The ruling, written by Chief Justice John Roberts and signed by the court’s five other conservatives, is a major blow to the nation’s chances of averting catastrophic climate change. And it is the latest instance of the court’s emboldened conservative majority flexing its muscle following its decision to strike down Roe v. Wade.

Here’s what the decision in West Virginia v. EPA means for the country – and the planet.

What did the Supreme Court decide?

In a 6-3 ruling, the court found the EPA does not have the authority to force electric utilities to close down coal-fired power plants and shift to wind, solar and other renewable forms of generation.

Writing for the majority, Roberts pointed to what is called the “major questions” doctrine, which says Congress must “speak clearly” when authorizing agency action on significant issues. The majority argued that Congress simply hasn’t given the agency the authority to issue such sweeping carbon regulations on the power sector.

The country’s main federal air pollution law, the Clean Air Act, was written more than a half-century ago, well before climate change was recognized as the crisis it is today.

“There is little reason to think Congress assigned such decisions to the Agency,” Roberts wrote. “A decision of such magnitude and consequence rests with Congress itself.”

The court’s three liberals, however, contend the Clean Air Act, despite its age, indeed gives the agency the power to combat climate change.

Pointing to a portion of the law allowing the EPA to regulate pollutants that “may reasonably be anticipated to endanger public health or welfare,” Justice Elena Kagan wrote in her dissenting opinion: “Carbon dioxide and other greenhouse gases fit that description.”

Was a carbon rule already on the books for power plants?

Nope. And that’s what made this case so strange from the start.

During President Barack Obama’s last year in office, the Supreme Court blocked his administration’s rule to cut power plants’ carbon, called the Clean Power Plan, from taking effect. The Trump administration replaced the plan with a more lenient version, but it, too, was blocked by an appellate court on his last day in office.

Normally, judges wait for regulators to act. But this high court decided to hear the case before the Biden administration could weigh in with its own proposal.

“Twenty years ago, there’s no way that court would ever have taken this case,” said Sambhav Sankar, a senior vice president at the environmental law group Earthjustice who clerked for the now-retired justice Sandra Day O’Connor. “It’s just not a real case.”

Do the companies that operate coal-fired power plants want this?

Not necessarily.

A group of electric utilities serving more than 40 million people, some of which have divested from coal, told the court its decision to even hear the case is “premature” and “untethered to actual circumstances” driving change in the power sector.

In reality, utilities have been closing coal plants over the past decade in the face of competition from cheaper forms of energy such as gas-fired generators, solar farms and wind turbines. In their own brief, Apple, Tesla and other major tech firms investing in renewable energy agree that “stable, nationwide rules” on emissions are needed to accelerate that trend.

“Regardless of what the decision looks like, we do not anticipate much near-term impact on the power sector,” Christine Tezak, managing director of the independent research group ClearView Energy Partners, wrote in a note on the court case.

But many companies in the coal business are firmly on the side of West Virginia, which led the court case against the EPA. A trade group called America’s Power – which consists of coal-mining firms, barge operators and equipment manufacturers as well as some electric utilities – argued in its own brief that the EPA must be reined in since coal is necessary for keeping energy prices low and the grid reliable.

“This is not a case in which business is on one side, to be sure,” said Jonathan Adler, a law professor at Case Western Reserve University.

What does the Biden administration do now?

Good question.

Both the White House and the EPA said the administration is reviewing the decision. “Our lawyers will study the ruling carefully and we will find ways to move forward under federal law,” White House spokesman Abdullah Hasan said in a statement.

But EPA officials have already signaled they have other tools for cutting pollution from power plants.

The agency, for instance, is working on new rules to compel power plants to cut down the emissions of smog-forming pollution blown across state lines and to stop toxic contaminants in ash pits from leaching into drinking water. Taken together, the new regulations may make running coal plants more costly to operate.

But the agency’s ability to meaningfully and directly regulate carbon dioxide – the chief driver of global warming – from power plants’ smokestacks is now kneecapped after the Supreme Court’s decision.

Does this decision mean other regulations are at risk?

Possibly.

By invoking the “major questions” doctrine, the court’s conservative majority has issued a ruling that may invite more challenges to other federal regulators – not just the EPA – in the future.

“The consequences potentially reach far beyond EPA and the Clean Air Act,” said Lisa Heinzerling, an environmental law professor at Georgetown. “This is a big statement on how it intends to act moving forward.”

Liberals have long worried conservative judges will use the “major questions” doctrine to dismantle regulations. In her dissent, Kagan argued the doctrine itself has little precedent in past rulings.

“The current Court is textualist only when being so suits it,” she wrote. “When that method would frustrate broader goals, special canons like the ‘major questions doctrine’ magically appear as get-out-of-text-free cards.”

When it comes to the EPA, there is still “something of a silver lining here,” according to Jody Freeman, a Harvard Law School professor.

The court declined to strike down a landmark 2007 ruling called Massachusetts v. EPA, in which a liberal majority said the EPA could use its Clean Air Act authority to cut greenhouse gas emissions.

And the majority allowed the EPA to still regulate power plants – it just cannot do so now by forcing utilities to shift from coal to renewables.

“It leaves a pathway for EPA to still set meaningful standards. Even though the Clean Power Plan is ruled out, the court didn’t go further,” Freeman said.

What does this decision mean for the planet?

It puts the country even further off track from Biden’s goal of running the U.S. power grid on clean energy by 2035 – and making the entire economy carbon-neutral by 2050.

Local efforts on global warming only go so far. About four in 10 Americans live in a state, city or territory that has committed to reaching 100 percent clean electricity by the middle of the century at the latest, according to an analysis by the League of Conservation Voters.

Even achieving Biden’s nationwide aims alone wouldn’t stop climate change, as the United States is responsible for one-seventh of annual carbon emissions from burning fossil fuels. China has double the share.

But Biden has always aimed to lead by example when it comes to countries cutting emissions. That kind of diplomacy just got harder, especially with world leaders scrambling for new sources of fossil fuels after Russia’s invasion of Ukraine.

With higher seas, fiercer wildfires and other consequences of climate change already apparent, we’re in unprecedented territory, with little time to act. The world is set to blow past the international goal of keeping warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) at the current rate of emissions.