulate greenhouse gases in the first place, Richard Revesz, a professor at NYU Law School, said in a statement.

What's next: With Biden's climate agenda stalled in Congress and a sweeping regulatory system through the EPA taken off the table, the White House now has fewer and less-effective options to achieve its ambitious climate commitments.

Go deeper:

Supreme Court reins in Biden's power on climate change

Conservative bench's new war on federal regulatory agencies