The Supreme Court hears Suncor Energy Inc. v. County Commissioners of Boulder County on Monday, October 5, the first argument of its new term and the case most likely to decide whether state and local governments can sue fossil fuel companies over the cost of a warming climate. It will hear it with eight justices. On Monday the Court's clerk, Scott Harris, sent the lawyers a letter informing them that Justice Samuel Alito will not take part. The letter ran to one sentence and offered no reason for the decision.

That is one sentence more than the rules require, and it lands seven days before argument in a case already briefed at every stage since 2018 and joined by the Trump administration on the companies' side. It is also, on its face, a change of position: Alito had declined to withdraw when the same request was made of him directly.

The letter the clerk sent, and the sentence it left out

Letters like this are ordinary business at the Court. Justices step away for reasons that run from a previous role in the litigation to a scheduling conflict to a stock holding, and the Court's long practice is that no explanation is owed. Harris wrote that Alito has determined that he will not continue to participate. Nothing in the letter says what changed between May and September.

The timing carries the weight the silence leaves behind. In May, a coalition of left-leaning watchdog groups wrote to the Senate Judiciary Committee asking it to examine Alito's participation in the dispute, contending that his holdings in individual oil and gas companies would undermine public confidence in the Court's impartiality. They noted that he had withdrawn at an earlier stage of the same litigation. A Court spokeswoman told NBC News at the time that Alito does not have a financial interest in any party to the case and that the Court's legal counsel had advised him that recusal was not required. He had also stepped aside in 2023, when the litigation first reached the Court on the question of whether it belonged in state or federal court.

So the record before Monday was a justice who had removed himself once, been pressed to do so again, declined on the ground that his portfolio did not touch the named defendants, and then removed himself anyway without saying why. Read one way that is a justice responding to a changed assessment; read the other, a justice conceding a point he had spent four months denying. The letter supports neither reading.

Eight justices can now divide evenly

The arithmetic is the immediate consequence. The Court's six conservative justices become five, and an even bench can split four to four. A tie affirms the judgment below without an opinion, a holding, or a precedent. Boulder's lawsuit would survive, the Colorado Supreme Court's reasoning would stand unexamined, and the same questions raised by more than two dozen similar suits would remain open.

That outcome is neither a loss for the companies nor a win. It is a case that consumes a term and decides nothing. The Court has moved in the companies' direction before: in April it unanimously sided with oil and gas companies in a suit over damage to the Louisiana coast, which both sides read as a sign that the Court is receptive to arguments about the federal system's limits on local climate claims.

There is a second question on the docket, and the recusal touches it too. The Court asked the parties to address whether it has jurisdiction at all, given that the Colorado ruling came before final judgment and reaches the Court in an interlocutory posture. A jurisdictional defect would end the matter without any ruling on preemption. Eight justices can still assemble the five votes needed to do anything at the Court, but they cannot resolve a four-to-four division over whether they should be there.

The standard the Court wrote for itself is a reasonable-person question

The operative text is the Code of Conduct for Justices, which the Court published in November 2023 after a stretch of reporting on undisclosed travel and gifts. It directs a justice to step aside from any proceeding in which his impartiality might reasonably be questioned, and defines that phrase from the standpoint of an informed member of the public: whether an unbiased and reasonable person who knows all the relevant circumstances would doubt that the justice could fairly do the job. The code names a financial interest in the subject matter or in a party as a ground for withdrawal.

Congress wrote a parallel rule in 28 U.S.C. 455, which reaches any justice, judge or magistrate judge. Its first subsection uses the same reasonable-question language. Its second lists specific circumstances, and the fourth of those covers a financial interest in the subject matter or in a party. The statute and the code point the same direction, and both ask about appearance rather than about bias. Neither asks how the justice would vote, and neither turns on whether he could set an investment aside and decide the case fairly. They ask what the public is entitled to assume.

The disagreement is about which holdings count

Alito's most recent financial disclosure, released in August, does not list ExxonMobil or Suncor Energy. It does list other fossil fuel interests, among them ConocoPhillips and Phillips 66. Everything that follows is a disagreement about what that fact means.

The Court's position in May was that the absence of the two named defendants from the portfolio settled the question. The watchdog groups' position is that the question is not confined to parties named in the caption, because this case is not an isolated dispute but a test case. Alexandra Nagy of the California nonprofit Consumer Watchdog told Agence France-Presse that nine city and municipal climate accountability suits from California are stayed pending the outcome of this one, and that all of them name ConocoPhillips or Phillips 66 or both. On that reading, a justice who owns stock in companies whose exposure turns on the rule the Court is about to announce has an interest in the subject matter even though he owns nothing in the two defendants in front of him. You should not be left wondering whether the justices in these cases are doing self-dealing, Nagy said. The advocacy group Court Accountability has estimated that Alito's oil and gas extraction interests returned between $390,000 and $2.9 million from 2005 to 2024, a range wide enough to be of limited use as a measure of anything. It is offered as an advocacy group's analysis rather than as a finding.

The other side of that argument deserves stating in its own terms. Recusal in the first instance is the justice's own call, reviewed by no one, and the practice around it has never treated a diversified portfolio as a general disability. If owning shares in companies that a ruling might affect disqualified a justice from hearing the case, a justice with broad index exposure would be disqualified from much of the Court's docket. What matters on that view is a stake in a party, and neither ExxonMobil nor Suncor Energy is one.

The Court knows how to explain a recusal. It did so in January.

In January, less than a week before argument in Chevron USA Inc. v. Plaquemines Parish, Louisiana, Harris sent the parties a letter that explained a recusal by the same justice in detail. He pointed to Alito's financial interest in ConocoPhillips, the parent corporation of Burlington Resources Oil and Gas, and then walked through the sequence: Alito had first decided not to withdraw because Burlington had been dismissed as a petitioner under Rule 46.1 in June 2025 after advising the Court that it was withdrawing and that neither Burlington nor ConocoPhillips would remain a party; later briefing showed that Burlington was still a party in the district court.

That paragraph is what makes Monday's single sentence conspicuous. Nothing in the code of conduct requires a justice to put a reason in writing, and the practice of explaining is strongest where the recusal follows from a justice's earlier judicial service. Silence is permitted. But January shows the Court is willing to say when the reason is a financial interest in a corporate parent, and it shows how specific the account can be when the Court chooses to give one. The public record after Monday is thinner than the record after January, and the difference is not a change in the rules.

What is at stake on October fifth

The merits question is whether federal law leaves room for state-law tort claims seeking damages for harms attributed to greenhouse gas emissions. The companies argue that the Clean Air Act and the federal scheme built around it occupy the field, so that no state law can apply even to injury suffered inside Colorado. Boulder argues the suit does not regulate emissions at all and seeks compensation for local costs the city attributes to extreme heat, wildfires, drought and poor air quality. Its position is that the question is who pays, the companies or Boulder's taxpayers.

The Trump administration filed an unusual unsolicited brief urging the Court to take the case and supporting the companies, and the Solicitor General sought permission to argue as an amicus. Former Attorney General Bill Barr has separately pressed the Court to halt what he describes as state climate litigation run as a pressure campaign. Boulder's argument will be delivered by Kevin Russell of Russell & Woofter; Kannon Shanmugam of Davis Polk will argue for Suncor.

The recusal will not appear in whatever the Court produces. If the argument divides the bench evenly the output is a one-line affirmance, and the most consequential act of the week will have been a sentence in a letter that declined to explain itself. Whatever a reader concludes about the merits, both sides have a reason to want the Court to say which holdings count, because a rule that lives only in an unexplained letter is a rule no one, including the justices who must apply it, can plan around. Monday's letter did not supply one.

Primary sources

  1. Supreme Court of the United States, Suncor Energy Inc. v. County Commissioners of Boulder County, No. 25-170, docket and briefing, argued Oct. 5, 2026.
  2. Supreme Court of the United States, Code of Conduct for Justices, Nov. 13, 2023, for the recusal standard and the financial-interest ground.
  3. 28 U.S.C. 455, Disqualification of justice, judge, or magistrate judge, for the statutory standard applied to the Court.
  4. Kelsey Dallas, Justice Alito will no longer participate in climate change dispute, SCOTUSblog, Sept. 28, 2026, for the clerk's letter, the watchdog groups' May request, the Court spokeswoman's statement, and the January letter in Chevron USA Inc. v. Plaquemines Parish, Louisiana.
  5. John Kruzel, US Supreme Court's Alito won't participate in climate case involving oil companies, Reuters, distributed via Kelo, Sept. 28, 2026, for the financial disclosure detail and the October 5 argument date.
  6. Agence France-Presse, Justice Alito steps aside from major US climate case, distributed via RTL Today, Sept. 28, 2026, for the Consumer Watchdog account and the Court Accountability estimate.
  7. City of Boulder, Supreme Court to hear Boulder climate case Monday, Sept. 28, 2026, for the respondents' framing and counsel.