Amicus Curiae Brief — Suncor Energy (U.S.A.) Inc., et al., Petitioners v. County Commissioners of Boulder County, et al.

No. 25-170

IN THE

Supreme Court of the United States

SUNCOR ENERGY (U.S.A.) INC., ET AL.,

Petitioners,

v.

COUNTY COMMISSIONERS OF BOULDER COUNTY, ET AL.,

Respondents.

On Writ of Certiorari

to the Supreme Court of Colorado

BRIEF FOR THE CHAMBER OF COMMERCE

OF THE UNITED STATES OF AMERICA

AS AMICUS CURIAE

SUPPORTING PETITIONERS

ANDREW R. VARCOE

STEPHANIE A. MALONEY

U.S. CHAMBER

LITIGATION CENTER

1615 H Street, NW

Washington, DC 20062

JESSE LEMPEL

GOODWIN PROCTER LLP

100 Northern Avenue

Boston, MA 02210

May 21, 2026

WILLIAM M. JAY

Counsel of Record

GOODWIN PROCTER LLP

1900 N Street, NW

Washington, DC 20036

wjay@goodwinlaw.com

(202) 346-4000

TABLE OF CONTENTS

Page

INTEREST OF THE AMICUS CURIAE.................... 1

SUMMARY OF ARGUMENT ..................................... 3

ARGUMENT ............................................................... 5

I.

A 50-state patchwork of greenhousegas-emissions regulation is unworkable

and encourages states to impose costs

on out-of-state consumers and

businesses. ........................................................ 5

II.

Under our federal structure and the

Clean Air Act, state law may not impose

liability for the climate effects of

emissions that originate all over the

world................................................................ 11

A.

Only federal law can govern

disputes like this one, which

implicates interstate and

international interests. ........................ 12

B.

Respondents’ packaging of their

claims makes no difference to the

conclusion that the claims are

preempted by federal law. ................... 20

C.

The displacement of federal

common law by federal statute

does not authorize state law to

regulate a uniquely federal area. ........ 22

D.

The Clean Air Act also preempts

respondents’ state-law claims. ............ 25

i

CONCLUSION .......................................................... 27

ii

TABLE OF AUTHORITIES

Page(s)

Cases:

Am. Elec. Power Co. v. Connecticut,

564 U.S. 410 (2011) .... 13, 14, 15, 16, 17, 22, 23, 25

Banco Nacional de Cuba v. Sabbatino,

376 U.S. 398 (1964) .............................................. 13

Bd. of Cnty. Comm’rs of Boulder Cnty. v.

Suncor Energy (U.S.A.) Inc.,

25 F.4th 1238 (10th Cir. 2022) ............................ 20

Bonaparte v. Tax Court,

104 U.S. 592 (1881) .............................................. 19

City & Cnty. of Honolulu v. Sunoco LP,

537 P.3d 1173 (Haw. 2023), cert.

denied, 145 S. Ct. 1111 (2025) ....................... 22, 23

City of Milwaukee v. Illinois

(Milwaukee II),

451 U.S. 304 (1981) .............................................. 23

City of New York v. Chevron Corp.,

993 F.3d 81 (2d Cir. 2021) ...... 16, 18, 20-22, 24, 26

Cnty. of Oneida v. Oneida Indian

Nation of N.Y.,

470 U.S. 226 (1985) .............................................. 13

iii

North Carolina ex rel. Cooper v. Tenn.

Valley Auth.,

615 F.3d 291 (4th Cir. 2010) ................................ 11

EPA v. EME Homer City Generation,

L.P.,

572 U.S. 489 (2014) ........................................ 25, 26

Fuld v. Palestine Liberation Org.,

606 U.S. 1 (2025) .................................................. 19

Gerling Glob. Reinsurance Corp. of Am.

v. Gallagher,

267 F.3d 1228 (11th Cir. 2001) ............................ 19

Hinderlider v. La Plata River & Cherry

Creek Ditch Co.,

304 U.S. 92 (1938) ................................................ 13

Home Ins. Co. v. Dick,

281 U.S. 397 (1930) .............................................. 19

Illinois v. City of Milwaukee

(Milwaukee I),

406 U.S. 91 (1972) .......... 5, 7, 13, 14, 15, 19, 22, 23

Illinois v. City of Milwaukee

(Milwaukee III),

731 F.2d 403 (7th Cir. 1984) .................... 22, 23, 24

Int’l Paper Co. v. Ouellette,

479 U.S. 481 (1987) .................. 4, 11, 14, 18, 25, 26

Kansas v. Colorado,

206 U.S. 46 (1907) ................................................ 13

iv

Kurns v. R.R. Friction Prods. Corp.,

565 U.S. 625 (2012) .............................................. 20

Mayor & City Council of Balt. v. B.P.

P.L.C.,

353 A.3d 1142 (Md. 2026) ............. 16, 18, 21-24, 26

Minnesota v. Am. Petroleum Inst.,

63 F.4th 703 (8th Cir. 2023) ................................ 20

Nat’l Pork Producers Council v. Ross,

598 U.S. 356 (2023) .............................................. 19

Ohio v. EPA,

603 U.S. 279 (2024) .............................................. 26

Oklahoma v. EPA,

605 U.S. 609 (2025) .............................................. 25

Provincial Gov’t of Marinduque v.

Placer Dome, Inc.,

582 F.3d 1083 (9th Cir. 2009) .............................. 13

Sam L. Majors Jewelers v. ABX, Inc.,

117 F.3d 922 (5th Cir. 1997) ................................ 13

San Diego Bldg. Trades Council v.

Garmon,

359 U.S. 236 (1959) .............................................. 20

Tex. Indus., Inc. v. Radcliff Materials,

Inc.,

451 U.S. 630 (1981) ...................... 12, 13, 15, 21, 23

Treiber & Straub, Inc. v. UPS, Inc.,

474 F.3d 379 (7th Cir. 2007) ................................ 13

v

Ungaro-Benages v. Dresdner Bank AG,

379 F.3d 1227 (11th Cir. 2004) ............................ 13

Statutes:

42 U.S.C. § 7410(a)(2)(D)(i) ....................................... 25

42 U.S.C. § 7411(b)(1)(A)-(B) .................................... 25

42 U.S.C. § 7411(d) .................................................... 25

42 U.S.C. § 7521(a)(1)-(2) .......................................... 25

42 U.S.C. § 7521(a)(3)(E) .......................................... 25

42 U.S.C. § 7547(a)(1) ............................................... 25

42 U.S.C. § 7571(a)(2)(A) .......................................... 25

42 U.S.C. § 7604(e) .................................................... 26

43 U.S.C. § 1802(1) .................................................... 17

Inflation Reduction Act of 2022,

Pub. L. No. 117-169, 136 Stat. 1818 .................... 17

Infrastructure Investment and Jobs Act,

Pub. L. No. 117-58, 135 Stat. 429

(2021) .................................................................... 17

Iowa Code § 673B.2 (2026) .......................................... 8

Okla. S.B. 1439 (2026 Reg. Sess.) ............................... 8

One Big Beautiful Bill Act,

Pub. L. No. 119-21, 139 Stat. 72

(2025) .................................................................... 18

vi

Tenn. H.B. 2070 (114th Gen. Assemb.) ...................... 8

Utah H.B. 222 (2026 Gen. Sess.) ................................ 8

10 Vt. Stat. Ann. § 597(1) ............................................ 9

Legislative Material:

La. H.B. 804 (2026 Reg. Sess.) .................................... 8

Regulatory Material:

Rescission of the Greenhouse Gas

Endangerment Finding and Motor

Vehicle Greenhouse Gas Emission

Standards Under the Clean Air Act,

91 Fed. Reg. 7686 (Feb. 18, 2026) ....................... 17

Other Authorities:

Mia Beams & Akkshath Subrahmanian,

Congress’s “One Big Beautiful Bill”

Will Shrink Renewable Energy

Investments-Yet Some Technologies

Are Preserved, Council on Foreign

Relations (Aug. 4, 2025),

https://www.cfr.org/article/congresssone-big-beautiful-bill-will-shrinkrenewable-energy-investments-yetsome ...................................................................... 18

E. Donald Elliott, Bruce A. Ackerman &

John C. Millian, Toward a Theory of

Statutory Evolution: The

Federalization of Environmental

Law, 1 J. L. Econ. & Org. 313 (1985) .................... 9

vii

Henry J. Friendly, In Praise of Erie-and

of the New Federal Common Law, 39

N.Y.U. L. Rev. 383 (1964) .................................... 13

Thomas W. Merrill, The New Public

Nuisance: Illegitimate and

Dysfunctional, 132 Yale L.J. Forum

985 (2023) ............................................................. 10

U.S. Chamber of Commerce, Our

Approach to Climate Change (Apr.

19, 2020),

https://www.uschamber.com/climatechange/our-approach-to-climatechange..................................................................... 1

U.S. Energy Info. Admin., New York,

https://www.eia.gov/states/NY/analy

sis (updated Feb. 19, 2026) .................................... 9

U.S. Energy Info. Admin., Vermont,

https://www.eia.gov/states/VT/analys

is (updated Jan. 15, 2026)...................................... 9

19 Wright & Miller, Fed. Prac. & Proc.,

Juris. § 4514 (3d ed. 2022) ................................... 14

viii

INTEREST OF THE AMICUS CURIAE1

The Chamber of Commerce of the United States of

America is the world’s largest business federation. It

represents approximately 300,000 direct members and

indirectly represents the interests of more than three

million companies and professional organizations of

every size, in every industry sector, and from every

region of the country. An important function of the

Chamber is to represent the interests of its members in

matters before Congress, the Executive Branch, and

the courts. To that end, the Chamber regularly files

amicus curiae briefs in cases, like this one, that raise

issues of concern to the nation’s business community.

The Chamber has a strong interest in the legal and

policy issues that underlie this case, including issues

relating to climate change. The global climate is

changing, and human activities contribute to those

changes. There is much common ground on which all

sides could come together to address climate change

with policies that are practical, flexible, predictable,

and durable, maintaining the national and

international competitiveness of U.S. industry and

ensuring consistency with free enterprise and free

trade principles. See U.S. Chamber of Commerce, Our

Approach to Climate Change (Apr. 19, 2020),

https://www.uschamber.com/climate-change/ourapproach-to-climate-change. Durable climate change

policy must be made by the federal government, which

should encourage innovation and investment to reduce

emissions and improve economic resilience and clean

1 No counsel for any party authored this brief in whole or in part,

and no entity or person, aside from amicus curiae, its members, or

its counsel, made any monetary contribution intended to fund the

preparation or submission of this brief.

1

2

energy deployment across the globe. Governmental

policies aimed at achieving these goals should not be

made by the courts, much less by a patchwork of

actions under state law that would do more harm than

good.

Climate change is an interstate and international

challenge, and putative state-law claims that would

impose liability for climate change must necessarily be

resolved by federal law. The cross-border nature of

climate change implicates “uniquely federal interests”

for which a uniform federal policy and the application

of federal law are essential.

In the limited range of circumstances in which

uniquely federal interests arise, the relevant legal

questions often intersect with the interests of many of

the Chamber’s members, as they rely on the

predictability and uniformity of federal policy. This

case falls within that limited range: the Chamber and

its members have a strong interest in ensuring that

claims for which a uniform federal standard is

necessary are governed by federal law, and not by a

patchwork of state laws applied in piecemeal fashion.

3

SUMMARY OF ARGUMENT

I. Allowing each State and municipality to regulate

nationwide and global emissions is simply unworkable.

The decision below is just the tip of the iceberg: there

are approximately 30 similar lawsuits currently

making their way through state courts. Companies

like petitioners thus face potentially overlapping and

conflicting decisions in dozens of state courts regarding

the same fundamental conduct—with possible

remedies ranging from injunctions of various stripes to

many millions or billions of dollars in damages.

Under such a fractured regime, compliance with

emissions control measures emanating from dozens (or

hundreds) of county courthouses would be expensive,

uncertain, and quite likely impossible. Companies

would be forced to dramatically limit products and

services that are essential to ordinary citizens’

everyday lives, driving up energy costs for consumers.

In addition, such a regime threatens to fragment

our country in ways that evoke the troubled days of the

Articles of Confederation. It does not take much

imagination to appreciate the havoc arising from

putting the regulation of national and global emissions

in the hands of each State and each local government.

Some States and municipalities, particularly those

without significant in-state industrial emissions, have

not resisted the temptation to impose all kinds of

restrictions and costs on out-of-state entities. Indeed,

that is evident from the so-called “climate Superfund”

laws that New York and Vermont have already enacted

based on the same impermissible and preempted

theory of liability as these cases. Other States,

meanwhile, have responded by seeking to protect instate industry from claims based on other States’ and

4

municipalities’ assertions of extraterritorial authority

to regulate greenhouse gas emissions. “[S]uch an

irrational system of regulation” that “lead[s] to chaotic

confrontation between sovereign states” is antithetical

to the Constitution and federal law. Int’l Paper Co. v.

Ouellette, 479 U.S. 481, 496 (1987) (citation omitted).

II. In cases implicating “uniquely federal interests,”

there is no room for state law to apply. This is such a

case. Respondents’ lawsuit is fundamentally about

global climate change—a cross-border, multinational

problem. A phenomenon of this nature, which affects

(and is affected by) not just every State but every

nation in the world, requires uniform regulation that

the laws of individual States simply cannot provide.

The law of a single State, or an order from a single

state court, is ill-equipped to govern the effects on

every State and every nation from greenhouse gas

emissions emanating from all States and all nations,

which routinely cross interstate and international

borders.

Solutions to the challenges posed by climate change

can be achieved only on a national and international

basis—which, within the United States, means

through federal law and the federal government acting

on behalf of the country as a whole. That is a

consequence of our constitutional structure, which

ensures that only federal law governs interstate

disputes of this kind. Reinforcing that limitation, the

Due Process Clause prohibits States from regulating

transactions or behavior with which they have

insufficient contact to support legislative jurisdiction.

The need for a uniform federal standard in cases

concerning cross-border emissions is why this Court

has long recognized that state law cannot supply a rule

5

of decision for disputes about “air and water in their

ambient or interstate aspects.” Illinois v. City of

Milwaukee, 406 U.S. 91, 103 (1972) (Milwaukee I)

(citation omitted). Those disputes must be resolved by

federal law; indeed, where no federal statute exists,

federal common law has governed such disputes.

Congress may displace federal common law by

statute, which then serves as the exclusive source of

remedies for the claim; if Congress displaces federal

common law but provides no private remedy, then

there is none. Whether the law governing these

matters is common law or statutory law, it is federal

law that governs. Displacement of federal common law

remedies does not mean that federal law disappears

from the field—much less that it allows fifty States and

their associated municipalities to rush into a uniquely

federal arena.

The Court should return this interstate and

international issue to the national government’s

domain, where our constitutional structure, as well as

the Clean Air Act, places it.

ARGUMENT

I. A 50-state patchwork of greenhouse-gasemissions regulation is unworkable and encourages states to impose costs on out-ofstate consumers and businesses.

1. This case is one of at least 33 lawsuits filed by

state, local, and tribal governments since 2017 that

seek competing remedies for overlapping claims alleging harm arising from emissions outside the borders of

6

the plaintiff governments’ respective jurisdictions. 2

And two States have now enacted so-called climate

2 Cnty. of San Mateo v. Chevron Corp., No. 17CIV03222 (Cal. Su-

per. Ct. July 17, 2017); City of Oakland v. BP p.l.c., No.

RG17875889 (Cal. Super. Ct. Sept. 19, 2017); City of Santa Cruz v.

Chevron Corp., No. 17CV03243 (Cal. Super. Ct. Dec. 20, 2017);

Cnty. of Santa Cruz v. Chevron Corp., No. 17CV03242 (Cal. Super.

Ct. Dec. 20, 2017); City of N.Y. v. BP p.l.c., No. 18-cv-182 (S.D.N.Y.

Jan. 9, 2018); City of Richmond v. Chevron Corp., No. C18-00055

(Cal. Super. Ct. Jan. 22, 2018); Bd. of Cnty. Comm’rs of Boulder

Cnty. v. Suncor Energy (U.S.A.), Inc., No. 2018CV30349 (Colo.

Dist. Ct. Apr. 17, 2018); King Cnty. v. BP p.l.c., No. 18-2-11859-0

(Wash. Super. Ct. May 9, 2018); Rhode Island v. Chevron Corp.,

No. PC-2018-4716 (R.I. Super. Ct. July 2, 2018); Mayor & City

Council of Balt. v. BP p.l.c., No. 24-C-18-004219 (Md. Cir. Ct. July

20, 2018); Massachusetts v. Exxon Mobil Corp., No. 1984CV03333

(Mass. Super. Ct. Oct. 24, 2019); City & Cnty. of Honolulu v.

Sunoco LP, No. 1CCV-20-0000380 (Haw. Cir. Ct. Mar. 9, 2020);

Minnesota v. Am. Petroleum Inst., No. 62-CV-20-3837 (Minn. Dist.

Ct. June 24, 2020); Dist. of Columbia v. Exxon Mobil Corp., No.

2020 CA 002892 B (D.C. Super. Ct. June 25, 2020); City of Hoboken v. Exxon Mobil Corp., No. HUD-L-003179-20 (N.J. Super. Ct.

Sept. 2, 2020); City of Charleston v. Brabham Oil Co., No.

2020CP1003975 (S.C. Ct. Com. Pleas Sept. 9, 2020); Delaware v.

BP Am. Inc., No. N20C-09-097 (Del. Super. Ct. Sept. 10, 2020);

Connecticut v. Exxon Mobil Corp., No. HHDCV206132568S (Conn.

Super. Ct. Sept. 14, 2020); Cnty. of Maui v. Sunoco LP, No. 2CCV20-000283 (Haw. Cir. Ct. Oct. 12, 2020); City of Annapolis v. BP

p.l.c., No. C-02-CV-21-000250 (Md. Cir. Ct. Feb. 22, 2021); Anne

Arundel Cnty. v. BP p.l.c., No. C-02-CV-21-000565 (Md. Cir. Ct.

Apr. 26, 2021); Vermont v. Exxon Mobil Corp., No. 21-CV-02778

(Vt. Super. Ct. Sept. 14, 2021); Platkin, Att’y Gen. of N.J. v. Exxon

Mobil Corp., No. MER-L-001797-22 (N.J. Super. Ct. Oct. 18,

2022); Mun. of Bayamon v. Exxon Mobil Corp., No. 3:22-cv-1550

(D.P.R. Nov. 22, 2022); Cnty. of Multnomah v. Exxon Mobil Corp.,

No. 23CV25164 (Or. Cir. Ct. June 22, 2023); People v. Exxon Mobil

Corp., No. CGC23609134 (Cal. Super. Ct. Sept. 15, 2023); Mun. of

San Juan v. Exxon Mobil Corp., No. 3:23-cv-01608 (D.P.R. Dec. 13,

2023); Shoalwater Bay Indian Tribe v. Exxon Mobil Corp., No. 232-25215-2 (Wash. Super. Ct. Dec. 20, 2023); Makah Indian Tribe

7

“Superfund” statutes that likewise seek to impose liability on energy producers for global greenhouse gas

emissions, prompting suits by the Chamber, the United

States, and other parties challenging the statutes as

precluded and preempted by federal law, among other

grounds for invalidation. See Chamber of Commerce of

the U.S.A. v. Moore, No. 24-cv-1513 (D. Vt.); Chamber

of Commerce of the U.S.A. v. James, No. 25-cv-1307

(N.D.N.Y.); United States v. Vermont, No. 25-cv-463 (D.

Vt.); United States v. New York, No. 25-cv-3656

(S.D.N.Y.); West Virginia v. James, No. 25-cv-168

(N.D.N.Y.).

If the 30-plus actions (and counting) similar to the

one permitted by the Colorado Supreme Court are allowed to proceed, and if States and municipalities succeed in applying their laws to claims of cross-border

pollution originating all over the world, the growth of

“conflicting disputes, increasing assertions[,] and proliferating contentions would seem to be inevitable.”

Milwaukee I, 406 U.S. at 107 n.9 (citation omitted).

Intensifying that chaos, other jurisdictions have

taken the diametrically opposing approach. Reacting

to the extraordinary (and extraterritorial) assertions of

authority by jurisdictions like Boulder that seek to

hold energy companies liable under state law for the

effects of global greenhouse gas emissions, others—

including two of Colorado’s neighboring States—have

v. Exxon Mobil Corp., No. 23-2-25216-1 (Wash. Super. Ct. Dec. 20,

2023); City of Chi. v. BP p.l.c., No. 2024CH01024 (Ill. Cir. Ct. Feb.

20, 2024); Bucks Cnty. v. BP p.l.c., No. 2024-01836-0000 (Pa. Ct.

Com. Pl. Mar. 25, 2024); Maine v. BP p.l.c., No. PORSC-CV24-442

(Me. Super. Ct. Nov. 26, 2024); Hawaii v. BP p.l.c., No. 1CCV-25717 (Haw. Cir. Ct. May 1, 2025).

8

sought to immunize energy companies against such

state-law claims.

Oklahoma, for example, enacted a law prohibiting

anyone in the State from bringing a lawsuit against an

energy company that “seeks relief of any kind arising

out of or relating to, climate change, the alleged effects

of climate change, or greenhouse emissions,” including

“any cause of action for fraud, misrepresentation, deception, or failure to warn, whether statutory or at

common law.” Okla. S.B. 1439, § 1(C)(1), (D)(1) (2026

Reg. Sess.). Similarly, Utah enacted a law providing

that a person may not be held liable “for damage or injury from any actual or potential effect on climate

caused wholly or partly by greenhouse gas emissions,

unless a court finds by clear and convincing evidence

that the person has” violated the express terms of a

permit or a statutory restriction on emissions within

Utah. Utah H.B. 222, § 1(2)(a) (2026 Gen. Sess.); see

Iowa Code § 673B.2 (2026) (law similar to Utah’s). Indeed, the Tennessee Energy Freedom Act makes it a

“substantive right” to produce, transport, sell, manufacture, refine or combust fossil fuels in Tennessee, and

prohibits anyone from bringing a lawsuit “in any forum” seeking to impose liability in connection with

emissions from such activities. Tenn. H.B. 2070, § 2

(114th Gen. Assemb.). Other States are considering

similar statutes. See, e.g., La. H.B. 804 (2026 Reg.

Sess.). Yet Boulder would penalize energy companies

for engaging in conduct that is perfectly lawful—or

even a protected right—under the laws of other States.

2. The dysfunction of such a regime is obvious.

States with little or no fossil fuel production have every

incentive to impose costs on out-of-state producers,

pursuing windfalls at the expense of other States’ citi-

9

zens. This cost-externalization dynamic is well known.

“Quite simply, dividing the nation into fifty geographic

zones makes it almost inevitable that some pollution

problems will be generated by out-of-staters,” and

“these issues promise politicians on the state level the

equivalent of a free lunch—‘tough’ legislation allows

them to garner public credit for bringing a benefit to

their constituents at somebody else’s expense.” E.

Donald Elliott, Bruce A. Ackerman & John C. Millian,

Toward a Theory of Statutory Evolution: The Federalization of Environmental Law, 1 J. L. Econ. & Org. 313,

329 (1985).

State law, dominated as it is by parochial concerns,

is inherently ill-suited for the regulation of national

and global emissions. Take Vermont, for instance,

which has both sued oil companies in litigation parallel

to this one, Vermont v. Exxon Mobil Corp., No. 21-CV02778 (Vt. Super. Ct.), and enacted a Climate “Superfund” Act “to secure compensatory payments from responsible parties based on a standard of strict liability,” 10 Vt. Stat. Ann. § 597(1). Vermont has few

qualms in pursuing such far-reaching policies because

it “has no fossil energy reserves,” “no crude oil … production” or “petroleum refineries,” and “does not have

any coal mines, coal reserves, or coal-fired power

plants.”

U.S. Energy Info. Admin., Vermont,

https://www.eia.gov/states/VT/analysis (updated Jan.

15, 2026).

And take New York State, which has enacted “Superfund” legislation similar to Vermont’s. Again, New

York “produces only a small amount of crude oil,” “does

not have any … economically recoverable coal reserves,

and the state no longer has any coal-fired electricity

generation.” U.S. Energy Info. Admin., New York,

10

https://www.eia.gov/states/NY/analysis (updated Feb.

19, 2026). Indeed, a coalition of 20-plus states argues

that “New York intends to wring funds from producers

and consumers in other States to subsidize certain

New-York-based ‘infrastructure’ projects,” and that

“[b]illions of dollars in fines will negatively impact energy production and drive-up energy costs in other

States, especially those States that rely heavily on the

fossil-fuel-related energy sector.” Am. Compl. ¶¶ 1, 12,

West Virginia v. New York, No. 25-cv-168 (N.D.N.Y.

Apr. 7, 2025), ECF No. 125.

Moreover, compliance with a hodgepodge of state

and local efforts to regulate greenhouse gas emissions

is extremely inefficient—and likely impossible. If companies are continually walloped by claim after claim of

staggering liability across hundreds of jurisdictions,

they will cease to offer the products and services that

the market (and the country) needs. Or, just as troubling, they will pass those costs onto consumers who

depend on these essential products to live their lives.

“Imposing damages liability on the oil-and-gas industry for every ill plausibly connected to climate change

would function like a massive excise tax, driving up the

costs of gasoline and home heating for ordinary consumers.” Thomas W. Merrill, The New Public Nuisance: Illegitimate and Dysfunctional, 132 Yale L.J.

Forum 985, 1007 (2023). As the various state-law suits

work their way through dozens of state courts, businesses will lose the ability to predict where, when, and

how they will be permitted to operate.

That is not a rational or workable system. As

Judge Wilkinson has explained in an analogous context, the “balkanization of clean air regulations and a

confused patchwork of standards” work “to the detri-

11

ment of industry and the environment alike.” North

Carolina ex rel. Cooper v. Tenn. Valley Auth., 615 F.3d

291, 312 (4th Cir. 2010). And this Court has refused to

interpret similar provisions of the Clean Water Act as

enabling “such an irrational system of regulation” that

“would lead to chaotic confrontation between sovereign

states.” Ouellette, 479 U.S. at 496-97 (citation omitted). The only sensible solution is to recognize that

this national and global issue belongs in the national

government’s exclusive domain and is governed by federal law, as the structure of the Constitution and the

Clean Air Act each demand.

This Court should reverse the deeply flawed

decision below.

II. Under our federal structure and the Clean

Air Act, state law may not impose liability

for the climate effects of emissions that originate all over the world.

Federal law precludes state-law claims for relief for

harm to the Earth’s climate that is attributed to

interstate and international greenhouse-gas emissions.

Because greenhouse gas emissions originate all over

the world, intermix in the global atmosphere, and cross

state and national borders, the laws of a single State

cannot possibly resolve a dispute like this one.

The Colorado Supreme Court incorrectly held that

respondents can pursue state-law claims for harms

that are allegedly caused by global greenhouse gas

emissions. To the extent that federal law would

ordinarily control in this area, the court reasoned, the

Clean Air Act (CAA) displaced federal common law

without providing any federal statutory cause of action,

12

and thus somehow opened the door for state law to

seize the wheel.

That is incorrect. Claims like respondents’ must be

brought under federal law—not because federal

statutory law shoved state law aside, but because the

nature of such claims requires a federal rule of

decision. Congress displaced federal common law

through the Clean Air Act and limited remedies to

those available under that Act. That deliberate choice

does not somehow deputize state law to control this

uniquely federal dispute.

A. Only federal law can govern disputes like

this one, which implicates interstate and

international interests.

There are certain controversies that “our federal

system does not permit … to be resolved under state

law,” where “the interstate or international nature of

the controversy makes it inappropriate for state law to

control.” Tex. Indus., Inc. v. Radcliff Materials, Inc.,

451 U.S. 630, 641 (1981). In a multi-state Union of

equals, a single State’s power to address interstate air

pollution or air quality issues must respect state borders. Thus, it is no surprise that federal law limits a

State’s authority to regulating emissions from within

the State. Disputes, like this one, over the impacts of

air emissions originating in other States or countries

are exactly the type of controversy that individual

States lack the power to address. The state supreme

court erred in refusing to recognize that it was therefore “inappropriate for state law to control.” Id.

1. Federal law must govern when “there is an overriding federal interest in the need for a uniform rule of

decision or where the controversy touches basic inter-

13

ests of federalism.” Milwaukee I, 406 U.S. at 105 n.6.

The areas where that is true include the areas where

this Court has allowed for the development of federal

common law—in other words, the areas where the only

constitutionally permissible rules of decision are federal ones. Thus, this Court has made clear that federal

common law, in its modern form, “addresses ‘subjects

within national legislative power where Congress has

so directed’ or where the basic scheme of the Constitution so demands.” Am. Elec. Power Co. v. Connecticut

(AEP), 564 U.S. 410, 421 (2011) (quoting Henry J.

Friendly, In Praise of Erie—and of the New Federal

Common Law, 39 N.Y.U. L. Rev. 383, 408, 421-22

(1964)). Federal law can supply such a “uniform rule of

decision” in those areas; state law cannot.

Courts have applied federal common law in cases

involving interstate water disputes, 3 tribal land

rights,4 interstate air carrier liability,5 and foreign relations.6 In such cases, federal law must govern: the

structure of the Constitution does not allow States to

engage in the cross-border regulation necessary to resolve such controversies. See Tex. Indus., 451 U.S. at

3 Hinderlider v. La Plata River & Cherry Creek Ditch Co., 304 U.S.

92, 109-10 (1938); Kansas v. Colorado, 206 U.S. 46, 95-96 (1907).

4 Cnty. of Oneida v. Oneida Indian Nation of N.Y., 470 U.S. 226,

235-36 (1985).

5 Treiber & Straub, Inc. v. UPS, Inc., 474 F.3d 379, 384 (7th Cir.

2007) (discussing the Fifth Circuit’s “extensive analysis of the history of federal common law liability of common carriers” in Sam L.

Majors Jewelers v. ABX, Inc., 117 F.3d 922, 925-29 (1997)).

6 Banco Nacional de Cuba v. Sabbatino, 376 U.S. 398, 425-27

(1964); Provincial Gov’t of Marinduque v. Placer Dome, Inc., 582

F.3d 1083, 1088-89 (9th Cir. 2009); Ungaro-Benages v. Dresdner

Bank AG, 379 F.3d 1227, 1233 (11th Cir. 2004).

14

641. Moreover, “local law will not be sufficiently sensitive to federal concerns, it is not likely to be uniform

across state lines, and it will develop at various rates of

speed in different states.” 19 Wright & Miller, Fed.

Prac. & Proc., Juris. § 4514 (3d ed. 2022).

One archetypal area in which the basic scheme of

the Constitution requires a federal rule concerns “the

environmental rights of a State against improper impairment by sources outside its domain.” Milwaukee I,

406 U.S. at 107 n.9 (citation omitted). In such cases,

where there is no federal statutory rule, “[f]ederal

common law and not the varying common law of the

individual States is . . . necessary” to provide a “uniform standard” for such disputes. Id. (citation omitted). Accordingly, this Court has held that “[w]hen we

deal with air and water in their ambient or interstate

aspects, there is a federal common law.” AEP, 564 U.S.

at 421 (quoting Milwaukee I, 406 U.S. at 103).

Claims regarding transboundary emissions implicate “uniquely federal interests.” Accordingly, when

Milwaukee I held that cases regarding interstate air

and water emissions “should be resolved by reference

to federal common law[,] the implicit corollary of this

ruling was that state common law was preempted.”

Ouellette, 479 U.S. at 488; see Milwaukee I, 406 U.S. at

107 n.9.

2. Climate change is an international and interstate phenomenon. Greenhouse gas emissions are released into the Earth’s atmosphere, where they intermix, from all over the world, and their effects are just

as global.

The Amended Complaint in this case does not

mince words about the scope of its allegations. It re-

15

peatedly states that it seeks to hold petitioners responsible for their worldwide “fossil fuel products” that “release CO2 and other GHGs into the atmosphere, and

contribute to changes in the planet’s climate.” J.A. 21,

24-25 (¶¶ 70, 85) (emphases added); J.A. 34 (¶ 123) (alleging that “the emission of GHGs into the atmosphere

… has increased the concentration of those gases in the

atmosphere, trapping heat in the climate system, and

warming the planet”); J.A. 98 (¶ 383) (“Exxon is one of

the largest sources of GHG emissions both globally and

historically.”); J.A. 102 (¶ 399) (“Suncor is one of the

largest sources of GHG emissions both globally and

historically.”). Respondents even seek to hold petitioners responsible for emissions by others. The Amended

Complaint acknowledges that both the emissions and

the harms alleged (and the atmospheric phenomena

that are indispensable causal links between the emissions and the harms) span the entire globe.

Respondents’ claims thus implicate uniquely federal interests, in multiple respects. It would be sufficient

that they concern “air and water in their ambient or

interstate aspects,” which “undoubtedly” calls for a

federal rule of decision, AEP, 564 U.S. at 421 (citation

omitted); Milwaukee I, 406 U.S. at 103. But there is

more: they also implicate foreign policy and the United

States’ sovereign interests. The “international nature

of the controversy” is another reason why it is “inappropriate for state law to control.” Tex. Indus., 451

U.S. at 641.

Notably, many state courts agree—and reject the

contrary view of the Colorado Supreme Court in this

case. Most recently, the Supreme Court of Maryland

firmly rejected an attempt by Baltimore and other

Maryland local governments to sue 26 multinational oil

16

and gas companies under state tort law, seeking to recover damages purportedly caused by global greenhouse gas emissions. Mayor & City Council of Balt. v.

B.P. P.L.C., 353 A.3d 1142, 1150 (Md. 2026). The court

held that such claims fall squarely within the inherently federal areas of interstate pollution and foreign affairs and may therefore only be brought under federal

law.” Id. at 1175. “Such a sprawling case is simply beyond the limits of state law.” Id. at 1174 (brackets and

citation omitted). The court built on an earlier decision

by the Second Circuit rejecting similar claims by New

York City. That court correctly understood that federal

law governs in this area, leaving no role for state law,

because this “is an interstate matter raising significant

federalism concerns,” in no small part since “a substantial damages award like the one requested by the City

would effectively regulate the [defendants’] behavior

far beyond New York’s borders.” City of New York v.

Chevron Corp., 993 F.3d 81, 92 (2d Cir. 2021). As these

decisions recognize, claims like these ask state courts

to exceed the role that our federal system allows them.

3. The necessity of a uniform federal approach in

mitigating climate change is accentuated by the difficult policy choices inherent in balancing the United

States’ environmental and energy needs. There are

important trade-offs to consider, all of which have

enormous consequences. As this Court has explained,

“[t]he appropriate amount of regulation in any particular greenhouse gas-producing sector” requires “informed assessment of competing interests”: “Along

with the environmental benefit potentially achievable,

our Nation’s energy needs and the possibility of economic disruption must weigh in the balance.” AEP,

564 U.S. at 427.

17

The federal government has been grappling with

this dilemma for decades. Congress undoubtedly takes

national energy needs very seriously, including by

providing for oil and gas production. E.g., 43 U.S.C.

§ 1802(1) (“establish[ing] policies and procedures for

managing the oil and natural gas resources of the Outer Continental Shelf … to achieve national economic

and energy policy goals, assure national security, reduce dependence on foreign sources, and maintain a

favorable balance of payments in world trade”).

Indeed, by enacting the CAA, Congress has designated the Environmental Protection Agency (EPA) “as

primary regulator of greenhouse gas emissions.” AEP,

564 U.S. at 428. As EPA has recently explained, its

regulatory authority under the CAA is “a critical part

of the comprehensive framework of regulating air pollution.” Rescission of the Greenhouse Gas Endangerment Finding and Motor Vehicle Greenhouse Gas

Emission Standards Under the Clean Air Act, 91 Fed.

Reg. 7686, 7696 (Feb. 18, 2026). In part for that reason, EPA has recently reaffirmed its position that the

CAA “continues to preempt state common-law claims

and statutes that seek to regulate out-of-state emissions,” even though EPA has determined that the CAA

does not authorize it to prescribe certain greenhouse

gas emission standards based on global climate change

concerns. Id. at 7739.

Even beyond the CAA, Congress has repeatedly

taken legislative action in this area. In the Inflation

Reduction Act of 2022, for example, the term “greenhouse gas” appears no fewer than 147 times. Pub. L.

No. 117-169, 136 Stat. 1818. That term appears another 35 times in the Infrastructure Investment and

Jobs Act, Pub. L. No. 117-58, 135 Stat. 429 (2021). And

18

Congress recently recalibrated its climate policy with

the One Big Beautiful Bill Act, Pub. L. No. 119-21, 139

Stat. 72 (2025), which “makes significant alterations to

public incentives for climate and energy-related investments.” Mia Beams & Akkshath Subrahmanian,

Congress’s “One Big Beautiful Bill” Will Shrink Renewable Energy Investments—Yet Some Technologies

Are Preserved, Council on Foreign Relations (Aug. 4,

2025), https://www.cfr.org/article/congresss-one-bigbeautiful-bill-will-shrink-renewable-energyinvestments-yet-some.

Against this backdrop, the overriding federal interest is clear. Subjecting companies’ “global operations

to a welter of different states’ laws,” as the Second Circuit cogently explained, “would further risk upsetting

the careful balance that has been struck between the

prevention of global warming, a project that necessarily requires national standards and global participation,

on the one hand, and energy production, economic

growth, foreign policy, and national security, on the

other.” City of New York, 993 F.3d at 93. In fact,

“[a]llowing each of the 50 states (and the countless individual local governments located within them) to impose their own preferred policy solutions for climate

change—with each state naturally focused on local rather than national or international impacts, would create a plainly ‘irrational system of regulation’ that

would lead to ‘chaotic confrontation between sovereign

states.’” Baltimore, 353 A.3d at 1176 (quoting Ouellette, 479 U.S. at 496-97).

In short, this is a case in which “there is an overriding federal interest in the need for a uniform rule of

decision or where the controversy touches basic inter-

19

ests of federalism.” Milwaukee I, 406 U.S. at 105 n.6.

Federal law must therefore control.

4. The structural limitations that the Constitution

imposes on the application of state law to quintessentially national issues are reinforced by the Due Process

Clause. That Clause likewise limits the authority of

States to regulate matters that are insufficiently connected to the State. See Gerling Glob. Reinsurance

Corp. of Am. v. Gallagher, 267 F.3d 1228, 1237-38

(11th Cir. 2001); Fuld v. Palestine Liberation Org., 606

U.S. 1, 14 (2025); Home Ins. Co. v. Dick, 281 U.S. 397,

407-08 (1930); Bonaparte v. Tax Court, 104 U.S. 592,

594 (1881) (State may not legislate “except with reference to its own jurisdiction”). This Court has referred

to these “territorial limits of state authority” as “the

Constitution’s horizontal separation of powers.” Nat’l

Pork Producers Council v. Ross, 598 U.S. 356, 376 &

n.1 (2023).

Respondents seek to regulate transactions far beyond their municipal borders (and even Colorado’s),

demanding that business practices and communications that occur elsewhere conform to their preferred

standards—or be penalized. In doing so, they seek to

control lawful activities in other States and effectively

override the energy policies of sister States, as well as

those of the federal government. Respondents’ theory

is in serious tension with the constitutional limits on

any one State’s authority to prescribe legal rules beyond its own borders.

20

B. Respondents’ packaging of their claims

makes no difference to the conclusion

that the claims are preempted by federal

law.

Regardless whether respondents seek to enjoin

greenhouse gas emissions directly, they certainly do

seek to regulate such emissions. As the Tenth Circuit

recognized in an earlier phase of this litigation, this

suit is, at least in part, a suit “for damages allegedly

caused by climate change.” Bd. of Cnty. Comm’rs of

Boulder Cnty. v. Suncor Energy (U.S.A.) Inc., 25 F.4th

1238, 1248 (2022). The Amended Complaint demands

that petitioners “pay[] their share of the costs Plaintiffs

have incurred and will incur because of Defendants’

contribution to alteration of the climate.” J.A. 3 (¶ 6).

It is a truism that “‘regulation can be . . . effectively exerted through an award of damages,’ and ‘[t]he obligation to pay compensation can be, indeed is designed to

be, a potent method of governing conduct and controlling policy.’” Kurns v. R.R. Friction Prods. Corp., 565

U.S. 625, 637 (2012) (quoting San Diego Bldg. Trades

Council v. Garmon, 359 U.S. 236, 247 (1959)) (brackets

in original); see also City of New York, 993 F.3d at 92

(same conclusion in similar climate suit); Minnesota v.

Am. Petroleum Inst., 63 F.4th 703, 719 (8th Cir. 2023)

(Stras, J., concurring) (recognizing that similar climate

suit sought to “change the companies’ behavior on a

global scale”).

It makes no difference that respondents have

framed this dispute as arising, in part, from misleading

marketing relating to climate change. The point is

that respondents accuse petitioners of causing greenhouse gas emissions (both from the use of their own

products and from other sources entirely), and that

21

they contend that global greenhouse gas emissions are

the source of harm to them and the basis for an award

of judicial relief. It is “the interstate or international

nature of the controversy [that] makes it inappropriate

for state law to control,” Tex. Indus., 451 U.S. at 641

(emphasis added), not the precise causes of action

pleaded. Here, the gravamen of the dispute is the oil

companies’ alleged responsibility for climate change

impacts attributed to greenhouse gas emissions. That

dispute must be governed by federal law, for the reasons given above. See pp. 12-19, supra.

As the Second Circuit held in rejecting a similar argument in a parallel climate suit by New York City,

“[a]rtful pleading cannot transform the City’s complaint into anything other than a suit over global

greenhouse gas emissions.” City of New York, 993 F.3d

at 91. The Maryland Supreme Court reached the same

conclusion regarding much the same allegations

brought by Baltimore and other municipalities: “No

amount of creative pleading can masquerade the fact

that the local governments are attempting to utilize

state law to regulate global conduct that is purportedly

causing global harm.” Baltimore, 353 A.3d at 1173.

“To state the obvious,” that court continued, “global

warming is created by global consumption”—and “[t]he

local governments’ police powers do not extend beyond

their respective borders, and certainly do not authorize

the policing of global conduct.” Id. at 1174. Such a suit

must be governed by federal law.

22

C. The displacement of federal common law

by federal statute does not authorize

state law to regulate a uniquely federal

area.

1. The Colorado Supreme Court’s principal reason

for concluding that respondents’ state-law claims are

not preempted is that federal common law related to

greenhouse gas emissions has been “displaced by the

federal legislation authorizing EPA to regulate carbondioxide emissions,” AEP, 564 U.S. at 423, and therefore

“that common law no longer exists.” Pet. App. 17a.

The majority below echoed the Hawaii Supreme

Court’s reasoning that “displaced federal common law

plays no part in this court’s preemption analysis.” Pet.

App. 20a (quoting City & Cnty. of Honolulu v. Sunoco

LP, 537 P.3d 1173, 1199 (Haw. 2023), cert. denied, 145

S. Ct. 1111 (2025)).

That reasoning cannot be reconciled with “the federalism concerns undergirding the entire rationale of

federal common law.” Baltimore, 353 A.3d at 1177. As

both the Second Circuit and Maryland Supreme Court

explained, “state law does not suddenly become presumptively competent to address issues that demand a

unified federal standard simply because Congress saw

fit to displace a federal court-made standard with a

legislative one.” City of New York, 993 F.3d at 98.

“Such an outcome is too strange to seriously contemplate.” Id. at 98-99; see Baltimore, 353 A.3d at 1177

(same).

The Second Circuit, in turn, embraced the reasoning of the Seventh Circuit in Illinois v. City of Milwaukee (Milwaukee III) that, despite Milwaukee II’s holding that the federal common law recognized in Mil-

23

waukee I was displaced, “[t]he very reasons … for resorting to federal common law in Milwaukee I are the

same reasons why the state claiming injury cannot apply its own state law to out-of-state discharges now.”

731 F.2d 403, 410 (7th Cir. 1984).

2. The Colorado Supreme Court criticized the Second Circuit’s “preemption analysis” as “‘backwards

reasoning.’” Pet. App. 19a (quoting Honolulu, 537 P.3d

at 1199). But there is nothing “backwards” about it.

The Second Circuit—as well as the Maryland Supreme

Court and Seventh Circuit—correctly applied the basic

rule that “if federal common law exists, it is because

state law cannot be used.” City of Milwaukee v. Illinois, 451 U.S. 304, 313 n.7 (1981) (Milwaukee II); see

Tex. Indus., 451 U.S. at 641 & n.13 (federal law governs where the nature of the claim “makes it inappropriate for state law to control”); Baltimore, 353 A.3d at

1177 n.22 (same).

That Congress displaced federal common law simply means that the federal courts are no longer in the

business of formulating federal standards. See AEP,

564 U.S. at 423-24 (explaining that “it is primarily the

office of Congress, not the federal courts, to prescribe

national policy in areas of special federal interest”).

Displacement in no way eliminates or undermines the

overriding federal interest in the dispute, much less

throws open the door for the courts of the fifty different

States to engage in their own piecemeal resolution of

these distinctly federal issues under a variety of competing and conflicting state and local laws. State law

was incompetent to address the issue before congressional action, and it remains so after it.

24

Precisely because of the need for uniformity—the

reason why federal common law was necessary in the

first place—a displacing federal statutory scheme must

provide the authoritative answer on what remedies are

available, even if the answer is “none.” Thus, “‘resorting to state law’ on a question previously governed by

federal common law is permissible only to the extent

‘authorized’ by federal statute.” City of New York, 993

F.3d at 99 (brackets omitted) (quoting Milwaukee III,

731 F.2d at 411); see Baltimore, 353 A.3d at 1177

(same).

Under the reasoning of the Colorado and Hawaii

Supreme Courts, however, congressional attempts to

supply a uniform federal standard by statute would

bring to life the very same disuniform state-law rules

that were, and remain, incompetent to address this national problem. That would be so even if that federal

legislation were to “adopt[] verbatim a judge-made

common law rule.” City of New York, 993 F.3d at 9899. Congress could enact statutes codifying the very

same court-supplied rules governing interstate water

rights, interstate air carrier liability, and interstate

disputes over intangible property, see p. 13, supra, and

according to the Colorado and Hawaii Supreme Courts

(and respondents), state law claims on those subjects

would suddenly become viable, triggering the very

same problems that initially prompted the formulation

of a federal rule.

That makes no sense. Federal problems remain

federal problems, regardless of whether the necessary

uniform, federal standard to deal with them is supplied

by federal courts or federal statute. In the (few) areas

where federal common law would apply but for displacement by Congress, “the implicit corollary” is that

25

“state common law [is] preempted.” Ouellette, 479 U.S.

at 488.

D. The Clean Air Act also preempts respondents’ state-law claims.

Respondents’ claims also conflict with, and are

preempted by, the CAA itself. The CAA “delegate[s]”

authority to EPA to “deci[de] whether and how to regulate” greenhouse gas emissions, and “entrusts” to EPA

the “complex balancing” of “competing interests.” AEP,

564 U.S. at 426-27. For example, Title II of the CAA

gives EPA authority to determine whether to establish

emissions standards for the transportation sector, including vehicles, aircraft, locomotives, motorcycles, and

nonroad engines and equipment.

42 U.S.C.

§§ 7521(a)(1)-(2), (a)(3)(E), 7571(a)(2)(A), 7547(a)(1),

(a)(5). The CAA also provides EPA with authority to

determine whether emissions of a pollutant from “stationary sources,” such as power plants, refineries, and

oil and gas wells, should be regulated and at what levels.

AEP, 564 U.S. at 426; see 42 U.S.C.

§ 7411(b)(1)(A)-(B), (d). “If EPA does not set emissions

limits for a particular pollutant or source of pollution,

States and private parties may petition [EPA] for a

rulemaking on the matter … [but there is] no room for

a parallel track.” AEP, 564 U.S. at 425.

Moreover, the CAA’s “Good Neighbor Provision,” 42

U.S.C. § 7410(a)(2)(D)(i), is a specific attempt “[t]o

tackle the problem” of “air pollution emitted in one

State, but causing harm in other States.” EPA v. EME

Homer City Generation, L.P., 572 U.S. 489, 495 (2014);

see Oklahoma v. EPA, 605 U.S. 609, 616 (2025) (explaining that the CAA’s Good Neighbor Provision “accounts for the ‘externality’ that ‘because air currents

26

can carry pollution across state borders, emissions in

upwind States sometimes affect air quality in downwind States.’” (brackets omitted; quoting Ohio v. EPA,

603 U.S. 279, 283–284 (2024)). The Good Neighbor

Provision is premised on the assumption that “downwind States … lack authority to control” out-of-state

pollution. EME Homer City Generation, 572 U.S. at

495. The CAA thus “contemplates no role for states

reaching out and applying their law in other states.”

Baltimore, 353 A.3d at 1179.

The citizen-suit savings clause of the CAA, 42

U.S.C. § 7604(e), preserves a “slim reservoir of state

common law” for suits brought under the law of the

State that is the source of the emissions. City of New

York, 993 F.3d at 99-100. But that narrow carveout

underscores that the CAA leaves no other avenue for

state law claims with respect to air pollution for which

the authority to regulate has been delegated to EPA.

In Ouellette, this Court analyzed parallel provisions of

the Clean Water Act and held that the statute “precludes a court from applying the law of an affected

State against an out-of-state source” but permits “a

nuisance claim pursuant to the law of the source

State.” 479 U.S. at 494-497. The same is true of the

CAA. See City of New York, 993 F.3d at 100.

Respondents complain of emissions from all over

the planet, not emissions originating in Colorado—yet

they seek to hold petitioners liable under Colorado law.

Such claims are preempted by the CAA’s comprehensive regulatory scheme.

27

CONCLUSION

The judgment should be reversed.

Respectfully submitted.

ANDREW R. VARCOE

STEPHANIE A. MALONEY

U.S. CHAMBER

LITIGATION CENTER

1615 H Street, NW

Washington, DC 20062

JESSE LEMPEL

GOODWIN PROCTER LLP

100 Northern Avenue

Boston, MA 02210

May 21, 2026

WILLIAM M. JAY

Counsel of Record

GOODWIN PROCTER LLP

1900 N Street, NW

Washington, DC 20036

wjay@goodwinlaw.com

(202) 346-4000

Counsel for Amicus Curiae

the Chamber of Commerce

of the United States of

America