U.S. Supreme Court agrees with U.S. Solicitor General not to intervene in climate change lawsuits: what now?

The U.S. Supreme Court chose not to review the Hawai'i Supreme Court's decision in Honolulu, following its receipt of U.S. Solicitor General Prelogar's opinion. The Bermuda Form team explore the Solicitor General's opinion and its implications for future climate change lawsuits in the US.

Introduction

In light of the climate change litigation suits being pursued across the United States, the United States Supreme Court (“SCOTUS”) requested the U.S. Solicitor General’s opinion on whether SCOTUS should review an interlocutory decision by the Hawai’i Supreme Court (“HSC”) in Sunoco LP v. City and County of Honolulu (“Honolulu”). In December 2024, Elizabeth Prelogar duly issued her opinion on Honolulu, urging SCOTUS not to intervene in Honolulu’s proceedings in state court. Following the Solicitor General’s opinion, SCOTUS decided not to review the HSC’s decision, rather allowing the matter to progress to trial in state court.

To recap, the City and County of Honolulu filed a claim against several energy companies, (including Sunoco, ExxonMobil, and Phillips 66) in 2020. Briefly, the claim alleged that the energy producer defendants (“the Defendants”) have known for decades that greenhouse gases (“GHG”) contribute to climate change and engaged in deceptive marketing practices which concealed the harms of using fossil fuel products. Defendants sought to move the case to federal court, arguing that the claims are pre-empted by federal common law or federal statue by way of the Clean Air Act (“CAA”).

The HSC had denied the Defendants’ motion to dismiss, leading them to petition SCOTUS for writ of certiorari for an answer to the question: “Whether federal law precludes state-law claims seeking redress for injuries allegedly caused by the effects of interstate and international greenhouse-gas emissions on the global climate?” The Defendants stood by their argument that Honolulu, as the plaintiff, in reality alleges torts regarding transboundary pollution (which are governed by CAA) rather than deceptive marketing practices.

On 10 June 2024, SCOTUS invited the Solicitor General to provide her opinion. In her December 2024 opinion, the Solicitor General maintained that state courts remain the most appropriate venue for plaintiffs to battle out climate change torts against fossil fuel companies. The opinion also notes that the HSC has in fact made decisions only on the Defendants’ motions to dismiss, and not on the merits of the case itself, which would require a full trial.

This article considers the Solicitor General’s justifications for urging SCOTUS to stay out of climate change suits at this stage, and its possible implications for the future of climate change litigation in view of the recent change of administration.

Previously in Suncor Energy v Boulder County [1]

In March 2023, the Solicitor General had previously issued an opinion on whether SCOTUS should hear climate change suits in the case of Suncor Energy v Boulder County (“Boulder”). The Boulder opinion dealt with a slightly different question from Honolulu, addressing “whether this suit may be removed to federal court on the ground that respondents’ state-law claims should be recharacterized as claims arising under federal common law”. Nonetheless, both questions focus on the inter-state/federal nature of the claims/allegations.

The Solicitor General’s Boulder opinion was devastating to the energy major defendants’ arguments that these cases should be heard in federal court, opining that plaintiffs’ claims did not present a federal question under the well-pleaded complaint rule, and there was no Circuit Court conflict that required SCOTUS’ involvement to resolve. Thus, it seems Boulder may have sealed Defendants’ fate, as Solicitor General Prelogar has now provided further justification for SCOTUS to stay out of climate change suits and allow the disputes to be battled out in state courts.

Why SCOTUS is not the correct forum for climate change suits – Honolulu 

     1.  The case is not at final adjudication

The Solicitor General argued that SCOTUS lacks jurisdiction to review the HSC’s interlocutory decision regarding Defendants’ motions to dismiss in Honolulu.

Citing statute, [2] the Solicitor General emphasised that the HSC’s interlocutory decision would not qualify as a final judgment for review by SCOTUS, as the HSC contemplates further proceedings. Reviewing these issues now would risk piecemeal consideration of issues, as the Defendants were unable to prove that plaintiffs would be precluded from pursuing claims involving in-state deceptive practices or in-state pollution. Further, “delaying review” at this time until final judgment, would not “seriously erode” an “identifiable federal policy”.

Furthermore, while Honolulu alleged the breach of various state common-law duties by the Defendants, the Defendants have consistently argued that plaintiffs’ claims are superseded by federal statute and federal common law on transboundary air pollution. The Solicitor General highlighted that the HSC and lower courts have not fully explored the Defendants’ constitutional arguments around the Interstate and Foreign Commerce Clauses, the Due Process Clause, and federal primacy in foreign affairs at trial. Consequently, review now of these pending constitutional issues would lead to fragmented consideration of important federal questions, as the HSC could still decide that the Constitution bars state law claims to the extent the alleged acts occur outside of Hawai’i at trial (as, indeed, the Defendants argue).

At that point, such a final decision by the lower courts would warrant a review of constitutional issues raised by the Defendants. So, in short, as there has been no final adjudication, nor exploration of the merits of plaintiffs’ claims in relation to the Defendants’ constitutional arguments, the Solicitor General did not recommend Honolulu’s review by SCOTUS.

     2.  SCOTUS review is not warranted

The Solicitor General affirmed the displacement of the federal common law of transboundary air pollution by the CAA, as raised by the Defendants in Honolulu, in respect of GHG emissions. However, the Solicitor General rejected the argument that federal common law could govern plaintiffs’ claims in spite of this displacement, stating that the lower courts need to consider whether a state-law suit would be available to plaintiffs in light of the pre-emptive effect of the CAA as – seemingly invoking Alice In Wonderland – the “displacement of the federal common law ‘did not leave behind a pre-emptive grin’ without a common-law ‘cat’”.

Additionally, even if federal common law had not been displaced, the Solicitor General noted that federal common law on transboundary pollution would not govern plaintiffs' claims because they allege a violation of a duty to disclose and to not deceive about the dangers of using fossil-fuel products, rather than a duty not to pollute. This distinction is crucial, as the Solicitor General emphasised that for federal common law to govern plaintiffs' claims, SCOTUS would need to create a new body of common law governing "tortious marketing". Defendants did (or could) not cite any case recognising such a body of law, and thus there is no argument to expand federal common law to cover plaintiffs' claims due to the CAA.

It is worth noting that the Solicitor General referred in her opinion to the “tortious marketing” argument adopted in another climate change case, Connecticut v Exxon Mobil Corp. She quoted the Second Circuit Court’s decision that the claims regarding defendants’ deceptive marketing can be resolved “without reaching the federal issues” and so do not necessarily raise a federal question. [3] It remains to be seen if climate change defendants may consider taking up a federal common law argument vis-à-vis “tortious marketing” in the future.

     3.  No appellate court would have reached a different outcome

Finally, given that the claims in question involve duties not to deceive rather than duties not to pollute, and no appellate court other than the HSC has addressed similar claims, the Solicitor General asserted that the Defendants have not demonstrated that any appellate court would have reached a different outcome. This lack of conflicting decisions among appellate courts means that SCOTUS would benefit from further percolation of these issues in the lower courts before taking them up for review.

Conclusion

In following Solicitor General Prelogar’s opinion, it appears that SCOTUS was of the view that its review of the HSC’s decision in Honolulu at this stage would result in piecemeal precedents being set on specific constitutional questions. In declining to review the HSC’s decision, SCOTUS seems to have allowed plaintiffs to avoid needing to craft arguments to work around federal pre-emption by the CAA – but this seems likely to be only a temporary reprieve. It must be borne in mind that (1) it was the same Solicitor General who provided the opinion in both Boulder and Honolulu, and a different Solicitor General may recommend SCOTUS’ intervention upon a future writ of certiorari; and (2) as Honolulu progresses to trial, plaintiffs still face the hurdle of proving the merit of their claims.

It may be that we are entering the next phase of climate change litigation, as more plaintiffs’ cases withstand the onslaught of motions to dismiss by the energy defendants, and state courts turn to considering the merits of plaintiffs’ arguments which, it seems increasingly to be settled, are based on a violation of a duty of disclosure, rather than a duty to pollute. It will be worth monitoring how defendants in future applications will circumvent the Solicitor General’s opinion, and how state and federal common law – especially the evolution of “tortious marketing” arguments – develop in the wake of this litigation.

[1] Suncor Energy (U.S.A.) Inc. v. Board of County Comm’rs of Boulder County, 143 S. Ct. 1795 (2023) (No. 21-1550
[2] 28 U.S.C. 1257(a)
[3] Connecticut v. Exxon Mobil Corp., 83 F.4th 122, 142 (2d Cir. 2023)