In Chernaik v. Brown, the Oregon Supreme Court rejected claims by young climate activists that the public trust doctrine compelled government action to combat climate change. The lawsuit was part of a broader local and national effort led by Our Children's Trust, a non-profit public interest law firm that has brought legal action in all 50 states over the last 10 years in an attempt to compel more aggressive action against climate change.

Similar litigation was brought by many of the same plaintiffs in federal court but asserting constitutional claims. In Juliana v. U. S., the 9th Circuit Court of Appeals brought that case to a near-certain end as well.

The Public Trust Doctrine (PTD) is a mostly judge-made concept under which a government, as sovereign, has a duty to preserve certain natural and cultural resources for the benefit of the public. Throughout the United States, courts have generally limited application of the PTD to navigable streams and their tributaries or beaches and shores. To that end, climate activists have sought to expand the PTD to the atmosphere.

The Oregon lawsuit was filed in 2011 against then-Governor John Kitzhaber and sought declaratory relief that the PTD covers water resources, navigable waters, submerged and submersible lands, islands, shorelands, coastal areas, wildlife and fish, and the atmosphere. Plaintiffs also argued that Oregon had failed to uphold its fiduciary obligations under the PTD by failing to regulate and reduce carbon dioxide emissions.

After a complicated procedural history, the case eventually made it to the Oregon Supreme Court on two primary issues: the scope of the PTD, and the obligations that it imposes on the State. On the first issue, the Court held that the PTD covers all submerged and submersible lands as well as navigable waters but declined to extend it further to cover all waters of the state, to wildlife, or to the atmosphere.

While the Court recognized that the common law doctrine was not fixed and "can be modified to reflect changes in society's needs," it was not the time to do so. Specifically, the Court rejected plaintiffs' two-pronged test to justify the expansion of the PTD to resources that were (1) "not easily held or improved" and (2) "of great value to the public for uses such as commerce, navigation, hunting, and fisheries." The Court reasoned that it was difficult to conceive of a resource that would not satisfy the test but declined to adopt a test of its own.

The Court dealt another blow to plaintiffs by rejecting the argument that the PTD imposed on the state obligations similar to the ones of trustee of a private trust to beneficiaries. Instead, the majority left it at the "recognized duty that the state has to protect public resources for the benefit of the public's use of navigable waterways for navigation, recreation, commerce, and fisheries."

Plaintiffs will find no more comfort in Chief Justice Walters' dissent that "the time is now" for the court to act than they did from the words of support for that position in the 9th Circuit's Juliana opinion. Nevertheless, similar legal actions remain ongoing in many states, and the U.S. Supreme Court is set to hear arguments in another case brought by the city of Baltimore seeking damages against energy companies for harms sustained due to those companies' impact on climate change.

Expect climate activists to continue testing various legal theories in court to compel government action.