How much can the federal courts do on a climate change? If you want more climate regulation than Congress is willing to provide, it’s an urgent question. The most recent and most ambitious climate lawsuit is Juliana v. United States, a lawsuit by children asking the courts to order the government to aggressively regulate carbon emissions. These plaintiffs argue that they have unwritten constitutional and federal common law rights to a stable climate and that the government must uphold these rights by imposing limits on private carbon emissions. The Ninth Circuit recently heard their argument and its upcoming decision will help define the outer boundaries of what the courts can do on climate change.

There has been no progress on federal climate legislation for ten years, since a 2009 cap-and-trade bill narrowly passed the House of Representatives and then died in the Senate. Since then, climate activists have pushed climate action in the courts, hoping to build on their major victory in Massachusetts v. EPA, 549 U.S. 497 (2007), which held (5-4) a) that states had standing to consider the government’s refusal to consider carbon regulations for cars under the Clean Air Act and b) that the government had to consider these regulations.

But in the ensuing decade climate efforts have largely been stymied in the courts, particularly in the Supreme Court:

The Juliana case will also likely prove fruitless in the end. The district court did initially allow the case to go forward and denied a government request for interlocutory appeal. But the Supreme Court again stepped in: it took the extraordinary step of first staying the case and then, while lifting the stay, suggesting it might reimpose it if the Ninth Circuit did not do so first. The Ninth Circuit then stayed the case and invited the district court to reconsider its decision on interlocutory appeal, which it did, allowing the appeal that was just argued to the Ninth Circuit.

The Supreme Court has already unanimously rejected federal common law climate claims. And it has already signaled its skepticism about this particular case. In fact, some have suggested that it would be best for the plaintiffs to lose in the Ninth Circuit, because if the case goes to the current Supreme Court, it might well overturn its 2007 decision in Massachusetts v. EPA, which would be an even greater setback for climate regulation.

For an extremely helpful breakdown of the Juliana v. United States case and appellate arguments, as well as the likely results and implications, check out this Regulatory Transparency Project podcast.

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James Coleman is an Associate Professor of Law at the SMU Dedman School of Law. He can be found on Twitter, @EnergyLawProf, and this post is cross-posted at