Buschbacher: Did Prof. Adler File His Amicus Brief for the Wrong Side in Suncor?

On Monday the Supreme Court will hear oral argument in Suncor Energy v. Boulder County. My amicus brief in Suncor has received a decent amount of attention–but not all of it favorable. Perhaps because I have been critical of much climate regulation and litigation, some were surprised that I believe Boulder County has the better of the preemption arguments here.

Michael Buschbacher, Managing Partner of Boyden Gray PLLC, is among those who think I have erred. Indeed, he thinks that my work actually supports the other side.

Following is a guest-post from Buschbacher making his case. I am unconvinced, and will reply in a follow-up post. For now, here is what Buschbacher has to say.

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Prof. Adler Filed His Suncor Amicus Brief in Support of the Wrong Party

Michael Buschbacher

The occasion for this guest post is Prof. Adler’s recent amicus brief submitted to the U.S. Supreme Court in Suncor v. Boulder County, set to be argued next month.[1] Suncor is probably the most important constitutional structure case of this decade and may also be the most economically significant in Supreme Court history. By some estimates, the litigation campaign of which Suncor is part asserts some $28 trillion in total putative damages against a select group of energy companies—nearly an entire year of American GDP.

The central question in Suncor is whether states and municipalities can apply their own law to regulate the greenhouse-gas emissions of fuel producers and users, not just for emissions within their own borders, but also for emissions anywhere in the world. If that sounds a bit out there, that’s because it is. So far, even some of the hand-picked state courts that have heard these claims have been slow to bite. For example, the Maryland Supreme Court earlier this year rejected similar arguments by the City of Baltimore, concluding that its claims about climate change were all preempted by federal law. Even the pro-climate litigation dissents in that case agreed that Maryland state law could not reach worldwide emissions directly. Several other state courts have reached similar conclusions.

Prof. Adler’s brief falls to the “left” of these decisions. But while his brief is offered in support of Boulder County, it also stops well short of the plaintiffs’ position that one state or municipality can apply its own law to the rest of the world. Although Prof. Adler opens with broad strokes—”Nothing in federal law, let alone the Constitution, preempts state-law claims seeking relief from injuries allegedly caused or exacerbated by petitioners’ conduct,” Adler Br. at 2—he later adds a very important caveat: perhaps only the law of the source state (that is, the jurisdiction where the emissions took place) can apply, and everything else is precluded. See id. at 21, 25. “No home cooking,” as he’s put it elsewhere.

There are several points in the brief where I think Prof. Adler errs or leaves key information out, but it’s the no-home-cooking caveat that I want to focus on. In my view, the reading of the Clean Air Act he advocates should require him to take the petitioners’ side or, at least, to file on behalf of neither party. Colorado’s case is all home cooking. As I’ll explain below, Prof. Adler comes out on the plaintiffs’ side here only by misdescribing (or misapprehending) the case that Boulder County has actually pled.

But first, some background.

The Law Governing Interstate Pollution. As Prof. Adler points out, state power over in-state pollution was historically very broad and remains broad today. But air and water aren’t respecters of state borders. What happens in Vegas (or anywhere else) doesn’t necessarily stay there. So, although in-state pollution can be governed by state law, interstate pollution—that is, pollution that originates in one jurisdiction and ends up having an alleged effect in another—was exclusively controlled by federal law from time immemorial. As my colleague Jared Kelson and I explain in our amicus brief for 74 members of the House, application of this principle to interstate air pollution goes back at least to Georgia v. Tennessee Copper Co., 206 U.S. 230 (1907).

Originally, the federal law in question was federal common law—or “general law,” as it was often called, in contrast with specific local law. Erie Railroad Company v. Tompkins did not abrogate this body of law since rules dealing “with air and water in their ambient or interstate aspects,” Illinois v. City of Milwaukee, 406 U.S. 91, 103 (1972), are “matters essentially of federal character,” United States v. Standard Oil Co. of Cal., 332 U.S. 301, 307 (1947).

However, the governing federal law changed in the 1970s, when Congress enacted the core environmental regulatory statutes we still have today: the Clean Air Act, the Clean Water Act, etc. These statutes not only displaced federal common law, they also significantly federalized pollution policy, albeit in a novel way. Rather than set uniform national command-and-control regulations as the default rule, the Clean Air Act and Clean Water Act mostly imposed a regime somewhat misleadingly described as “cooperative federalism.” Basically, Congress makes an offer the states can’t refuse, using funding strings and sanctions to pressure them to regulate stringently enough to meet federal pollution-control targets set by EPA.

Prof. Adler spins all this as Congress “preserving” a large amount of state discretion. That’s a rosy version of the history as to traditional areas of state territorial sovereignty—the Clean Air Act in particular drove much American industry overseas contrary to state wishes—but in many areas Congress did at least leave states room to choose how to reduce in-state pollution. As Prof. Adler acknowledges, there are some exceptions where Congress took away even traditional in-state regulatory authority when doing so was necessary to avoid a patchwork of inconsistent state regulations over, e.g., motor vehicle emissions. But he’s right that, generally, Congress did not disturb the pre-existing balance of federal and state power over emissions regulation.

The problem for Boulder County is that under that pre-existing balance, states had no authority to apply their own law to out-of-state air emissions, which had always been governed by federal common law. That cuts strongly against Boulder County, since nothing in the Clean Air Act purports to give states any new power to impose their own specific state law on emissions that originate outside their borders, much less authorizes them to do so with the “exceedingly clear language” required if Congress “wishes to significantly alter the balance between federal and state power.” Sackett v. EPA, 598 U.S. 651, 679 (2023) (cleaned up). Indeed, the various Clean Air Act provisions that expressly address interstate and international air emissions concerns all presuppose the continued existence of traditional territorial limits on governmental authority. See 42 U.S.C. §§ 7402, 7410(a)(2)(D), 7415, 7426, 7506a. Prof. Adler says nothing about these provisions.

Where “Climate Nuisance” Fits In. This brings me to the first point of disagreement with Prof. Adler. He suggests that climate “nuisance and trespass” claims would have been matters of state law prior to the Clean Air Act, and that they are thus part of the broad array of state powers “preserved” by that statute. I’m skeptical. Boulder County’s suit is almost entirely about conduct far outside of Colorado. The Suncor complaint doesn’t target specific emissions from individual facilities that have caused it some particularized harm; instead, it seeks to hold companies liable for purported undifferentiated and future harms that originate on a global scale from emissions everywhere.

Pace Prof. Adler, that looks nothing like a claim against a neighboring “city whose sewer discharged across the state line.” Adler Br. at 6 (describing Carmichael v. City of Texarkana, 94 F. 561 (C.C.W.D. Ark. 1899)). Indeed, Carmichael highlights how different Boulder County’s theories are from historic nuisance claims. Mr. Carmichael lived in Bowie County, Texas, and sued Texarkana, Arkansas, in Arkansas federal court for sewage discharge that harmed his property. Mr. Carmichael’s claim was that Texarkana built a sewer system with “one main sewer leading to a point immediately opposite plaintiff’s homestead, about eight feet from the state line, on the Arkansas side” that flowed into a stream on his homestead. Carmichael, 94 F. at 562. The court ordered Texarkana to abate the nuisance, noting that this outcome followed “an almost unbroken line of authorities” from courts across America, as well as English practice—i.e., the general or federal common law, rather than any distinct local law of Mr. Carmichael’s home state of Texas. Id. at 572.

But Boulder County didn’t pursue this type of claim—a federal common law claim in federal court. There’s no mystery why. Climate litigants initially did allege federal common law claims in federal court. The Supreme Court (in an opinion by Justice Ginsburg) in American Electric Power Co. v. Connecticut, 564 U.S. 410, 429 (2011), unanimously shut that down, holding that climate nuisance claims must be dismissed because the Clean Air Act displaces federal common law for interstate air emissions.

Displacement and Preemption. This brings me to my second, and primary, disagreement with Prof. Adler. He argues that the Clean Air Act’s displacement of federal common law opens the door for state law to apply. “Federal common law may once have preempted state attempts to control interstate air pollution under state law, but federal common law has been displaced, and no longer serves that function.” Adler Br. at 3. The Clean Air Act’s displacement of federal common law thus silently unpreempts at least some state common law. His key case here is International Paper Co. v. Ouellette, 479 U.S. 481 (1987). Ouellette was brought by Vermont landowners against a New York paper mill under Vermont law for pollution discharges into Lake Champlain. The Court rejected the plaintiffs’ argument, holding that Vermont law could not apply to pollution that took place outside of that state’s borders. As discussed above, interstate nuisance had originally been covered exclusively by federal common law. Ouellette holds that, although the Clean Water Act displaced that body of common law, Congress did not thereby tacitly authorize states to apply their own distinct local law to pollution discharged from other states. But Ouellette added that the Act’s savings clause “specifically preserve[d]” the ability of courts to apply the law of the source state to those discharges. Id. at 497. The Court therefore remanded the case for proceedings under the proper state law, as authorized by the Clean Water Act.

Prof. Adler asserts that Ouellette supports the conclusion that the Clean Air Act at least permits climate change claims under the law of the source state, Adler Br. at 19–22, which he calls a “fundamental weakness of the substantive argument” made by defendants. See also Jonathan H. Adler, Displacement and Preemption of Climate Nuisance Claims, 17 J.L. Econ. & Pol’y 217, 255 (2022) (“Accordingly, state law claims may proceed, so long as they rely upon the law of the source state[.]”). Prof. Adler is right that defendants argue that climate torts simply don’t fit even under Ouellette, but he skips over their larger alternative point that Ouellette‘s holding applies with equal force to the Clean Air Act: so, at most, it’s law of the source state or bust, “no home cooking.” See Pet. Br. at 33–34.

I think the petitioners are right in arguing that climate torts are not the kind of source-state action that Ouellette preserved. Suncor isn’t about a discharge of sewage across state lines, but about global carbon emissions all mixed in the troposphere. Regulating that with a combination of state tort laws would displace federal preeminence and risks the “chaotic confrontation between sovereign states” that Ouellette sought to avoid. 479 U.S. at 496–497.

But put this all aside for the moment. Could Boulder County have pled a case under the law of 50 states and 194 other countries seeking relief on a pro rata basis? Based on Prof. Adler’s no-home-cooking rule, perhaps so.

Did it? No.

This is where Prof. Adler goes astray. To be sure, Boulder County’s opposition brief attempts to suggest that the choice of law has not yet occurred, as if—eight years in—nobody had yet figured out what law the County was invoking. But that eleventh-hour pivot is not credible. For example, page 1 of Boulder County’s brief to the Colorado Supreme Court says that “Plaintiffs seek damages under Colorado tort law,” adding later that “[l]iability in this case is based on Colorado’s law of trespass, private and public nuisance, unjust enrichment, and civil conspiracy.” And the County said the same thing to the trial court too: “Plaintiffs filed this case under Colorado’s common law…and its Consumer Protection Act….” In other words, Boulder County made its choice.

The question before the Supreme Court is thus whether the state law under which Boulder County has pled its claims can apply to emissions elsewhere: Ouellette says that it cannot. That choice of law is preempted. There is no reason for the Court to wait to say so. On Prof. Adler’s reasoning, then, the Court—at the very least—should reverse and remand the same way it did in Ouellette.

Perhaps Prof. Adler agrees. But if so, why did he file his brief in support of the plaintiffs rather than defendants, or in support of neither party?

[1] Full disclosure: my colleague Jared Kelson and I submitted an amicus brief on behalf of 74 members of Congress in support of Defendants in Suncor. Another colleague, Jen Hardy, submitted a (very interesting) brief on behalf of Prof. Prakash in support of Defendants as well. Prof. Eugene Volokh also co-authored an excellent brief about the free speech implications of the case.

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Here are Professor Adler’s prior posts on Suncor and related climate litigation:

• Why State Common Law Nuisance Claims Against Fossil Fuel Companies Are Not Preempted, Oct. 27, 2021;
• Third Circuit Rejects Oil Company Efforts to Remove Climate Claims to Federal Court, Aug. 17, 2022;
• Oil Companies Fail to Convince the Eighth Circuit Climate Cases Should Be Removed to Federal Court (Updated), Mar. 25, 2023;
• Is Climate Change Going Back to the Supreme Court? (Minnesota Edition) [UPDATED], Dec. 11, 2023;
• D.C. Circuit Rejects Oil Company Attempt to Remove District’s Climate Suit to Federal Court, Dec. 19, 2023;
• William Barr Responds on American Petroleum Institute v. Minnesota, Dec. 26, 2023;
• Supreme Court Takes a Pass on Minnesota Climate Change Case, Jan. 8, 2024;
• Are State Law Climate Change Tort Suits Preempted by Federal Law?, May 3, 2024;
• Supreme Court Denies Certiorari in Climate Tort Suits, Jan. 13, 2025;
• Supreme Court Rejects Red State Attempt to Sue Blue States Over Climate Suits, Mar. 10, 2025;
• William Barr Discovers the Economics of Tort Law (and Misrepresents the Law Governing Interstate Pollution), Nov. 3, 2025;
• Placing Climate Tort Litigation in Context (Updated), Nov. 7, 2025;
• A Second Round with William Barr on Litigation Over Interstate Pollution, Dec. 2, 2025;
• Court Dismisses Trump Administration Effort to Block Michigan Climate Lawsuit, Feb. 4, 2026
• Climate Change Goes Back to the Supreme Court — Colorado Edition, Feb. 23, 2026.
• Previewing Suncor Energy v. Boulder County, Mar. 6, 2026.
• Amicus Brief in Suncor Energy v. County Commissioners of Boulder County, Aug. 3, 2026.
• Supreme Court Term to Start Hot, Aug. 6, 2026
• As Suncor Approaches, Justice Alito Recuses, Sept. 28, 2026.
• Justice Alito Says Recusal in Suncor Energy v. Boulder County a “Difficult Judgment Call”, Sept. 30, 2026