Plaintiffs-Appellees Kelsey Cascadia Rose Juliana, et al., (collectively, “Juliana”) ask this Court to order the federal government to comprehensively regulate greenhouse gas emissions nationwide based upon a purported federal common law public trust doctrine that in fact does not exist. Although some federal courts have applied ancient, state-based public trust common law principles to resolve property rights conflicts regarding lands submerged beneath tidal and navigable waterways, see, e.g., Phillips Petroleum v. Mississippi, 484 U.S. 469, 473-74 (1988), no court has ever invoked any such state doctrine to compel regulatory action by the federal government. Moreover, no court has ever recognized a federal common law public trust doctrine in natural resources, let alone air resources. In fact, the sweeping new regulatory agenda for greenhouse gas emissions sought by Juliana is unprecedented in federal jurisprudence. 

A number of well-settled legal principles should have led the trial court to dismiss this extraordinary lawsuit as a matter of law. As the Supreme Court held in PPL Montana, LLC v. Montana, the public trust doctrine does not arise under federal law but instead “remains a matter of state law,” 132 S.Ct. 1215, 1235 (2012), and therefore provides no cause of action against the federal government and presents no “federal question” within the jurisdiction of the federal judiciary under 28 U.S.C. § 1331. PPL Montana flatly precludes recognition or adoption of a federal common law public trust doctrine. Moreover, even had the Supreme Court not addressed this issue in PPL Montana, establishing a new federal common law along the lines suggested by Juliana would violate constitutional precepts established by the Supreme Court limiting federal court jurisdiction. See, e.g., Ziglar v. Abbasi, 137 S.Ct. 1843, 1855 (2017) (creation of implied causes of action for constitutional violations “now a disfavored judicial activity”). Finally, the Clean Air Act displaced any conceivable federal public trust doctrine in greenhouse gases, thereby precluding a non-statutory cause of action along the lines suggested by Juliana. See AEP v. Connecticut, 131 S.Ct. 2527, 2537-38 (2011).