The Supreme Court might throw a big wrench in the EPA’s attempt to fight climate change

The court is expected to rule this week on whether the Environmental Protection Agency can continue to regulate carbon dioxide and other greenhouse gases using the Clean Air Act.

And depending on how broad the court’s ruling is, it could also drastically weaken the government’s power to regulate anything.

Any progress the federal government has made on climate change has stemmed in large part from a 2007 Supreme Court case, Massachusetts v. EPA. It established the agency’s right to regulate greenhouse gases including CO2 and methane as “pollutants” under the Clean Air Act. Though it has moved forward in fits and starts, allowing the EPA to set limits on these emissions under the Clean Air Act is, alongside the technological and economic advances of the solar and wind power industries, among the most important developments of the last few decades.

None, some or all of that result is currently at risk.

Interestingly, the rule in question isn’t even a rule anymore; in fact, it never really was.

Improvident Hail Mary

The strange hole at the center of West Virginia v. EPA offers a tiny glimmer of hope for a less-than-dire outcome.

Another possibility is that it could rule that the EPA lacks the authority to institute what are known as “beyond the fence-line” controls, meaning that the agency cannot issue systemwide requirements for emissions but instead can regulate individual facilities and their smokestack emissions — a much more limited mandate, but not one that overturns the Mass. v. EPA result and removes greenhouse gases from the agency’s purview entirely.

A darker possibility lies in what’s known as the “major questions” doctrine — the premise that if Congress intended agencies to make sweeping, economywide changes with their regulations, the relevant legislation must say so specifically and clearly.

That would send the agency more or less back to square one, without a mandate to regulate greenhouse gases at all. But Flatt said that’s still not even the worst-case scenario.

“It relegates them to a much more limited role,” Flatt said, though he added that, thankfully, he does not expect the court to invoke the non-delegation doctrine.

A surprisingly positive legacy

But if the major questions-related outcome comes to pass, or even a more limited ruling that shuts off widespread greenhouse gas regulation, it would mark the end of a relatively short but meaningful era in American efforts to combat climate change. The biggest impact of Massachusetts v. EPA was the Obama administration efforts to limit tailpipe emissions from cars and trucks — efforts that clearly worked to a large extent.

“Those [rules] are effective,” Flatt said. “They can do a lot. The automobile thing already has done a lot.”