A Supreme Court greenhouse gases petition worth watching

West Virginia Attorney General Patrick Morrisey is leading 19 states seeking Supreme Court review of the scope of EPA's authority over greenhouse gases.

Driving the news: The petition asks the high court to review January's appellate ruling that struck down a Trump-era rule on power plant CO2 emissions.

The big picture: The Trump rule adopted a narrow view of EPA's Clean Air Act authority that the U.S. Court of Appeals for the D.C. Circuit rejected.

• So if the high court accepts the case, it would set up an extremely high stakes legal battle before the court's 6-3 conservative majority.
• "If EPA lacks such expansive authority, as we argue, the Supreme Court should make that clear now," Morrissey said in a statement alongside the petition from conservative-leaning states.

Why it matters: "The case, if granted, would be the biggest climate question to reach the Supreme Court in more than a decade," Bloomberg Law notes.

The intrigue: The Supreme Court takes just a tiny fraction of petitions. E&E News (subscription) reports that while this effort may face long odds, it’s a preview of challenges coming against Biden administration regulatory efforts around power plants.

Catch up fast: The high court's 2007 ruling in Massachusetts v. EPA gave EPA the power to regulate heat-trapping emissions.

• It's unlikely the current court would overturn this recent precedent.
• But legal observers say it could support significant constraints on federal regulators' running room under current law.
• The new petition comes as the Biden administration plans wide-ranging climate initiatives.

Go deeper: The Supreme Court's coming rightward shift on climate