Massachusetts v. Environmental Protection Agency

(Slip Opinion) OCTOBER TERM, 2006 1

Syllabus

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is

being done in connection with this case, at the time the opinion is issued.

The syllabus constitutes no part of the opinion of the Court but has been

prepared by the Reporter of Decisions for the convenience of the reader.

See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.

SUPREME COURT OF THE UNITED STATES

Syllabus

MASSACHUSETTS ET AL. v. ENVIRONMENTAL PRO

TECTION AGENCY ET AL.

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR

THE DISTRICT OF COLUMBIA CIRCUIT

No. 05–1120. Argued November 29, 2006—Decided April 2, 2007

Based on respected scientific opinion that a well-documented rise in

global temperatures and attendant climatological and environmental

changes have resulted from a significant increase in the atmospheric

concentration of “greenhouse gases,” a group of private organizations

petitioned the Environmental Protection Agency (EPA) to begin regu

lating the emissions of four such gases, including carbon dioxide, un

der §202(a)(1) of the Clean Air Act, which requires that the EPA

“shall by regulation prescribe . . . standards applicable to the emis

sion of any air pollutant from any class . . . of new motor vehicles . . .

which in [the EPA Administrator’s] judgment cause[s], or contrib

ute[s] to, air pollution . . . reasonably . . . anticipated to endanger

public health or welfare,” 42 U. S. C. §7521(a)(1). The Act defines

“air pollutant” to include “any air pollution agent . . . , including any

physical, chemical . . . substance . . . emitted into . . . the ambient

air.” §7602(g). EPA ultimately denied the petition, reasoning that

(1) the Act does not authorize it to issue mandatory regulations to

address global climate change, and (2) even if it had the authority to

set greenhouse gas emission standards, it would have been unwise to

do so at that time because a causal link between greenhouse gases

and the increase in global surface air temperatures was not un

equivocally established. The agency further characterized any EPA

regulation of motor-vehicle emissions as a piecemeal approach to cli

mate change that would conflict with the President’s comprehensive

approach involving additional support for technological innovation,

the creation of nonregulatory programs to encourage voluntary pri

vate-sector reductions in greenhouse gas emissions, and further re

search on climate change, and might hamper the President’s ability

2 MASSACHUSETTS v. EPA

Syllabus

to persuade key developing nations to reduce emissions.

Petitioners, now joined by intervenor Massachusetts and other

state and local governments, sought review in the D. C. Circuit. Al

though each of the three judges on the panel wrote separately, two of

them agreed that the EPA Administrator properly exercised his dis

cretion in denying the rulemaking petition. One judge concluded that

the Administrator’s exercise of “judgment” as to whether a pollutant

could “reasonably be anticipated to endanger public health or wel

fare,” §7521(a)(1), could be based on scientific uncertainty as well as

other factors, including the concern that unilateral U. S. regulation of

motor-vehicle emissions could weaken efforts to reduce other coun

tries’ greenhouse gas emissions. The second judge opined that peti

tioners had failed to demonstrate the particularized injury to them

that is necessary to establish standing under Article III, but accepted

the contrary view as the law of the case and joined the judgment on

the merits as the closest to that which he preferred. The court there

fore denied review.

Held:

1. Petitioners have standing to challenge the EPA’s denial of their

rulemaking petition. Pp. 12–23.

(a) This case suffers from none of the defects that would preclude

it from being a justiciable Article III “Controvers[y].” See, e.g., Lu

ther v. Borden, 7 How. 1. Moreover, the proper construction of a con

gressional statute is an eminently suitable question for federal-court

resolution, and Congress has authorized precisely this type of chal

lenge to EPA action, see 42 U. S. C. §7607(b)(1). Contrary to EPA’s

argument, standing doctrine presents no insuperable jurisdictional

obstacle here. To demonstrate standing, a litigant must show that it

has suffered a concrete and particularized injury that is either actual

or imminent, that the injury is fairly traceable to the defendant, and

that a favorable decision will likely redress that injury. See Lujan v.

Defenders of Wildlife, 504 U. S. 555, 560–561. However, a litigant to

whom Congress has “accorded a procedural right to protect his con

crete interests,” id., at 573, n. 7—here, the right to challenge agency

action unlawfully withheld, §7607(b)(1)—“can assert that right with

out meeting all the normal standards for redressability and immedi

acy,” ibid. Only one petitioner needs to have standing to authorize

review. See Rumsfeld v. Forum for Academic and Institutional

Rights, Inc., 547 U. S. 47, 52, n. 2. Massachusetts has a special posi

tion and interest here. It is a sovereign State and not, as in Lujan, a

private individual, and it actually owns a great deal of the territory

alleged to be affected. The sovereign prerogatives to force reductions

in greenhouse gas emissions, to negotiate emissions treaties with de

veloping countries, and (in some circumstances) to exercise the police

Cite as: 549 U. S. ____ (2007) 3

Syllabus

power to reduce motor-vehicle emissions are now lodged in the Fed

eral Government. Because congress has ordered EPA to protect Mas

sachusetts (among others) by prescribing applicable standards,

§7521(a)(1), and has given Massachusetts a concomitant procedural

right to challenge the rejection of its rulemaking petition as arbitrary

and capricious, §7607(b)(1), petitioners’ submissions as they pertain

to Massachusetts have satisfied the most demanding standards of the

adversarial process. EPA’s steadfast refusal to regulate greenhouse

gas emissions presents a risk of harm to Massachusetts that is both

“actual” and “imminent,” Lujan, 504 U. S., at 560, and there is a

“substantial likelihood that the judicial relief requested” will prompt

EPA to take steps to reduce that risk, Duke Power Co. v. Carolina

Environmental Study Group, Inc., 438 U. S. 59, 79. Pp. 12–17.

(b) The harms associated with climate change are serious and

well recognized. The Government’s own objective assessment of the

relevant science and a strong consensus among qualified experts in

dicate that global warming threatens, inter alia, a precipitate rise in

sea levels, severe and irreversible changes to natural ecosystems, a

significant reduction in winter snowpack with direct and important

economic consequences, and increases in the spread of disease and

the ferocity of weather events. That these changes are widely shared

does not minimize Massachusetts’ interest in the outcome of this liti

gation. See Federal Election Comm’n v. Akins, 524 U. S. 11, 24. Ac

cording to petitioners’ uncontested affidavits, global sea levels rose

between 10 and 20 centimeters over the 20th century as a result of

global warming and have already begun to swallow Massachusetts’

coastal land. Remediation costs alone, moreover, could reach hun

dreds of millions of dollars. Pp. 17–19.

(c) Given EPA’s failure to dispute the existence of a causal con

nection between man-made greenhouse gas emissions and global

warming, its refusal to regulate such emissions, at a minimum, “con

tributes” to Massachusetts’ injuries. EPA overstates its case in argu

ing that its decision not to regulate contributes so insignificantly to

petitioners’ injuries that it cannot be haled into federal court, and

that there is no realistic possibility that the relief sought would miti

gate global climate change and remedy petitioners’ injuries, espe

cially since predicted increases in emissions from China, India, and

other developing nations will likely offset any marginal domestic de

crease EPA regulation could bring about. Agencies, like legislatures,

do not generally resolve massive problems in one fell swoop, see Wil

liamson v. Lee Optical of Okla., Inc., 348 U. S. 483, 489, but instead

whittle away over time, refining their approach as circumstances

change and they develop a more nuanced understanding of how best

to proceed, cf. SEC v. Chenery Corp., 332 U. S. 194, 202–203. That a

4 MASSACHUSETTS v. EPA

Syllabus

first step might be tentative does not by itself negate federal-court ju

risdiction. And reducing domestic automobile emissions is hardly

tentative. Leaving aside the other greenhouse gases, the record indi

cates that the U. S. transportation sector emits an enormous quantity

of carbon dioxide into the atmosphere. Pp. 20–21.

(d) While regulating motor-vehicle emissions may not by itself

reverse global warming, it does not follow that the Court lacks juris

diction to decide whether EPA has a duty to take steps to slow or re

duce it. See Larson v. Valente, 456 U. S. 228, 243, n. 15. Because of

the enormous potential consequences, the fact that a remedy’s effec

tiveness might be delayed during the (relatively short) time it takes

for a new motor-vehicle fleet to replace an older one is essentially ir

relevant. Nor is it dispositive that developing countries are poised to

substantially increase greenhouse gas emissions: A reduction in do

mestic emissions would slow the pace of global emissions increases,

no matter what happens elsewhere. The Court attaches considerable

significance to EPA’s espoused belief that global climate change must

be addressed. Pp. 21–23.

2. The scope of the Court’s review of the merits of the statutory is

sues is narrow. Although an agency’s refusal to initiate enforcement

proceedings is not ordinarily subject to judicial review, Heckler v.

Chaney, 470 U. S. 821, there are key differences between nonen

forcement and denials of rulemaking petitions that are, as in the pre

sent circumstances, expressly authorized. EPA concluded alterna

tively in its petition denial that it lacked authority under §7521(a)(1)

to regulate new vehicle emissions because carbon dioxide is not an

“air pollutant” under §7602, and that, even if it possessed authority,

it would decline to exercise it because regulation would conflict with

other administration priorities. Because the Act expressly permits

review of such an action, §7607(b)(1), this Court “may reverse [it if it

finds it to be] arbitrary, capricious, an abuse of discretion, or other

wise not in accordance with law,” §7607(d)(9). Pp. 24–25.

3. Because greenhouse gases fit well within the Act’s capacious

definition of “air pollutant,” EPA has statutory authority to regulate

emission of such gases from new motor vehicles. That definition—

which includes “any air pollution agent . . . , including any physical,

chemical, . . . substance . . . emitted into . . . the ambient air . . . ,”

§7602(g) (emphasis added)—embraces all airborne compounds of

whatever stripe. Moreover, carbon dioxide and other greenhouse

gases are undoubtedly “physical [and] chemical . . . substance[s].”

Ibid. EPA’s reliance on postenactment congressional actions and de

liberations it views as tantamount to a command to refrain from

regulating greenhouse gas emissions is unavailing. Even if pos

tenactment legislative history could shed light on the meaning of an

Cite as: 549 U. S. ____ (2007) 5

Syllabus

otherwise-unambiguous statute, EPA identifies nothing suggesting

that Congress meant to curtail EPA’s power to treat greenhouse

gases as air pollutants. The Court has no difficulty reconciling Con

gress’ various efforts to promote interagency collaboration and re

search to better understand climate change with the agency’s pre

existing mandate to regulate “any air pollutant” that may endanger

the public welfare. FDA v. Brown & Williamson Tobacco Corp., 529

U. S. 120, 133, distinguished. Also unpersuasive is EPA’s argument

that its regulation of motor-vehicle carbon dioxide emissions would

require it to tighten mileage standards, a job (according to EPA) that

Congress has assigned to the Department of Transportation. The

fact that DOT’s mandate to promote energy efficiency by setting

mileage standards may overlap with EPA’s environmental responsi

bilities in no way licenses EPA to shirk its duty to protect the public

“health” and “welfare,” §7521(a)(1). Pp. 25–30.

4. EPA’s alternative basis for its decision—that even if it has statu

tory authority to regulate greenhouse gases, it would be unwise to do

so at this time—rests on reasoning divorced from the statutory text.

While the statute conditions EPA action on its formation of a “judg

ment,” that judgment must relate to whether an air pollutant

“cause[s], or contribute[s] to, air pollution which may reasonably be

anticipated to endanger public health or welfare.” §7601(a)(1). Under

the Act’s clear terms, EPA can avoid promulgating regulations only if

it determines that greenhouse gases do not contribute to climate

change or if it provides some reasonable explanation as to why it

cannot or will not exercise its discretion to determine whether they

do. It has refused to do so, offering instead a laundry list of reasons

not to regulate, including the existence of voluntary Executive

Branch programs providing a response to global warming and im

pairment of the President’s ability to negotiate with developing na

tions to reduce emissions. These policy judgments have nothing to do

with whether greenhouse gas emissions contribute to climate change

and do not amount to a reasoned justification for declining to form a

scientific judgment. Nor can EPA avoid its statutory obligation by

noting the uncertainty surrounding various features of climate

change and concluding that it would therefore be better not to regu

late at this time. If the scientific uncertainty is so profound that it

precludes EPA from making a reasoned judgment, it must say so.

The statutory question is whether sufficient information exists for it

to make an endangerment finding. Instead, EPA rejected the rule-

making petition based on impermissible considerations. Its action

was therefore “arbitrary, capricious, or otherwise not in accordance

with law,” §7607(d)(9). On remand, EPA must ground its reasons for

action or inaction in the statute. Pp. 30–32.

6 MASSACHUSETTS v. EPA

Syllabus

415 F. 3d 50, reversed and remanded.

STEVENS, J., delivered the opinion of the Court, in which KENNEDY,

SOUTER, GINSBURG, and BREYER, JJ., joined. ROBERTS, C. J., filed a dis

senting opinion, in which SCALIA, THOMAS, and ALITO, JJ., joined.

SCALIA, J., filed a dissenting opinion, in which ROBERTS, C. J., and

THOMAS and ALITO, JJ., joined.

Cite as: 549 U. S. ____ (2007) 1

Opinion of the Court

NOTICE: This opinion is subject to formal revision before publication in the

preliminary print of the United States Reports. Readers are requested to

notify the Reporter of Decisions, Supreme Court of the United States, Wash

ington, D. C. 20543, of any typographical or other formal errors, in order

that corrections may be made before the preliminary print goes to press.

SUPREME COURT OF THE UNITED STATES

_________________

No. 05–1120

_________________

MASSACHUSETTS, ET AL., PETITIONERS v. ENVIRON

MENTAL PROTECTION AGENCY ET AL.

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE DISTRICT OF COLUMBIA CIRCUIT

[April 2, 2007]

JUSTICE STEVENS delivered the opinion of the Court.

A well-documented rise in global temperatures has

coincided with a significant increase in the concentration

of carbon dioxide in the atmosphere. Respected scientists

believe the two trends are related. For when carbon diox

ide is released into the atmosphere, it acts like the ceiling

of a greenhouse, trapping solar energy and retarding the

escape of reflected heat. It is therefore a species—the

most important species—of a “greenhouse gas.”

Calling global warming “the most pressing environ

mental challenge of our time,”1 a group of States,2 local

governments,3 and private organizations,4 alleged in a

——————

1 Pet. for Cert. 22.

2 California, Connecticut, Illinois, Maine, Massachusetts, New Jersey,

New Mexico, New York, Oregon, Rhode Island, Vermont, and Washington.

3 District of Columbia, American Samoa, New York City, and Baltimore.

4 Center for Biological Diversity, Center for Food Safety, Conserva

tion Law Foundation, Environmental Advocates, Environmental

Defense, Friends of the Earth, Greenpeace, International Center for

Technology Assessment, National Environmental Trust, Natural

Resources Defense Council, Sierra Club, Union of Concerned Scientists,

and U. S. Public Interest Research Group.

2 MASSACHUSETTS v. EPA

Opinion of the Court

petition for certiorari that the Environmental Protection

Agency (EPA) has abdicated its responsibility under the

Clean Air Act to regulate the emissions of four greenhouse

gases, including carbon dioxide. Specifically, petitioners

asked us to answer two questions concerning the meaning

of §202(a)(1) of the Act: whether EPA has the statutory

authority to regulate greenhouse gas emissions from new

motor vehicles; and if so, whether its stated reasons for

refusing to do so are consistent with the statute.

In response, EPA, supported by 10 intervening States5

and six trade associations,6 correctly argued that we may

not address those two questions unless at least one peti

tioner has standing to invoke our jurisdiction under Arti

cle III of the Constitution. Notwithstanding the serious

character of that jurisdictional argument and the absence

of any conflicting decisions construing §202(a)(1), the

unusual importance of the underlying issue persuaded us

to grant the writ. 548 U. S. __ (2006).

I

Section 202(a)(1) of the Clean Air Act, as added by Pub.

L. 89–272, §101(8), 79 Stat. 992, and as amended by, inter

alia, 84 Stat. 1690 and 91 Stat. 791, 42 U. S. C. §7521(a)(1),

provides:

“The [EPA] Administrator shall by regulation pre

scribe (and from time to time revise) in accordance

with the provisions of this section, standards applica

ble to the emission of any air pollutant from any class

or classes of new motor vehicles or new motor vehicle

engines, which in his judgment cause, or contribute

to, air pollution which may reasonably be anticipated

——————

5 Alaska, Idaho, Kansas, Michigan, Nebraska, North Dakota, Ohio,

South Dakota, Texas, and Utah.

6 Alliance of Automobile Manufacturers, National Automobile Dealers

Association, Engine Manufacturers Association, Truck Manufacturers

Association, CO2 Litigation Group, and Utility Air Regulatory Group.

Cite as: 549 U. S. ____ (2007) 3

Opinion of the Court

to endanger public health or welfare . . . .”7

The Act defines “air pollutant” to include “any air pollu

tion agent or combination of such agents, including any

physical, chemical, biological, radioactive . . . substance or

matter which is emitted into or otherwise enters the am

bient air.” §7602(g). “Welfare” is also defined broadly:

among other things, it includes “effects on . . . weather . . .

and climate.” §7602(h).

When Congress enacted these provisions, the study of

climate change was in its infancy.8 In 1959, shortly after

the U. S. Weather Bureau began monitoring atmospheric

carbon dioxide levels, an observatory in Mauna Loa, Ha

waii, recorded a mean level of 316 parts per million. This

was well above the highest carbon dioxide concentration—

no more than 300 parts per million—revealed in the

420,000-year-old ice-core record.9 By the time Congress

——————

7 The 1970 version of §202(a)(1) used the phrase “which endangers

the public health or welfare” rather than the more-protective “which

may reasonably be anticipated to endanger public health or welfare.”

See §6(a) of the Clean Air Amendments of 1970, 84 Stat. 1690. Con

gress amended §202(a)(1) in 1977 to give its approval to the decision in

Ethyl Corp. v. EPA, 541 F. 2d 1, 25 (CADC 1976) (en banc), which held

that the Clean Air Act “and common sense . . . demand regulatory

action to prevent harm, even if the regulator is less than certain that

harm is otherwise inevitable.” See §401(d)(1) of the Clean Air Act

Amendments of 1977, 91 Stat. 791; see also H. R. Rep. No. 95–294,

p. 49 (1977).

8 The Council on Environmental Quality had issued a report in 1970

concluding that “[m]an may be changing his weather.” Environmental

Quality: The First Annual Report 93. Considerable uncertainty remained

in those early years, and the issue went largely unmentioned in the

congressional debate over the enactment of the Clean Air Act. But see

116 Cong. Rec. 32914 (1970) (statement of Sen. Boggs referring to

Council’s conclusion that “[a]ir pollution alters the climate and may

produce global changes in temperature”).

9 See Intergovernmental Panel on Climate Change, Climate Change

2001: Synthesis Report, pp. 202–203 (2001). By drilling through thick

Antarctic ice sheets and extracting “cores,” scientists can examine ice

4 MASSACHUSETTS v. EPA

Opinion of the Court

drafted §202(a)(1) in 1970, carbon dioxide levels had

reached 325 parts per million.10

In the late 1970’s, the Federal Government began devot

ing serious attention to the possibility that carbon dioxide

emissions associated with human activity could provoke

climate change. In 1978, Congress enacted the National

Climate Program Act, 92 Stat. 601, which required the

President to establish a program to “assist the Nation and

the world to understand and respond to natural and man-

induced climate processes and their implications,” id., §3.

President Carter, in turn, asked the National Research

Council, the working arm of the National Academy of

Sciences, to investigate the subject. The Council’s re

sponse was unequivocal: “If carbon dioxide continues to

increase, the study group finds no reason to doubt that

climate changes will result and no reason to believe that

these changes will be negligible. . . . A wait-and-see policy

may mean waiting until it is too late.”11

Congress next addressed the issue in 1987, when it

enacted the Global Climate Protection Act, Title XI of Pub.

L. 100–204, 101 Stat. 1407, note following 15 U. S. C.

§2901. Finding that “manmade pollution—the release of

carbon dioxide, chlorofluorocarbons, methane, and other

trace gases into the atmosphere—may be producing a

——————

from long ago and extract small samples of ancient air. That air can

then be analyzed, yielding estimates of carbon dioxide levels. Ibid.

10 A more dramatic rise was yet to come: In 2006, carbon dioxide lev

els reached 382 parts per million, see Dept. of Commerce, National

Oceanic & Atmospheric Administration, Mauna Loa CO2 Monthly Mean

Data, www.esrl.noaa.gov/gmd/ccgg/trends/co2_mm_mlo.dat (all Internet

materials as visited Mar. 29, 2007, and available in Clerk of Court’s

case file), a level thought to exceed the concentration of carbon dioxide

in the atmosphere at any point over the past 20-million years. See

Intergovernmental Panel on Climate Change, Technical Summary of

Working Group I Report 39 (2001).

11 Climate Research Board, Carbon Dioxide and Climate: A Scientific

Assessment, p. vii (1979).

Cite as: 549 U. S. ____ (2007) 5

Opinion of the Court

long-term and substantial increase in the average tem

perature on Earth,” §1102(1), 101 Stat. 1408, Congress

directed EPA to propose to Congress a “coordinated na

tional policy on global climate change,” §1103(b), and

ordered the Secretary of State to work “through the chan

nels of multilateral diplomacy” and coordinate diplomatic

efforts to combat global warming, §1103(c). Congress

emphasized that “ongoing pollution and deforestation may

be contributing now to an irreversible process” and that

“[n]ecessary actions must be identified and implemented

in time to protect the climate.” §1102(4).

Meanwhile, the scientific understanding of climate

change progressed. In 1990, the Intergovernmental Panel

on Climate Change (IPCC), a multinational scientific body

organized under the auspices of the United Nations, pub

lished its first comprehensive report on the topic. Draw

ing on expert opinions from across the globe, the IPCC

concluded that “emissions resulting from human activities

are substantially increasing the atmospheric concentra

tions of . . . greenhouse gases [which] will enhance the

greenhouse effect, resulting on average in an additional

warming of the Earth’s surface.”12

Responding to the IPCC report, the United Nations

convened the “Earth Summit” in 1992 in Rio de Janeiro.

The first President Bush attended and signed the United

Nations Framework Convention on Climate Change

(UNFCCC), a nonbinding agreement among 154 nations to

reduce atmospheric concentrations of carbon dioxide and

other greenhouse gases for the purpose of “prevent[ing]

dangerous anthropogenic [i.e., human-induced] interfer

ence with the [Earth’s] climate system.”13 S. Treaty Doc.

——————

12 IPCC, Climate Change: The IPCC Scientific Assessment, p. xi (J.

Houghton, G. Jenkins, & J. Ephraums eds. 1991).

13 The industrialized countries listed in Annex I to the UNFCCC un

dertook to reduce their emissions of greenhouse gases to 1990 levels by

the year 2000. No immediate restrictions were imposed on developing

6 MASSACHUSETTS v. EPA

Opinion of the Court

No. 102–38, Art. 2, p. 5 (1992). The Senate unanimously

ratified the treaty.

Some five years later—after the IPCC issued a second

comprehensive report in 1995 concluding that “[t]he bal

ance of evidence suggests there is a discernible human

influence on global climate”14—the UNFCCC signatories

met in Kyoto, Japan, and adopted a protocol that assigned

mandatory targets for industrialized nations to reduce

greenhouse gas emissions. Because those targets did not

apply to developing and heavily polluting nations such as

China and India, the Senate unanimously passed a resolu

tion expressing its sense that the United States should not

enter into the Kyoto Protocol. See S. Res. 98, 105th Cong.,

1st Sess. (July 25, 1997) (as passed). President Clinton did

not submit the protocol to the Senate for ratification.

II

On October 20, 1999, a group of 19 private organiza

tions15 filed a rulemaking petition asking EPA to regulate

“greenhouse gas emissions from new motor vehicles under

§202 of the Clean Air Act.” App. 5. Petitioners main

tained that 1998 was the “warmest year on record”; that

carbon dioxide, methane, nitrous oxide, and hydrofluoro

carbons are “heat trapping greenhouse gases”; that green

——————

countries, including China and India. They could choose to become

Annex I countries when sufficiently developed.

14 IPCC, Climate Change 1995, The Science of Climate Change, p. 4.

15 Alliance for Sustainable Communities; Applied Power Technologies,

Inc.; Bio Fuels America; The California Solar Energy Industries Assn.;

Clements Environmental Corp.; Environmental Advocates; Environ

mental and Energy Study Institute; Friends of the Earth; Full Circle

Energy Project, Inc.; The Green Party of Rhode Island; Greenpeace

USA; International Center for Technology Assessment; Network for

Environmental and Economic Responsibility of the United Church of

Christ; New Jersey Environmental Watch; New Mexico Solar Energy

Assn.; Oregon Environmental Council; Public Citizen; Solar Energy

Industries Assn.; The SUN DAY Campaign. See App. 7–11.

Cite as: 549 U. S. ____ (2007) 7

Opinion of the Court

house gas emissions have significantly accelerated climate

change; and that the IPCC’s 1995 report warned that

“carbon dioxide remains the most important contributor to

[man-made] forcing of climate change.” Id., at 13 (internal

quotation marks omitted). The petition further alleged

that climate change will have serious adverse effects on

human health and the environment. Id., at 22–35. As to

EPA’s statutory authority, the petition observed that the

agency itself had already confirmed that it had the power

to regulate carbon dioxide. See id., at 18, n. 21. In 1998,

Jonathan Z. Cannon, then EPA’s General Counsel, pre

pared a legal opinion concluding that “CO2 emissions are

within the scope of EPA’s authority to regulate,” even as

he recognized that EPA had so far declined to exercise

that authority. Id., at 54 (memorandum to Carol M.

Browner, Administrator (Apr. 10, 1998) (hereinafter Can

non memorandum)). Cannon’s successor, Gary S. Guzy,

reiterated that opinion before a congressional committee

just two weeks before the rulemaking petition was filed.

See id., at 61.

Fifteen months after the petition’s submission, EPA

requested public comment on “all the issues raised in [the]

petition,” adding a “particular” request for comments on

“any scientific, technical, legal, economic or other aspect of

these issues that may be relevant to EPA’s consideration

of this petition.” 66 Fed. Reg. 7486, 7487 (2001). EPA

received more than 50,000 comments over the next five

months. See 68 Fed. Reg. 52924 (2003).

Before the close of the comment period, the White House

sought “assistance in identifying the areas in the science

of climate change where there are the greatest certainties

and uncertainties” from the National Research Council,

asking for a response “as soon as possible.” App. 213. The

result was a 2001 report titled Climate Change: An Analysis

of Some Key Questions (NRC Report), which, drawing heav

ily on the 1995 IPCC report, concluded that “[g]reenhouse

8 MASSACHUSETTS v. EPA

Opinion of the Court

gases are accumulating in Earth’s atmosphere as a result

of human activities, causing surface air temperatures and

subsurface ocean temperatures to rise. Temperatures are,

in fact, rising.” NRC Report 1.

On September 8, 2003, EPA entered an order denying the

rulemaking petition. 68 Fed. Reg. 52922. The agency gave

two reasons for its decision: (1) that contrary to the opin

ions of its former general counsels, the Clean Air Act does

not authorize EPA to issue mandatory regulations to

address global climate change, see id., at 52925–52929;

and (2) that even if the agency had the authority to set

greenhouse gas emission standards, it would be unwise to

do so at this time, id., at 52929–52931.

In concluding that it lacked statutory authority over

greenhouse gases, EPA observed that Congress “was well

aware of the global climate change issue when it last

comprehensively amended the [Clean Air Act] in 1990,”

yet it declined to adopt a proposed amendment establish

ing binding emissions limitations. Id., at 52926. Congress

instead chose to authorize further investigation into cli

mate change. Ibid. (citing §§103(g) and 602(e) of the

Clean Air Act Amendments of 1990, 104 Stat. 2652, 2703,

42 U. S. C. §§7403(g)(1) and 7671a(e)). EPA further rea

soned that Congress’ “specially tailored solutions to global

atmospheric issues,” 68 Fed. Reg. 52926—in particular, its

1990 enactment of a comprehensive scheme to regulate

pollutants that depleted the ozone layer, see Title VI, 104

Stat. 2649, 42 U. S. C. §§7671–7671q—counseled against

reading the general authorization of §202(a)(1) to confer

regulatory authority over greenhouse gases.

EPA stated that it was “urged on in this view” by this

Court’s decision in FDA v. Brown & Williamson Tobacco

Corp., 529 U. S. 120 (2000). In that case, relying on “to

bacco[’s] unique political history,” id., at 159, we invali

dated the Food and Drug Administration’s reliance on its

general authority to regulate drugs as a basis for asserting

Cite as: 549 U. S. ____ (2007) 9

Opinion of the Court

jurisdiction over an “industry constituting a significant

portion of the American economy,” ibid.

EPA reasoned that climate change had its own “political

history”: Congress designed the original Clean Air Act to

address local air pollutants rather than a substance that

“is fairly consistent in its concentration throughout the

world’s atmosphere,” 68 Fed. Reg. 52927 (emphasis

added); declined in 1990 to enact proposed amendments to

force EPA to set carbon dioxide emission standards for

motor vehicles, ibid. (citing H. R. 5966, 101st Cong., 2d

Sess. (1990)); and addressed global climate change in

other legislation, 68 Fed. Reg. 52927. Because of this

political history, and because imposing emission limita

tions on greenhouse gases would have even greater eco

nomic and political repercussions than regulating tobacco,

EPA was persuaded that it lacked the power to do so. Id.,

at 52928. In essence, EPA concluded that climate change

was so important that unless Congress spoke with exact

ing specificity, it could not have meant the agency to

address it.

Having reached that conclusion, EPA believed it fol

lowed that greenhouse gases cannot be “air pollutants”

within the meaning of the Act. See ibid. (“It follows from

this conclusion, that [greenhouse gases], as such, are not

air pollutants under the [Clean Air Act’s] regulatory pro

visions . . .”). The agency bolstered this conclusion by

explaining that if carbon dioxide were an air pollutant, the

only feasible method of reducing tailpipe emissions would

be to improve fuel economy. But because Congress has

already created detailed mandatory fuel economy stan

dards subject to Department of Transportation (DOT)

administration, the agency concluded that EPA regulation

would either conflict with those standards or be superflu

ous. Id., at 52929.

Even assuming that it had authority over greenhouse

gases, EPA explained in detail why it would refuse to exer

10 MASSACHUSETTS v. EPA

Opinion of the Court

cise that authority. The agency began by recognizing that

the concentration of greenhouse gases has dramatically

increased as a result of human activities, and acknowledged

the attendant increase in global surface air temperatures.

Id., at 52930. EPA nevertheless gave controlling impor

tance to the NRC Report’s statement that a causal link

between the two “ ‘cannot be unequivocally established.’ ”

Ibid. (quoting NRC Report 17). Given that residual uncer

tainty, EPA concluded that regulating greenhouse gas

emissions would be unwise. 68 Fed. Reg. 52930.

The agency furthermore characterized any EPA regula

tion of motor-vehicle emissions as a “piecemeal approach” to

climate change, id., at 52931, and stated that such regula

tion would conflict with the President’s “comprehensive

approach” to the problem, id., at 52932. That approach

involves additional support for technological innovation, the

creation of nonregulatory programs to encourage voluntary

private-sector reductions in greenhouse gas emissions, and

further research on climate change—not actual regulation.

Id., at 52932–52933. According to EPA, unilateral EPA

regulation of motor-vehicle greenhouse gas emissions might

also hamper the President’s ability to persuade key devel

oping countries to reduce greenhouse gas emissions. Id., at

52931.

III

Petitioners, now joined by intervenor States and local

governments, sought review of EPA’s order in the United

States Court of Appeals for the District of Columbia Cir

cuit.16 Although each of the three judges on the panel

wrote a separate opinion, two judges agreed “that the EPA

——————

16 See 42 U. S. C. §7607(b)(1) (“A petition for review of action of the

Administrator in promulgating any . . . standard under section 7521 of

this title . . . or final action taken, by the Administrator under this

chapter may be filed only in the United States Court of Appeals for the

District of Columbia”).

Cite as: 549 U. S. ____ (2007) 11

Opinion of the Court

Administrator properly exercised his discretion under

§202(a)(1) in denying the petition for rule making.” 415 F.

3d 50, 58 (2005). The court therefore denied the petition

for review.

In his opinion announcing the court’s judgment, Judge

Randolph avoided a definitive ruling as to petitioners’

standing, id., at 56, reasoning that it was permissible to

proceed to the merits because the standing and the merits

inquiries “overlap[ped],” ibid. Assuming without deciding

that the statute authorized the EPA Administrator to

regulate greenhouse gas emissions that “in his judgment”

may “reasonably be anticipated to endanger public health

or welfare,” 42 U. S. C. §7521(a)(1), Judge Randolph con

cluded that the exercise of that judgment need not be

based solely on scientific evidence, but may also be in

formed by the sort of policy judgments that motivate

congressional action. 415 F. 3d, at 58. Given that frame

work, it was reasonable for EPA to base its decision on

scientific uncertainty as well as on other factors, including

the concern that unilateral regulation of U. S. motor-

vehicle emissions could weaken efforts to reduce green

house gas emissions from other countries. Ibid.

Judge Sentelle wrote separately because he believed

petitioners failed to “demonstrat[e] the element of injury

necessary to establish standing under Article III.” Id., at

59 (opinion dissenting in part and concurring in judg

ment). In his view, they had alleged that global warming

is “harmful to humanity at large,” but could not allege

“particularized injuries” to themselves. Id., at 60 (citing

Lujan v. Defenders of Wildlife, 504 U. S. 555, 562 (1992)).

While he dissented on standing, however, he accepted the

contrary view as the law of the case and joined Judge

Randolph’s judgment on the merits as the closest to that

which he preferred. 415 F. 3d, at 60–61.

Judge Tatel dissented. Emphasizing that EPA nowhere

challenged the factual basis of petitioners’ affidavits, id.,

12 MASSACHUSETTS v. EPA

Opinion of the Court

at 66, he concluded that at least Massachusetts had “satis

fied each element of Article III standing—injury, causa

tion, and redressability,” id., at 64. In Judge Tatel’s view,

the “ ‘substantial probability,’ ” id., at 66, that projected

rises in sea level would lead to serious loss of coastal

property was a “far cry” from the kind of generalized harm

insufficient to ground Article III jurisdiction. Id., at 65.

He found that petitioners’ affidavits more than adequately

supported the conclusion that EPA’s failure to curb green

house gas emissions contributed to the sea level changes

that threatened Massachusetts’ coastal property. Ibid. As

to redressability, he observed that one of petitioners’

experts, a former EPA climatologist, stated that

“ ‘[a]chievable reductions in emissions of CO2 and other

[greenhouse gases] from U. S. motor vehicles would . . .

delay and moderate many of the adverse impacts of global

warming.’ ” Ibid. (quoting declaration of Michael Mac-

Cracken, former Executive Director, U. S. Global Change

Research Program ¶5(e) (hereinafter MacCracken Decl.),

available in 2 Petitioners’ Standing Appendix in No. 03–

1361, etc., (CADC), p. 209 (Stdg. App.)). He further noted

that the one-time director of EPA’s motor-vehicle pollution

control efforts stated in an affidavit that enforceable emis

sion standards would lead to the development of new

technologies that “ ‘would gradually be mandated by other

countries around the world.’ ” 415 F. 3d, at 66 (quoting

declaration of Michael Walsh ¶¶7–8, 10, Stdg. App. 309–

310, 311). On the merits, Judge Tatel explained at length

why he believed the text of the statute provided EPA with

authority to regulate greenhouse gas emissions, and why

its policy concerns did not justify its refusal to exercise

that authority. 415 F. 3d, at 67–82.

IV

Article III of the Constitution limits federal-court juris

diction to “Cases” and “Controversies.” Those two words

Cite as: 549 U. S. ____ (2007) 13

Opinion of the Court

confine “the business of federal courts to questions pre

sented in an adversary context and in a form historically

viewed as capable of resolution through the judicial proc

ess.” Flast v. Cohen, 392 U. S. 83, 95 (1968). It is there

fore familiar learning that no justiciable “controversy”

exists when parties seek adjudication of a political ques

tion, Luther v. Borden, 7 How. 1 (1849), when they ask for

an advisory opinion, Hayburn’s Case, 2 Dall. 409 (1792),

see also Clinton v. Jones, 520 U. S. 681, 700, n. 33 (1997),

or when the question sought to be adjudicated has been

mooted by subsequent developments, California v. San

Pablo & Tulare R. Co., 149 U. S. 308 (1893). This case

suffers from none of these defects.

The parties’ dispute turns on the proper construction of a

congressional statute, a question eminently suitable to

resolution in federal court. Congress has moreover author

ized this type of challenge to EPA action. See 42 U. S. C.

§7607(b)(1). That authorization is of critical importance to

the standing inquiry: “Congress has the power to define

injuries and articulate chains of causation that will give

rise to a case or controversy where none existed before.”

Lujan, 504 U. S., at 580 (KENNEDY, J., concurring in part

and concurring in judgment). “In exercising this power,

however, Congress must at the very least identify the

injury it seeks to vindicate and relate the injury to the

class of persons entitled to bring suit.” Ibid. We will not,

therefore, “entertain citizen suits to vindicate the public’s

nonconcrete interest in the proper administration of the

laws.” Id., at 581.

EPA maintains that because greenhouse gas emissions

inflict widespread harm, the doctrine of standing presents

an insuperable jurisdictional obstacle. We do not agree.

At bottom, “the gist of the question of standing” is whether

petitioners have “such a personal stake in the outcome of

the controversy as to assure that concrete adverseness

which sharpens the presentation of issues upon which the

14 MASSACHUSETTS v. EPA

Opinion of the Court

court so largely depends for illumination.” Baker v. Carr,

369 U. S. 186, 204 (1962). As JUSTICE KENNEDY explained

in his Lujan concurrence:

“While it does not matter how many persons have

been injured by the challenged action, the party bring

ing suit must show that the action injures him in a

concrete and personal way. This requirement is not

just an empty formality. It preserves the vitality of

the adversarial process by assuring both that the par

ties before the court have an actual, as opposed to pro

fessed, stake in the outcome, and that the legal ques

tions presented . . . will be resolved, not in the rarified

atmosphere of a debating society, but in a concrete

factual context conducive to a realistic appreciation of

the consequences of judicial action.” 504 U. S., at 581

(internal quotation marks omitted).

To ensure the proper adversarial presentation, Lujan

holds that a litigant must demonstrate that it has suffered

a concrete and particularized injury that is either actual

or imminent, that the injury is fairly traceable to the

defendant, and that it is likely that a favorable decision

will redress that injury. See id., at 560–561. However, a

litigant to whom Congress has “accorded a procedural

right to protect his concrete interests,” id., at 572, n. 7—

here, the right to challenge agency action unlawfully

withheld, §7607(b)(1)—“can assert that right without

meeting all the normal standards for redressability and

immediacy,” ibid. When a litigant is vested with a proce

dural right, that litigant has standing if there is some

possibility that the requested relief will prompt the injury-

causing party to reconsider the decision that allegedly

harmed the litigant. Ibid.; see also Sugar Cane Growers

Cooperative of Fla. v. Veneman, 289 F. 3d 89, 94–95

(CADC 2002) (“A [litigant] who alleges a deprivation of a

procedural protection to which he is entitled never has to

Cite as: 549 U. S. ____ (2007) 15

Opinion of the Court

prove that if he had received the procedure the substan

tive result would have been altered. All that is necessary

is to show that the procedural step was connected to the

substantive result”).

Only one of the petitioners needs to have standing to

permit us to consider the petition for review. See Rumsfeld

v. Forum for Academic and Institutional Rights, Inc., 547

U. S. 47, 52, n. 2 (2006). We stress here, as did Judge Tatel

below, the special position and interest of Massachusetts.

It is of considerable relevance that the party seeking re

view here is a sovereign State and not, as it was in Lujan,

a private individual.

Well before the creation of the modern administrative

state, we recognized that States are not normal litigants

for the purposes of invoking federal jurisdiction. As Jus

tice Holmes explained in Georgia v. Tennessee Copper Co.,

206 U. S. 230, 237 (1907), a case in which Georgia sought

to protect its citizens from air pollution originating outside

its borders:

“The case has been argued largely as if it were one

between two private parties; but it is not. The very

elements that would be relied upon in a suit between

fellow-citizens as a ground for equitable relief are

wanting here. The State owns very little of the terri

tory alleged to be affected, and the damage to it capa

ble of estimate in money, possibly, at least, is small.

This is a suit by a State for an injury to it in its capac

ity of quasi-sovereign. In that capacity the State has

an interest independent of and behind the titles of its

citizens, in all the earth and air within its domain. It

has the last word as to whether its mountains shall be

stripped of their forests and its inhabitants shall

breathe pure air.”

Just as Georgia’s “independent interest . . . in all the earth

and air within its domain” supported federal jurisdiction a

16 MASSACHUSETTS v. EPA

Opinion of the Court

century ago, so too does Massachusetts’ well-founded

desire to preserve its sovereign territory today. Cf. Alden

v. Maine, 527 U. S. 706, 715 (1999) (observing that in the

federal system, the States “are not relegated to the role of

mere provinces or political corporations, but retain the

dignity, though not the full authority, of sovereignty”).

That Massachusetts does in fact own a great deal of the

“territory alleged to be affected” only reinforces the con

clusion that its stake in the outcome of this case is suffi

ciently concrete to warrant the exercise of federal judicial

power.

When a State enters the Union, it surrenders certain

sovereign prerogatives. Massachusetts cannot invade

Rhode Island to force reductions in greenhouse gas emis

sions, it cannot negotiate an emissions treaty with China

or India, and in some circumstances the exercise of its

police powers to reduce in-state motor-vehicle emissions

might well be pre-empted. See Alfred L. Snapp & Son,

Inc. v. Puerto Rico ex rel. Barez, 458 U. S. 592, 607 (1982)

(“One helpful indication in determining whether an al

leged injury to the health and welfare of its citizens suf

fices to give the State standing to sue parens patriae is

whether the injury is one that the State, if it could, would

likely attempt to address through its sovereign lawmaking

powers”).

These sovereign prerogatives are now lodged in the

Federal Government, and Congress has ordered EPA to

protect Massachusetts (among others) by prescribing stan

dards applicable to the “emission of any air pollutant from

any class or classes of new motor vehicle engines, which in

[the Administrator’s] judgment cause, or contribute to, air

pollution which may reasonably be anticipated to endanger

public health or welfare.” 42 U. S. C. §7521(a)(1). Con

gress has moreover recognized a concomitant procedural

right to challenge the rejection of its rulemaking petition

as arbitrary and capricious. §7607(b)(1). Given that pro

Cite as: 549 U. S. ____ (2007) 17

Opinion of the Court

cedural right and Massachusetts’ stake in protecting its

quasi-sovereign interests, the Commonwealth is entitled to

special solicitude in our standing analysis.17

——————

17 THE CHIEF JUSTICE accuses the Court of misreading Georgia v. Ten

nessee Copper Co., 206 U. S. 230 (1907), see post, at 3–4 (dissenting

opinion), and “devis[ing] a new doctrine of state standing,” id., at 15.

But no less an authority than Hart & Wechsler’s The Federal Courts

and the Federal System understands Tennessee Copper as a standing

decision. R. Fallon, D. Meltzer, & D. Shapiro, Hart & Wechsler’s The

Federal Courts and the Federal System 290 (5th ed. 2003). Indeed, it

devotes an entire section to chronicling the long development of cases

permitting States “to litigate as parens patriae to protect quasi-

sovereign interests—i.e., public or governmental interests that concern

the state as a whole.” Id., at 289; see, e.g., Missouri v. Illinois, 180

U. S. 208, 240–241 (1901) (finding federal jurisdiction appropriate not

only “in cases involving boundaries and jurisdiction over lands and

their inhabitants, and in cases directly affecting the property rights

and interests of a state,” but also when the “substantial impairment of

the health and prosperity of the towns and cities of the state” are at

stake).

Drawing on Massachusetts v. Mellon, 262 U. S. 447 (1923), and Alfred

L. Snapp & Son, Inc. v. Puerto Rico ex rel. Barez, 458 U. S. 592 (1982)

(citing Missouri v. Illinois, 180 U. S. 208 (1901)), THE CHIEF JUSTICE

claims that we “overloo[k] the fact that our cases cast significant doubt

on a State’s standing to assert a quasi-sovereign interest . . . against

the Federal Government.” Post, at 5. Not so. Mellon itself disavowed

any such broad reading when it noted that the Court had been “called

upon to adjudicate, not rights of person or property, not rights of

dominion over physical domain, [and] not quasi sovereign rights actu

ally invaded or threatened.” 262 U. S., at 484–485 (emphasis added).

In any event, we held in Georgia v. Pennsylvania R. Co., 324 U. S. 439,

447 (1945), that there is a critical difference between allowing a State

“to protect her citizens from the operation of federal statutes” (which is

what Mellon prohibits) and allowing a State to assert its rights under

federal law (which it has standing to do). Massachusetts does not here

dispute that the Clean Air Act applies to its citizens; it rather seeks to

assert its rights under the Act. See also Nebraska v. Wyoming, 515

U. S. 1, 20 (1995) (holding that Wyoming had standing to bring a cross-

claim against the United States to vindicate its “ ‘quasi-sovereign’

interests which are ‘independent of and behind the titles of its citizens,

in all the earth and air within its domain’ ” (quoting Tennessee Copper,

206 U. S., at 237)).

18 MASSACHUSETTS v. EPA

Opinion of the Court

With that in mind, it is clear that petitioners’ submis

sions as they pertain to Massachusetts have satisfied the

most demanding standards of the adversarial process.

EPA’s steadfast refusal to regulate greenhouse gas emis

sions presents a risk of harm to Massachusetts that is

both “actual” and “imminent.” Lujan, 504 U. S., at 560

(internal quotation marks omitted). There is, moreover, a

“substantial likelihood that the judicial relief requested”

will prompt EPA to take steps to reduce that risk. Duke

Power Co. v. Carolina Environmental Study Group, Inc.,

438 U. S. 59, 79 (1978).

The Injury

The harms associated with climate change are serious

and well recognized. Indeed, the NRC Report itself—

which EPA regards as an “objective and independent

assessment of the relevant science,” 68 Fed. Reg. 52930—

identifies a number of environmental changes that have

already inflicted significant harms, including “the global

retreat of mountain glaciers, reduction in snow-cover

extent, the earlier spring melting of rivers and lakes, [and]

the accelerated rate of rise of sea levels during the 20th

century relative to the past few thousand years . . . .”

NRC Report 16.

Petitioners allege that this only hints at the environ

mental damage yet to come. According to the climate

scientist Michael MacCracken, “qualified scientific experts

involved in climate change research” have reached a

“strong consensus” that global warming threatens (among

other things) a precipitate rise in sea levels by the end of

the century, MacCracken Decl. ¶15, Stdg. App. 207, “se

vere and irreversible changes to natural ecosystems,” id.,

¶5(d), at 209, a “significant reduction in water storage in

winter snowpack in mountainous regions with direct and

important economic consequences,” ibid., and an increase

in the spread of disease, id., ¶28, at 218–219. He also

Cite as: 549 U. S. ____ (2007) 19

Opinion of the Court

observes that rising ocean temperatures may contribute to

the ferocity of hurricanes. Id., ¶¶23–25, at 216–217.18

That these climate-change risks are “widely shared”

does not minimize Massachusetts’ interest in the outcome

of this litigation. See Federal Election Comm’n v. Akins,

524 U. S. 11, 24 (1998) (“[W]here a harm is concrete,

though widely shared, the Court has found ‘injury in

fact’ ”). According to petitioners’ unchallenged affidavits,

global sea levels rose somewhere between 10 and 20 cen

timeters over the 20th century as a result of global warm

ing. MacCracken Decl. ¶5(c), Stdg. App. 208. These rising

seas have already begun to swallow Massachusetts’

coastal land. Id., at 196 (declaration of Paul H. Kirshen

¶5), 216 (MacCracken Decl. ¶23). Because the Common

wealth “owns a substantial portion of the state’s coastal

property,” id., at 171 (declaration of Karst R. Hoogeboom

¶4),19 it has alleged a particularized injury in its capacity

——————

18 In this regard, MacCracken’s 2004 affidavit—drafted more than a

year in advance of Hurricane Katrina—was eerily prescient. Immedi

ately after discussing the “particular concern” that climate change

might cause an “increase in the wind speed and peak rate of precipita

tion of major tropical cyclones (i.e., hurricanes and typhoons),” Mac-

Cracken noted that “[s]oil compaction, sea level rise and recurrent

storms are destroying approximately 20–30 square miles of Louisiana

wetlands each year. These wetlands serve as a ‘shock absorber’ for

storm surges that could inundate New Orleans, significantly enhancing

the risk to a major urban population.” ¶¶24–25, Stdg. App. 217.

19 “For example, the [Massachusetts Department of Conservation and

Recreation] owns, operates and maintains approximately 53 coastal

state parks, beaches, reservations, and wildlife sanctuaries. [It] also

owns, operates and maintains sporting and recreational facilities in

coastal areas, including numerous pools, skating rinks, playgrounds,

playing fields, former coastal fortifications, public stages, museums,

bike trails, tennis courts, boathouses and boat ramps and landings.

Associated with these coastal properties and facilities is a significant

amount of infrastructure, which the Commonwealth also owns, oper

ates and maintains, including roads, parkways, stormwater pump

stations, pier[s], sea wal[l] revetments and dams.” Hoogeboom Decl.

¶4, at 171.

20 MASSACHUSETTS v. EPA

Opinion of the Court

as a landowner. The severity of that injury will only

increase over the course of the next century: If sea levels

continue to rise as predicted, one Massachusetts official

believes that a significant fraction of coastal property will

be “either permanently lost through inundation or temporar

ily lost through periodic storm surge and flooding events.”

Id., ¶6, at 172.20 Remediation costs alone, petitioners allege,

could run well into the hundreds of millions of dollars. Id.,

¶7, at 172; see also Kirshen Decl. ¶12, at 198.21

Causation

EPA does not dispute the existence of a causal connec

tion between man-made greenhouse gas emissions and

global warming. At a minimum, therefore, EPA’s refusal

to regulate such emissions “contributes” to Massachusetts’

injuries.

EPA nevertheless maintains that its decision not to

regulate greenhouse gas emissions from new motor vehi

cles contributes so insignificantly to petitioners’ injuries

that the agency cannot be haled into federal court to an

swer for them. For the same reason, EPA does not believe

——————

20 See also id., at 179 (declaration of Christian Jacqz) (discussing

possible loss of roughly 14 acres of land per miles of coastline by 2100);

Kirshen Decl. ¶10, at 198 (alleging that “[w]hen such a rise in sea level

occurs, a 10-year flood will have the magnitude of the present 100-year

flood and a 100-year flood will have the magnitude of the present 500

year flood”).

21 In dissent, THE CHIEF JUSTICE dismisses petitioners’ submissions as

“conclusory,” presumably because they do not quantify Massachusetts’

land loss with the exactitude he would prefer. Post, at 8. He therefore

asserts that the Commonwealth’s injury is “conjectur[al].” See ibid.

Yet the likelihood that Massachusetts’ coastline will recede has nothing

to do with whether petitioners have determined the precise metes and

bounds of their soon-to-be-flooded land. Petitioners maintain that the

seas are rising and will continue to rise, and have alleged that such a

rise will lead to the loss of Massachusetts’ sovereign territory. No one,

save perhaps the dissenters, disputes those allegations. Our cases

require nothing more.

Cite as: 549 U. S. ____ (2007) 21

Opinion of the Court

that any realistic possibility exists that the relief petition

ers seek would mitigate global climate change and remedy

their injuries. That is especially so because predicted

increases in greenhouse gas emissions from developing

nations, particularly China and India, are likely to offset

any marginal domestic decrease.

But EPA overstates its case. Its argument rests on the

erroneous assumption that a small incremental step,

because it is incremental, can never be attacked in a fed

eral judicial forum. Yet accepting that premise would

doom most challenges to regulatory action. Agencies, like

legislatures, do not generally resolve massive problems in

one fell regulatory swoop. See Williamson v. Lee Optical

of Okla., Inc., 348 U. S. 483, 489 (1955) (“[A] reform may

take one step at a time, addressing itself to the phase of

the problem which seems most acute to the legislative

mind”). They instead whittle away at them over time,

refining their preferred approach as circumstances change

and as they develop a more-nuanced understanding of how

best to proceed. Cf. SEC v. Chenery Corp., 332 U. S. 194,

202 (1947) (“Some principles must await their own devel

opment, while others must be adjusted to meet particular,

unforeseeable situations”). That a first step might be

tentative does not by itself support the notion that federal

courts lack jurisdiction to determine whether that step

conforms to law.

And reducing domestic automobile emissions is hardly a

tentative step. Even leaving aside the other greenhouse

gases, the United States transportation sector emits an

enormous quantity of carbon dioxide into the atmos

phere—according to the MacCracken affidavit, more than

1.7 billion metric tons in 1999 alone. ¶30, Stdg. App. 219.

That accounts for more than 6% of worldwide carbon

dioxide emissions. Id., at 232 (Oppenheimer Decl. ¶3); see

also MacCracken Decl. ¶31, at 220. To put this in per

spective: Considering just emissions from the transporta

22 MASSACHUSETTS v. EPA

Opinion of the Court

tion sector, which represent less than one-third of this

country’s total carbon dioxide emissions, the United States

would still rank as the third-largest emitter of carbon

dioxide in the world, outpaced only by the European Union

and China.22 Judged by any standard, U. S. motor-vehicle

emissions make a meaningful contribution to greenhouse

gas concentrations and hence, according to petitioners, to

global warming.

The Remedy

While it may be true that regulating motor-vehicle

emissions will not by itself reverse global warming, it by no

means follows that we lack jurisdiction to decide whether

EPA has a duty to take steps to slow or reduce it. See also

Larson v. Valente, 456 U. S. 228, 244, n. 15 (1982) (“[A]

plaintiff satisfies the redressability requirement when he

shows that a favorable decision will relieve a discrete

injury to himself. He need not show that a favorable

decision will relieve his every injury”). Because of the

enormity of the potential consequences associated with

man-made climate change, the fact that the effectiveness

of a remedy might be delayed during the (relatively short)

time it takes for a new motor-vehicle fleet to replace an

older one is essentially irrelevant.23 Nor is it dispositive

——————

22 See UNFCCC, National Greenhouse Gas Inventory Data for the Period

1990–2004 and Status of Reporting 14 (2006) (hereinafter Inventory Data)

(reflecting emissions from Annex I countries); UNFCCC, Sixth Compilation

and Synthesis of Initial National Communications from Parties not In

cluded in Annex I to the Convention 7–8 (2005) (reflecting emissions from

non-Annex I countries); see also Dept. of Energy, Energy Information

Admin., International Energy Annual 2004, H.1co2 World Carbon Dioxide

Emissions from the Consumption and Flaring of Fossil Fuels, 1980–2004

(Table), http://www.eia.doe.gov/pub/international/iealf/tableh1co2.xls.

23 See also Mountain States Legal Foundation v. Glickman, 92 F. 3d

1228, 1234 (CADC 1996) (“The more drastic the injury that government

action makes more likely, the lesser the increment in probability to

establish standing”); Village of Elk Grove Village v. Evans, 997 F. 2d

328, 329 (CA7 1993) (“[E]ven a small probability of injury is sufficient

Cite as: 549 U. S. ____ (2007) 23

Opinion of the Court

that developing countries such as China and India are

poised to increase greenhouse gas emissions substantially

over the next century: A reduction in domestic emissions

would slow the pace of global emissions increases, no

matter what happens elsewhere.

We moreover attach considerable significance to EPA’s

“agree[ment] with the President that ‘we must address the

issue of global climate change,’ ” 68 Fed. Reg. 52929 (quot

ing remarks announcing Clear Skies and Global Climate

Initiatives, 2002 Public Papers of George W. Bush, Vol. 1,

Feb. 14, p. 227 (2004)), and to EPA’s ardent support for

various voluntary emission-reduction programs, 68 Fed.

Reg. 52932. As Judge Tatel observed in dissent below,

“EPA would presumably not bother with such efforts if it

thought emissions reductions would have no discernable

impact on future global warming.” 415 F. 3d, at 66.

In sum—at least according to petitioners’ uncontested

affidavits—the rise in sea levels associated with global

warming has already harmed and will continue to harm

Massachusetts. The risk of catastrophic harm, though

remote, is nevertheless real. That risk would be reduced

to some extent if petitioners received the relief they seek.

We therefore hold that petitioners have standing to chal

lenge the EPA’s denial of their rulemaking petition.24

——————

to create a case or controversy—to take a suit out of the category of the

hypothetical—provided of course that the relief sought would, if

granted, reduce the probability”).

24 In his dissent, THE CHIEF JUSTICE expresses disagreement with the

Court’s holding in United States v. Students Challenging Regulatory

Agency Procedures (SCRAP), 412 U. S. 669, 687–688 (1973). He does

not, however, disavow this portion of Justice Stewart’s opinion for the

Court:

“Unlike the specific and geographically limited federal action of which

the petitioner complained in Sierra Club [v. Morton, 405 U. S. 727

(1972)], the challenged agency action in this case is applicable to

substantially all of the Nation’s railroads, and thus allegedly has an

adverse environmental impact on all the natural resources of the

24 MASSACHUSETTS v. EPA

Opinion of the Court

V

The scope of our review of the merits of the statutory

issues is narrow. As we have repeated time and again, an

agency has broad discretion to choose how best to marshal

its limited resources and personnel to carry out its dele

gated responsibilities. See Chevron U. S. A. Inc. v. Natu

ral Resources Defense Council, Inc., 467 U. S. 837, 842–845

(1984). That discretion is at its height when the agency

decides not to bring an enforcement action. Therefore, in

Heckler v. Chaney, 470 U. S. 821 (1985), we held that an

agency’s refusal to initiate enforcement proceedings is not

ordinarily subject to judicial review. Some debate re

mains, however, as to the rigor with which we review an

agency’s denial of a petition for rulemaking.

There are key differences between a denial of a petition

for rulemaking and an agency’s decision not to initiate an

enforcement action. See American Horse Protection Assn.,

Inc. v. Lyng, 812 F. 2d 1, 3–4 (CADC 1987). In contrast to

nonenforcement decisions, agency refusals to initiate

rulemaking “are less frequent, more apt to involve legal as

opposed to factual analysis, and subject to special formali

——————

country. Rather than a limited group of persons who used a pictur

esque valley in California, all persons who utilize the scenic resources

of the country, and indeed all who breathe its air, could claim harm

similar to that alleged by the environmental groups here. But we have

already made it clear that standing is not to be denied simply because

many people suffer the same injury. Indeed some of the cases on which

we relied in Sierra Club demonstrated the patent fact that persons

across the Nation could be adversely affected by major governmental

actions. To deny standing to persons who are in fact injured simply

because many others are also injured, would mean that the most injuri

ous and widespread Government actions could be questioned by nobody.

We cannot accept that conclusion.” Ibid. (citations omitted and empha

sis added).

It is moreover quite wrong to analogize the legal claim advanced by

Massachusetts and the other public and private entities who challenge

EPA’s parsimonious construction of the Clean Air Act to a mere “law

yer’s game.” See post, at 14.

Cite as: 549 U. S. ____ (2007) 25

Opinion of the Court

ties, including a public explanation.” Id., at 4; see also 5

U. S. C. §555(e). They moreover arise out of denials of

petitions for rulemaking which (at least in the circum

stances here) the affected party had an undoubted proce

dural right to file in the first instance. Refusals to prom

ulgate rules are thus susceptible to judicial review, though

such review is “extremely limited” and “highly deferen

tial.” National Customs Brokers & Forwarders Assn of

America, Inc. v. United States, 883 F. 2d 93, 96 (CADC

1989).

EPA concluded in its denial of the petition for rulemak

ing that it lacked authority under 42 U. S. C. §7521(a)(1)

to regulate new vehicle emissions because carbon dioxide

is not an “air pollutant” as that term is defined in §7602.

In the alternative, it concluded that even if it possessed

authority, it would decline to do so because regulation

would conflict with other administration priorities. As

discussed earlier, the Clean Air Act expressly permits

review of such an action. §7607(b)(1). We therefore “may

reverse any such action found to be . . . arbitrary, capri

cious, an abuse of discretion, or otherwise not in accor

dance with law.” §7607(d)(9).

VI

On the merits, the first question is whether §202(a)(1) of

the Clean Air Act authorizes EPA to regulate greenhouse

gas emissions from new motor vehicles in the event that it

forms a “judgment” that such emissions contribute to

climate change. We have little trouble concluding that it

does. In relevant part, §202(a)(1) provides that EPA “shall

by regulation prescribe . . . standards applicable to the

emission of any air pollutant from any class or classes of

new motor vehicles or new motor vehicle engines, which in

[the Administrator’s] judgment cause, or contribute to, air

pollution which may reasonably be anticipated to endan

ger public health or welfare.” 42 U. S. C. §7521(a)(1).

26 MASSACHUSETTS v. EPA

Opinion of the Court

Because EPA believes that Congress did not intend it to

regulate substances that contribute to climate change, the

agency maintains that carbon dioxide is not an “air pollut

ant” within the meaning of the provision.

The statutory text forecloses EPA’s reading. The Clean

Air Act’s sweeping definition of “air pollutant” includes

“any air pollution agent or combination of such agents,

including any physical, chemical . . . substance or matter

which is emitted into or otherwise enters the ambient

air . . . .” §7602(g) (emphasis added). On its face, the

definition embraces all airborne compounds of whatever

stripe, and underscores that intent through the repeated

use of the word “any.”25 Carbon dioxide, methane, nitrous

oxide, and hydrofluorocarbons are without a doubt “physi

cal [and] chemical . . . substance[s] which [are] emitted

into . . . the ambient air.” The statute is unambiguous.26

Rather than relying on statutory text, EPA invokes

——————

25 See Department of Housing and Urban Development v. Rucker, 535

U. S. 125, 131 (2002) (observing that “ ‘any’ . . . has an expansive mean

ing, that is, one or some indiscriminately of whatever kind” (some inter

nal quotation marks omitted)).

26 In dissent, JUSTICE SCALIA maintains that because greenhouse

gases permeate the world’s atmosphere rather than a limited area near

the earth’s surface, EPA’s exclusion of greenhouse gases from the

category of air pollution “agent[s]” is entitled to deference under Chev

ron U. S. A. Inc. v. Natural Resources Defense Council, Inc. 467 U. S.

837 (1984). See post, at 11–13. EPA’s distinction, however, finds no

support in the text of the statute, which uses the phrase “the ambient

air” without distinguishing between atmospheric layers. Moreover, it is

a plainly unreasonable reading of a sweeping statutory provision

designed to capture “any physical, chemical . . . substance or matter

which is emitted into or otherwise enters the ambient air.” 42 U. S. C.

§7602(g). JUSTICE SCALIA does not (and cannot) explain why Congress

would define “air pollutant” so carefully and so broadly, yet confer on

EPA the authority to narrow that definition whenever expedient by

asserting that a particular substance is not an “agent.” At any rate, no

party to this dispute contests that greenhouse gases both “ente[r] the

ambient air” and tend to warm the atmosphere. They are therefore

unquestionably “agent[s]” of air pollution.

Cite as: 549 U. S. ____ (2007) 27

Opinion of the Court

postenactment congressional actions and deliberations it

views as tantamount to a congressional command to re

frain from regulating greenhouse gas emissions. Even if

such postenactment legislative history could shed light on

the meaning of an otherwise-unambiguous statute, EPA

never identifies any action remotely suggesting that Con

gress meant to curtail its power to treat greenhouse gases

as air pollutants. That subsequent Congresses have es

chewed enacting binding emissions limitations to combat

global warming tells us nothing about what Congress

meant when it amended §202(a)(1) in 1970 and 1977.27

And unlike EPA, we have no difficulty reconciling Con

gress’ various efforts to promote interagency collaboration

and research to better understand climate change28 with

the agency’s pre-existing mandate to regulate “any air

pollutant” that may endanger the public welfare. See 42

U. S. C. §7601(a)(1). Collaboration and research do not

——————

27 See United States v. Price, 361 U. S. 304, 313 (1960) (holding that

“the views of a subsequent Congress form a hazardous basis for infer

ring the intent of an earlier one”); see also Cobell v. Norton, 428 F. 3d

1070, 1075 (CADC 2005) (“[P]ost-enactment legislative history is not

only oxymoronic but inherently entitled to little weight”).

28 See, e.g., National Climate Program Act, §5, 92 Stat. 601, 15 U. S. C.

§2901 et seq. (calling for the establishment of a National Climate

Program and for additional climate change research); Global Climate

Protection Act of 1987, §1103, 101 Stat. 1408–1409 (directing EPA and

the Secretary of State to “jointly” develop a “coordinated national policy

on global climate change” and report to Congress); Global Change

Research Act of 1990, Tit. I, 104 Stat. 3097, 15 U. S. C. §§2921–2938

(establishing for the “development and coordination of a comprehensive

and integrated United States research program” to aid in “under

stand[ing] . . . human-induced and natural processes of climate

change”); Global Climate Change Prevention Act of 1990, 104 Stat.

4058, 7 U. S. C. §6701 et seq. (directing the Dept. of Agriculture to

study the effects of climate change on forestry and agriculture); Energy

Policy Act of 1992, §§1601–1609, 106 Stat. 2999, 42 U. S. C. §§13381–

13388 (requiring the Secretary of Energy to report on information

pertaining to climate change).

28 MASSACHUSETTS v. EPA

Opinion of the Court

conflict with any thoughtful regulatory effort; they com

plement it.29

EPA’s reliance on Brown & Williamson Tobacco Corp.,

529 U. S. 120, is similarly misplaced. In holding that

tobacco products are not “drugs” or “devices” subject to

Food and Drug Administration (FDA) regulation pursuant

to the Food, Drug and Cosmetic Act (FDCA), see 529 U. S.,

at 133, we found critical at least two considerations that

have no counterpart in this case.

First, we thought it unlikely that Congress meant to ban

tobacco products, which the FDCA would have required

had such products been classified as “drugs” or “devices.”

Id., at 135–137. Here, in contrast, EPA jurisdiction would

lead to no such extreme measures. EPA would only regu

late emissions, and even then, it would have to delay any

action “to permit the development and application of the

requisite technology, giving appropriate consideration to

the cost of compliance,” §7521(a)(2). However much a ban

on tobacco products clashed with the “common sense”

intuition that Congress never meant to remove those

products from circulation, Brown & Williamson, 529 U. S.,

at 133, there is nothing counterintuitive to the notion that

EPA can curtail the emission of substances that are put

ting the global climate out of kilter.

Second, in Brown & Williamson we pointed to an unbro

ken series of congressional enactments that made sense

only if adopted “against the backdrop of the FDA’s consis

tent and repeated statements that it lacked authority under

the FDCA to regulate tobacco.” Id., at 144. We can point to

no such enactments here: EPA has not identified any con

gressional action that conflicts in any way with the regula

——————

29 We are moreover puzzled by EPA’s roundabout argument that be

cause later Congresses chose to address stratospheric ozone pollution in

a specific legislative provision, it somehow follows that greenhouse

gases cannot be air pollutants within the meaning of the Clean Air Act.

Cite as: 549 U. S. ____ (2007) 29

Opinion of the Court

tion of greenhouse gases from new motor vehicles. Even if

it had, Congress could not have acted against a regulatory

“backdrop” of disclaimers of regulatory authority. Prior to

the order that provoked this litigation, EPA had never

disavowed the authority to regulate greenhouse gases, and

in 1998 it in fact affirmed that it had such authority. See

App. 54 (Cannon memorandum). There is no reason, much

less a compelling reason, to accept EPA’s invitation to read

ambiguity into a clear statute.

EPA finally argues that it cannot regulate carbon diox

ide emissions from motor vehicles because doing so would

require it to tighten mileage standards, a job (according to

EPA) that Congress has assigned to DOT. See 68 Fed.

Reg. 52929. But that DOT sets mileage standards in no

way licenses EPA to shirk its environmental responsibili

ties. EPA has been charged with protecting the public’s

“health” and “welfare,” 42 U. S. C. §7521(a)(1), a statutory

obligation wholly independent of DOT’s mandate to pro

mote energy efficiency. See Energy Policy and Conserva

tion Act, §2(5), 89 Stat. 874, 42 U. S. C. §6201(5). The two

obligations may overlap, but there is no reason to think

the two agencies cannot both administer their obligations

and yet avoid inconsistency.

While the Congresses that drafted §202(a)(1) might not

have appreciated the possibility that burning fossil fuels

could lead to global warming, they did understand that

without regulatory flexibility, changing circumstances and

scientific developments would soon render the Clean Air

Act obsolete. The broad language of §202(a)(1) reflects an

intentional effort to confer the flexibility necessary to

forestall such obsolescence. See Pennsylvania Dept. of

Corrections v. Yeskey, 524 U. S. 206, 212 (1998) (“[T]he

fact that a statute can be applied in situations not ex

pressly anticipated by Congress does not demonstrate

ambiguity. It demonstrates breadth” (internal quotation

marks omitted)). Because greenhouse gases fit well within

30 MASSACHUSETTS v. EPA

Opinion of the Court

the Clean Air Act’s capacious definition of “air pollutant,”

we hold that EPA has the statutory authority to regulate

the emission of such gases from new motor vehicles.

VII

The alternative basis for EPA’s decision—that even if it

does have statutory authority to regulate greenhouse

gases, it would be unwise to do so at this time—rests on

reasoning divorced from the statutory text. While the

statute does condition the exercise of EPA’s authority on

its formation of a “judgment,” 42 U. S. C. §7521(a)(1), that

judgment must relate to whether an air pollutant

“cause[s], or contribute[s] to, air pollution which may

reasonably be anticipated to endanger public health or

welfare,” ibid. Put another way, the use of the word “judg

ment” is not a roving license to ignore the statutory text.

It is but a direction to exercise discretion within defined

statutory limits.

If EPA makes a finding of endangerment, the Clean Air

Act requires the agency to regulate emissions of the dele

terious pollutant from new motor vehicles. Ibid. (stating

that “[EPA] shall by regulation prescribe . . . standards

applicable to the emission of any air pollutant from any

class of new motor vehicles”). EPA no doubt has signifi

cant latitude as to the manner, timing, content, and coor

dination of its regulations with those of other agencies.

But once EPA has responded to a petition for rulemaking,

its reasons for action or inaction must conform to the

authorizing statute. Under the clear terms of the Clean

Air Act, EPA can avoid taking further action only if it

determines that greenhouse gases do not contribute to

climate change or if it provides some reasonable explana

tion as to why it cannot or will not exercise its discretion

to determine whether they do. Ibid. To the extent that

this constrains agency discretion to pursue other priorities

of the Administrator or the President, this is the congres

sional design.

Cite as: 549 U. S. ____ (2007) 31

Opinion of the Court

EPA has refused to comply with this clear statutory

command. Instead, it has offered a laundry list of reasons

not to regulate. For example, EPA said that a number of

voluntary executive branch programs already provide an

effective response to the threat of global warming, 68 Fed.

Reg. 52932, that regulating greenhouse gases might im

pair the President’s ability to negotiate with “key develop

ing nations” to reduce emissions, id., at 52931, and that

curtailing motor-vehicle emissions would reflect “an ineffi

cient, piecemeal approach to address the climate change

issue,” ibid.

Although we have neither the expertise nor the author

ity to evaluate these policy judgments, it is evident they

have nothing to do with whether greenhouse gas emis

sions contribute to climate change. Still less do they

amount to a reasoned justification for declining to form a

scientific judgment. In particular, while the President has

broad authority in foreign affairs, that authority does not

extend to the refusal to execute domestic laws. In the

Global Climate Protection Act of 1987, Congress author

ized the State Department—not EPA—to formulate United

States foreign policy with reference to environmental mat

ters relating to climate. See §1103(c), 101 Stat. 1409. EPA

has made no showing that it issued the ruling in question

here after consultation with the State Department. Con

gress did direct EPA to consult with other agencies in the

formulation of its policies and rules, but the State Depart

ment is absent from that list. §1103(b).

Nor can EPA avoid its statutory obligation by noting the

uncertainty surrounding various features of climate change

and concluding that it would therefore be better not to

regulate at this time. See 68 Fed. Reg. 52930–52931. If the

scientific uncertainty is so profound that it precludes EPA

from making a reasoned judgment as to whether green

house gases contribute to global warming, EPA must say

so. That EPA would prefer not to regulate greenhouse

32 MASSACHUSETTS v. EPA

Opinion of the Court

gases because of some residual uncertainty—which, con

trary to JUSTICE SCALIA’s apparent belief, post, at 5–8, is

in fact all that it said, see 68 Fed. Reg. 52929 (“We do not

believe . . . that it would be either effective or appropriate

for EPA to establish [greenhouse gas] standards for motor

vehicles at this time” (emphasis added))—is irrelevant.

The statutory question is whether sufficient information

exists to make an endangerment finding.

In short, EPA has offered no reasoned explanation for

its refusal to decide whether greenhouse gases cause or

contribute to climate change. Its action was therefore

“arbitrary, capricious, . . . or otherwise not in accordance

with law.” 42 U. S. C. §7607(d)(9)(A). We need not and do

not reach the question whether on remand EPA must

make an endangerment finding, or whether policy con

cerns can inform EPA’s actions in the event that it makes

such a finding. Cf. Chevron U. S. A. Inc. v. Natural Re

sources Defense Council, Inc., 467 U. S. 837, 843–844

(1984). We hold only that EPA must ground its reasons

for action or inaction in the statute.

VIII

The judgment of the Court of Appeals is reversed, and

the case is remanded for further proceedings consistent

with this opinion.

It is so ordered.

Cite as: 549 U. S. ____ (2007) 1

ROBERTS, C. J., dissenting

SUPREME COURT OF THE UNITED STATES

_________________

No. 05–1120

_________________

MASSACHUSETTS, ET AL., PETITIONERS v. ENVIRON

MENTAL PROTECTION AGENCY ET AL.

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE DISTRICT OF COLUMBIA CIRCUIT

[April 2, 2007]

CHIEF JUSTICE ROBERTS, with whom JUSTICE SCALIA,

JUSTICE THOMAS, and JUSTICE ALITO join, dissenting.

Global warming may be a “crisis,” even “the most press

ing environmental problem of our time.” Pet. for Cert. 26,

22. Indeed, it may ultimately affect nearly everyone on

the planet in some potentially adverse way, and it may be

that governments have done too little to address it. It is

not a problem, however, that has escaped the attention of

policymakers in the Executive and Legislative Branches of

our Government, who continue to consider regulatory,

legislative, and treaty-based means of addressing global

climate change.

Apparently dissatisfied with the pace of progress on this

issue in the elected branches, petitioners have come to the

courts claiming broad-ranging injury, and attempting to

tie that injury to the Government’s alleged failure to

comply with a rather narrow statutory provision. I would

reject these challenges as nonjusticiable. Such a conclu

sion involves no judgment on whether global warming

exists, what causes it, or the extent of the problem. Nor

does it render petitioners without recourse. This Court’s

standing jurisprudence simply recognizes that redress of

grievances of the sort at issue here “is the function of

Congress and the Chief Executive,” not the federal courts.

Lujan v. Defenders of Wildlife, 504 U. S. 555, 576 (1992). I

2 MASSACHUSETTS v. EPA

ROBERTS, C. J., dissenting

would vacate the judgment below and remand for dis

missal of the petitions for review.

I

Article III, §2, of the Constitution limits the federal

judicial power to the adjudication of “Cases” and “Contro

versies.” “If a dispute is not a proper case or controversy,

the courts have no business deciding it, or expounding the

law in the course of doing so.” DaimlerChrysler Corp. v.

Cuno, 547 U. S. ___, ___ (2006) (slip op., at 5). “Standing

to sue is part of the common understanding of what it

takes to make a justiciable case,” Steel Co. v. Citizens for

Better Environment, 523 U. S. 83, 102 (1998), and has

been described as “an essential and unchanging part of the

case-or-controversy requirement of Article III,” Defenders

of Wildlife, supra, at 560.

Our modern framework for addressing standing is famil

iar: “A plaintiff must allege personal injury fairly trace

able to the defendant’s allegedly unlawful conduct and

likely to be redressed by the requested relief.” Daimler-

Chrysler, supra, at ___ (slip op., at 6) (quoting Allen v.

Wright, 468 U. S. 737, 751 (1984) (internal quotation

marks omitted)). Applying that standard here, petitioners

bear the burden of alleging an injury that is fairly trace

able to the Environmental Protection Agency’s failure to

promulgate new motor vehicle greenhouse gas emission

standards, and that is likely to be redressed by the pro

spective issuance of such standards.

Before determining whether petitioners can meet this

familiar test, however, the Court changes the rules. It

asserts that “States are not normal litigants for the pur

poses of invoking federal jurisdiction,” and that given

“Massachusetts’ stake in protecting its quasi-sovereign

interests, the Commonwealth is entitled to special solici

tude in our standing analysis.” Ante, at 15, 17 (emphasis

added).

Cite as: 549 U. S. ____ (2007) 3

ROBERTS, C. J., dissenting

Relaxing Article III standing requirements because

asserted injuries are pressed by a State, however, has no

basis in our jurisprudence, and support for any such “spe

cial solicitude” is conspicuously absent from the Court’s

opinion. The general judicial review provision cited by the

Court, 42 U. S. C. §7607(b)(1), affords States no special

rights or status. The Court states that “Congress has

ordered EPA to protect Massachusetts (among others)”

through the statutory provision at issue, §7521(a)(1), and

that “Congress has . . . recognized a concomitant proce

dural right to challenge the rejection of its rulemaking

petition as arbitrary and capricious.” Ante, at 16. The

reader might think from this unfortunate phrasing that

Congress said something about the rights of States in this

particular provision of the statute. Congress knows how

to do that when it wants to, see, e.g., §7426(b) (affording

States the right to petition EPA to directly regulate cer

tain sources of pollution), but it has done nothing of the

sort here. Under the law on which petitioners rely, Con

gress treated public and private litigants exactly the same.

Nor does the case law cited by the Court provide any

support for the notion that Article III somehow implicitly

treats public and private litigants differently. The Court

has to go back a full century in an attempt to justify its

novel standing rule, but even there it comes up short. The

Court’s analysis hinges on Georgia v. Tennessee Copper

Co., 206 U. S. 230 (1907)—a case that did indeed draw a

distinction between a State and private litigants, but

solely with respect to available remedies. The case had

nothing to do with Article III standing.

In Tennessee Copper, the State of Georgia sought to

enjoin copper companies in neighboring Tennessee from

discharging pollutants that were inflicting “a wholesale

destruction of forests, orchards and crops” in bordering

Georgia counties. Id., at 236. Although the State owned

very little of the territory allegedly affected, the Court

4 MASSACHUSETTS v. EPA

ROBERTS, C. J., dissenting

reasoned that Georgia—in its capacity as a “quasi

sovereign”—“has an interest independent of and behind

the titles of its citizens, in all the earth and air within its

domain.” Id., at 237. The Court explained that while

“[t]he very elements that would be relied upon in a suit

between fellow-citizens as a ground for equitable relief

[were] wanting,” a State “is not lightly to be required to

give up quasi-sovereign rights for pay.” Ibid. Thus while

a complaining private litigant would have to make do with

a legal remedy—one “for pay”—the State was entitled to

equitable relief. See id., at 237–238.

In contrast to the present case, there was no question in

Tennessee Copper about Article III injury. See id., at 238–

239. There was certainly no suggestion that the State

could show standing where the private parties could not;

there was no dispute, after all, that the private landown

ers had “an action at law.” Id., at 238. Tennessee Copper

has since stood for nothing more than a State’s right, in an

original jurisdiction action, to sue in a representative

capacity as parens patriae. See, e.g., Maryland v. Louisi

ana, 451 U. S. 725, 737 (1981). Nothing about a State’s

ability to sue in that capacity dilutes the bedrock require

ment of showing injury, causation, and redressability to

satisfy Article III.

A claim of parens patriae standing is distinct from an

allegation of direct injury. See Wyoming v. Oklahoma, 502

U. S. 437, 448–449, 451 (1992). Far from being a substi

tute for Article III injury, parens patriae actions raise an

additional hurdle for a state litigant: the articulation of a

“quasi-sovereign interest” “apart from the interests of

particular private parties.” Alfred L. Snapp & Son, Inc. v.

Puerto Rico ex rel. Barez, 458 U. S. 592, 607 (1982) (em

phasis added) (cited ante, at 16). Just as an association

suing on behalf of its members must show not only that it

represents the members but that at least one satisfies

Article III requirements, so too a State asserting quasi

Cite as: 549 U. S. ____ (2007) 5

ROBERTS, C. J., dissenting

sovereign interests as parens patriae must still show that

its citizens satisfy Article III. Focusing on Massachu

setts’s interests as quasi-sovereign makes the required

showing here harder, not easier. The Court, in effect,

takes what has always been regarded as a necessary condi

tion for parens patriae standing—a quasi-sovereign inter

est—and converts it into a sufficient showing for purposes

of Article III.

What is more, the Court’s reasoning falters on its own

terms. The Court asserts that Massachusetts is entitled

to “special solicitude” due to its “quasi-sovereign inter

ests,” ante, at 17, but then applies our Article III standing

test to the asserted injury of the State’s loss of coastal

property. See ante, at 19 (concluding that Massachusetts

“has alleged a particularized injury in its capacity as a

landowner” (emphasis added)). In the context of parens

patriae standing, however, we have characterized state

ownership of land as a “nonsovereign interes[t]” because a

State “is likely to have the same interests as other simi

larly situated proprietors.” Alfred L. Snapp & Son, supra,

at 601.

On top of everything else, the Court overlooks the fact

that our cases cast significant doubt on a State’s standing

to assert a quasi-sovereign interest—as opposed to a direct

injury—against the Federal Government. As a general

rule, we have held that while a State might assert a quasi-

sovereign right as parens patriae “for the protection of its

citizens, it is no part of its duty or power to enforce their

rights in respect of their relations with the Federal Gov

ernment. In that field it is the United States, and not the

State, which represents them.” Massachusetts v. Mellon,

262 U. S. 447, 485–486 (1923) (citation omitted); see also

Alfred L. Snapp & Son, supra, at 610, n. 16.

All of this presumably explains why petitioners never

cited Tennessee Copper in their briefs before this Court or

the D. C. Circuit. It presumably explains why not one of

6 MASSACHUSETTS v. EPA

ROBERTS, C. J., dissenting

the legion of amici supporting petitioners ever cited the

case. And it presumably explains why not one of the three

judges writing below ever cited the case either. Given that

one purpose of the standing requirement is “ ‘to assure

that concrete adverseness which sharpens the presenta

tion of issues upon which the court so largely depends for

illumination,’ ” ante, at 13–14 (quoting Baker v. Carr, 369

U. S. 186, 204 (1962)), it is ironic that the Court today

adopts a new theory of Article III standing for States

without the benefit of briefing or argument on the point.1

II

It is not at all clear how the Court’s “special solicitude”

for Massachusetts plays out in the standing analysis,

except as an implicit concession that petitioners cannot

establish standing on traditional terms. But the status of

Massachusetts as a State cannot compensate for petition

ers’ failure to demonstrate injury in fact, causation, and

redressability.

When the Court actually applies the three-part test, it

focuses, as did the dissent below, see 415 F. 3d 50, 64

——————

1 The Court seems to think we do not recognize that Tennessee Copper

is a case about parens patriae standing, ante, at 17, n. 17, but we have

no doubt about that. The point is that nothing in our cases (or Hart &

Wechsler) suggests that the prudential requirements for parens patriae

standing, see Republic of Venezuela v. Philip Morris Inc., 287 F. 3d 192,

199, n. (CADC 2002) (observing that “parens patriae is merely a species

of prudential standing” (internal quotation marks omitted)), can

somehow substitute for, or alter the content of, the “irreducible consti

tutional minimum” requirements of injury in fact, causation, and

redressability under Article III. Lujan v. Defenders of Wildlife, 504

U. S. 555, 560 (1992).

Georgia v. Pennsylvania R. Co., 324 U. S. 439 (1945), is not to the

contrary. As the caption makes clear enough, the fact that a State may

assert rights under a federal statute as parens patriae in no way refutes

our clear ruling that “[a] State does not have standing as parens patriae

to bring an action against the Federal Government.” Alfred L. Snapp &

Son, Inc. v. Puerto Rico ex rel. Barez, 458 U. S. 592, 610, n. 16 (1982).

Cite as: 549 U. S. ____ (2007) 7

ROBERTS, C. J., dissenting

(CADC 2005) (opinion of Tatel, J.), on the State’s asserted

loss of coastal land as the injury in fact. If petitioners rely

on loss of land as the Article III injury, however, they

must ground the rest of the standing analysis in that

specific injury. That alleged injury must be “concrete and

particularized,” Defenders of Wildlife, 504 U. S., at 560,

and “distinct and palpable,” Allen, 468 U. S., at 751 (in

ternal quotation marks omitted). Central to this concept

of “particularized” injury is the requirement that a plain

tiff be affected in a “personal and individual way,” Defend

ers of Wildlife, 504 U. S., at 560, n. 1, and seek relief that

“directly and tangibly benefits him” in a manner distinct

from its impact on “the public at large,” id., at 573–574.

Without “particularized injury, there can be no confidence

of ‘a real need to exercise the power of judicial review’ or

that relief can be framed ‘no broader than required by the

precise facts to which the court’s ruling would be applied.’ ”

Warth v. Seldin, 422 U. S. 490, 508 (1975) (quoting

Schlesinger v. Reservists Comm. to Stop the War, 418 U. S.

208, 221–222 (1974)).

The very concept of global warming seems inconsistent

with this particularization requirement. Global warming

is a phenomenon “harmful to humanity at large,” 415

F. 3d, at 60 (Sentelle, J., dissenting in part and concurring

in judgment), and the redress petitioners seek is focused

no more on them than on the public generally—it is liter

ally to change the atmosphere around the world.

If petitioners’ particularized injury is loss of coastal

land, it is also that injury that must be “actual or immi

nent, not conjectural or hypothetical,” Defenders of Wild

life, supra, at 560 (internal quotation marks omitted),

“real and immediate,” Los Angeles v. Lyons, 461 U. S. 95,

102 (1983) (internal quotation marks omitted), and “cer

tainly impending,” Whitmore v. Arkansas, 495 U. S. 149,

158 (1990) (internal quotation marks omitted).

As to “actual” injury, the Court observes that “global sea

8 MASSACHUSETTS v. EPA

ROBERTS, C. J., dissenting

levels rose somewhere between 10 and 20 centimeters over

the 20th century as a result of global warming” and that

“[t]hese rising seas have already begun to swallow Massa

chusetts’ coastal land.” Ante, at 19. But none of petition

ers’ declarations supports that connection. One declara

tion states that “a rise in sea level due to climate change is

occurring on the coast of Massachusetts, in the metropoli

tan Boston area,” but there is no elaboration. Petitioners’

Standing Appendix in No. 03–1361, etc. (CADC), p. 196

(Stdg. App.). And the declarant goes on to identify a “sig

nifican[t]” non-global-warming cause of Boston’s rising sea

level: land subsidence. Id., at 197; see also id., at 216.

Thus, aside from a single conclusory statement, there is

nothing in petitioners’ 43 standing declarations and ac

companying exhibits to support an inference of actual loss

of Massachusetts coastal land from 20th century global

sea level increases. It is pure conjecture.

The Court’s attempts to identify “imminent” or “cer

tainly impending” loss of Massachusetts coastal land fares

no better. See ante, at 19–20. One of petitioners’ decla

rants predicts global warming will cause sea level to rise

by 20 to 70 centimeters by the year 2100. Stdg. App. 216.

Another uses a computer modeling program to map the

Commonwealth’s coastal land and its current elevation,

and calculates that the high-end estimate of sea level rise

would result in the loss of significant state-owned coastal

land. Id., at 179. But the computer modeling program

has a conceded average error of about 30 centimeters and

a maximum observed error of 70 centimeters. Id., at 177–

178. As an initial matter, if it is possible that the model

underrepresents the elevation of coastal land to an extent

equal to or in excess of the projected sea level rise, it is

difficult to put much stock in the predicted loss of land.

But even placing that problem to the side, accepting a

century-long time horizon and a series of compounded

estimates renders requirements of imminence and imme

Cite as: 549 U. S. ____ (2007) 9

ROBERTS, C. J., dissenting

diacy utterly toothless. See Defenders of Wildlife, supra,

at 565, n. 2 (while the concept of “ ‘imminence’ ” in stand

ing doctrine is “somewhat elastic,” it can be “stretched

beyond the breaking point”). “Allegations of possible

future injury do not satisfy the requirements of Art. III. A

threatened injury must be certainly impending to consti

tute injury in fact.” Whitmore, supra, at 158. (internal

quotation marks omitted; emphasis added).

III

Petitioners’ reliance on Massachusetts’s loss of coastal

land as their injury in fact for standing purposes creates

insurmountable problems for them with respect to causa

tion and redressability. To establish standing, petitioners

must show a causal connection between that specific

injury and the lack of new motor vehicle greenhouse gas

emission standards, and that the promulgation of such

standards would likely redress that injury. As is often the

case, the questions of causation and redressability overlap.

See Allen, 468 U. S., at 753, n. 19 (observing that the two

requirements were “initially articulated by this Court as

two facets of a single causation requirement” (internal

quotation marks omitted)). And importantly, when a

party is challenging the Government’s allegedly unlawful

regulation, or lack of regulation, of a third party, satisfy

ing the causation and redressability requirements be

comes “substantially more difficult.” Defenders of Wildlife,

supra, at 562 (internal quotation marks omitted); see also

Warth, supra, at 504–505.

Petitioners view the relationship between their injuries

and EPA’s failure to promulgate new motor vehicle green

house gas emission standards as simple and direct: Do

mestic motor vehicles emit carbon dioxide and other

greenhouse gases. Worldwide emissions of greenhouse

gases contribute to global warming and therefore also to

petitioners’ alleged injuries. Without the new vehicle

10 MASSACHUSETTS v. EPA

ROBERTS, C. J., dissenting

standards, greenhouse gas emissions—and therefore

global warming and its attendant harms—have been

higher than they otherwise would have been; once EPA

changes course, the trend will be reversed.

The Court ignores the complexities of global warming,

and does so by now disregarding the “particularized”

injury it relied on in step one, and using the dire nature of

global warming itself as a bootstrap for finding causation

and redressability. First, it is important to recognize the

extent of the emissions at issue here. Because local

greenhouse gas emissions disperse throughout the atmos

phere and remain there for anywhere from 50 to 200

years, it is global emissions data that are relevant. See

App. to Pet. for Cert. A–73. According to one of petition

ers’ declarations, domestic motor vehicles contribute about

6 percent of global carbon dioxide emissions and 4 percent

of global greenhouse gas emissions. Stdg. App. 232. The

amount of global emissions at issue here is smaller still;

§202(a)(1) of the Clean Air Act covers only new motor

vehicles and new motor vehicle engines, so petitioners’

desired emission standards might reduce only a fraction of

4 percent of global emissions.

This gets us only to the relevant greenhouse gas emis

sions; linking them to global warming and ultimately to

petitioners’ alleged injuries next requires consideration of

further complexities. As EPA explained in its denial of

petitioners’ request for rulemaking,

“predicting future climate change necessarily involves

a complex web of economic and physical factors in

cluding: our ability to predict future global anthropo

genic emissions of [greenhouse gases] and aerosols;

the fate of these emissions once they enter the atmos

phere (e.g., what percentage are absorbed by vegeta

tion or are taken up by the oceans); the impact of

those emissions that remain in the atmosphere on the

Cite as: 549 U. S. ____ (2007) 11

ROBERTS, C. J., dissenting

radiative properties of the atmosphere; changes in

critically important climate feedbacks (e.g., changes in

cloud cover and ocean circulation); changes in tem

perature characteristics (e.g., average temperatures,

shifts in daytime and evening temperatures); changes

in other climatic parameters (e.g., shifts in precipita

tion, storms); and ultimately the impact of such

changes on human health and welfare (e.g., increases

or decreases in agricultural productivity, human

health impacts).” App. to Pet. for Cert. A–83 through

A–84.

Petitioners are never able to trace their alleged injuries

back through this complex web to the fractional amount of

global emissions that might have been limited with EPA

standards. In light of the bit-part domestic new motor

vehicle greenhouse gas emissions have played in what

petitioners describe as a 150-year global phenomenon, and

the myriad additional factors bearing on petitioners’ al

leged injury—the loss of Massachusetts coastal land—the

connection is far too speculative to establish causation.

IV

Redressability is even more problematic. To the tenu

ous link between petitioners’ alleged injury and the inde

terminate fractional domestic emissions at issue here, add

the fact that petitioners cannot meaningfully predict what

will come of the 80 percent of global greenhouse gas emis

sions that originate outside the United States. As the

Court acknowledges, “developing countries such as China

and India are poised to increase greenhouse gas emissions

substantially over the next century,” ante, at 23, so the

domestic emissions at issue here may become an increas

ingly marginal portion of global emissions, and any de

creases produced by petitioners’ desired standards are

likely to be overwhelmed many times over by emissions

increases elsewhere in the world.

12 MASSACHUSETTS v. EPA

ROBERTS, C. J., dissenting

Petitioners offer declarations attempting to address this

uncertainty, contending that “[i]f the U. S. takes steps to

reduce motor vehicle emissions, other countries are very

likely to take similar actions regarding their own motor

vehicles using technology developed in response to the

U. S. program.” Stdg. App. 220; see also id., at 311–312.

In other words, do not worry that other countries will

contribute far more to global warming than will U. S.

automobile emissions; someone is bound to invent some

thing, and places like the People’s Republic of China or

India will surely require use of the new technology, re

gardless of cost. The Court previously has explained that

when the existence of an element of standing “depends on

the unfettered choices made by independent actors not

before the courts and whose exercise of broad and legiti

mate discretion the courts cannot presume either to con

trol or to predict,” a party must present facts supporting

an assertion that the actor will proceed in such a manner.

Defenders of Wildlife, 504 U. S., at 562 (quoting ASARCO

Inc. v. Kadish, 490 U. S. 605, 615 (1989) (opinion of

KENNEDY, J.); internal quotation marks omitted). The

declarations’ conclusory (not to say fanciful) statements do

not even come close.

No matter, the Court reasons, because any decrease in

domestic emissions will “slow the pace of global emissions

increases, no matter what happens elsewhere.” Ante, at

23. Every little bit helps, so Massachusetts can sue over

any little bit.

The Court’s sleight-of-hand is in failing to link up the

different elements of the three-part standing test. What

must be likely to be redressed is the particular injury in

fact. The injury the Court looks to is the asserted loss of

land. The Court contends that regulating domestic motor

vehicle emissions will reduce carbon dioxide in the atmos

phere, and therefore redress Massachusetts’s injury. But

even if regulation does reduce emissions—to some inde

Cite as: 549 U. S. ____ (2007) 13

ROBERTS, C. J., dissenting

terminate degree, given events elsewhere in the world—

the Court never explains why that makes it likely that the

injury in fact—the loss of land—will be redressed. School

children know that a kingdom might be lost “all for the

want of a horseshoe nail,” but “likely” redressability is a

different matter. The realities make it pure conjecture to

suppose that EPA regulation of new automobile emissions

will likely prevent the loss of Massachusetts coastal land.

V

Petitioners’ difficulty in demonstrating causation and

redressability is not surprising given the evident mis

match between the source of their alleged injury—

catastrophic global warming—and the narrow subject

matter of the Clean Air Act provision at issue in this suit.

The mismatch suggests that petitioners’ true goal for this

litigation may be more symbolic than anything else. The

constitutional role of the courts, however, is to decide

concrete cases—not to serve as a convenient forum for

policy debates. See Valley Forge Christian College v.

Americans United for Separation of Church and State,

Inc., 454 U. S. 464, 472 (1982) (“[Standing] tends to assure

that the legal questions presented to the court will be

resolved, not in the rarified atmosphere of a debating

society, but in a concrete factual context conducive to

a realistic appreciation of the consequences of judicial

action”).

When dealing with legal doctrine phrased in terms of

what is “fairly” traceable or “likely” to be redressed, it is

perhaps not surprising that the matter is subject to some

debate. But in considering how loosely or rigorously to

define those adverbs, it is vital to keep in mind the pur

pose of the inquiry. The limitation of the judicial power to

cases and controversies “is crucial in maintaining the

tripartite allocation of power set forth in the Constitution.”

DaimlerChrysler, 547 U. S., at ___ (slip op., at 5) (internal

14 MASSACHUSETTS v. EPA

ROBERTS, C. J., dissenting

quotation marks omitted). In my view, the Court today—

addressing Article III’s “core component of standing,”

Defenders of Wildlife, supra, at 560—fails to take this

limitation seriously.

To be fair, it is not the first time the Court has done so.

Today’s decision recalls the previous high-water mark of

diluted standing requirements, United States v. Students

Challenging Regulatory Agency Procedures (SCRAP), 412

U. S. 669 (1973). SCRAP involved “[p]robably the most

attenuated injury conferring Art. III standing” and “surely

went to the very outer limit of the law”—until today.

Whitmore, 495 U. S., at 158–159; see also Lujan v. Na

tional Wildlife Federation, 497 U. S. 871, 889 (1990)

(SCRAP “has never since been emulated by this Court”).

In SCRAP, the Court based an environmental group’s

standing to challenge a railroad freight rate surcharge on

the group’s allegation that increases in railroad rates

would cause an increase in the use of nonrecyclable goods,

resulting in the increased need for natural resources to

produce such goods. According to the group, some of these

resources might be taken from the Washington area,

resulting in increased refuse that might find its way into

area parks, harming the group’s members. 412 U. S., at

688.

Over time, SCRAP became emblematic not of the loose

ness of Article III standing requirements, but of how

utterly manipulable they are if not taken seriously as a

matter of judicial self-restraint. SCRAP made standing

seem a lawyer’s game, rather than a fundamental limita

tion ensuring that courts function as courts and not in

trude on the politically accountable branches. Today’s

decision is SCRAP for a new generation.2

——————

2 The difficulty with SCRAP, and the reason it has not been followed,

is not the portion cited by the Court. See ante, at 23–24, n. 24. Rather,

it is the attenuated nature of the injury there, and here, that is so

Cite as: 549 U. S. ____ (2007) 15

ROBERTS, C. J., dissenting

Perhaps the Court recognizes as much. How else to

explain its need to devise a new doctrine of state standing

to support its result? The good news is that the Court’s

“special solicitude” for Massachusetts limits the future

applicability of the diluted standing requirements applied

in this case. The bad news is that the Court’s self-

professed relaxation of those Article III requirements has

caused us to transgress “the proper—and properly lim

ited—role of the courts in a democratic society.” Allen, 468

U. S., at 750 (internal quotation marks omitted).

I respectfully dissent.

——————

troubling. Even in SCRAP, the Court noted that what was required

was “something more than an ingenious academic exercise in the

conceivable,” 412 U. S., at 688, and we have since understood the

allegation there to have been “that the string of occurrences alleged

would happen immediately,” Whitmore v. Arkansas, 495 U. S. 149, 159

(1990) (emphasis added). That is hardly the case here.

The Court says it is “quite wrong” to compare petitioners’ challenging

“EPA’s parsimonious construction of the Clean Air Act to a mere

‘lawyer’s game.’ ” Ante, at 24, n. 24. Of course it is not the legal chal

lenge that is merely “an ingenious academic exercise in the conceiv

able,” SCRAP, supra, at 688, but the assertions made in support of

standing.

Cite as: 549 U. S. ____ (2007) 1

SCALIA, J., dissenting

SUPREME COURT OF THE UNITED STATES

_________________

No. 05–1120

_________________

MASSACHUSETTS, ET AL., PETITIONERS v. ENVIRON

MENTAL PROTECTION AGENCY ET AL.

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

APPEALS FOR THE DISTRICT OF COLUMBIA CIRCUIT

[April 2, 2007]

JUSTICE SCALIA, with whom THE CHIEF JUSTICE,

JUSTICE THOMAS, and JUSTICE ALITO join, dissenting.

I join THE CHIEF JUSTICE’s opinion in full, and would

hold that this Court has no jurisdiction to decide this case

because petitioners lack standing. The Court having

decided otherwise, it is appropriate for me to note my

dissent on the merits.

I

A

The provision of law at the heart of this case is

§202(a)(1) of the Clean Air Act (CAA), which provides that

the Administrator of the Environmental Protection Agency

(EPA) “shall by regulation prescribe . . . standards appli

cable to the emission of any air pollutant from any class or

classes of new motor vehicles or new motor vehicle en

gines, which in his judgment cause, or contribute to, air

pollution which may reasonably be anticipated to endan

ger public health or welfare.” 42 U. S. C. §7521(a)(1)

(emphasis added). As the Court recognizes, the statute

“condition[s] the exercise of EPA’s authority on its forma

tion of a ‘judgment.’ ” Ante, at 30. There is no dispute that

the Administrator has made no such judgment in this

case. See ante, at 32 (“We need not and do not reach the

question whether on remand EPA must make an endan

2 MASSACHUSETTS v. EPA

SCALIA, J., dissenting

germent finding”); 68 Fed. 52929 (2003) (“[N]o Adminis

trator has made a finding under any of the CAA’s regula

tory provisions that CO2 meets the applicable statutory

criteria for regulation”).

The question thus arises: Does anything require the

Administrator to make a “judgment” whenever a petition

for rulemaking is filed? Without citation of the statute or

any other authority, the Court says yes. Why is that so?

When Congress wishes to make private action force an

agency’s hand, it knows how to do so. See, e.g., Brock v.

Pierce County, 476 U. S. 253, 254–255 (1986) (discussing

the Comprehensive Employment and Training Act

(CETA), 92 Stat. 1926, 29 U. S. C. §816(b) (1976 ed., Supp.

V), which “provide[d] that the Secretary of Labor ‘shall’

issue a final determination as to the misuse of CETA

funds by a grant recipient within 120 days after receiving

a complaint alleging such misuse”). Where does the CAA

say that the EPA Administrator is required to come to a

decision on this question whenever a rulemaking petition

is filed? The Court points to no such provision because

none exists.

Instead, the Court invents a multiple-choice question

that the EPA Administrator must answer when a petition

for rulemaking is filed. The Administrator must exercise

his judgment in one of three ways: (a) by concluding that

the pollutant does cause, or contribute to, air pollution

that endangers public welfare (in which case EPA is re

quired to regulate); (b) by concluding that the pollutant

does not cause, or contribute to, air pollution that endan

gers public welfare (in which case EPA is not required to

regulate); or (c) by “provid[ing] some reasonable explana

tion as to why it cannot or will not exercise its discretion

to determine whether” greenhouse gases endanger public

welfare, ante, at 30, (in which case EPA is not required to

regulate).

I am willing to assume, for the sake of argument, that

Cite as: 549 U. S. ____ (2007) 3

SCALIA, J., dissenting

the Administrator’s discretion in this regard is not entirely

unbounded—that if he has no reasonable basis for defer

ring judgment he must grasp the nettle at once. The

Court, however, with no basis in text or precedent, rejects

all of EPA’s stated “policy judgments” as not “amount[ing]

to a reasoned justification,” ante, at 31, effectively narrow

ing the universe of potential reasonable bases to a single

one: Judgment can be delayed only if the Administrator

concludes that “the scientific uncertainty is [too] pro

found.” Ibid. The Administrator is precluded from con

cluding for other reasons “that it would . . . be better not to

regulate at this time.” Ibid.1 Such other reasons—

perfectly valid reasons—were set forth in the agency’s

statement.

“We do not believe . . . that it would be either effective

or appropriate for EPA to establish [greenhouse gas]

standards for motor vehicles at this time. As de

scribed in detail below, the President has laid out a

comprehensive approach to climate change that calls

for near-term voluntary actions and incentives along

with programs aimed at reducing scientific uncertain

ties and encouraging technological development so

that the government may effectively and efficiently

address the climate change issue over the long term.

. . . . .

“[E]stablishing [greenhouse gas] emission standards

for U. S. motor vehicles at this time would . . . result

in an inefficient, piecemeal approach to addressing

the climate change issue. The U. S. motor vehicle

fleet is one of many sources of [greenhouse gas] emis

sions both here and abroad, and different [greenhouse

——————

1 The Court’s way of putting it is, of course, not quite accurate. The

issue is whether it would be better to defer the decision about whether to

exercise judgment. This has the effect of deferring regulation but is

quite a different determination.

4 MASSACHUSETTS v. EPA

SCALIA, J., dissenting

gas] emission sources face different technological and

financial challenges in reducing emissions. A sensible

regulatory scheme would require that all significant

sources and sinks of [greenhouse gas] emissions be

considered in deciding how best to achieve any needed

emission reductions.

“Unilateral EPA regulation of motor vehicle [green

house gas] emissions could also weaken U. S. efforts

to persuade developing countries to reduce the

[greenhouse gas] intensity of their economies. Con

sidering the large populations and growing economies

of some developing countries, increases in their

[greenhouse gas] emissions could quickly overwhelm

the effects of [greenhouse gas] reduction measures in

developed countries. Any potential benefit of EPA

regulation could be lost to the extent other nations de

cided to let their emissions significantly increase in

view of U. S. emissions reductions. Unavoidably, cli

mate change raises important foreign policy issues,

and it is the President’s prerogative to address them.”

68 Fed. Reg. 52929–52931 (footnote omitted).

The Court dismisses this analysis as “rest[ing] on rea

soning divorced from the statutory text.” Ante, at 30.

“While the statute does condition the exercise of EPA’s

authority on its formation of a ‘judgment,’ . . . that judg

ment must relate to whether an air pollutant ‘cause[s], or

contribute[s] to, air pollution which may reasonably be

anticipated to endanger public health or welfare.’ ” Ibid.

True but irrelevant. When the Administrator makes a

judgment whether to regulate greenhouse gases, that

judgment must relate to whether they are air pollutants

that “cause, or contribute to, air pollution which may

reasonably be anticipated to endanger public health or

welfare.” 42 U. S. C. §7521(a)(1). But the statute says

nothing at all about the reasons for which the Administra

Cite as: 549 U. S. ____ (2007) 5

SCALIA, J., dissenting

tor may defer making a judgment—the permissible rea

sons for deciding not to grapple with the issue at the

present time. Thus, the various “policy” rationales, ante,

at 31, that the Court criticizes are not “divorced from the

statutory text,” ante, at 30, except in the sense that the

statutory text is silent, as texts are often silent about

permissible reasons for the exercise of agency discretion.

The reasons the EPA gave are surely considerations ex

ecutive agencies regularly take into account (and ought to

take into account) when deciding whether to consider

entering a new field: the impact such entry would have on

other Executive Branch programs and on foreign policy.

There is no basis in law for the Court’s imposed limitation.

EPA’s interpretation of the discretion conferred by the

statutory reference to “its judgment” is not only reason

able, it is the most natural reading of the text. The Court

nowhere explains why this interpretation is incorrect, let

alone why it is not entitled to deference under Chevron

U. S. A. Inc. v. Natural Resources Defense Council, Inc.,

467 U. S. 837 (1984). As the Administrator acted within

the law in declining to make a “judgment” for the policy

reasons above set forth, I would uphold the decision to

deny the rulemaking petition on that ground alone.

B

Even on the Court’s own terms, however, the same

conclusion follows. As mentioned above, the Court gives

EPA the option of determining that the science is too

uncertain to allow it to form a “judgment” as to whether

greenhouse gases endanger public welfare. Attached to

this option (on what basis is unclear) is an essay require

ment: “If,” the Court says, “the scientific uncertainty is so

profound that it precludes EPA from making a reasoned

judgment as to whether greenhouse gases contribute to

global warming, EPA must say so.” Ante, at 31. But EPA

has said precisely that—and at great length, based on

6 MASSACHUSETTS v. EPA

SCALIA, J., dissenting

information contained in a 2001 report by the National

Research Council (NRC) entitled Climate Change Science:

An Analysis of Some Key Questions:

“As the NRC noted in its report, concentrations of

[greenhouse gases (GHGs)] are increasing in the at

mosphere as a result of human activities (pp. 9–12).

It also noted that ‘[a] diverse array of evidence points

to a warming of global surface air temperatures’ (p.

16). The report goes on to state, however, that

‘[b]ecause of the large and still uncertain level of

natural variability inherent in the climate record and

the uncertainties in the time histories of the various

forcing agents (and particularly aerosols), a [causal]

linkage between the buildup of greenhouse gases in

the atmosphere and the observed climate changes

during the 20th century cannot be unequivocally es

tablished. The fact that the magnitude of the ob

served warming is large in comparison to natural

variability as simulated in climate models is sugges

tive of such a linkage, but it does not constitute proof

of one because the model simulations could be defi

cient in natural variability on the decadal to century

time scale’ (p. 17).

“The NRC also observed that ‘there is considerable

uncertainty in current understanding of how the cli

mate system varies naturally and reacts to emissions

of [GHGs] and aerosols’ (p. 1). As a result of that un

certainty, the NRC cautioned that ‘current estimate of

the magnitude of future warming should be regarded

as tentative and subject to future adjustments (either

upward or downward).’ Id. It further advised that

‘[r]educing the wide range of uncertainty inherent in

current model predictions of global climate change

will require major advances in understanding and

modeling of both (1) the factors that determine at

Cite as: 549 U. S. ____ (2007) 7

SCALIA, J., dissenting

mospheric concentrations of [GHGs] and aerosols and

(2) the so-called “feedbacks” that determine the sensi

tivity of the climate system to a prescribed increase in

[GHGs].’ Id.

“The science of climate change is extraordinarily

complex and still evolving. Although there have been

substantial advances in climate change science, there

continue to be important uncertainties in our under

standing of the factors that may affect future climate

change and how it should be addressed. As the NRC

explained, predicting future climate change necessar

ily involves a complex web of economic and physical

factors including: Our ability to predict future global

anthropogenic emissions of GHGs and aerosols; the

fate of these emissions once they enter the atmos

phere (e.g., what percentage are absorbed by vegeta

tion or are taken up by the oceans); the impact of

those emissions that remain in the atmosphere on the

radiative properties of the atmosphere; changes in

critically important climate feedbacks (e.g., changes in

cloud cover and ocean circulation); changes in tem

perature characteristics (e.g., average temperatures,

shifts in daytime and evening temperatures); changes

in other climatic parameters (e.g., shifts in precipita

tion, storms); and ultimately the impact of such

changes on human health and welfare (e.g., increases

or decreases in agricultural productivity, human

health impacts). The NRC noted, in particular, that

‘[t]he understanding of the relationships between

weather/climate and human health is in its infancy

and therefore the health consequences of climate

change are poorly understood’ (p. 20). Substantial

scientific uncertainties limit our ability to assess each

of these factors and to separate out those changes re

sulting from natural variability from those that are

directly the result of increases in anthropogenic

8 MASSACHUSETTS v. EPA

SCALIA, J., dissenting

GHGs.

“Reducing the wide range of uncertainty inherent in

current model predictions will require major advances

in understanding and modeling of the factors that de

termine atmospheric concentrations of greenhouse

gases and aerosols, and the processes that determine

the sensitivity of the climate system.” 68 Fed. Reg.

52930.

I simply cannot conceive of what else the Court would like

EPA to say.

II

A

Even before reaching its discussion of the word “judg

ment,” the Court makes another significant error when it

concludes that Ҥ202(a)(1) of the Clean Air Act authorizes

EPA to regulate greenhouse gas emissions from new motor

vehicles in the event that it forms a ‘judgment’ that such

emissions contribute to climate change.” Ante, at 25 (em

phasis added). For such authorization, the Court relies on

what it calls “the Clean Air Act’s capacious definition of

‘air pollutant.’ ” Ante, at 30.

“Air pollutant” is defined by the Act as “any air pollution

agent or combination of such agents, including any physi

cal, chemical, . . . substance or matter which is emitted

into or otherwise enters the ambient air.” 42 U. S. C.

§7602(g). The Court is correct that “[c]arbon dioxide,

methane, nitrous oxide, and hydrofluorocarbons,” ante, at

26, fit within the second half of that definition: They are

“physical, chemical, . . . substance[s] or matter which [are]

emitted into or otherwise ente[r] the ambient air.” But the

Court mistakenly believes this to be the end of the analy

sis. In order to be an “air pollutant” under the Act’s defi

nition, the “substance or matter [being] emitted into . . .

the ambient air” must also meet the first half of the defini

tion—namely, it must be an “air pollution agent or combi

Cite as: 549 U. S. ____ (2007) 9

SCALIA, J., dissenting

nation of such agents.” The Court simply pretends this

half of the definition does not exist.

The Court’s analysis faithfully follows the argument

advanced by petitioners, which focuses on the word “in

cluding” in the statutory definition of “air pollutant.” See

Brief for Petitioners 13–14. As that argument goes, any

thing that follows the word “including” must necessarily

be a subset of whatever precedes it. Thus, if greenhouse

gases qualify under the phrase following the word “includ

ing,” they must qualify under the phrase preceding it.

Since greenhouse gases come within the capacious phrase

“any physical, chemical, . . . substance or matter which is

emitted into or otherwise enters the ambient air,” they

must also be “air pollution agent[s] or combination[s] of

such agents,” and therefore meet the definition of “air

pollutant[s].”

That is certainly one possible interpretation of the

statutory definition. The word “including” can indeed

indicate that what follows will be an “illustrative” sam

pling of the general category that precedes the word.

Federal Land Bank of St. Paul v. Bismarck Lumber Co.,

314 U. S. 95, 100 (1941). Often, however, the examples

standing alone are broader than the general category, and

must be viewed as limited in light of that category. The

Government provides a helpful (and unanswered) exam

ple: “The phrase ‘any American automobile, including any

truck or minivan,’ would not naturally be construed to

encompass a foreign-manufactured [truck or] minivan.”

Brief for Federal Respondent 34. The general principle

enunciated—that the speaker is talking about American

automobiles—carries forward to the illustrative examples

(trucks and minivans), and limits them accordingly, even

though in isolation they are broader. Congress often uses

the word “including” in this manner. In 28 U. S. C.

§1782(a), for example, it refers to “a proceeding in a for

eign or international tribunal, including criminal investi

10 MASSACHUSETTS v. EPA

SCALIA, J., dissenting

gations conducted before formal accusation.” Certainly

this provision would not encompass criminal investiga

tions underway in a domestic tribunal. See also, e.g., 2

U. S. C. §54(a) (“The Clerk of the House of Representatives

shall, at the request of a Member of the House of Repre

sentatives, furnish to the Member, for official use only, one

set of a privately published annotated version of the

United States Code, including supplements and pocket

parts”); 22 U. S. C. §2304(b)(1) (“the relevant findings of

appropriate international organizations, including non

governmental organizations”).

In short, the word “including” does not require the

Court’s (or the petitioners’) result. It is perfectly reason

able to view the definition of “air pollutant” in its entirety:

An air pollutant can be “any physical, chemical, . . . sub

stance or matter which is emitted into or otherwise enters

the ambient air,” but only if it retains the general charac

teristic of being an “air pollution agent or combination of

such agents.” This is precisely the conclusion EPA

reached: “[A] substance does not meet the CAA definition

of ‘air pollutant’ simply because it is a ‘physical, chemical,

. . . substance or matter which is emitted into or otherwise

enters the ambient air.’ It must also be an ‘air pollution

agent.’ ” 68 Fed. Reg. 52929, n. 3. See also id., at 52928

(“The root of the definition indicates that for a substance

to be an ‘air pollutant,’ it must be an ‘agent’ of ‘air pollu

tion’ ”). Once again, in the face of textual ambiguity, the

Court’s application of Chevron deference to EPA’s inter

pretation of the word “including” is nowhere to be found.2

——————

2 Not only is EPA’s interpretation reasonable, it is far more plausible

than the Court’s alternative. As the Court correctly points out, “all

airborne compounds of whatever stripe,” ante, at 26, would qualify as

“physical, chemical, . . . substance[s] or matter which [are] emitted into

or otherwise ente[r] the ambient air,” 42 U. S. C. §7602(g). It follows

that everything airborne, from Frisbees to flatulence, qualifies as an

“air pollutant.” This reading of the statute defies common sense.

Cite as: 549 U. S. ____ (2007) 11

SCALIA, J., dissenting

Evidently, the Court defers only to those reasonable inter

pretations that it favors.

B

Using (as we ought to) EPA’s interpretation of the defi

nition of “air pollutant,” we must next determine whether

greenhouse gases are “agent[s]” of “air pollution.” If so,

the statute would authorize regulation; if not, EPA would

lack authority.

Unlike “air pollutants,” the term “air pollution” is not

itself defined by the CAA; thus, once again we must accept

EPA’s interpretation of that ambiguous term, provided its

interpretation is a “permissible construction of the stat

ute.” Chevron, 467 U. S., at 843. In this case, the petition

for rulemaking asked EPA for “regulation of [greenhouse

gas] emissions from motor vehicles to reduce the risk of

global climate change.” 68 Fed. Reg. 52925. Thus, in

deciding whether it had authority to regulate, EPA had to

determine whether the concentration of greenhouse gases

assertedly responsible for “global climate change” quali

fies as “air pollution.” EPA began with the commonsense

observation that the “[p]roblems associated with atmos

pheric concentrations of CO2,” id., at 52927, bear little

resemblance to what would naturally be termed “air

pollution”:

“EPA’s prior use of the CAA’s general regulatory

provisions provides an important context. Since the

inception of the Act, EPA has used these provisions to

address air pollution problems that occur primarily at

ground level or near the surface of the earth. For ex

ample, national ambient air quality standards

(NAAQS) established under CAA section 109 address

concentrations of substances in the ambient air and

the related public health and welfare problems. This

has meant setting NAAQS for concentrations of ozone,

carbon monoxide, particulate matter and other sub

12 MASSACHUSETTS v. EPA

SCALIA, J., dissenting

stances in the air near the surface of the earth, not

higher in the atmosphere. . . . CO2, by contrast, is

fairly consistent in concentration throughout the

world’s atmosphere up to approximately the lower

stratosphere.” Id., at 52926–52927.

In other words, regulating the buildup of CO2 and other

greenhouse gases in the upper reaches of the atmosphere,

which is alleged to be causing global climate change, is not

akin to regulating the concentration of some substance

that is polluting the air.

We need look no further than the dictionary for confir

mation that this interpretation of “air pollution” is emi

nently reasonable. The definition of “pollute,” of course, is

“[t]o make or render impure or unclean.” Webster’s New

International Dictionary 1910 (2d ed. 1949). And the first

three definitions of “air” are as follows: (1) “[t]he invisible,

odorless, and tasteless mixture of gases which surrounds

the earth”; (2) “[t]he body of the earth’s atmosphere; esp.,

the part of it near the earth, as distinguished from the

upper rarefied part”; (3) “[a] portion of air or of the air

considered with respect to physical characteristics or as

affecting the senses.” Id., at 54. EPA’s conception of “air

pollution”—focusing on impurities in the “ambient air” “at

ground level or near the surface of the earth”—is perfectly

consistent with the natural meaning of that term.

In the end, EPA concluded that since “CAA authoriza

tion to regulate is generally based on a finding that an air

pollutant causes or contributes to air pollution,” 68 Fed.

Reg. 52928, the concentrations of CO2 and other green

house gases allegedly affecting the global climate are

beyond the scope of CAA’s authorization to regulate.

“[T]he term ‘air pollution’ as used in the regulatory provi

sions cannot be interpreted to encompass global climate

change.” Ibid. Once again, the Court utterly fails to

explain why this interpretation is incorrect, let alone so

Cite as: 549 U. S. ____ (2007) 13

SCALIA, J., dissenting

unreasonable as to be unworthy of Chevron deference.

* * *

The Court’s alarm over global warming may or may not

be justified, but it ought not distort the outcome of this

litigation. This is a straightforward administrative-law

case, in which Congress has passed a malleable statute

giving broad discretion, not to us but to an executive

agency. No matter how important the underlying policy

issues at stake, this Court has no business substituting its

own desired outcome for the reasoned judgment of the

responsible agency.