The Supreme Court just made it much harder for the U.S. government to respond to climate change in a 6-3 decision in the case of West Virginia v. EPA.

The Thursday decision, written by Chief Justice John Roberts and joined by the other five conservative justices, preemptively strikes down any regulations the Biden administration might consider issuing under a provision of the Clean Air Act to limit carbon emissions at power plants.

The court ruled that EPA regulations aimed at reducing carbon emissions under a specific provision of the 1970 Clean Air Act are not permissible because Congress did not specifically authorize the EPA to regulate CO2.

Carbon functions differently from other air pollutants power plants spew, such as mercury or acid gasses, in that it harms human health primarily by accumulating in the atmosphere and warming the planet. As such, the EPA tried under the Obama administration to regulate power plant emissions by encouraging plant operators to limit emissions across the board, not just from individual facilities.

According to the court, the EPA has the authority to regulate individual plans, but not to make more sweeping efforts to regulate carbon emissions that has to come from Congress.

The courts decision follows the expanding logic of its so-called major questions doctrine . The doctrine states that the Supreme Court can strike down regulatory action of vast economic and political significance if Congress did not specifically delegate a rule-issuing agency to issue that regulation.

This is a major questions case, Roberts writes. EPA claimed to discover an unheralded power representing a transformative expansion of its regulatory authority in the vague language of a long-extant, but rarely used, statute designed as a gap filler. That discovery allowed it to adopt a regulatory program that Congress had conspicuously declined to enact itself. Given these circumstances, there is every reason to hesitate before concluding that Congress meant to confer on EPA the authority it claims.

Capping carbon emissions from power plants may be a sensible solution to the crisis of the day, Roberts writes. But, he continues, it is not plausible that Congress gave EPA the authority to adopt on its own such a regulatory scheme. Instead, a regulation of such magnitude and consequence rests with Congress itself.