United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued February 28 and 29, 2012 Decided June 26, 2012

No. 09-1322

COALITION FOR RESPONSIBLE REGULATION, INC., ET AL.,

PETITIONERS

v.

ENVIRONMENTAL PROTECTION AGENCY,

RESPONDENT

STATE OF MICHIGAN, ET AL.,

INTERVENORS

Consolidated with 10-1024, 10-1025, 10-1026, 10-1030,

10-1035, 10-1036, 10-1037, 10-1038, 10-1039, 10-1040,

10-1041, 10-1042, 10-1044, 10-1045, 10-1046, 10-1234,

10-1235, 10-1239, 10-1245, 10-1281, 10-1310, 10-1318,

10-1319, 10-1320, 10-1321

On Petitions for Review of Final Actions 

of the Environmental Protection Agency

Patrick R. Day, Harry W. MacDougald, and Jeffrey Bossert

Clark argued the causes for Non-State Petitioners and

Supporting Intervenors. With them on the briefs were John J.

Burns, Attorney General, Office of the Attorney General of the

State of Alaska, Steven E. Mulder, Chief Assistant Attorney
2

General, Peter Glaser, Mark E. Nagle, Matthew Dukes, Paul D.

Phillips, John A. Bryson, Ellen Steen, Eric Groten, John P.

Elwood, James A. Holtkamp, Chet M. Thompson, Robin S.

Conrad, Rachel L. Brand, Sheldon Gilbert, Quentin Riegel,

Jeffrey A. Rosen, Robert R. Gasaway, William H. Burgess, Sam

Kazman, Hans Bader, Matthew G. Paulson, Harry Moy Ng,

Michele Marie Schoeppe, Michael R. Barr, Alexandra M.

Walsh, Adam J. White, Jeffrey A. Lamken, Timothy K. Webster,

Roger R. Martella, Neal J. Cabral, Theodore Hadzi-Antich,

Ashley C. Parrish, Cynthia A. M. Stroman, Scott C. Oostdyk,

Gordon R. Alphonso, Shannon L. Goessling, Edward A.

Kazmarek, F. William Brownell, Norman W. Fichthorn, Henry

V. Nickel, and Allison D. Wood. Paul D. Clement, Mark W.

DeLaquil, Andrew M. Grossman, and David B. Rivin, Jr. entered

appearances.

E. Duncan Getchell, Jr., Solicitor General, Office of the

Attorney General for the Commonwealth of Virginia, argued the

cause for State Petitioners Texas and Virginia on Denial of

Reconsideration of the Endangerment Finding and State

Petitioners and Supporting Intervenors on Endangerment

Finding Delegation Issues. With him on the briefs were

Kenneth T. Cuccinelli, II, Attorney General, Stephen R.

McCullough, Senior Appellate Counsel, Charles E. James Jr.,

Chief Deputy Attorney General, and Wesley G. Russell, Jr.,

Deputy Attorney General.

Greg Abbott, Attorney General, Office of the Attorney

General for the State of Texas, Bill Cobb, Deputy Attorney

General for Civil Litigation, J. Reed Clay, Jr., Special Assistant

and Senior Counsel to the Attorney General, Jonathan F.

Mitchell, Solicitor General, Michael P. Murphy, Assistant

Solicitor General, Luther Strange III, Attorney General, Office

of the Attorney General for the State of Alabama, Pamela Jo

Bondi, Attorney General, Office of the Attorney General for the
3

State of Florida, Gregory F. Zoeller, Attorney General, Office

of the Attorney General for the State of Indiana, Jack Conway,

Attorney General, Office of the Attorney General for the

Commonwealth of Kentucky, James D. “Buddy” Caldwell,

Attorney General, Office of the Attorney General for the State

of Louisiana, Bill Schuette, Attorney General, Office of the

Attorney General for the State of Michigan, John J. Bursch,

Solicitor General, Neil D. Gordon, Assistant Attorney General,

Gary C. Rikard, Jon Bruning, Attorney General, Office of the

Attorney General for the State of Nebraska, Katherine J. Spohn,

Special Counsel to the Attorney General, Wayne Stenehjem,

Attorney General, Office of the Attorney General for the State

of North Dakota, Margaret Olson, Assistant Attorney General,

Scott Pruitt, Attorney General, Office of the Attorney General

for the State of Oklahoma, Alan Wilson, Attorney General,

Office of the Attorney General for the State of South Carolina,

Marty Jackley, Attorney General, Office of the Attorney General

for the States of South Dakota, Roxanne Giedd, Chief, Civil

Litigation Division, Mark L. Shurtleff, Attorney General, Office

of the Attorney General for the State of Utah, and Kenneth T.

Cuccinelli, II, Attorney General, Office of the Attorney General

for the Commonwealth of Virginia were on the briefs for State

Petitioners and Supporting Intervenors. Robert D. Tambling,

Assistant Attorney General, Office of the Attorney General for

the State of Alabama, entered an appearance.

Christian J. Ward, Scott A. Keller, and April L. Farris were

on the brief for amici curiae Scientists in support of Petitioners. 

Derek Schmidt, Attorney General, Office of the Attorney

General for the State of Kansas, and John Campbell, Chief

Deputy Attorney General, were on the brief for amicus curiae

State of Kansas in support of Petitioners. 

Martin R. Levin, Michael J. O’Neill, Donald M. Falk, Mark
4

S. Kaufman, Steven J. Lechner, and Richard P. Hutchison were

on the brief for amici curiae Landmark Legal Foundation, et al.

in support of Petitioners. 

Jon M. Lipshultz and Angeline Purdy, Attorneys, U.S.

Department of Justice, argued the causes for respondent. With

them on the brief were John Hannon, Carol Holmes, and Steven

Silverman, U.S. Environmental Protection Agency, Attorneys. 

Thomas A. Lorenzen, Attorney, U.S. Department of Justice,

entered an appearance.

Carol Iancu, Assistant Attorney General, Office of the

Attorney General for the Commonwealth of Massachusetts,

argued the cause for State and Environmental Intervenors in

support of respondents. With her on the briefs were Martha

Coakley, Attorney General, William L. Pardee, Attorney

Assistant General, Sean H. Donahue, Howard I. Fox, David S.

Baron, Megan Ceronsky, Vickie L. Patton, Peter Zalzal, Kamala

D. Harris, Attorney General, Office of the Attorney General for

the State of California, Kathleen A. Kenealy, Senior Assistant

Attorney General, Marc N. Melnick and Nicholas Stern, Deputy

Attorneys General, Joseph R. Biden, III, Attorney General,

Office of the Attorney General for the State of Delaware,

Valerie M. Satterfield, Deputy Attorney General, George

Jepsen, Attorney General, Office of the Attorney General for the

State of Connecticut, Kimberly P. Massicotte, Matthew I.

Levine, Scott N. Koschwitz, Assistant Attorneys General, Lisa

Madigan, Attorney General, Office of the Attorney General for

the State of Illinois, Gerald T. Karr, Assistant Attorney General,

Thomas J. Miller, Attorney General, Office of the Attorney

General for the State of Iowa, David R. Sheridan, Assistant

Attorney General, Douglas F. Gansler, Attorney General, Office

of the Attorney General for the State of Maryland, Mary E.

Raivel, Assistant Attorney General, Michael A. Delaney,

Attorney General, Office of the Attorney General for the State
5

of New Hampshire, K. Allen Brooks, Senior Assistant Attorney

General, William J. Schneider, Attorney General, Office of the

Attorney General for the State of Maine, Gerald D. Reid,

Assistant Attorney General, Lori Swanson, Attorney General,

Office of the Attorney General for the State of Minnesota,

Jocelyn F. Olson, Assistant Attorney General, Gary K. King,

Attorney General, Office of the Attorney General for the State

of New Mexico, Stephen R. Farris, Assistant Attorney General,

Eric T. Schneiderman, Attorney General, Office of the Attorney

General for the State of New York, Michael J. Myers and

Yueh-Ru Chu, Assistant Attorneys General, John Kroger,

Attorney General, Office of the Attorney General for the State

of Oregon, Paul Logan, Assistant Attorney-in-Charge, Robert M.

McKenna, Attorney General, Office of the Attorney General for

the State of Washington, Leslie R. Seffern, Assistant Attorney

General, Peter F. Kilmartin, Attorney General, Office of the

Attorney General for the State of Rhode Island, Gregory S.

Schultz, Special Assistant Attorney General, William H. Sorrell,

Attorney General, Office of the Attorney General for the State

of Vermont, Thea J. Schwartz, Assistant Attorney General,

Christopher King, Assistant Corporation Counsel, Corporation

Counsel for the City Of New York, Ann B. Weeks, Helen D.

Silver, David Doniger, Meleah Geertsma, Morgan Butler, Frank

W. Rambo, Joseph Mendelson III, Craig Holt Segall, and Joanne

Spalding.

 Deborah Sivas, Douglas A. Ruley, Edward Lloyd, and Susan

J. Kraham were on the brief for amici curiae America's Great

Waters Coalition, et al. in support of respondent. James K.

Thornton entered an appearance.

_____
6

No. 10-1073

COALITION FOR RESPONSIBLE REGULATION, INC., ET AL.,

PETITIONERS

v.

ENVIRONMENTAL PROTECTION AGENCY,

RESPONDENT

AMERICAN FROZEN FOOD INSTITUTE, ET AL.,

INTERVENORS

Consolidated with 10-1083, 10-1099, 10-1109, 10-1110,

10-1114, 10-1118, 10-1119, 10-1120, 10-1122, 10-1123,

10-1124, 10-1125, 10-1126, 10-1127, 10-1128, 10-1129,

10-1131, 10-1132, 10-1145, 10-1147, 10-1148, 10-1199,

10-1200, 10-1201, 10-1202, 10-1203, 10-1206, 10-1207,

10-1208, 10-1210, 10-1211, 10-1212, 10-1213, 10-1216,

10-1218, 10-1219, 10-1220, 10-1221, 10-1222

On Petitions for Review of Final Agency Action

of the Environmental Protection Agency

Jonathan F. Mitchell, Solicitor General, Office of the

Attorney General for the State of Texas, argued the cause for

State Petitioners and Supporting Intervenor. With him on the

briefs were Gregg Abbott, Attorney General, Bill Cobb, Deputy

Attorney General, J. Reed Clay, Jr., Special Assistant and

Senior Counsel to the Attorney General, Michael P. Murphy and
7

James P. Sullivan, Assistant Solicitors General, Luther Strange,

Attorney General, Office of the Attorney General for the State

of Alabama, Herman Robinson, Donald Trahan, Kathy M.

Wright, Gary C. Rikard, John Bruning, Attorney General, Office

of the Attorney General for the State of Nebraska, Katherine J.

Spohn, Special Counsel, Wayne Stenehjem, Attorney General,

Office of the Attorney General for the State of North Dakota,

Margaret Olson, Assistant Attorney General, Alan Wilson,

Attorney General, Office of the Attorney General for the State

of South Carolina, J. Emory Smith, Jr., Assistant Deputy

Attorney General, Marty Jackley, Attorney General, Office of

the Attorney General for the State of South Dakota, Roxanne

Giedd, Chief, and Kenneth T. Cuccinelli, II, Attorney General,

Office of the Attorney General for the Commonwealth of

Virginia. Mark W. DeLaquil, Earle D. Getchell, Jr., Assistant

Attorney General, Office of the Attorney General for the

Commonwealth of Virginia, Andrew M. Grossman, David B.

Rivkin, Jr., and Robert D. Tambling, Assistant Attorney General,

Office of the Attorney General for the State of Alabama, entered

appearances.

F. William Brownell and Peter Keisler argued the causes for

Non-State Petitioners and Supporting Intervenors. With them

on the briefs were Norman W. Fichthorn, Henry V. Nickel,

Allison D. Wood, Charles H. Knauss, Shannon S. Broome,

Timothy K. Webster, Roger R. Martella, Eric Groten, Patrick R.

Day, John A. Bryson, Matthew G. Paulson, John P. Elwood,

Paul D. Phillips, James A. Holtkamp, Shannon L. Goessling,

Harry W. MacDougald, William H. Lewis, Jr., Ronald J.

Tenpas, Gordon R. Alphonso, Edward A. Kazmarek, Chet M.

Thompson, Neal J. Cabral, Scott C. Oostdyk, Richard P.

Hutchison, John J. McMackin, Jr., Robin S. Conrad, Sheldon

Gilbert, Michael W. Steinberg, Levi McAllister, Jeffrey A.

Rosen, Robert R. Gasaway, Jeffrey Bossert Clark, William H.

Burgess, Ashley C. Parrish, Cynthia A.M. Stroman, Ellen Steen,
8

Leslie Sue Ritts, Peter Glaser, Mark E. Nagle, Terry J. Satterlee,

Thomas J. Grever, Margaret Claiborne Campbell, Bryon W.

Kirkpatrick, Quentin Riegel, Elizabeth Gaudio, Elizabeth Henry

Warner, Harry Moy Ng, Michele Marie Schoeppe, Thomas J.

Ward, and Peter H. Wyckoff. Mark A. Behrens, Paul D.

Clement, Matthew Dukes, Virginia L. Hudson, and David B.

Salmons entered appearances.

Jonathan S. Massey was on the brief for amicus curiae

Municipal Gas Commission of Missouri.

John G. Horne, II, Samuel B. Boxerman and Leslie A. Hulse

were on the brief for amici curiae the Commonwealth of

Kentucky and the American Chemistry Council in support of

petitioners. Angus Macbeth entered an appearance.

Amanda Shafer Berman and Perry M Rosen, Attorneys,

U.S. Department of Justice, argued the causes for respondents. 

With them on the briefs were Howard Hoffman, Elliott Zenick,

Brian Doster, and David Orlin, Counsel, U.S. Environmental

Protection Agency. Thomas A. Lorenzen and Kim N. Smaczniak,

Attorneys, U.S. Department of Justice, and John D. Gunter, II

and Michele L. Walter, Counsel, U.S. Environmental Protection

Agency, entered appearances. 

Sean H. Donahue and Michael J. Myers argued the causes

for State and Environmental Intervenors in support of

respondents. With them on the briefs were Vickie L. Patton,

Pamela A. Campos, Megan Ceronsky, Petere Zalzal, Eric T.

Schneiderman, Attorney General, Office of the Attorney General

for the State of New York, Barbara D. Underwood, Solicitor

General, Morgan A. Costello, Assistant Attorney General,

Monica Wagner, Howard I. Fox, David S. Baron, Lisa Madigan,

Attorney General, Office of the Attorney General for the State

of Illinois, Gerald T. Karr, Assistant Attorney General, Joanne
9

Spalding, Nathan Matthews, Craig Holt Segall, Kamala D.

Harris, Attorney General, Office of the Attorney General for the

State of California, Kathleen A. Kenealy, Senior Assistant

Attorney General, Susan Durbin, Raissa Lerner, Marc N.

Melnick, and Nicholas Stern, Deputy Attorneys General, Martha

Coakley, Attorney General, Office of the Attorney General for

the Commonwealth of Massachusetts, William L. Pardee and

Carol Iancu, Assistant Attorneys General, David Doniger,

Meleah Geertsma, William J. Schneider, Attorney General,

Office of the Attorney General for the State of Maine, Gerald D.

Ried, Assistant Attorney General, Ann B. Weeks, Helen D.

Silver, Thomas J. Miller, Attorney General, Office of the

Attorney General for the State of Iowa, David R. Sheridan,

Assistant Attorney General, Douglas F. Gansler, Attorney

General, Office of the Attorney General for the State of

Maryland, Mary Raivel, Deputy Attorney General, Michael A.

Delaney, Attorney General, Office of the Attorney General for

the State of New Hampshire, K. Allen Brooks, Senior Assistant

Attorney General, Barbara Baird, William B.Wong, Peter F.

Kilmartin, Attorney General, Office of the Attorney General for

the State of Rhode Island, Gregory S. Schultz, Special Assistant

Attorney General, Frank Rambo, Morgan Butler, Gary K. King,

Attorney General, Office of the Attorney General for the State

of New Mexico, Stephen Farris, Assistant Attorney General,

John Kroger, Attorney General, Office of the Attorney General

for the State of Oregon, Paul Logan, Assistant Attorney-inCharge, Roy Cooper, Attorney General, Office of the Attorney

General for the State of North Carolina, and J. Allen Jernigan

and Marc Bernstein, Special Deputy Attorneys General. 

Kenneth P. Alex and Gavin G. McCabe, Deputy Assistant

Attorneys General, Office of the Attorney General for the State

of California, entered appearances.
10

No. 10-1092

COALITION FOR RESPONSIBLE REGULATION, INC., ET AL.,

PETITIONERS

v.

ENVIRONMENTAL PROTECTION AGENCY,

RESPONDENT

LANGBOARD, INC. - MDF, ET AL.,

INTERVENORS

Consolidated with 10-1094, 10-1134, 10-1143, 10-1144,

10-1152, 10-1156, 10-1158, 10-1159, 10-1160, 10-1161,

10-1162, 10-1163, 10-1164, 10-1166, 10-1182

On Petitions for Review of Final Actions 

of the Environmental Protection Agency

Peter Glaser argued the cause for petitioners. With him on

the briefs were John P. Elwood, Eric Groten, Patrick R. Day,

John A. Bryson, Shannon L. Goessling, Harry W. MacDougald,

Paul D. Phillips, James A. Holtkamp, Edward A. Kazmarek,

Chet M. Thompson, Sam Kazman, Hans Bader, Gordon R.

Alphonso, Richard P. Hutchison, Neal J. Cabral, Scott C.

Oostdyk, Ronald J. Tenpas, Michael W. Steinberg, Levi

McAllister, John J. McMackin Jr., Robin S. Conrad, Rachel L.

Brand, Sheldon Gilbert, F. William Brownell, Norman W.

Fichthorn, Henry V. Nickel, Allison D. Wood, Ashley C. Parrish,

Cynthia A.M. Stroman, Mark E. Nagle, Michael Higgins, Ellen
11

Steen, Timothy K. Webster, Roger R. Martella, Matthew G.

Paulson, Charles H. Knauss, Shannon S. Broome, Quentin

Riegel, Elizabeth Gaudio, Thomas J. Ward, Harry Moy Ng, and

Michele Marie Schoeppe.

Greg Abbott, Attorney General, Office of the Attorney

General for the State of Texas, Bill Cobb, Deputy Attorney

General for Civil Litigation, Jonathan F. Mitchell, Solicitor

General, J. Reed Clay Jr., Special Assistant and Senior Counsel

to the Attorney General, Michael P. Murphy, Assistant Solicitor

General, Luther Strange, Attorney General, Office of the

Attorney General for the State of Alabama, Samuel S. Olens,

Attorney General, Office of the Attorney General for the State

of Georgia, John E. Hennelly, Senior Assistant Attorney

General, Gary C. Rikard, Jon C. Bruning, Attorney General,

Office of the Attorney General for the State of Nebraska,

Katherine J. Spohn, Special Counsel to the Attorney General,

Wayne K. Stenehjem, Attorney General, Office of the Attorney

General for the State of North Dakota, Margaret Olson,

Assistant Attorney General, Alan Wilson, Attorney General,

Office of the Attorney General for the State of South Carolina,

J. Emory Smith, Jr., Assistant Deputy Attorney General, Marty

Jackley, Attorney General, Office of the Attorney General for

the State of North Dakota, Roxanne Giedd, Chief, Civil

Litigation Division, and Kenneth T. Cuccinelli, II, Attorney

General, Office of the Attorney General for the Commonwealth

of Virginia, were on the briefs for State Petitioners and

Supporting Intervenor. Paul D. Clement, James W. Coleman,

Wayne J. D'Angelo, Mark W. DeLaquil, E. Duncan Getchell Jr.,

Solicitor General, Office of the Attorney General for the

Commonwealth of Virginia, Andrew M. Grossman, Virginia L.

Hudson, David B. Rivkin Jr., and Robert D. Tambling, Assistant

Attorney General, Office of the Attorney General for the State

of Alabama, entered appearances. 
12

Samuel B. Boxerman and Leslie A. Hulse were on the brief

for amicus curiae American Chemistry Council in support of

petitioners. Angus Macbeth entered an appearance.

Eric G. Hostetler, Attorney, U.S. Department of Justice,

argued the cause for respondents. With him on the brief were

John Hannon and Steven Silverman, Attorneys, U.S.

Environmental Protection Agency.

Raymond B. Ludwiszewski argued the cause for intervenors

Association of Global Automakers, et al. With him on the brief

were Kathleen M. Sullivan, Sanford I. Weisburst, and William B.

Adams. 

Gavin G. McCabe, Deputy Attorney General, Office of the

Attorney General for the State of California, argued the cause

for intervenor State of California. On the brief were Kamala D.

Harris, Attorney General, Kathleen A. Kenealy, Senior Assistant

Attorney General, Marc N. Melnick and Nicholas Stern, Deputy

Attorneys General, Sean H. Donahue, Howard I. Fox, David S.

Baron, Pamela Campos, Megan Ceronsky, Vickie L. Patton,

Peter Zalzal, Joseph R. Biden, III, Attorney General, Office of

the Attorney General for the State of Delaware, Valerie M.

Satterfield, Deputy Attorney General, Thomas J. Miller,

Attorney General, Office of the Attorney General for the State

of Iowa, David R. Sheridan, Assistant Attorney General,

Douglas F. Gansler, Attorney General, Office of the Attorney

General for the State of Maryland, Roberta R. James, Assistant

Attorney General, Lisa Madigan, Attorney General, Office of

the Attorney General for the State of Illinois, Gerald T. Karr,

Assistant Attorney General, William T. Schneider, Attorney

General, Office of the Attorney General for the State of Maine,

Gerald D. Reid, Assistant Attorney General, Martha Coakley,

Attorney General, Office of the Attorney General for the
13

Commonwealth of Massachusetts, Carol Iancu, Tracy Triplett,

and William L. Pardee, Assistant Attorneys General, Gary K.

King, Attorney General, Office of the Attorney General for the

State of New Mexico, Stephen R. Farris, Assistant Attorney

General, John Kroger, Attorney General, Office of the Attorney

General for the State of Oregon, Paul Logan, Assistant

Attorney-in-Charge, William H. Sorrell, Attorney General,

Office of the Attorney General for the State of Vermont, Thea

J. Schwartz, Assistant Attorney General, Eric T. Schneiderman,

Attorney General, Office of the Attorney General for the State

of New York, Michael J. Myers and Yueh-Ru Chu, Assistant

Attorneys General, Peter F. Kilmartin, Attorney General, Office

of the Attorney General for the State of Rhode Island, Gregory

S. Schultz, Special Assistant Attorney General, Robert M.

McKenna, Attorney General, Office of the Attorney General for

the State of Washington, Leslie R. Seffern, Assistant Attorney

General, Christopher King, Assistant Corporation Counsel,

Corporation Counsel for the City of New York, Joanne

Spalding, Craig Holt Segall, David Doniger and Meleah

Geertsma. Judith A. Stahl Moore, Assistant Attorney General,

Office of the Attorney General for the State of New Mexico, and

John D. Walke entered appearances.

Richard E. Ayres, Jessica L. Olson, and Kristin L. Hines

were on the brief for amicus curiae Honeywell International,

Inc. in support of respondents. 

Richard L. Revesz, Michael A. Livermore, and Jennifer S.

Rosenberg were on the brief for amicus curiae Institute for

Policy Integrity at New York University School of Law in

support of respondents.
14

No. 10-1167

AMERICAN CHEMISTRY COUNCIL,

PETITIONER

v.

ENVIRONMENTAL PROTECTION AGENCY AND LISA PEREZ

JACKSON, ADMINISTRATOR, U.S. ENVIRONMENTAL

PROTECTION AGENCY,

RESPONDENTS

CHAMBER OF COMMERCE OF THE UNITED STATES OF

AMERICA, ET AL.,

INTERVENORS

Consolidated with 10-1168, 10-1169, 10-1170, 10-1173,

10-1174, 10-1175, 10-1176, 10-1177, 10-1178, 10-1179,

10-1180

On Petitions for Review of a Final Action 

of the Environmental Protection Agency

Timothy K. Webster, Roger R. Martella, Jr., James W.

Coleman, William H. Lewis, Jr., Ronald J. Tenpas, Charles H.

Knauss, Shannon S. Broome, Bryan M. Killian, and Matthew G.

Paulson were on the briefs for petitioners. Peter D. Keisler,

Leslie A. Hulse, and Quentin Riegel entered appearances.
15

Amanda Shafer Berman and Perry M. Rosen, Attorneys,

U.S. Department of Justice, and Elliott Zenick and Howard J.

Hoffman, Counsel, U.S. Environmental Protection Agency, were

on the brief for respondents. Jon M. Lipshultz, Senior Counsel,

U.S. Department of Justice, entered and appearance.

Ann Brewster Weeks, Sean H. Donahue, Vickie Patton,

Peter Zalzal, Joanne Spalding, Craig Segall, David Doniger,

and Meleah Geertsma were on the brief of intervenors in support

of respondents. David S. Baron, Pamela A. Campos, Colin C.

O’Brien, and John D. Walke entered appearances.

Vera P. Pardee, Brendan R. Cummings, and Kevin P. Bundy

were on the brief for amicus curiae Center for Biological

Diversity in support of respondents.

Before: SENTELLE, Chief Judge; ROGERS and TATEL,

Circuit Judges.

Opinion for the Court filed PER CURIAM.

PER CURIAM: Following the Supreme Court’s decision in

Massachusetts v. EPA, 549 U.S. 497 (2007)—which clarified

that greenhouse gases are an “air pollutant” subject to regulation

under the Clean Air Act (CAA)—the Environmental Protection

Agency promulgated a series of greenhouse gas-related rules.

First, EPA issued an Endangerment Finding, in which it

determined that greenhouse gases may “reasonably be

anticipated to endanger public health or welfare.” See 42 U.S.C.

§ 7521(a)(1). Next, it issued the Tailpipe Rule, which set

emission standards for cars and light trucks. Finally, EPA

determined that the CAA requires major stationary sources of

greenhouse gases to obtain construction and operating permits.

But because immediate regulation of all such sources would

result in overwhelming permitting burdens on permitting
16

authorities and sources, EPA issued the Timing and Tailoring

Rules, in which it determined that only the largest stationary

sources would initially be subject to permitting requirements. 

Petitioners, various states and industry groups, challenge all

these rules, arguing that they are based on improper

constructions of the CAA and are otherwise arbitrary and

capricious. But for the reasons set forth below, we conclude: 1)

the Endangerment Finding and Tailpipe Rule are neither

arbitrary nor capricious; 2) EPA’s interpretation of the

governing CAA provisions is unambiguously correct; and 3) no

petitioner has standing to challenge the Timing and Tailoring

Rules. We thus dismiss for lack of jurisdiction all petitions for

review of the Timing and Tailoring Rules, and deny the

remainder of the petitions.

I.

We begin with a brief primer on greenhouse gases. As their

name suggests, when released into the atmosphere, these gases

act “like the ceiling of a greenhouse, trapping solar energy and

retarding the escape of reflected heat.” Massachusetts v. EPA,

549 U.S. at 505. A wide variety of modern human activities

result in greenhouse gas emissions; cars, power plants, and

industrial sites all release significant amounts of these heattrapping gases. In recent decades “[a] well-documented rise in

global temperatures has coincided with a significant increase in

the concentration of [greenhouse gases] in the atmosphere.” Id.

at 504-05. Many scientists believe that mankind’s greenhouse

gas emissions are driving this climate change. These scientists

predict that global climate change will cause a host of

deleterious consequences, including drought, increasingly severe

weather events, and rising sea levels.

The genesis of this litigation came in 2007, when the
17

Supreme Court held in Massachusetts v. EPA that greenhouse

gases “unambiguous[ly]” may be regulated as an “air pollutant”

under the Clean Air Act (“CAA”). Id. at 529. Squarely rejecting

the contention—then advanced by EPA—that “greenhouse gases

cannot be ‘air pollutants’ within the meaning of the Act,” id. at

513, the Court held that the CAA’s definition of “air pollutant”

“embraces all airborne compounds of whatever stripe.” Id. at

529 (emphasis added). Moreover, because the CAA requires

EPA to establish motor-vehicle emission standards for “any air

pollutant . . . which may reasonably be anticipated to endanger

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

added), the Court held that EPA had a “statutory obligation” to

regulate harmful greenhouse gases. Id. at 534. “Under the clear

terms of the Clean Air Act,” the Court concluded, “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 explanation as to why it cannot or will not exercise

its discretion to determine whether they do.” Id. at 533. The

Court thus directed EPA to determine “whether sufficient

information exists to make an endangerment finding” for

greenhouse gases. Id. at 534.

Massachusetts v. EPA spurred a cascading series of

greenhouse gas-related rules and regulations. First, in direct

response to the Supreme Court’s directive, EPA issued an

Endangerment Finding for greenhouse gases. Endangerment and

Cause or Contribute Findings for Greenhouse Gases Under

Section 202(a) of the Clean Air Act (“Endangerment Finding”),

74 Fed. Reg. 66,496 (Dec. 15, 2009). The Endangerment

Finding defined as a single “air pollutant” an “aggregate group

of six long-lived and directly-emitted greenhouse gases” that are

“well mixed” together in the atmosphere and cause global

climate change: carbon dioxide, methane, nitrous oxide,

hydroflourocarbons, perflourocarbons, and sulfur hexafluoride.

Id. at 66,536-37. Following “common practice,” EPA measured
18

the impact of these gases on a “carbon dioxide equivalent basis,”

(CO2e) which is based on the gases’ “warming effect relative to

carbon dioxide . . . over a specified timeframe.” Id. at 66,519.

(Using the carbon dioxide equivalent equation, for example, a

mixture of X amount of nitrous oxide and Y amount of sulfur

hexafluoride is expressed as Z amount of CO2e). After

compiling and considering a considerable body of scientific

evidence, EPA concluded that motor-vehicle emissions of these

six well-mixed gases “contribute to the total greenhouse gas air

pollution, and thus to the climate change problem, which is

reasonably anticipated to endanger public health and welfare.”

Id. at 66,499.

Next, and pursuant to the CAA’s requirement that EPA

establish motor-vehicle emission standards for “any air pollutant

. . . which may reasonably be anticipated to endanger public

health or welfare,” 42 U.S.C. § 7521(a)(1), the agency

promulgated its Tailpipe Rule for greenhouse gases. Light-Duty

Vehicle Greenhouse Gas Emission Standards and Corporate

Average Fuel Economy Standards; Final Rule (“Tailpipe

Rule”), 75 Fed. Reg. 25,324 (May 7, 2010). Effective January 2,

2011, the Tailpipe Rule set greenhouse gas emission standards

for cars and light trucks as part of a joint rulemaking with fuel

economy standards issued by the National Highway Traffic

Safety Administration (NHTSA). Id. at 25,326. 

Under EPA’s longstanding interpretation of the CAA, the

Tailpipe Rule automatically triggered regulation of stationary

greenhouse gas emitters under two separate sections of the Act.

The first, the Prevention of Significant Deterioration of Air

Quality (PSD) program, requires state-issued construction

permits for certain types of stationary sources—for example,

iron and steel mill plants—if they have the potential to emit over

100 tons per year (tpy) of “any air pollutant.” See 42 U.S.C.

§ 7475; 7479(1). All other stationary sources are subject to PSD
19

permitting if they have the potential to emit over 250 tpy of “any

air pollutant.” Id. § 7479(1). The second provision, Title V,

requires state-issued operating permits for stationary sources

that have the potential to emit at least 100 tpy of “any air

pollutant.” Id. § 7602(j). EPA has long interpreted the phrase

“any air pollutant” in both these provisions to mean any air

pollutant that is regulated under the CAA. See Requirements for

Preparation, Adoption, and Submittal of Implementation Plans;

Approval and Promulgation of Implementation Plans (“1980

Implementation Plan Requirements”), 45 Fed. Reg. 52,676,

52,711 (Aug. 7, 1980) (PSD program); Prevention of Significant

Deterioration and Title V Greenhouse Gas Tailoring Rule

(“Tailoring Rule”), 75 Fed. Reg. 31,514, 31,553-54 (June 3,

2010) (discussing history of Title V regulation and

applicability). And once the Tailpipe Rule set motor-vehicle

emission standards for greenhouse gases, they became a

regulated pollutant under the Act, requiring PSD and Title V

greenhouse permitting. 

Acting pursuant to this longstanding interpretation of the

PSD and Title V programs, EPA issued two rules phasing in

stationary source greenhouse gas regulation. First, in the Timing

Rule, EPA concluded that an air pollutant becomes “subject to

regulation” under the Clean Air Act—and thus subject to PSD

and Title V permitting—only once a regulation requiring control

of that pollutant takes effect. Reconsideration of Interpretation

of Regulations That Determine Pollutants Covered by Clean Air

Act Permitting Programs (“Timing Rule”), 75 Fed. Reg. 17,004

(Apr. 2, 2010). Therefore, EPA concluded, major stationary

emitters of greenhouse gases would be subject to PSD and Title

V permitting regulations on January 2, 2011—the date on which

the Tailpipe Rule became effective, and thus, the date when

greenhouse gases first became regulated under the CAA. Id. at

17,019. 
20

Next, EPA promulgated the Tailoring Rule. In the Tailoring

Rule, EPA noted that greenhouse gases are emitted in far greater

volumes than other pollutants. Indeed, millions of industrial,

residential, and commercial sources exceed the 100/250 tpy

statutory emissions threshold for CO2e. Tailoring Rule, 75 Fed.

Reg. at 31,534-36. Immediately adding these sources to the PSD

and Title V programs would, EPA predicted, result in

tremendous costs to industry and state permitting authorities.

See id. As a result, EPA announced that it was “relieving

overwhelming permitting burdens that would, in the absence of

this rule, fall on permitting authorities and sources.” Id. at

31,516. Departing from the CAA’s 100/250 tpy emissions

threshold, the Tailoring Rule provided that only the largest

sources—those exceeding 75,000 or 100,000 tpy CO2e,

depending on the program and project—would initially be

subject to greenhouse gas permitting. Id. at 31,523. (The

Tailoring Rule further provided that regulated sources must also

emit greenhouse gases at levels that exceed the 100/250 tpy

emissions threshold on a mass basis. That is, they must emit

over 100/250 tpy of actual pollutants, in addition to exceeding

the 75,000/100,000 tpy carbon dioxide equivalent. Id. at

31,523.) 

A number of groups—including states and regulated

industries—filed petitions for review of EPA’s greenhouse gas

regulations, contending that the agency misconstrued the CAA

and otherwise acted arbitrarily and capriciously. This appeal

consolidates the petitions for review of the four aforementioned

rules: the Endangerment Finding, the Tailpipe Rule, the Timing

Rule, and the Tailoring Rule. 

“The Clean Air Act empowers us to reverse the

Administrator’s action in rulemaking if it is ‘arbitrary,

capricious, an abuse of discretion, or otherwise not in

accordance with the law.’” Med. Waste Inst. & Energy Recovery
21

Council v. EPA, 645 F.3d 420, 424 (D.C. Cir. 2011) (quoting 42

U.S.C. § 7607(d)(9)(A)). Questions of statutory interpretation

are governed by the familiar Chevron two-step: “First . . . if the

intent of Congress is clear, that is the end of the matter; for the

court, as well as the agency, must give effect to the

unambiguously expressed intent of Congress.” Chevron, U.S.A.

Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837,

842-43 (1984). But “if the statute is silent or ambiguous with

respect to the specific issue, the question for the court is whether

the agency’s answer is based on a permissible construction of

the statute.” Id. at 843.

This opinion proceeds in severalsteps. Part II explains why

the Endangerment Finding was neither arbitrary nor capricious,

while Part III does the same for the Tailpipe Rule. Turning to

stationary source regulation, Part IV examines whether any

petitioners may timely challenge EPA’s longstanding

interpretation of the PSD statute. Because we conclude that they

may, Part V addresses the merits of their statutory arguments,

and explains why EPA’s interpretation of the CAA was

compelled by the statute. Next, Part VI explains why petitioners

lack standing to challenge the Timing and Tailoring Rules

themselves. Finally, Part VII disposes of several arguments that

have nothing to do with the rules under review, and thus are not

properly before us.

II.

We turn first to State and Industry Petitioners’ challenges

to the Endangerment Finding, the first of the series of rules EPA

issued after the Supreme Court remanded Massachusetts v. EPA.

In the decision ordering the remand, the Supreme Court held

that EPA had failed in its statutory obligations when it “offered

no reasoned explanation for its refusal to decide whether

greenhouse gases cause or contribute to climate change.”
22

Massachusetts v. EPA, 549 U.S. at 534. On remand, EPA

compiled a substantial scientific record, which is before us in the

present review, and determined that “greenhouse gases in the

atmosphere may reasonably be anticipated both to endanger

public health and to endanger public welfare.” Endangerment

Finding, 74 Fed. Reg. at 66,497. EPA went on to find that

motor-vehicle emissions of greenhouse gases “contribute to the

total greenhouse gas air pollution, and thus to the climate change

problem, which is reasonably anticipated to endanger public

health and welfare.” Id. at 66,499. 

State and Industry Petitioners challenge several aspects of

EPA’s decision, including (1) EPA’s interpretation of CAA

§ 202(a)(1), which sets out the endangerment-finding standard;

(2) the adequacy of the scientific record supporting the

Endangerment Finding; (3) EPA’s decision not to “quantify” the

risk of endangerment to public health or welfare created by

climate change; (4) EPA’s choice to define the “air pollutant” at

issue as an aggregate of six greenhouse gases; (5) EPA’s failure

to consult its Science Advisory Board before issuing the

Endangerment Finding; and (6) EPA’s denial of all petitions for

reconsideration of the Endangerment Finding. We ultimately

conclude that the Endangerment Finding is consistent with

Massachusetts v. EPA and the text and structure of the CAA,

and is adequately supported by the administrative record.

A.

Industry Petitioners contend that EPA improperly

interpreted CAA § 202(a)(1) as restricting the Endangerment

Finding to a science-based judgment devoid of considerations of

policy concerns and regulatory consequences. They assert that

CAA § 202(a)(1) requires EPA to consider, e.g., the benefits of

activities that require greenhouse gas emissions, the

effectiveness of emissions regulation triggered by the
23

Endangerment Finding, and the potential for societal adaptation

to or mitigation of climate change. They maintain that

eschewing those considerations also made the Endangerment

Finding arbitrary and capricious.

These contentions are foreclosed by the language of the

statute and the Supreme Court’s decision in Massachusetts v.

EPA. Section 202(a) of the CAA states in relevant part that

EPA’s Administrator 

shall by regulation prescribe (and from time to time

revise) in accordance with the provisions of this

section, 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 his

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). This language requires that the

endangerment evaluation “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.’”

Massachusetts v. EPA, 549 U.S. at 532–33. At bottom,

§ 202(a)(1) requires EPA to answer only two questions: whether

particular “air pollution”—here, greenhouse gases—“may

reasonably be anticipated to endanger public health or welfare,”

and whether motor-vehicle emissions “cause, or contribute to”

that endangerment. 

These questions require a “scientific judgment” about the

potential risks greenhouse gas emissions pose to public health or

welfare—not policy discussions. Massachusetts v. EPA, 549

U.S. at 534. In Massachusetts v. EPA, the Supreme Court

rebuffed an attempt by EPA itself to inject considerations of
24

policy into its decision. At the time, EPA had “offered a laundry

list of reasons not to regulate” greenhouse gases, including

that a number of voluntary Executive Branch programs

already provide an effective response to the threat of

global warming, that regulating greenhouse gases

might impair the President’s ability to negotiate with

“key developing nations” to reduce emissions, and that

curtailing motor-vehicle emissions would reflect “an

inefficient, piecemeal approach to address the climate

change issue.”

Id. at 533 (citations omitted). The Court noted that “these policy

judgments . . . have nothing to do with whether greenhouse gas

emissions contribute to climate change. Still less do they amount

to a reasoned justification for declining to form a scientific

judgment.” Id. at 533–34. In the Court’s view, EPA’s policybased explanations contained “no reasoned explanation for

[EPA’s] refusal to decide” the key part of the endangerment

inquiry: “whether greenhouse gases cause or contribute to

climate change.” Id. at 534. 

As in Massachusetts v. EPA, a “laundry list of reasons not

to regulate” simply has “nothing to do with whether greenhouse

gas emissions contribute to climate change.” Id. at 533–34. The

additional exercises State and Industry Petitioners would have

EPA undertake—e.g., performing a cost-benefit analysis for

greenhouse gases, gauging the effectiveness of whatever

emission standards EPA would enact to limit greenhouse gases,

and predicting society’s adaptive response to the dangers or

harms caused by climate change—do not inform the “scientific

judgment” that § 202(a)(1) requires of EPA. Instead of focusing

on the question whether greenhouse gas emissions may

reasonably be anticipated to endanger public health or welfare,

the factors State and Industry Petitioners put forth only address
25

what might happen were EPA to answer that question in the

affirmative. As EPA stated in the Endangerment Finding, such

inquiries “muddle the rather straightforward scientific judgment

about whether there may be endangerment by throwing the

potential impact of responding to the danger into the initial

question.” 74 Fed. Reg. at 66,515. To be sure, the subsection

following § 202(a)(1), § 202(a)(2), requires that EPA address

limited questions about the cost of compliance with new

emission standards and the availability of technology for

meeting those standards, see infra Part III, but these judgments

are not part of the § 202(a)(1) endangerment inquiry. The

Supreme Court made clear in Massachusetts v. EPA that it was

not addressing the question “whether policy concerns can inform

EPA’s actions in the event that it makes such a finding,” 549

U.S. at 534–35, but that policy concerns were not part of the

calculus for the determination of the endangerment finding in

the first instance. The Supreme Court emphasized that it was

holding “that EPA must ground its reasons for action or inaction

in the statute.” Id. at 535. The statute speaks in terms of

endangerment, not in terms of policy, and EPA has complied

with the statute.

State and Industry Petitioners insist that because statutes

should be interpreted to avoid absurd results, EPA should have

considered at least the “absurd” consequences that would follow

from an endangerment finding for greenhouse gases.

Specifically: having made an endangerment finding, EPA will

proceed to promulgate emission standards under § 202(a)(1).

Issuing those standards triggers regulation—under EPA’s PSD

and Title V programs—of stationary sources that emit

greenhouse gases at levels above longstanding statutory

thresholds. Because greenhouse gases are emitted in much

higher volumes than other air pollutants, hundreds of thousands

of small stationary sources would exceed those thresholds. This

would subject those sources to PSD and Title V permitting
26

requirements despite what Petitioners claim was Congress’s

clear intent that the requirements apply only to large industrial

sources. Petitioners assert that even EPA believed such

overbroad regulation to be an absurd result, which it attempted

to rectify by adopting the Tailoring Rule to raise the statutory

thresholds, see infra Part VI. 

However “absurd” Petitioners consider this consequence,

though, it is still irrelevant to the endangerment inquiry. That

EPA adjusted the statutory thresholds to accommodate

regulation of greenhouse gases emitted by stationary sources

may indicate that the CAA is a regulatory scheme less-thanperfectly tailored to dealing with greenhouse gases. But the

Supreme Court has already held that EPA indeed wields the

authority to regulate greenhouse gases under the CAA. See

Massachusetts v. EPA. The plain language of § 202(a)(1) of that

Act does not leave room for EPA to consider as part of the

endangerment inquiry the stationary-source regulation triggered

by an endangerment finding, even if the degree of regulation

triggered might at a later stage be characterized as “absurd.” 

B.

State and Industry Petitioners next challenge the adequacy

of the scientific record underlying the Endangerment Finding,

objecting to both the type of evidence upon which EPA relied

and EPA’s decision to make an Endangerment Finding in light

of what Industry Petitioners view as significant scientific

uncertainty. Neither objection has merit.

1.

As an initial matter, State and Industry Petitioners question

EPA’s reliance on “major assessments” addressing greenhouse

gases and climate change issued by the Intergovernmental Panel
27

on Climate Change (IPCC), the U.S. Global Climate Research

Program (USGCRP), and the National Research Council (NRC).

Endangerment Finding, 74 Fed. Reg. at 66,510–11. These peerreviewed assessments synthesized thousands of individual

studies on various aspects of greenhouse gases and climate

change and drew “overarching conclusions” about the state of

the science in this field. Id. at 66,511. The assessments provide

data and information on, inter alia, “the amount of greenhouse

gases being emitted by human activities”; their continued

accumulation in the atmosphere; the resulting observed changes

to Earth’s energy balance, temperature and climate at global and

regional levels, and other “climate-sensitive sectors and systems

of the human and natural environment”; the extent to which

these changes “can be attributed to human-induced buildup of

atmospheric greenhouse gases”; “future projected climate

change”; and “projected risks and impacts to human health,

society and the environment.”Id. at 66,510–11.

State and Industry Petitioners assert that EPA improperly

“delegated” its judgment to the IPCC, USGCRP, and NRC by

relying on these assessments of climate-change science. See U.S.

Telecom Ass’n v. FCC, 359 F.3d 554, 566 (D.C. Cir. 2004). This

argument is little more than a semantic trick. EPA did not

delegate, explicitly or otherwise, any decision-making to any of

those entities. EPA simply did here what it and other decisionmakers often must do to make a science-based judgment: it

sought out and reviewed existing scientific evidence to

determine whether a particular finding was warranted. It makes

no difference that much of the scientific evidence in large part

consisted of “syntheses” of individual studies and research.

Even individual studies and research papers often synthesize

past work in an area and then build upon it. This is how science

works. EPA is not required to re-prove the existence of the atom

every time it approaches a scientific question. 
28

Moreover, it appears from the record that EPA used the

assessment reports not as substitutes for its own judgment but as

evidence upon which it relied to make that judgment. EPA

evaluated the processes used to develop the various assessment

reports, reviewed their contents, and considered the depth of the

scientific consensus the reports represented. Based on these

evaluations, EPA determined the assessments represented the

best source material to use in deciding whether greenhouse gas

emissions may be reasonably anticipated to endanger public

health or welfare. Endangerment Finding, 74 Fed. Reg. at

66,510–11. It then reviewed those reports along with comments

relevant to the scientific considerations involved to determine

whether the evidence warranted an endangerment finding for

greenhouse gases as it was required to do under the Supreme

Court’s mandate in Massachusetts v. EPA. 

2.

Industry Petitioners also assert that the scientific evidence

does not adequately support the Endangerment Finding. As we

have stated before in reviewing the science-based decisions of

agencies such as EPA, “[a]lthough we perform a searching and

careful inquiry into the facts underlying the agency’s decisions,

we will presume the validity of agency action as long as a

rational basis for it is presented.” Am. Farm Bureau Fed’n v.

EPA, 559 F.3d 512, 519 (D.C. Cir. 2009) (internal quotation

marks omitted). In so doing, “we give an extreme degree of

deference to the agency when it is evaluating scientific data

within its technical expertise.” Id. (internal quotation marks

omitted).

The body of scientific evidence marshaled by EPA in

support of the Endangerment Finding is substantial. EPA’s

scientific evidence of record included support for the proposition
29

that greenhouse gases trap heat on earth that would otherwise

dissipate into space; that this “greenhouse effect” warms the

climate; that human activity is contributing to increased

atmospheric levels of greenhouse gases; and that the climate

system is warming. 

Based on this scientific record, EPA made the linchpin

finding: in its judgment, the “root cause” of the recently

observed climate change is “very likely” the observed increase

in anthropogenic greenhouse gas emissions. Endangerment

Finding, 74 Fed. Reg. at 66,518. EPA found support for this

finding in three lines of evidence. First, it drew upon our “basic

physical understanding” of the impacts of various natural and

manmade changes on the climate system. For instance, EPA

relied on evidence that the past half-century of warming has

occurred at a time when natural forces such as solar and

volcanic activity likely would have produced cooling.

Endangerment Finding, Response to Comments (RTC) Vol. 3,

at 20. Other evidence supports EPA’s conclusion that the

observed warming pattern—warming of the bottommost layer

of the atmosphere and cooling immediately above it—is

consistent with greenhouse-gas causation. Id.

EPA further relied upon evidence of historical estimates of

past climate change, supporting EPA’s conclusion that global

temperatures over the last half-century are unusual.

Endangerment Finding, 74 Fed. Reg. at 66,518. Scientific

studies upon which EPA relied place high confidence in the

assertion that global mean surface temperatures over the last few

decades are higher than at any time in the last four centuries.

Technical Support Document for the Endangerment Finding

(TSD), at 31. These studies also show, albeit with significant

uncertainty, that temperatures at many individual locations were

higher over the last twenty-five years than during any period of

comparable length since 900 A.D. Id.
30

For its third line of evidence that anthropogenic emissions

of greenhouse gases spurred the perceived warming trend, EPA

turned to computer-based climate-model simulations. Scientists

have used global climate models built on basic principles of

physics and scientific knowledge about the climate to try to

simulate the recent climate change. These models have only

been able to replicate the observed warming by including

anthropogenic emissions of greenhouse gases in the simulations.

Endangerment Finding, 74 Fed. Reg. at 66,523.

To recap, EPA had before it substantial record evidence that

anthropogenic emissions of greenhouse gases “very likely”

caused warming of the climate over the last several decades.

EPA further had evidence of current and future effects of this

warming on public health and welfare. Relying again upon

substantial scientific evidence, EPA determined that

anthropogenically induced climate change threatens both public

health and public welfare. It found that extreme weather events,

changes in air quality, increases in food- and water-borne

pathogens, and increases in temperatures are likely to have

adverse health effects. Id. at 66,497–98. The record also

supports EPA’s conclusion that climate change endangers

human welfare by creating risk to food production and

agriculture, forestry, energy, infrastructure, ecosystems, and

wildlife. Substantial evidence further supported EPA’s

conclusion that the warming resulting from the greenhouse gas

emissions could be expected to create risks to water resources

and in general to coastal areas as a result of expected increase in

sea level. Id. at 66,498. Finally, EPA determined from

substantial evidence that motor-vehicle emissions of greenhouse

gases contribute to climate change and thus to the endangerment

of public health and welfare.

Industry Petitioners do not find fault with much of the

substantial record EPA amassed in support of the Endangerment
31

Finding. Rather, they contend that the record evidences too

much uncertainty to support that judgment. But the existence of

some uncertainty does not, without more, warrant invalidation

of an endangerment finding. If a statute is “precautionary in

nature” and “designed to protect the public health,” and the

relevant evidence is “difficult to come by, uncertain, or

conflicting because it is on the frontiers of scientific

knowledge,” EPA need not provide “rigorous step-by-step proof

of cause and effect” to support an endangerment finding. Ethyl

Corp. v. EPA, 541 F.2d 1, 28 (D.C. Cir. 1976). As we have

stated before, “Awaiting certainty will often allow for only

reactive, not preventive, regulation.” Id. at 25.

Congress did not restrict EPA to remedial regulation when

it enacted CAA § 202(a). That section mandates that EPA

promulgate new emission standards if it determines that the air

pollution at issue “may reasonably be anticipated to endanger

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

requires a precautionary, forward-looking scientific judgment

about the risks of a particular air pollutant, consistent with the

CAA’s “precautionary and preventive orientation.” Lead Indus.

Ass’n, Inc. v. EPA, 647 F.2d 1130, 1155 (D.C. Cir. 1980).

Requiring that EPA find “certain” endangerment of public

health or welfare before regulating greenhouse gases would

effectively prevent EPA from doing the job Congress gave it in

§ 202(a)—utilizing emission standards to prevent reasonably

anticipated endangerment from maturing into concrete harm. Cf.

id. (“[R]equiring EPA to wait until it can conclusively

demonstrate that a particular effect is adverse to health before it

acts is inconsistent with both the [CAA]’s precautionary and

preventive orientation and the nature of the Administrator's

statutory responsibilities. Congress provided that the

Administrator is to use his judgment in setting air quality

standards precisely to permit him to act in the face of

uncertainty.”).
32

In Massachusetts v. EPA the Supreme Court confirmed that

EPA may make an endangerment finding despite lingering

scientific uncertainty. Indeed, the Court held that the existence

of “some residual uncertainty” did not excuse EPA’s decision to

decline to regulate greenhouse gases. Massachusetts v. EPA, 549

U.S. at 534. To avoid regulating emissions of greenhouse gases,

EPA would need to show “scientific uncertainty . . . so profound

that it precludes EPA from making a reasoned judgment as to

whether greenhouse gases contribute to global warming.” Id.

Clearly, then, EPA may issue an endangerment finding even

while the scientific record still contains at least “some residual

uncertainty.” Industry Petitioners have shown no more than that. 

In the end, Petitioners are asking us to re-weigh the

scientific evidence before EPA and reach our own conclusion.

This is not our role. As with other reviews of administrative

proceedings, we do not determine the convincing force of

evidence, nor the conclusion it should support, but only whether

the conclusion reached by EPA is supported by substantial

evidence when considered on the record as a whole. See, e.g.,

New York v. EPA, 413 F.3d 3, 30 (D.C. Cir. 2005). When EPA

evaluates scientific evidence in its bailiwick, we ask only that it

take the scientific record into account “in a rational manner.”

Am. Petroleum Inst. v. Costle, 665 F.2d 1176, 1187 (D.C. Cir.

1981). Industry Petitioners have not shown that EPA failed to do

so here.

C.

State Petitioners, here led by Texas, contend that the

Endangerment Finding is arbitrary and capricious because EPA

did not “define,” “measure,” or “quantify” either the

atmospheric concentration at which greenhouse gases endanger

public health or welfare, the rate or type of climate change that

it anticipates will endanger public health or welfare, or the risks
33

or impacts of climate change. According to Texas, without

defining these thresholds and distinguishing “safe” climate

change from climate change that endangers, EPA’s

Endangerment Finding is just a “subjective conviction.”

It is true that EPA did not provide a quantitative threshold

at which greenhouse gases or climate change will endanger or

cause certain impacts to public health or welfare. The text of

CAA § 202(a)(1) does not require that EPA set a precise

numerical value as part of an endangerment finding. Quite the

opposite; the § 202(a)(1) inquiry necessarily entails a case-bycase, sliding-scale approach to endangerment because “[d]anger

. . . is not set by a fixed probability of harm, but rather is

composed of reciprocal elements of risk and harm, or probability

and severity.” Ethyl, 541 F.2d at 18. EPA need not establish a

minimum threshold of risk or harm before determining whether

an air pollutant endangers. It may base an endangerment finding

on “a lesser risk of greater harm . . . or a greater risk of lesser

harm” or any combination in between. Id.

Ethyl is instructive. There, EPA made an endangerment

finding for airborne lead. During its endangerment inquiry, EPA

initially tried to do what Texas asks of it here: find a specific

concentration of the air pollutant below which it would be

considered “safe” and above which it would endanger public

health. Id. at 56. However, EPA abandoned that approach

because it failed to account for “the wide variability of dietary

lead intake” and lacked predictive value. EPA substituted a

“more qualitative” approach, which relied on “predictions based

on uncertain data” along with clinical studies. Id. at 56–57. This

court upheld the endangerment finding that used that qualitative

approach despite the lack of a specific endangerment

“threshold.”

In its essence, Texas’s call for quantification of the
34

endangerment is no more than a specialized version of Industry

Petitioners’ claim that the scientific record contains too much

uncertainty to find endangerment. EPA relied on a substantial

record of empirical data and scientific evidence, making many

specific and often quantitative findings regarding the impacts of

greenhouse gases on climate change and the effects of climate

change on public health and welfare. Its failure to distill this

ocean of evidence into a specific number at which greenhouse

gases cause “dangerous” climate change is a function of the

precautionary thrust of the CAA and the multivariate and

sometimes uncertain nature of climate science, not a sign of

arbitrary or capricious decision-making.

D.

EPA defined both the “air pollution” and the “air pollutant”

that are the subject of the Endangerment Finding as an aggregate

of six greenhouse gases, which EPA called “well mixed

greenhouse gases”: carbon dioxide (CO2), methane (CH4),

nitrous oxide (N2O), hydrofluorocarbons (HFCs),

perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). Industry

Petitioners argue that EPA’s decision to include PFCs and SF6

in this group of greenhouse gases was arbitrary and capricious

primarily because motor vehicles generally do not emit these

two gases.

No petitioner for review of the Endangerment Finding has

established standing to make this argument. Industry Petitioners

concede that EPA’s decision to regulate PFCs and SF6 along

with the other four greenhouse gases does not injure any motorvehicle-related petitioner. Nor has any non-motor-vehiclerelated petitioner shown an injury-in-fact resulting from EPA’s

inclusion of these two gases in the six-gas amalgam of “wellmixed greenhouse gases.” At oral argument, Industry Petitioners

asserted for the first time that certain utility
35

companies—members of associations that petitioned for review

of the Endangerment Finding—own utility transformers that

emit SF6. However, they never demonstrated or even

definitively asserted that any of these companies would not be

subject to regulation or permitting requirements but for EPA’s

decision to include SF6 as part of the “well-mixed greenhouse

gases” that are the subject of the Endangerment Finding. See

Sierra Club v. EPA, 292 F.3d 895, 898–900 (D.C. Cir. 2002)

(requiring that a petitioner seeking review of agency action

demonstrate standing by affidavit or other evidence if standing

is not “self-evident” from the administrative record). Absent a

petitioner with standing to challenge EPA’s inclusion of PFCs

and SF6 in the “air pollution” at issue, this court lacks

jurisdiction to address the merits of Industry Petitioners’

contention.

E.

EPA did not submit the Endangerment Finding for review

by its Science Advisory Board (SAB). Industry Petitioners claim

that EPA’s failure to do so violates its mandate to “make

available” to the SAB “any proposed criteria document,

standard, limitation, or regulation under the Clean Air Act” at

the time it provides the same “to any other Federal agency for

formal review and comment.” 42 U.S.C. § 4365(c)(1); see Am.

Petroleum Inst., 665 F.2d at 1188.

To begin with, it is not clear that EPA provided the

Endangerment Finding “to any other Federal agency for formal

review and comment,” which triggers this duty to submit a

regulation to the SAB. EPA only submitted a draft of the

Endangerment Finding to the Office of Information and

Regulatory Affairs pursuant to Executive Order 12,866. EPA

contends that this was merely an informal review process, not

“formal review and comment”—at least when compared with a
36

statutory review-and-comment requirement in which other

agencies are given the opportunity to provide written comments

about the impacts of a proposed regulation on the reviewing

agency’s universe of responsibility. See, e.g., 49 U.S.C.

§ 32902(j). Industry Petitioners failed to respond to this

contention. 

In any event, even if EPA violated its mandate by failing to

submit the Endangerment Finding to the SAB, Industry

Petitioners have not shown that this error was “of such central

relevance to the rule that there is a substantial likelihood that the

rule would have been significantly changed if such errors had

not been made.” 42 U.S.C. § 7607(d)(8); see Am. Petroleum

Inst., 665 F.2d at 1188–89 (applying this standard to EPA’s

failure to submit an ozone standard to the SAB).

F.

Lastly, State Petitioners maintain that EPA erred by

denying all ten petitions for reconsideration of the

Endangerment Finding. Those petitions asserted that internal emails and documents released from the University of East

Anglia’s Climate Research Unit (CRU)—a contributor to one of

the global temperature records and to the IPCC’s assessment

report—undermined the scientific evidence supporting the

Endangerment Finding by calling into question whether the

IPCC scientists adhered to “best science practices.” EPA’s

Denial of the Petitions To Reconsider the Endangerment and

Cause or Contribute Findings for Greenhouse Gases Under

Section 202(a) of the Clean Air Act (“Reconsideration Denial”),

75 Fed. Reg. 49,556, 49,556–57 (Aug. 13, 2010). The petitions

pointed to factual mistakes in the IPCC’s assessment report
37

resulting from the use of non-peer-reviewed studies and several

scientific studies postdating the Endangerment Finding as

evidence that the Endangerment Finding was flawed. Id.

On August 13, 2010, EPA issued a denial of the petitions

for reconsideration accompanied by a 360-page response to

petitions (RTP). Id. at 49,556. It determined that the petitions

did not provide substantial support for the argument that the

Endangerment Finding should be revised. According to EPA,

the petitioners’ claims based on the CRU documents were

exaggerated, contradicted by other evidence, and not a material

or reliable basis for questioning the credibility of the body of

science at issue; two of the factual inaccuracies alleged in the

petitions were in fact mistakes, but both were “tangential and

minor” and did not change the key IPCC conclusions; and the

new scientific studies raised by some petitions were either

already considered by EPA, misinterpreted or misrepresented by

petitioners, or put forth without acknowledging other new

studies. Id. at 49,557–58.

1.

EPA is required to convene a proceeding for

reconsideration of a rule if a party raising an objection to the

rule

can demonstrate to the Administrator that it was

impracticable to raise such objection within such time

or if the grounds for such objection arose after the

period for public comment (but within the time

specified for judicial review) and if such objection is of

central relevance to the outcome of the rule.

42 U.S.C. § 7607(d)(7)(B). For the purpose of determining

whether to commence reconsideration of a rule, EPA considers
38

an objection to be of “central relevance to the outcome” of that

rule “if it provides substantial support for the argument that the

regulation should be revised.” Reconsideration Denial, 75 Fed.

Reg. at 49,561.

State Petitioners have not provided substantial support for

their argument that the Endangerment Finding should be

revised. State Petitioners point out that some studies the IPCC

referenced in its assessment were not peer-reviewed, but they

ignore the fact that (1) the IPCC assessment relied on around

18,000 studies that were peer-reviewed, and (2) the IPCC’s

report development procedures expressly permitted the inclusion

in the assessment of some non-peer-reviewed studies (“gray”

literature). 

Moreover, as EPA determined, the limited inaccurate

information developed from the gray literature does not appear

sufficient to undermine the substantial overall evidentiary

support for the Endangerment Finding. State Petitioners have

not, as they assert, uncovered a “pattern” of flawed science.

Only two of the errors they point out seem to be errors at all, and

EPA relied on neither in making the Endangerment Finding.

First, as State Petitioners assert, the IPCC misstated the

percentage of the Netherlands that is below sea level, a statistic

that was used for background information. However, the IPCC

corrected the error, and EPA concluded that the error was

“minor and had no impact,” and the Endangerment Finding did

not refer to the statistic in any way. Id. at 49,576–77. Second,

the IPCC acknowledged misstating the rate at which Himalayan

glaciers are receding. EPA also did not rely on that projection in

the Endangerment Finding. Id. at 49,577.

State Petitioners also contend that a new study contradicts

EPA’s reliance on a projection of more violent storms in the

future as a result of climate change, but the study they cite only
39

concerns past trends, not projected future storms. The record

shows that EPA considered the new studies on storm trends and

concluded that the studies were consistent with the

Endangerment Finding. In sum, State Petitioners have failed to

show that these isolated “errors” provide substantial support for

their argument to overturn the Endangerment Finding.

2.

State Petitioners’ further argument that EPA erred in

denying reconsideration fails as well. These Petitioners claim

EPA erred by failing to provide notice and comment before

denying the petitions for reconsideration because EPA’s

inclusion of a 360-page RTP amounted to a revision of the

Endangerment Finding, and revision of a rule requires notice

and comment. The RTP, however, appears to be exactly what

EPA called it—a response to the petitions for reconsideration,

not a revision of the Endangerment Finding itself. EPA certainly

may deny petitions for reconsideration of a rule and provide an

explanation for that denial, including by providing support for

that decision, without triggering a new round of notice and

comment for the rule.

III.

State and Industry Petitioners contend that in promulgating

the Tailpipe Rule, EPA relied on an improper interpretation of

CAA § 202(a)(1), and was arbitrary and capricious in failing to

justify and consider the cost impacts of its conclusion that the

Rule triggers stationary-source regulation under the PSD and

Title V provisions. They do not challenge the substantive

standards of the Rule and focus principally on EPA’s failure to

consider the cost of stationary-source permitting requirements

triggered by the Rule. Positing an absurd-consequences

scenario, Petitioners maintain that if EPA had considered these
40

costs it “would have been forced” to exclude carbon dioxide

from the scope of the emission standards, to decline to issue

greenhouse gas emission standards at all, or “to interpret the

statute so as not to automatically trigger stationary source

regulation.” Industry Tailpipe Br. 17; see also Industry Tailpipe

Reply Br. 8–9. Both the plain text of Section 202(a) and

precedent refute Petitioners’ contentions. 

A.

Section 202(a)(1) provides:

The Administrator 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 his

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). By employing the verb “shall,”

Congress vested a non-discretionary duty in EPA. See Sierra

Club v. Jackson, 648 F.3d 848, 856 (D.C. Cir. 2011). The plain

text of Section 202(a)(1) thus refutes Industry Petitioners’

contention that EPA had discretion to defer issuance of motorvehicle emission standards on the basis of stationary-source

costs. Neither the adjacent text nor the statutory context

otherwise condition this clear “language of command,” id.

(citation omitted). Having made the Endangerment Finding

pursuant to CAA § 202(a), 42 U.S.C. § 7521(a), EPA lacked

discretion to defer promulgation of the Tailpipe Rule on the

basis of its trigger of stationary-source permitting requirements

under the PSD program and Title V.

The Supreme Court’s decision in Massachusetts v. EPA
41

compels this interpretation of Section 202(a)(1). “If EPA makes

a finding of endangerment, the Clean Air Act requires the

[a]gency to regulate emissions of the deleterious pollutant from

new motor vehicles.” 549 U.S. at 533. “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 explanation as

to why it cannot or will not exercise its discretion to determine

whether they do.” Id. (emphasis added). In the Endangerment

Finding, EPA determined that motor-vehicle emissions

contribute to greenhouse gas emissions that, in turn, endanger

the public health and welfare; the agency therefore was in no

position to “avoid taking further action,” id., by deferring

promulgation of the Tailpipe Rule. Given the non-discretionary

duty in Section 202(a)(1) and the limited flexibility available

under Section 202(a)(2), which this court has held relates only

to the motor-vehicle industry, see infra Part III.C, EPA had no

statutory basis on which it could “ground [any] reasons for”

further inaction, Massachusetts v. EPA, 549 U.S. at 535. 

The plain text of Section 202(a)(1) also negates Industry

Petitioners’ contention that EPA had discretion to defer the

Tailpipe Rule on the basis of NHTSA’s authority to regulate fuel

economy. The Supreme Court dismissed a near-identical

argument in Massachusetts v. EPA, rejecting the suggestion that

EPA could decline to regulate carbon-dioxide emissions because

the Department of Transportation (DOT) had independent

authority to set fuel-efficiency standards. Id. at 531–32. “[T]hat

DOT sets mileage standards in no way licenses EPA to shirk its

environmental responsibilities,” because EPA’s duty to

promulgate emission standards derives from “a statutory

obligation wholly independent of DOT’s mandate to promote

energy efficiency.” Id. at 532. Just as EPA lacks authority to

refuse to regulate on the grounds of NHTSA’s regulatory

authority, EPA cannot defer regulation on that basis. A
42

comparison of the relevant statutes bolsters this conclusion.

Compare 49 U.S.C. § 32902(f) (“When deciding maximum

feasible average fuel economy . . . , the Secretary of

Transportation shall consider . . . the effect of other motor

vehicle standards of the Government on fuel economy . . . .”),

with 42 U.S.C. § 7521(a) (including no such direction). Nor,

applying the same reasoning, was EPA required to treat

NHTSA’s proposed regulations as establishing the baseline for

the Tailpipe Rule. Furthermore, the Tailpipe Rule provides

benefits above and beyond those resulting from NHTSA’s fueleconomy standards. See, e.g., Tailpipe Rule, 75 Fed. Reg. at

25,490 (Table III.F.1-2), 25,636 (Table IV.G.1-4). Petitioners’

related contentions regarding the PSD permitting triggers are

addressed in Part V.

B.

 

Turning to the APA, Industry Petitioners contend, relying

on Small Refiner Lead Phase-Down Task Force v. EPA, 705

F.2d 506, 525 (D.C. Cir. 1983), and Ethyl Corp. v. EPA, 541

F.2d 1 (D.C. Cir. 1976), that EPA failed both to justify the

Tailpipe Rule in terms of the risk identified in the Endangerment

Finding and to show that the proposed standards “would

meaningfully mitigate the alleged endangerment,” Industry

Tailpipe Br. 35. Instead, they maintain that EPA “separated

these two integral steps,” id. at 11, and “concluded that it had no

obligation to show . . . ‘the resulting emissions control strategy

or strategies will have some significant degree of harm reduction

or effectiveness in addressing the endangerment,’” id. at 11–12

(quoting Endangerment Finding, 74 Fed. Reg. at 66,508). These

contentions fail.

Petitioners’ reliance on Small Refiner, 705 F.2d at 525, is

misplaced; the court there laid out guidelines for assessing
43

EPA’s discretion to set numerical standards and Petitioners do

not challenge the substance of the emission standards. In Ethyl,

541 F.2d at 7, the court assessed the scope of EPA’s authority,

under CAA § 211(c)(1), 42 U.S.C. § 1857f-6c(c)(1) (1970)

(currently codified as amended at 42 U.S.C. § 7545(c)(1)), to

regulate lead particulate in motor-vehicle emissions. The court

rejected the argument that the regulations had to “be premised

upon factual proof of actual harm,” Ethyl, 541 F.2d at 12, and

instead deferred to EPA’s reasonable interpretation that

regulations could be based on a “significant risk of harm,” id. at

13. Nothing in Ethyl implied that EPA’s authority to regulate

was conditioned on evidence of a particular level of mitigation;

only a showing of significant contribution was required. EPA

made such a determination in the Endangerment Finding,

concluding that vehicle emissions are a significant contributor

to domestic greenhouse gas emissions. See, e.g., Endangerment

Finding, 74 Fed. Reg. at 66,499. Further, in the preamble to the

Tailpipe Rule itself, EPA found that the emission standards

would result in meaningful mitigation of greenhouse gas

emissions. For example, EPA estimated that the Rule would

result in a reduction of about 960 million metric tons of CO2e

emissions over the lifetime of the model year 2012–2016

vehicles affected by the new standards. See Tailpipe Rule, 75

Fed. Reg. at 25,488–90. Other precedent is likewise unhelpful

to Petitioners: in Chemical Manufacturers Association v. EPA,

217 F.3d 861, 866 (D.C. Cir. 2000), “nothing in the record”

indicated that the challenged regulatory program would “directly

or indirectly, further the Clean Air Act’s environmental goals,”

whereas here the record is fulsome, see supra Part II. 

C.

Petitioners also invoke Section 202(a)(2) as support for

their contention that EPA must consider stationary-source costs

in the Tailpipe Rule. Section 202(a)(2) provides:
44

Any regulation prescribed under paragraph (1) of this

subsection . . . shall take effect after such period as the

Administrator finds necessary to permit the

development and application of the requisite

technology, giving appropriate consideration to the

cost of compliance within such period.

42 U.S.C. § 7521(a)(2). State Petitioners maintain the reference

to compliance costs encompasses those experienced by

stationary sources under the PSD program, while Industry

Petitioners maintain stationary-source costs are a relevant factor

in EPA’s Section 202(a)(1) rulemaking. This court, however,

has held that the Section 202(a)(2) reference to compliance costs

encompasses only the cost to the motor-vehicle industry to come

into compliance with the new emission standards, and does not

mandate consideration of costs to other entities not directly

subject to the proposed standards. See Motor & Equip. Mfrs.

Ass’n, Inc. v. EPA, 627 F.2d 1095, 1118 (D.C. Cir. 1979).

D.

Petitioners’ remaining challenges to the Tailpipe Rule fail

as well. In Part II, the court rejects the contention that the

Tailpipe Rule fails due to flaws in the underlying Endangerment

Finding. The record also refutes Industry Petitioners’ suggestion

that EPA “employed a shell game to avoid,” Industry Tailpipe

Reply Br. 9 (capitalization removed), responding to comments

regarding stationary-source costs. Industry Tailpipe Br. 19–20;

see also Industry Tailpipe Reply Br. 14–15. EPA adequately

responded to “significant comments,” 42 U.S.C. §

7607(d)(6)(B). See, e.g., Tailpipe Rule, 75 Fed. Reg. at

25,401–02; Tailpipe Rule, Response to Comments at 7-65 to 7-

69. And, assuming other statutory mandates provide a basis for

judicial review, see Industry Tailpipe Br. 21–22 (listing

mandates); see, e.g., Small Refiner, 705 F.2d at 537–39, the
45

record shows EPA’s compliance, see Tailpipe Rule, 75 Fed.

Reg. at 25,539–42, and that EPA was not arbitrary and

capricious by not considering stationary-source costs in its

analyses. See, e.g., Michigan v. EPA, 213 F.3d 663, 689 (D.C.

Cir. 2000); Mid-Tex Elec. Coop., Inc. v. FERC, 773 F.2d 327,

341–42 (D.C. Cir. 1985). EPA’s economic impact assessment

conducted pursuant to CAA § 317, 42 U.S.C. § 7617, does not

provide grounds for granting the petitions because Petitioners’

contentions that EPA, “[i]n defiance of these requirements, . . .

refused to estimate or even consider the costs of the [Tailpipe

Rule] for stationary sources,” Industry Tailpipe Br. 22, are no

more than another attempt to avoid the plain text of Section

202(a). See also 42 U.S.C. § 7617(e).

IV.

We turn next to the stationary source regulations. As noted

supra in Part I, EPA’s interpretation of the CAA requires PSD

and Title V permits for stationary sources whose potential

emissions exceed statutory thresholds for any regulated

pollutant—including greenhouse gases. Industry Petitioners now

challenge EPA’s longstanding interpretation of the scope of the

permitting requirements for construction and modification of

major emitting facilities under CAA Sections 165(a) and 169(1),

42 U.S.C. §§ 7475(a) & 7479(1) (“the PSD permitting

triggers”). EPA maintains that this challenge is untimely

because its interpretation of the PSD permitting triggers was set

forth in its 1978, 1980, and 2002 Rules. 

In 1978, EPA defined “major stationary source” as a source

that emits major amounts of “any air pollutant regulated under

the [CAA].” Part 51–Requirements for Preparation, Adoption,

and Submittal of Implementation Plans; Prevention of

Significant Air Quality Deterioration (“1978 Implementation

Plan Requirements”), 43 Fed. Reg. 26,380, 26,382 (June 19,
46

1978). Industry petitioners’ challenge to the 1978 Rule in

Alabama Power Co. v. Costle, 636 F.2d 323 (D.C. Cir. 1980)

reflected their understanding that EPA would apply the PSD

permitting program to both pollutants regulated pursuant to

National Ambient Air Quality Standards (NAAQS) and other

regulated pollutants. See Br. for Industry Pet’rs on Regulation of

Pollutants other than Sulfur Dioxide and Particulates, No. 78-

1006 (and consolidated cases) (Dec. 19, 1978) at 10, 12. In the

1980 Rule, EPA highlighted that to be subject to PSD review, a

“source need only emit any pollutant in major amounts (i.e., the

amounts specified in [CAA § 169(1)]) and be located in an area

designated attainment or unclassifiable for that or any other

pollutant.” 1980 Implementation Plan Requirements, 45 Fed.

Reg. at 52,711 (emphasis in original). EPA explained that “any

pollutant” meant “both criteria pollutants, for which national

ambient air quality standards have been promulgated, and noncriteria pollutants subject to regulation under the Act.” Id. The

same explanation of EPA’s interpretation appeared in the 2002

Rule. Prevention of Significant Deterioration and

Nonattainment New Source Review, 67 Fed. Reg. 80,186,

80,239-40, 80,264 (Dec. 31, 2002). 

CAA Section 307(b)(1) provides that a petition for review

of any promulgated nationally applicable regulations: 

“shall be filed within sixty days from the date notice of

such promulgation . . . appears in the Federal Register,

except that if such petition is based solely on grounds

arising after such sixtieth day, then any petition for review

. . . shall be filed within sixty days after such grounds

arise.” 

42 U.S.C. § 7607(b)(1). The exception encompasses the

occurrence of an event that ripens a claim. See Chamber of

Commerce v. EPA, 642 F.3d 192, 208 n.14 (D.C. Cir. 2011);
47

Am. Rd. & Transp. Builders Ass’n v. EPA, 588 F.3d 1109, 1113

(D.C. Cir. 2009). EPA acknowledges this precedent, but

maintains that the “new grounds” exception is narrow and

inapplicable because Industry Petitioners’ challenge to EPA’s

interpretation of the PSD permitting triggers is based on legal

arguments that were available during the normal judicial review

periods for the 1978, 1980, and 2002 Rules, and the “new

ground” on which they now rely is a factual development,

namely the regulation of greenhouse gases by the Tailpipe Rule.

This is correct so far as it goes, but fails to demonstrate that

Industry Petitioners’ challenge is untimely. 

Industry Petitioners point out that two petitioners—the

National Association of Home Builders ( NAHB ) and National

Oilseed Processors Association ( NOPA ) – have newly ripened

claims as a result of the Tailpipe Rule, which had the effect of

expanding the PSD program to never-regulated sources:

• NAHB’s members construct single family homes,

apartment buildings, and commercial buildings. According

to the Vice President of Legal Affairs, prior to the Tailpipe

Rule, no member of NAHB was a major source of any

regulated pollutant, and thus no member was ever required

to obtain a PSD permit. Decl. of Thomas J. Ward, Vice

President of Legal Affairs for NAHB, ¶ 6 (May 10, 2011).

Since the Tailpipe Rule rendered greenhouse gases a

regulated pollutant, it is now certain that NAHB members

that engage in construction projects that emit greenhouse

gases in major amounts will have to obtain PSD permits

sometime in the future. Id. at ¶¶ 7, 8. Indeed, EPA

estimated that 6,397 multifamily buildings and 515 single

family homes would trigger PSD review annually absent

the Tailoring Rule. See Prevention of Significant

Deterioration and Title V Greenhouse Gas Tailoring Rule;

Proposed Rule (“Proposed Tailoring Rule”), 74 Fed. Reg.
48

55,292, 55,338 (Oct. 27, 2009).

• NOPA’s members are large companies that monthly

produce millions of tons of vegetable meals and over a

billion pounds of oils from oilseeds, such as soybeans. See,

e.g., NOPA, January 2012 Statistical Report (Feb. 14, 2012)

available at www.nopa.org; NOPA, February 2012

Statistical Report (Mar. 14, 2012), available at

www.nopa.org. According to the Executive Vice President

of Regulatory Affairs, NOPA members operate facilities

that are major sources of criteria pollutants and, for this

reason, are subject to PSD review. Decl. of David C. Ailor,

Executive Vice President of Regulatory Affairs of NOPA,

¶ 8 (May 10, 2011). Prior to promulgation of the Tailpipe

Rule, no member’s facility had triggered PSD review by

virtue of emissions of a non-criteria pollutant. Id. Now that

greenhouse gases are a regulated non-criteria pollutant,

many NOPA members will have to obtain PSD permits as

result of their facilities’ emissions of a non-criteria

pollutant. Id. at ¶¶ 9,10. For some NOPA members this time

is not far off because renovations to their facilities will

result in greenhouse gas emissions above the significance

thresholds set by the Tailoring Rule, 75 Fed. Reg. at 31,567.

Id. at ¶ 9. 

Industry Petitioners thus maintain that because NAHB and

NOPA filed their petitions on July 6, 2010, within 60 days of the

promulgation of the Tailpipe Rule in the Federal Register on

May 7, 2010, their challenges are timely. 

“Ripeness, while often spoken of as a justiciability doctrine

distinct from standing, in fact shares the constitutional

requirement of standing that an injury in fact be certainly

impending.” Nat’l Treasury Emp. Union v. United States, 101

F.3d 1423, 1427 (D.C. Cir. 1996). During an initial review
49

period, although purely legal claims may be justiciable and,

thus, prudentially ripe, a party without an immediate or

threatened injury lacks a constitutionally ripe claim. See

Baltimore Gas & Elec. Co. v. ICC, 672 F.2d 146, 149 (D.C. Cir.

1982). EPA’s position would conflate the constitutional and

prudential considerations. Constitutional ripeness exists where

a challenge “involve[s], at least in part, the existence of a live

‘Case or Controversy.’” Duke Power Co. v. Carolina Envtl.

Study Group, 438 U.S. 59, 81 (1978). Prudential considerations

embodied in the ripeness doctrine relate to “the fitness of the

issues for judicial decision and the hardship to the parties of

withholding court consideration.” Abbott Labs. v. Gardner, 387

U.S. 136, 149 (1967); see Duke Power, 438 U.S. at 81. Standing

to challenge agency action exists where a petitioner can

demonstrate an “injury in fact” that is fairly traceable to the

challenged action and is likely to be redressed by a favorable

judicial decision. Reytblatt v. NRC, 105 F.3d 715, 721 (D.C. Cir.

1997) (citing Lujan v. Defenders of Wildlife, 504 U.S. 555,

560–61 (1992)). 

Had NAHB and NOPA challenged EPA’s interpretation of

the PSD permitting triggers in 1978, 1980, or 2002, as EPA

suggests, the court would have lacked jurisdiction under Article

III of the Constitution because their alleged injuries were only

speculative. See, e.g., Occidental Permian Ltd. v. FERC, 673

F.3d 1024, 1026 (D.C. Cir. 2012); Baltimore Gas & Elec. Co.,

672 F.2d at 149. At that time, NAHB and NOPA could have

shown only the possibility that their members would be injured

if EPA were someday to determine that greenhouse gases were

a pollutant that endangers human health and welfare and to

adopt a rule regulating the greenhouse gas emissions of

stationary sources. EPA does not challenge the assertions in the

NAHB and NOPA declarations, which establish no such rule

was promulgated prior to the Tailpipe Rule. 
50

The NAHB and NOPA challenges ceased to be speculative

when EPA promulgated the Tailpipe Rule regulating greenhouse

gases and their challenges ripened because of the “substantial

probability” of injury to them. See Baltimore Gas & Elec. Co.,

672 F.2d at 149. Although, as EPA notes, other Industry

Petitioners’ challenges to EPA’s interpretation of the PSD

permitting triggers ripened decades earlier, this court has

assured petitioners with unripe claims that “they will not be

foreclosed from judicial review when the appropriate time

comes,” Grand Canyon Air Tour Coalition v. FAA, 154 F.3d

455, 473 (D.C. Cir. 1998), and that they “need not fear

preclusion by reason of the 60-day stipulation [barring judicial

review],” Baltimore Gas & Elec. Co., 672 F.2d at 149–50. EPA

expresses concern that allowing NAHB and NOPA to litigate

their newly ripened claims will have far-reaching implications

for finality of agency actions, but “the ripeness doctrine reflects

a judgment that the disadvantages of a premature review that

may prove too abstract or unnecessary ordinarily outweigh the

additional costs of – even repetitive – . . . litigation.” Ohio

Forestry Ass’n, Inc. v. Sierra Club, 523 U.S. 726, 735 (1998).

Some limitations inhere in doctrines such as stare decisis or the

law-of-the-circuit doctrine, see LaShawn A. v. Barry, 87 F.3d

1389, 1395 (D.C. Cir. 1996) (en banc). 

Because petitioners NAHB and NOPA’s challenges to

EPA’s PSD permitting triggers are newly ripened upon

promulgation of the Tailpipe Rule and they filed petitions for

review within sixty days thereof, their challenge to EPA’s

interpretation of the PSD permitting triggers is timely. 

V.

Having established that Industry Petitioners’ challenges to

the PSD permitting triggers are both timely and ripe, we turn to

the merits of their claims. 
51

A.

CAA Title I, Part C—entitled “Prevention of Significant

Deterioration of Air Quality” (PSD)—largely focuses on the

maintenance of national ambient air quality standards

(NAAQS). Under the PSD program, EPA designates specific

pollutants as “NAAQS pollutants” and sets national ambient air

quality standards for those pollutants—requiring, for example,

that the concentration of a given NAAQS pollutant may not

exceed more than a certain number of parts per billion in the

ambient air. See generally 42 U.S.C. § 7407. Thus far, EPA has

designated six NAAQS pollutants: carbon monoxide, lead,

nitrogen dioxide, ozone, particle pollution, and sulfur dioxide.

None of these NAAQS pollutants is one of the six well-mixed

greenhouse gases defined as an “air pollutant” in the

Endangerment Finding. See Environmental Protection Agency,

National Ambient Air Quality Standards, available at

http://www.epa.gov/air/criteria.html (last visited May 3, 2012);

Endangerment Finding, 74 Fed. Reg. 66,536-37. 

Acting upon information submitted by states, EPA then

determines whether each region of the country is in “attainment”

or “nonattainment” with the promulgated air quality standard for

each NAAQS pollutant, or, alternatively, whether a region is

“unclassifiable” for that pollutant. 42 U.S.C. § 7407(d)(1)(A).

An area in attainment for a NAAQS pollutant is “any area . . .

that meets the . . . ambient air quality standard for the pollutant.”

Id. § 7407(d)(1)(A)(ii). By contrast, an area in nonattainment for

a NAAQS pollutant is “any area that does not meet (or that

contributes to ambient air quality in a nearby area that does not

meet) the national . . . ambient air quality standard for the

pollutant.” Id. § 7407(d)(1)(A)(i). Finally, an unclassifiable area

is any area that “cannot be classified on the basis of available

information as meeting or not meeting the . . . ambient air

quality standard for the pollutant.” Id. § 7407(d)(1)(A)(iii). 
52

The PSD program applies to those areas of the United States

designated as in “attainment” or “unclassifiable” for any

NAAQS pollutant, see id. § 7471, and requires permits for major

emitting facilities embarking on construction or modification

projects in those regions. Id. § 7475(a). A separate part of Title

I of the CAA, Part D, governs the construction and modification

of sources in nonattainment regions. See id. §§ 7501, 7502. It

bears emphasis that attainment classifications are pollutantspecific: depending on the levels of each NAAQS pollutant in

an area, a region can be designated as in attainment for NAAQS

pollutant A, but in nonattainment for NAAQS pollutant B. If a

major emitting facility in such a region wishes to undertake a

construction or modification project, both Part C and Part D’s

substantive requirements apply—that is, the source must obtain

a general PSD permit and must also abide by Part D’s more

stringent, pollutant-specific requirements for any NAAQS

pollutants for which the area is in nonattainment. See 1980

Implementation Plan Requirements, 45 Fed. Reg. at 52,711-12

(“where a source emits in major amounts a pollutant for which

the area in which the source would locate is designated

nonattainment, Part D NSR rather than Part C PSD review

should apply to those pollutants.”) (emphasis added).

The key substantive provision in the PSD program is CAA

Section 165(a), which establishes permitting requirements for

“major emitting facilities” located in attainment or unclassifiable

regions. In relevant part, section 165(a) provides that “[n]o

major emitting facility . . . may be constructed in any area to

which this part applies unless” the facility obtains a PSD permit.

42 U.S.C. § 7475(a). To obtain a PSD permit, a covered source

must, among other things, install the “best available control

technology [BACT] for each pollutant subject to regulation

under [the CAA]”—regardless of whether that pollutant is a

NAAQS pollutant. Id. § 7475(a)(4). Since the Tailpipe Rule

became effective, EPA has regulated automotive greenhouse gas
53

emissions under Title II of the Act. Thus, greenhouse gases are

now a “pollutant subject to regulation under” the Act, and, as

required by the statute itself, any “major emitting facility”

covered by the PSD program must install BACT for greenhouse

gases. See id.

The dispute in this case centers largely on the scope of the

PSD program—specifically, which stationary sources count as

“major emitting facilities” subject to regulation. CAA Section

169(1) defines “major emitting facility,” for the purposes of the

PSD program, as a stationary source “which emit[s], or [has] the

potential to emit” either 100 tons per year (tpy) or 250 tpy of

“any air pollutant.” 42 U.S.C. § 7479(1) (emphasis added). As

discussed supra in Part I, whether the 100 or 250 tpy threshold

applies depends on the type of source. Certain listed categories

of sources—for example, iron and steel mill plants—qualify as

“major emitting facilities” if they have the potential to emit over

100 tons per year of “any air pollutant.” Id. All other stationary

sources are “major emitting facilities” if they have the potential

to emit over 250 tons per year of “any air pollutant.” Id. 

As mentioned above, since 1978 EPA has interpreted

the phrase “any air pollutant” in the definition of “major

emitting facility” as “any air pollutant regulated under the

CAA.” See 1978 Implementation Plan Requirements, 43 Fed.

Reg. at 26,388, 26,403; supra Part IV. Thus, because the PSD

program covers “major emitting facilities” in “any area to which

this part applies,” 42 U.S.C. § 7475, EPA requires PSD permits

for stationary sources that 1) are located in an area designated as

attainment or unclassifiable for any NAAQS pollutant, and 2)

emit 100/250 tpy of any regulated air pollutant, regardless of

whether that pollutant is itself a NAAQS pollutant. See 1980

Implementation Plan Requirements, 45 Fed. Reg. at 52,710-11.

Consequently, once the Tailpipe Rule took effect and made
54

greenhouse gases a regulated pollutant under Title II of the Act,

the PSD program automatically applied to facilities emitting

over 100/250 tpy of greenhouse gases. But because immediate

regulation of greenhouse gas-emitting sources exceeding the

100/250 tpy benchmark would result in “overwhelming

permitting burdens that would . . . fall on permitting authorities

and sources,” Tailoring Rule, 75 Fed. Reg. at 31,516, EPA’s

Tailoring Rule provided that, for now, sources are subject to

PSD permitting requirements only if they have the potential to

emit over 100,000 tpy of greenhouse gases (for a construction

project) or 75,000 tpy (for a modification project). Id. at 31,523;

see also infra, Part VI. 

According to EPA, its longstanding interpretation of the

phrase “any air pollutant”—“any air pollutant regulated under

the CAA”—is compelled by the statute. See id. at 31,517.

Disputing this point, Industry Petitioners argue that the phrase

is capable of a far more circumscribed meaning and that EPA

could have—and should have—avoided extending the PSD

permitting program to major greenhouse gas emitters. For the

reasons discussed below, we agree with EPA that its

longstanding interpretation of the PSD permitting trigger is

statutorily compelled. Thus, as EPA argues, it “must give effect

to the unambiguously expressed intent of Congress,” Chevron,

467 U.S. at 843, which here requires PSD coverage for major

emitters of any regulated air pollutant. 

We begin our analysis, as we must, with the statute’s plain

language. See Chevron, 467 U.S. at 842 (“First, always, is the

question whether Congress has directly spoken to the precise

question at issue.”). CAA Section 169(1) requires PSD permits

for stationary sources emitting major amounts of “any air

pollutant.” 42 U.S.C. § 7479(1) (emphasis added). On its face,

“the word ‘any’ has an expansive meaning, that is, ‘one or some

indiscriminately of whatever kind,’ ” United States v. Gonzales,
55

520 U.S. 1, 5 (1997) (quoting WEBSTER’S THIRD NEW

INTERNATIONAL DICTIONARY 97 (1976)). Greenhouse gases are

indisputably an “air pollutant.” See Massachusetts v. EPA, 549

U.S. at 528–29. Congress’s use of the broad, indiscriminate

modifier “any” thus strongly suggests that the phrase “any air

pollutant” encompasses greenhouse gases. 

This plain-language reading of the statute is buttressed by

the Supreme Court’s decision in Massachusetts v. EPA. There

the Court determined that CAA’s overarching definition of “air

pollutant” in Section 302(g)—which applies to all provisions of

the Act, including the PSD program—unambiguously includes

greenhouse gases. Noting that “[t]he Clean Air Act’s sweeping

definition of ‘air pollutant’ includes ‘any air pollution agent or

combination of such agents . . . . which is emitted into or

otherwise enters the ambient air,” the Court held that “the

definition embraces all airborne compounds of whatever stripe,

and underscores that intent through repeated use of the word

‘any.’” Id. at 529 (quoting 42 U.S.C. § 7602(g)) (second and

third emphases added). Crucially for purposes of the issue

before us, the Court concluded that “[t]he statute is

unambiguous.” Id. 

Thus, we are faced with a statutory term—“air

pollutant”—that the Supreme Court has determined

unambiguously encompasses greenhouse gases. This phrase is

preceded by the expansive term “any,” a word the Court held

“underscores” Congress’s intent to include “all” air pollutants

“of whatever stripe.” See id. Absent some compelling reason to

think otherwise, “ ‘any’ . . . means any,” Ford v. Mabus, 629

F.3d 198, 206 (D.C. Cir. 2010), and Petitioners have given us no

reason to construe that word narrowly here. To the contrary:

given both the statute’s plain language and the Supreme Court’s

decision in Massachusetts v. EPA, we have little trouble

concluding that the phrase “any air pollutant” includes all
56

regulated air pollutants, including greenhouse gases. 

In reaching this conclusion, we recognize that EPA’s

definition of “any air pollutant” slightly narrows the literal

statutory definition, which nowhere requires that “any air

pollutant” be a regulated pollutant. See 42 U.S.C. § 7479(1). But

this does not make the statutory language ambiguous. Indeed,

“any regulated air pollutant” is the only logical reading of the

statute. The CAA’s universal definition of “air pollutant”—the

one at issue in Massachusetts v. EPA—provides that the term

includes “any physical, chemical, biological [or] radioactive . .

. substance or matter which is emitted into or otherwise enters

the ambient air.” Id. § 7602(g). Of course, nothing in the CAA

requires regulation of a substance simply because it qualifies as

an “air pollutant” under this broad definition. As discussed

supra in Parts II and III, for example, the Act requires EPA to

prescribe motor vehicle “standards applicable to the emission of

any air pollutant” only if that pollutant “cause[s], or

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

anticipated to endanger public health or welfare.” Id.

§ 7521(a)(1). But if “any air pollutant” in the definition of

“major emitting facility” was read to encompass both regulated

and nonregulated air pollutants, sources could qualify as major

emitting facilities—and thus be subjected to PSD permitting

requirements—if they emitted 100/250 tpy of a “physical,

chemical, [or] biological” substance EPA had determined was

harmless. It is absurd to think that Congress intended to subject

stationary sources to the PSD permitting requirements due to

emissions of substances that do not “endanger public health or

welfare.” Id. § 7521(a)(1). Thus, “any regulated air pollutant” is,

in this context, the only plausible reading of “any air pollutant.” 

We find further support for this definition throughout

the CAA. First, as previously mentioned, the PSD program

provides that all major emitting facilities must install BACT for
57

“each pollutant subject to regulation under [the CAA].” Id.

§ 7475(a)(4). “Each pollutant subject to regulation under” the

Act is, of course, synonymous with “any air pollutant regulated

under the Act.” Thus, EPA’s interpretation of “any air pollutant”

in the definition of “major emitting facilities” harmonizes the

PSD program’s scope (i.e., which pollutants trigger PSD

coverage) with its substantive requirements (i.e., which

pollutants must be controlled to obtain a permit). In other words,

because a covered source must control greenhouse gas

emissions, it makes sense that major emissions of greenhouse

gases would subject that source to the PSD program.

Second, a PSD permittee is required to establish that it

will not cause, or contribute to, air pollution in excess of

any (A) maximum allowable increase or maximum

allowable concentration for any pollutant in any area to

which this part applies more than one time per year, (B)

national ambient air quality standard in any air quality

control region, or (C) any other applicable emission

standard or standard of performance under [the CAA].

Id. § 7475(a)(3). Subsections (A) and (B) prohibit a permitted

source from contributing to a concentration of NAAQS

pollutants that exceeds EPA’s standards. By contrast, subsection

(C) has an entirely different focus: it prohibits a permitted

source from causing or contributing to air pollution in excess of

any CAA emission standard. Thus, as EPA notes, “what this

provision establishes is that while the PSD program was

certainly directed towards NAAQS-criteria pollutants, it also

was directed at maintaining air quality for other pollutants

regulated under other provisions.” EPA Timing & Tailoring Br.

101. EPA’s determination that “any air pollutant” means “any

air pollutant regulated under the Act”—encompassing the

greenhouse gases regulated under Title II—is entirely consistent
58

with this focus.

Finally, Congress made perfectly clear that the PSD

program was meant to protect against precisely the types of

harms caused by greenhouse gases. The PSD provision contains

a section entitled “Congressional declaration of purpose,” which

provides, in relevant part, that “[t]he purposes of this part

are . . . to protect public health and welfare from any actual or

potential adverse effect which in the Administrator’s judgment

may reasonably be anticipated to occur from air pollution.” 42

U.S.C. § 7470(1). The CAA further provides that “[a]ll language

referring to effects on welfare includes, but is not limited to,

effects on . . . weather . . . and climate.” Id. § 7602(h). As

previously noted, EPA in the Endangerment Finding

“marshaled . . . substantial . . . . scientific evidence . . . for the

proposition that greenhouse gases trap heat on earth that would

otherwise dissipate into space [and] that this ‘greenhouse effect’

warms the climate.” Part II, supra at 28–29. It further concluded

that this “anthropogenically induced climate change” was likely

to threaten the public welfare through, among other things,

“extreme weather events.” Id. at 15–16. Thus, one express

purpose of the program is to protect against the harms caused by

greenhouse gases.

In sum, we are faced with a statutory term—“any air

pollutant”—that the Supreme Court has determined is

“expansive,” and “unambiguous[ly]” includes greenhouse gases.

Massachusetts v. EPA, 549 U.S. at 529. Moreover, the PSD

program requires covered sources to install control technology

for “each pollutant” regulated under the CAA, 42 U.S.C.

§ 7475(a)(4), and to establish that they “will not cause, or

contribute to, air pollution in excess of any . . . emission

standard . . . under [the CAA].” Id. § 7475(a)(3) (emphasis

added). These provisions demonstrate that the PSD program was

intended to control pollutants regulated under every section of
59

the Act. Finally, Congress’s “Declaration of Purpose” expressly

states that the PSD program was meant, in part, to protect

against adverse effects on “weather” and “climate”—precisely

the types of harm caused by greenhouse gases. See id. § 7470(1).

Given all this, we have little trouble concluding that “any air

pollutant” in the definition of “major emitting facility”

unambiguously means “any air pollutant regulated under the

CAA.” 

B.

Industry Petitioners offer three alternative interpretations of

the PSD permitting triggers, none of which cast doubt on the

unambiguous nature of the statute. 

As a preliminary matter, we note that none of Petitioners’

alternative interpretations applies to Title V. To the contrary, all

of the proposed alternative interpretations are based on the

structure of—and purported Congressional intent behind—the

PSD program. Indeed, Industry Petitioners never argue that their

proposed alternative interpretations are relevant to Title V.

Petitioners have thus forfeited any challenges to EPA’s

greenhouse gas-inclusive interpretation of Title V. See, e.g.,

Nat’l Steel & Shipbuilding Co. v. NLRB, 156 F.3d 1268, 1273

(D.C. Cir. 1998) (petitioners forfeit an argument by failing to

raise it in their opening brief). 

Industry Petitioners’ first alternative is simple enough.

Because the PSD program focuses on “the air people breathe in

certain geographically defined . . . areas,” Coalition for

Responsible Reg. Timing & Tailoring Br. 38, Industry

Petitioners contend that the term “pollutant” in the PSD statute

encompasses only air pollutants that, unlike greenhouse gases,
60

“pollute locally.” Id. at 35. Industry Petitioners would thus apply

a greenhouse gas-exclusive interpretation of “pollutant”

throughout the statute’s PSD provision. Under this reading, a

source would qualify as a “major emitting facility” only if it

emits 100/250 tpy of “any air pollutant” except greenhouse

gases. See 42 U.S.C. § 7479(1). Moreover, sources that are

subject to PSD permitting requirements would be required to

install BACT for “each pollutant subject to regulation under [the

CAA]”—except greenhouse gases. Id. § 7475(a)(4).

We can easily dispose of Industry Petitioners’ argument that

the PSD program’s “concerns with local emissions,” Coalition

for Responsible Reg. Timing & Tailoring Br. 36, somehow limit

the BACT provision. The statutory text provides, without

qualification, that covered sources must install the “best

available control technology for each pollutant subject to

regulation under [the CAA].” 42 U.S.C. § 7475(a)(4) (emphasis

added). Because greenhouse gases are indisputably a pollutant

subject to regulation under the Act, it is crystal clear that PSD

permittees must install BACT for greenhouse gases. “When the

words of a statute are unambiguous . . . judicial inquiry is

complete.” Connecticut Nat’l Bank v. Germain, 503 U.S. 249,

254 (1992) (internal quotation marks omitted).

Equally without merit is Industry Petitioners’ argument that

the PSD program’s regional focus requires a greenhouse gasexclusive interpretation of “any air pollutant” in the definition

of “major emitting facility.” In support of this contention,

Industry Petitioners note that CAA Section 161 provides that

states’ implementation plans for the PSD program “shall contain

emission limitations and such other measures as may be

necessary . . . to prevent significant deterioration of air quality

in each region.” 42 U.S.C. § 7471 (emphasis added). The term

“air quality,” Industry Petitioners contend, implies a focus on

“the air people breathe,” and the term “in each region” suggests
61

that Congress was concerned about local, not global, effects. See

Coalition for Responsible Reg. Timing & Tailoring Br. 36.

Moreover, Industry Petitioners note that when Congress enacted

the PSD program in 1977, it did so “against the backdrop of a

known universe of CAA-regulated pollutants.” Id. All these

pollutants, Industry Petitioners argue, “were regulated because

they could cause elevated ground-level concentrations in

ambient air people breathe.” Id. And as Industry Petitioners

point out, EPA itself has concluded that greenhouse gases are

problematic for reasons other than local health and

environmental concerns. In EPA’s Advance Notice of Proposed

Rulemaking for the regulations at issue here, for example, the

agency noted that “[a] significant difference between the major

[greenhouse gases] and most air pollutants regulated under the

CAA is that [greenhouse gases] have much longer atmospheric

lifetimes [and] . . . can remain in the atmosphere for decades to

centuries.” Regulating Greenhouse Gas Emissions Under the

Clean Air Act (“Greenhouse Gas Advance Notice”), 73 Fed.

Reg. 44,354, 44,400–01 (July 30, 2008). Moreover, “unlike

traditional air pollutants,” greenhouse gases “become well

mixed throughout the global atmosphere so that the long-term

distribution of [greenhouse gas] concentrations is not dependant

on local emission sources.” Id. Thus, Industry Petitioners

conclude, greenhouse gases are problematic for reasons entirely

distinct from the local concerns that provided the basis for the

PSD program. Given this, the phrase “any air pollutant” cannot

be applied to greenhouse gases in the context of the regionallyfocused PSD program. 

As an initial matter, we note that the Supreme Court

rejected a very similar argument in Massachusetts v. EPA.

There, EPA attempted to distinguish between greenhouse gases

and other air pollution agents “because greenhouse gases

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

the earth’s surface.” Massachusetts v. EPA, 549 U.S. at 529
62

n.26. The Court held that this was “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,” id. (quoting 42 U.S.C.

§ 7602(g)), thus rejecting the dissent’s view that “EPA’s

exclusion of greenhouse gases . . . is entitled to deference.” Id.

As the Court noted, the purported distinction between

greenhouse gases and “traditional” air pollutants “finds no

support in the text of the statute, which uses the phrase ‘the

ambient air’ without distinguishing between atmospheric

layers.” Id. Massachusetts v. EPA thus forecloses Industry

Petitioners’ argument that because greenhouse gases do not

“cause elevated ground-level concentrations in ambient air

people breathe,” Coalition for Responsible Reg. Timing &

Tailoring Br. 36, EPA should have adopted a greenhouse gasexclusive interpretation of “any air pollutant.” 

We also have little trouble disposing of Industry Petitioners’

argument that the PSD program is specifically focused solely on

localized air pollution. True, as Industry Petitioners note, one

part of the PSD program requires states to “prevent significant

deterioration of air quality in each region.” 42 U.S.C. § 7471

(emphasis added). But while localized air quality is obviously

one concern of the PSD program, a comprehensive reading of

the statute shows it was also meant to address a much broader

range of harms. As an initial matter, the PSD provision’s

“Congressional declaration of purpose” section expansively

provides that the program is intended “to protect public health

and welfare from any actual or potential adverse effect . . . from

air pollution.” Id. § 7470(1) (emphasis added). Nothing in this

section limits the PSD program to adverse effects on local air

quality; to the contrary, the word “any” here gives this clause an

“expansive meaning” which we see “no reason to contravene.”

New York, 443 F.3d at 885 (internal quotation marks omitted).

Indeed, the CAA expressly provides that effects on “welfare”
63

means “effects on . . . weather . . . and climate.” 42 U.S.C.

§ 7602(h). It seems quite clear to us, then, that the PSD program

was intended to protect against precisely the types of harms

caused by greenhouse gases. This broad understanding of the

PSD program’s scope is buttressed by the fact that the program

requires covered sources to control “each pollutant subject to

regulation under [the CAA],” and further requires sources to

comply with “any . . . emission standard” under the CAA. Id. §§

7475(a)(3); (a)(4) (emphasis added). These substantive

requirements amount to further evidence that Congress wanted

the PSD program to cover all regulated pollutants, regardless of

the type of harm those pollutants cause. 

In light of the PSD program’s broad scope of regulation and

the express purposes of the program, we conclude—consistent

with the Supreme Court in Massachusetts v. EPA—that Industry

Petitioners’ greenhouse gas-exclusive interpretation of

“pollutant” is “a plainly unreasonable reading” of the statute.

Massachusetts v. EPA, 549 U.S. at 529 n.26.

2.

For their second alternative interpretation, Industry

Petitioners argue that the PSD program’s definition of “major

emitting facility” establishes a “pollutant-specific situs

requirement.” Am. Chemistry Council Br. 33. Under this

reading of the statute, a stationary source is subject to PSD

permitting requirements only if “(1) a source has major

emissions of a NAAQS criteria pollutant and (2) the source is

located in an area attaining that pollutant’s” air quality standard.

Coalition for Responsible Reg. Timing & Tailoring Br. 23.

Thus, for example, a source would be subject to the PSD

permitting requirements if it 1) emits over 100/250 tpy of sulfur

dioxide (a NAAQS criteria pollutant), and 2) is located in an

area that is in “attainment,” or is “unclassifiable,” for sulfur
64

dioxide. But under this approach, a stationary source could

never be subject to the PSD program solely because of its

greenhouse gas emissions. After all, Industry Petitioners

observe, EPA declined to make greenhouse gases a NAAQS

criteria pollutant. Instead, EPA regulated greenhouse gases only

under Title II of the Act, dealing with motor vehicle emissions.

Because “no major source of [greenhouse gases] can be located

in an area attaining the nonexistent [air quality standard] for

[greenhouse gases],” id. at 24, Industry Petitioners point out that

their reading of the statute would bring no new stationary

sources under the PSD program’s ambit—alleviating any

“absurd results” caused by excessive permitting requirements,

id. at 25.

Industry Petitioners emphasize that, unlike their first

proposed alternative, nothing in this approach would “wholly

exempt [greenhouse gases] from PSD.” Coalition for

Responsible Reg. Timing & Tailoring Reply Br. 20. Although

a pollutant-specific situs requirement would limit the number of

sources subject to the PSD program, nothing in this proposed

reading of the statute would alter the substantive requirements

for PSD permits, including the requirement that all regulated

sources install BACT “for each pollutant subject to regulation

under [the CAA].” 42 U.S.C. § 7475(a)(4). So, for example,

under this interpretation, a hypothetical stationary source

emitting more than 100/250 tpy of sulfur dioxide and located in

an area designated as “in attainment” for sulfur dioxide, must

still install BACT for “each pollutant subject to regulation”

under the Act, including greenhouse gases. Their key point,

though, is that sources emitting only major amounts of

greenhouse gases—but not major amounts of a NAAQS criteria

pollutant—would escape PSD permitting requirements.

Industry Petitioners’ argument in support of this

interpretation proceeds in several steps. First, they argue that the
65

term “any air pollutant,” though “capacious and flexible by

itself,” “is a chameleon term” when placed in certain contexts.

Am. Chemistry Council Br. 38. Indeed, Industry Petitioners note

that EPA has already narrowed the literal meaning of the term

“any air pollutant” here. After all, and as discussed supra,

although the statutory term “air pollutant” includes “any

physical [or] chemical . . . substance or matter,” 42 U.S.C.

§ 7602(g), EPA has long maintained that the term “any air

pollutant” in the definition of “major emitting facility”

encompasses only air pollutants regulated under the Act.

Moreover, Industry Petitioners point out that when interpreting

CAA Part C, Subpart 2, entitled “Visibility Protection,” EPA

determined that the term “any pollutant” in the definition of

“major stationary source” meant “any visibility-impairing

pollutant.” See Coalition for Responsible Reg. Timing &

Tailoring Br. 34 (emphasis added). The statute’s definition of

“major stationary source” in the visibility-protection subpart is

quite similar to the definition of “major emitting facility” in the

PSD subpart: for the purposes of the visibility program, a “major

stationary source” is defined as a “stationary source[ ] with the

potential to emit 250 tons or more of any pollutant.” 42 U.S.C.

§ 7491(g)(7)); compare 42 U.S.C. § 7479(1) (“major emitting

facility” for the purposes of the PSD program is a source which

“emit[s], or [has] the potential to emit,” either 100 or 250 tons

per year “of any air pollutant”). These narrowed interpretations,

Industry Petitioners argue, prove that the seemingly capacious

term “any air pollutant” is, notwithstanding that the Supreme

Court called this term “expansive” and “sweeping,”

Massachusetts v. EPA, 549 U.S. at 529 nn.25–26, capable of a

far more circumscribed meaning.

According to Industry Petitioners, EPA should have adopted

that more circumscribed meaning by interpreting “any air

pollutant” as establishing a pollutant-specific situs requirement.

As Industry Petitioners point out, the PSD program requires
66

permits for “major emitting facilit[ies] . . . in any area to which

this part applies,” 42 U.S.C. § 7479(1), and defines “major

emitting facilities” as stationary sources emitting 100/250 tpy of

“any air pollutant.” Id. § 7475(a). In this context, Industry

Petitioners contend, the phrases “any air pollutant” and “in any

area to which this part applies” must be read in concert. And,

Industry Petitioners argue, these phrases “together mean” that a

source is subject to PSD permitting requirements only if it emits

major amounts of “any [NAAQS] air pollutant whose NAAQS

an area is attaining.” Am. Chemistry Council Br. 33.

In support of this supposedly holistic interpretation of the

statute, Industry Petitioners cite CAA § 163(b), a different

section of the PSD provision in which the phrase “any air

pollutant” and “any area to which this part applies” are used in

conjunction with one another. Unlike § 165(a), which sets

permitting requirements for sources covered by the PSD

program, § 163 provides guidelines for areas designated as “in

attainment” under the program. Specifically, § 163(b) limits the

“maximum allowable increase in concentrations of” airborne

NAAQS pollutants that may occur in an attainment area before

that area’s “attainment” status is jeopardized. See 42 U.S.C.

§ 7473(b)(1). Subsections (1) through (3) of § 163(b)—not

directly relevant here—set limits on the maximum allowable

increases for two specific NAAQS pollutants, sulfur dioxide and

particulate matter. Subsection (4) is a catchall provision, which

limits the maximum allowable increases for all other NAAQS

pollutants. It is in subsection (4) that Industry Petitioners find

what they believe is their payoff: the terms “any air pollutant”

and “any area to which this part applies” in conjunction with one

another. Section 163(b)(4) provides:

The maximum allowable concentration of any air pollutant

in any area to which this part applies shall not exceed a

concentration for such pollutant for each period of exposure
67

equal to—

(A) the concentration permitted under the national

secondary ambient air quality standard, or

(B) the concentration permitted under the national

primary ambient air quality standard,

whichever concentration is lowest for such pollutant for

such period of exposure. 

42 U.S.C. § 7473(b)(4) (emphasis added). As Industry

Petitioners correctly point out, in this context the phrase “any air

pollutant” must mean “any NAAQS pollutant,” and “in any area

to which this part applies” must mean “any area that is in

attainment for that NAAQS pollutant.” After all, the statute

states that the “maximum allowable concentration of any air

pollutant . . . shall not exceed” either the primary or secondary

national ambient air quality standards. But, as Industry

Petitioners observe, national ambient air standards exist only for

NAAQS pollutants, so even if “any air pollutant” in CAA

§ 163(b)(4) was read to include non-NAAQS pollutants, the

phrase, in context, would have no practical effect for those

pollutants. Moreover, “any area to which this part applies” must

mean “any area that is in attainment for that NAAQS pollutant,”

because if an area was in nonattainment for a particular

pollutant, Part D—rather than the PSD program—would govern

emissions limits for that specific pollutant. See id. § 7501(2)

(“[t]he term ‘nonattainment area’ means, for any air pollutant,

an area which is designated ‘nonattainment’ with respect to that

pollutant”); § 7502(c) (setting out required “Nonattainment plan

provisions”). Finally, Industry Petitioners correctly note that a

pollutant-specific reading of the phrase “air pollutant” must also

apply to CAA § 165(a)(3)(A), which prohibits PSD permittees

from “caus[ing], or contribut[ing] to, air pollution in excess of

any . . . maximum allowable concentration for any air pollutant

in any area to which this part applies more than one time per

year.” Id. § 7475(a)(3)(A) (emphasis added). This clause, as
68

Industry Petitioners point out, piggybacks off the NAAQS

pollutant-specific definition of “maximum allowable

concentration” in § 163(b)(4), prophylactically restricting PSD

permittees from endangering an area’s attainment status. See

Am. Chemistry Council Br. 32 (describing the interplay between

the two provisions as “Section 163(b)(4) (and Section

165(a)(3)(A), which implements it) . . .”).

Based on all of this, Industry Petitioners conclude that

because the phrase “any air pollutant in any area to which this

part applies” in § 163(b)(4) means “any NAAQS pollutant in

any area in attainment for that NAAQS pollutant,” an identical

reading must apply to the definition of “major emitting facility.”

As a result, a stationary source may be subject to the PSD

program only if it emits 100/250 tpy of any NAAQS pollutant

and is located in an area designated as in attainment for that

NAAQS pollutant. We are unpersuaded. 

Although we agree that the term “any air pollutant” is, in

some contexts, capable of narrower interpretations, we see

nothing in the definition of “major emitting facility” that would

allow EPA to adopt a NAAQS pollutant-specific reading of that

phrase. The contrast with the visibility program is instructive.

There, EPA determined that “any pollutant” in the definition of

“major stationary source” meant “any visibility-impairing

pollutant.” See 40 C.F.R. pt. 51, App. Y, § II.A. But as EPA

notes, the entire visibility program, codified in CAA Part C,

Subpart 2, deals with visibility-impairing pollutants, as reflected

in that subpart’s title: “Visibility Protection.” See 42 U.S.C.

prec. § 7491. From this, “it naturally follows that EPA’s

regulations under that section should address ‘visibilityimpairing pollutants.’ ” EPA Timing & Tailoring Br. 99 n.19.

No similar guidance can be garnered from Part C, Subpart 1,

which contains the phrase “any air pollutant” at issue here.

Dealing with far more than NAAQS pollutants, Part C, Subpart
69

1 requires, for example, covered sources to install BACT for

“each pollutant subject to regulation under [the CAA].” 42

U.S.C. § 7475(a)(4). Indeed, Subpart 1 is simply—and

expansively—entitled “Clean Air.” Id. prec. § 7470. Moreover,

Congress designed the PSD program broadly to protect against

“adverse effect[s]” on “public health and welfare,” Id.

§ 7470(1), including effects on global problems like weather and

climate. Id. § 7602(h). 

Furthermore, the phrases “any air pollutant” and “in any

area to which this part applies” are used differently in Section

163(b)(4) and in the PSD program’s definition of “major

emitting facility.” The presumption that “[a] term appearing in

several places in a statutory text is generally read the same way

each time it appears,” Ratzlaf v. United States, 510 U.S. 135,

143 (1994), “readily yields whenever there is such variation in

the connection in which the words are used as reasonably to

warrant the conclusion that they were employed in different

parts of the act with different intent,” Atl. Cleans & Dryers, Inc.

v. United States, 286 U.S. 427, 433 (1933). Here, the focus and

structure of § 163(b)(4) is entirely distinct from the PSD

permitting trigger. Section 163(b)(4) provides that “[t]he

maximum allowable concentration of any air pollutant in any

area to which this part applies shall not exceed a [particular]

concentration.” 42 U.S.C. § 7473(b)(4). By contrast, § 165(a)

provides that “[n]o major emitting facility . . . may be

constructed in any area to which this part applies” unless certain

conditions are met, id. § 7475(a), and § 169(1) defines “major

emitting facility” as any stationary source that emits or has the

potential to emit threshold amounts of “any air pollutant,” id. §

7479(1). The differences between these two provisions are

manifest. In § 163(b)(4), the phrases “any air pollutant” and “in

any area to which this part applies” appear next to one another,

and it is the concentration of the pollutant in an area that

matters. In the PSD permitting trigger, the phrases appear in
70

different subsections and it is the location of the facility that

matters. Section 163(b)(4) thus does nothing to undermine the

unambiguous meaning of “any air pollutant” in the definition of

“major emitting facility.”

Industry Petitioners’ pollutant-specific reading of “any air

pollutant” is further undermined by contrasting Part C of the Act

(the PSD program) with Part D (which regulates areas in

nonattainment). Unlike Part C, Part D is expressly pollutantspecific, providing that “[t]he term ‘nonattainment area’ means,

for any air pollutant, an area which is designated

‘nonattainment’ with respect to that pollutant.” Id. § 7501(2)

(emphasis added). Congress thus clearly knew how to

promulgate a narrow, pollutant-specific definition of “any air

pollutant.” That it did so in Part D but not in Part C strongly

suggests that the phrase “any air pollutant” in Part C was meant

to be construed broadly. Keene Corp. v. United States, 508 U.S.

200, 208 (1993) (“[W]here Congress includes particular

language in one section of a statute but omits it in another . . . ,

it is generally presumed that Congress acts intentionally and

purposely in the disparate inclusion or exclusion.”) (quoting

Russello v. United States, 464 U.S. 16, 23 (1983)).

A final point: Industry Petitioners observe that every area

in the country has always been in attainment for at least one

NAAQS criteria pollutant. See Tailoring Rule, 75 Fed. Reg. at

31,561. Thus, pursuant to EPA’s pollutant-indifferent reading of

§ 165(a), under which a major emitting facility must abide by

PSD requirements so long as it is located in an attainment area

for any NAAQS pollutant, every facility in the United States has

always been in an “area to which this part applies.”

Consequently, Industry Petitioners argue, “[i]f EPA’s

interpretation were right, Congress simply could have left out

the phrase ‘in any area to which this part applies’” in the PSD

permitting trigger. Am. Chemistry Council Br. 36. But
71

“Congress does not enact ‘stillborn’ laws,” id. (quoting Sosa v.

Alvarez-Machain, 542 U.S. 692, 714 (2004)), and interpretations

that render statutory language superfluous are disfavored. Am.

Chemistry Council Reply Br. 19. The fact that the PSD program

has applied nationwide since its inception, Industry Petitioners

conclude, thus militates against EPA’s pollutant-indifferent

approach. 

This argument fails at its premise, for Industry Petitioners

confuse a lack of practical import with a lack of meaning. To

say that the phrase “in any area to which this part applies” is

currently without practical import is quite different than showing

that the phrase means nothing. Indeed, under different

circumstances, the phrase would have a significant effect. If,

hypothetically, one area of the country was designated as

“nonattainment” for every NAAQS pollutant, the phrase “in any

area to which this part applies” would limit PSD coverage, as

covered sources in that area would be subject only to Part D

requirements. In fact, Environmental Intervenors point out that

when Congress drafted the PSD permitting triggers “the

prospect that some areas could be in nonattainment for all

NAAQS was not far-fetched.” Sierra Club Historic Reg. Br. 23.

“In the years leading up to 1977, EPA air quality data identified

a number of areas that failed to meet all five of the then-current

[air quality standards] for which EPA had gathered data.” Id.

Accordingly, “in any area to which this part applies” is a

meaningful phrase under EPA’s pollutant-indifferent

interpretation of the PSD permitting triggers: it provides that

sources need not obtain PSD permits if they are located in areas

designated “nonattainment” for all six NAAQS pollutants.

In short, although we agree with Industry Petitioners that

phrases like “any air pollutant” are, in certain contexts, capable

of a more limited meaning, they have failed to identify any

reasons that the phrase should be read narrowly here. Nor do we
72

know of one. We thus conclude that EPA’s 34-year-old

interpretation of the PSD permitting triggers is statutorily

compelled: a source must obtain a permit if it emits major

amounts of any regulated pollutant and is located in an area that

is in attainment or unclassifiable for any NAAQS pollutant.

3.

We can quickly dispose of Industry Petitioners’ third

alternative interpretation, namely, that in order to regulate new

pollutants through the PSD program, EPA was required to go

through the process prescribed by CAA § 166. Section 166

provides specific steps that EPA must take when designating

new “pollutants for which national ambient air quality

standards” apply. 42 U.S.C. § 7476(a). Here, Industry

Petitioners argue, EPA unlawfully failed to follow the steps laid

out in Section 166, including a required study of the pollutant

and a one-year delay before the effective date of regulations,

before adding greenhouse gases “to the PSD [c]onstellation.”

Coalition for Responsible Reg. Timing & Tailoring Br. 41. 

This argument fails on its face. By its terms, § 166 applies

only to new “pollutants for which national ambient air quality

standards” apply, 42 U.S.C. § 7476(a) (emphasis added), i.e.,

NAAQS criteria pollutants for which regions may be classified

as in “attainment,” “non-attainment,” or “unclassifiable.” And

EPA never classified greenhouse gases as a NAAQS criteria

pollutant. Instead, it simply determined that under § 165, major

emitters of greenhouse gases are subject to the PSD program and

all covered sources must install BACT for greenhouse gases.

Contrary to Industry Petitioners’ arguments, then, § 166 has no

bearing on this addition of greenhouse gases into “the PSD

[c]onstellation.” Coalition for Responsible Reg. Timing &

Tailoring Br. 41. Indeed, we rejected a nearly identical argument

in Alabama Power, holding that there is “no implied or apparent
73

conflict between sections 165 and 166; nor . . . must the

requirements of section 165 be ‘subsumed’ with those of section

166.” Alabama Power, 636 F.2d at 406. Stating what should

have been obvious from the text of the statute, we concluded:

“[S]ection 166 has a different focus from section 165.” Id. 

Thus, because EPA has never classified greenhouse gases

as a NAAQS criteria pollutant, the § 166 requirements are

entirely inapplicable here. This section of the CAA has

absolutely no bearing on our conclusion that EPA’s

interpretation of the PSD permitting trigger is compelled by the

statute itself.

VI.

Having concluded that the CAA requires PSD and Title V

permits for major emitters of greenhouse gases, we turn to

Petitioners’ challenges to the Tailoring and Timing Rules

themselves. 

As an initial matter, we note that Petitioners fail to make

any real arguments against the Timing Rule. To be sure, at one

point State Petitioners contend that the Timing Rule constitutes

an attempt “to extend the PSD and Title V permitting

requirements to greenhouse-gas emissions,” State Pet’rs’ Timing

& Tailoring Br. 67. This is plainly incorrect. As discussed in the

previous section, greenhouse gases are regulated under PSD and

Title V pursuant to automatic operation of the CAA. All the

Timing Rule did was delay the applicability of these programs,

providing that major emitters of greenhouse gases would be

subject to PSD and Title V permitting requirements only once

the Tailpipe Rule actually took effect on January 2, 2011. See

Timing Rule, 75 Fed. Reg. at 17,017-19. Despite this,

Petitioners confusingly urge us to vacate “[t]he Tailoring and

Timing Rules,” e.g. State Pet’rs’ Timing & Tailoring Br. 24
74

(emphasis added), although it is unclear what practical effect

vacature of the Timing Rule would have. Nonetheless, given this

phrasing of their argument, and given our conclusion that

Petitioners lack Article III standing to challenge both rules, we

shall, where appropriate, discuss the Timing Rule in conjunction

with the Tailoring Rule.

In the Tailoring Rule, EPA announced that it was “relieving

overwhelming permitting burdens that would, in the absence of

this rule, fall on permitting authorities and sources.” Tailoring

Rule, 75 Fed. Reg. at 31,516. Although the PSD statute requires

permits for sources with the potential to emit 100/250 tpy of

“any air pollutant,” 42 U.S.C. § 7479(1), EPA noted that

immediate application of that threshold to greenhouse gasemitting sources would cause permit applications to jump from

280 per year to over 81,000 per year. Tailoring Rule, 75 Fed.

Reg. at 31,554. Many of these applications would come from

commercial and residential sources, which would “each incur,

on average, almost $60,000 in PSD permitting expenses.” Id. at

31,556. Similarly, if the Title V 100 tpy threshold applied

immediately to greenhouse gases, sources needing operating

permits would jump from 14,700 per year to 6.1 million per

year. Id. at 31,562. “The great majority of these sources would

be small commercial and residential sources” which “would

incur, on average, expenses of $23,175.” Id. And were

permitting authorities required to hire the 230,000 full-time

employees necessary to address these permit applications,

“authorities would face over $21 billion in additional permitting

costs each year due to [greenhouse gases], compared to the

current program cost of $62 million each year.” Id. at 31,563. 

 Thus, instead of immediately requiring permits for all

sources exceeding the 100/250 tpy emissions threshold, EPA

decided to “phas[e] in the applicability of these programs to

[greenhouse gas] sources, starting with the largest [greenhouse
75

gas] emitters.” Id. at 31,514. The Tailoring Rule established the

first two steps in this phased-in process. During Step One, only

sources that were “subject to PSD requirements for their

conventional pollutants anyway” (i.e., those sources that

exceeded the statutory emissions threshold for non-greenhouse

gas pollutants) were required to install BACT for their

greenhouse gas emissions. Id. at 31,567. Step Two, which took

effect on July 1, 2011, also requires PSD permits for sources

with the potential to emit over 100,000 tpy CO2e after a

proposed construction project, or 75,000 tpy CO2e after a

proposed modification project. Id. at 31,523. Step Two further

requires Title V permits for sources which have the potential to

emit over 100,000 tpy CO2e. Id. at 31,516. EPA has since

proposed—but has yet to finalize—a “Step Three,” which would

maintain the current thresholds while the agency evaluates the

possibility of regulating smaller sources. See EPA’s 28(j) Letter

1-2, February 27, 2012. 

In the Tailoring Rule, EPA justified its phased-in approach

on three interrelated grounds, each of which rests on a distinct

doctrine of administrative law. First, EPA concluded “the costs

to sources and administrative burdens . . . that would result from

[immediate] application of the PSD and title V programs . . .at

the statutory levels . . . should be considered ‘absurd results,’”

which Congress never intended. Id. at 31,517; see Am. Water

Works Ass’n v. EPA, 40 F.3d 1266, 1271 (D.C. Cir. 1994)

(“[W]here a literal reading of a statutory term would lead to

absurd results, the term simply has no meaning . . and is the

proper subject of construction by EPA and the courts.”). Thus,

under the “absurd results” doctrine, EPA concluded that the PSD

and Title V programs “should not [immediately] be read to

apply to all [greenhouse gas] sources at or above the 100/250

tpy threshold.” Tailoring Rule, 75 Fed. Reg. at 31,554. Second,

emphasizing that immediate regulation at the 100/250 tpy

threshold would cause tremendous administrative burden, EPA
76

justified its deviation from this threshold on the basis of the

“administrative necessity” doctrine. Id. at 31,576; see Envtl. Def.

Fund, Inc. v. EPA, 636 F.2d 1267, 1283 (D.C. Cir. 1980) (“[A]n

agency may depart from the requirements of a regulatory statute

. . . to cope with the administrative impossibility of applying the

commands of the substantive statute.”). Finally, asserting that

there exists a judicial doctrine that allows agencies to implement

regulatory programs in a piecemeal fashion, EPA stated that the

Tailoring Rule was justified pursuant to this “one-step-at-atime” doctrine. Tailoring Rule, 75 Fed. Reg. at 31,578; see

Massachusetts v. EPA, 549 U.S. at 524 (“Agencies, like

legislatures, do not generally resolve massive problems in one

fell regulatory swoop.”). 

Petitioners—particularly State Petitioners—argue that none

of these doctrines permit EPA to “depart unilaterally from the

[CAA’s] permitting thresholds and replace them with numbers

of its own choosing.” State Pet’rs’ Timing & Tailoring Br. 29.

Admitting the “lamentable policy consequences of adhering to

the unambiguous numerical thresholds in the Clean Air Act,”

State Petitioners rather colorfully argue that EPA’s attempts to

alleviate those burdens “establish only that EPA is acting as a

benevolent dictator rather than a tyrant.” Id. at 26. And because

EPA exceeded the boundaries of its lawful authority, Petitioners

urge us to vacate the Tailoring Rule. 

Before we may address the merits of these claims, however,

we must determine whether we have jurisdiction. “No

principle,” the Supreme Court has repeatedly explained, “is

more fundamental to the judiciary’s proper role in our system of

government than the constitutional limitation of federal-court

jurisdiction to actual cases or controversies.” Raines v. Byrd,

521 U.S. 811, 818 (1997) (internal quotation marks omitted).

The doctrine of standing “is an essential and unchanging part of

the case-or-controversy requirement.” Lujan v. Defenders of
77

Wildlife, 504 U.S. 555, 560 (1992). To establish standing, a

petitioner must have suffered an “injury in fact” that is 1)

“concrete and particularized . . . [and] actual or imminent, not

conjectural or hypothetical,” 2) was caused by the conduct

complained of, and 3) is “likely, as opposed to merely

speculative [to] be redressed by a favorable decision.” Id. at

560–61 (internal quotation marks and citations omitted). 

Petitioners fall far short of these “irreducible constitutional

. . . elements” of standing, id. at 560. Simply put, Petitioners

have failed to establish that the Timing and Tailoring Rules

caused them “injury in fact,” much less injury that could be

redressed by the Rules’ vacatur. Industry Petitioners contend

that they are injured because they are subject to regulation of

greenhouse gases, Coalition for Responsible Reg. Timing &

Tailoring Br. 14. State Petitioners claim injury because they own

some regulated sources and because they now carry a heavier

administrative burden. State Pet’rs’ Timing & Tailoring Br.

22–23. But as discussed above, see supra Part V, the CAA

mandates PSD and Title V coverage for major emitters of

greenhouse gases. Thus, Industry Petitioners were regulated and

State Petitioners required to issue permits not because of

anything EPA did in the Timing and Tailoring Rules, but by

automatic operation of the statute. Given this, neither the Timing

nor Tailoring Rules caused the injury Petitioners allege: having

to comply with PSD and Title V for greenhouse gases.

Indeed, the Timing and Tailoring Rules actually mitigate

Petitioners’ purported injuries. Without the Timing Rule,

Petitioners may well have been subject to PSD and Title V for

greenhouse gases before January 2, 2011. Without the Tailoring

Rule, an even greater number of industry and state-owned

sources would be subject to PSD and Title V, and state

authorities would be overwhelmed with millions of additional

permit applications. Thus, Petitioners have failed to “show that,
78

absent the government’s allegedly unlawful actions, there is a

substantial probability that they would not be injured and that,

if the court affords the relief requested, the injury will be

removed.” Chamber of Commerce v. EPA, 642 F.3d 192, 201

(D.C. Cir. 2011) (quotations and alterations omitted). Far from

it. If anything, vacature of the Tailoring Rule would

significantly exacerbate Petitioners’ injuries.

Attempting to remedy this obvious jurisdictional defect,

State Petitioners present two alternative theories, neither of

which comes close to meeting the “irreducible

constitutional . . . elements” of standing. Lujan, 504 U.S. at 560.

First, State Petitioners counterintuitively suggest that they

actually want EPA to immediately “appl[y] the 100/250 tpy

permitting thresholds to greenhouse-gas emissions.” State

Pet’rs’ Timing & Tailoring Reply Br. 15. Admitting that

vacature of the Tailoring Rule would result in astronomical costs

and unleash chaos on permitting authorities, State Petitioners

predict that Congress will be forced to enact “corrective

legislation” to relieve the overwhelming permitting burdens on

permitting authorities and sources, thus mitigating their

purported injuries. Id. 

This theory fails. To establish standing, plaintiffs must

demonstrate that it is “likely, as opposed to merely speculative,

that the injury will be redressed by a favorable decision,” Lujan,

504 U.S. at 561 (internal quotation marks omitted), but here,

State Petitioners simply hypothesize that Congress will enact

“corrective legislation.” State Pet’rs’ Timing & Tailoring Reply

Br. 15. We have serious doubts as to whether, for standing

purposes, it is ever “likely” that Congress will enact legislation

at all. After all, a proposed bill must make it through committees

in both the House of Representatives and the Senate and garner

a majority of votes in both chambers—overcoming, perhaps, a

filibuster in the Senate. If passed, the bill must then be signed
79

into law by the President, or go back to Congress so that it may

attempt to override his veto. As a generation of schoolchildren

knows, “by that time, it’s very unlikely that [a bill will] become

a law. It’s not easy to become a law.” Schoolhouse Rock, I’m

Just a Bill , at 2:41, available at

http://video.google.com/videoplay?docid=7266360872513258

185# (last visited June 1, 2012). 

And even if the astronomical costs associated with a

100/250 tpy permitting threshold make some Congressional

action likely, State Petitioners are still unable to show that it is

“likely, as opposed to merely speculative,” Lujan, 504 U.S. at

561, that Congress will redress their injury. State Petitioners

apparently assume that if the 100/250 tpy permitting threshold

was immediately applied to greenhouse gases, Congress would

exempt those pollutants from the PSD and Title V programs

entirely. But this is just one of many forms “corrective

legislation” could take. For example, were we to vacate the

Tailoring Rule, Congress could decide to readopt its key

provisions in the PSD and Title V statutes. Or it could set PSD

and Title V permitting thresholds at 25,000 tpy for greenhouse

gases—higher than the 100/250 tpy threshold, but lower (and

thus more costly to Petitioners) than the thresholds promulgated

in the Tailoring Rule. Or it could do something else entirely. All

of this is guesswork, which is precisely the point: State

Petitioners’ faith that Congress will alleviate their injury is

inherently speculative. 

State Petitioners’ second alternative theory of standing fares

no better. In their reply brief, they contend that even if vacating

the Timing or Tailoring Rules would indeed exacerbate their

costs and administrative burdens (the purported injuries they

claimed in their opening brief), “then State Petitioners can

establish Article III standing under Massachusetts by asserting

injuries caused by EPA’s failure to regulate sooner.” State
80

Pet’rs’ Timing & Tailoring Reply Br. 5. Essentially, State

Petitioners’ reply brief contends that, contrary to the position

taken in the opening brief, they want more regulation, not less,

and that they wanted regulation sooner rather than later. And

because the Commonwealth of Massachusetts had standing to

seek regulation of greenhouse gases in Massachusetts v. EPA,

State Petitioners argue that they now have standing to seek more

regulation of greenhouse gases as well.

This argument is completely without merit. As an initial

matter, we are aware of no authority which permits a party to

assert an entirely new injury (and thus, an entirely new theory of

standing) in its reply brief. Quite to the contrary, we have held

that, where standing is not self-evident, “[i]n its opening brief,

the petitioner should . . . include . . . a concise recitation of the

basis upon which it claims standing.” Sierra Club v. EPA, 292

F.3d 895, 901 (D.C. Cir. 2002) (emphasis added); see also D.C.

Cir. R. 28(a)(7) (“[i]n cases involving direct review in this court

of administrative actions, the brief of the appellant or petitioner

must set forth the basis for the claim of standing.”); American

Library Ass’n v. FCC, 401 F.3d 489, 493–94 (D.C. Cir. 2005)

(discussing limitations on this principle). After all, “it is often

the case . . . that some of the relevant facts are known only to the

petitioner, to the exclusion of both the respondent and the

court.” Sierra Club, 292 F.3d at 901. If “the petitioner does not

submit evidence of those facts with its opening brief,” the

respondent is “left to flail at the unknown in an attempt to prove

the negative.” Id. This principle is particularly important here,

for State Petitioners’ asserted fear of global warming stands in

stark contrast to the position they took throughout this litigation.

In an earlier brief, for example, they characterized the

Endangerment Finding as “a subjective conviction” State Pet’rs’

Endangerment Br. 19, “supported by highly uncertain climate

forecasts,” id. at 18, and “offer[ing] no criteria for determining

a harmful, as opposed to a safe, climate,” id. at 17. Given this,
81

EPA could not possibly have anticipated that State Petitioners,

abruptly donning what they themselves call “an

environmentalist hat,” State Pet’rs’ Timing & Tailoring Reply

Br. 4, would assert that global warming causes them concrete

and particularized harm.

In any event, State Petitioners fail to cite any record

evidence to suggest that they are adversely affected by global

climate change. This is in stark contrast to the evidence put

forward in Massachusetts v. EPA, where the Commonwealth

submitted unchallenged affidavits and declarations showing that

1) rising sea tides due to global warming had “already begun to

swallow Massachusetts’ coastal land,” and 2) “[t]he severity of

that injury will only increase over the course of the next

century.” Massachusetts v. EPA, 549 U.S. at 522–23. These

specific, factual submissions were key to the standing analysis

in Massachusetts v. EPA: the Court held that “petitioners’

submissions as they pertain to Massachusetts have satisfied the

most demanding standards of the adversarial process.” Id. at 521

(emphasis added). It is true, as State Petitioners emphasize, that

the Supreme Court held that states are “entitled to special

solicitude in our standing analysis.” Id. at 522. But nothing in

the Court’s opinion remotely suggests that states are somehow

exempt from the burden of establishing a concrete and

particularized injury in fact. State Petitioners, like Industry

Petitioners, failed to do so here. We shall thus dismiss all

challenges to the Timing and Tailoring Rules for lack of

jurisdiction.

VII.

Following promulgation of the Timing and Tailoring Rules,

EPA issued a series of rules ordering states to revise their PSD

State Implementation Plans (SIPs) to accommodate greenhouse

gas regulation. See Action to Ensure Authority to Issue Permits
82

Under the Prevention of Significant Deterioration Program to

Sources of Greenhouse Gas Emissions: Finding of Substantial

Inadequacy and SIP Call, 75 Fed. Reg. 53,892 (Sept. 2, 2010),

75 Fed. Reg. 77,698 (Dec. 13, 2010); Action to Ensure Authority

to Issue Permits Under the Prevention of Significant

Deterioration Program to Sources of Greenhouse Gas

Emissions: Finding of Failure to Submit State Implementation

Plan Revisions Required for Greenhouse Gases, 75 Fed. Reg.

81,874 (Dec. 29, 2010). Industry Petitioners present several

challenges to these SIP-related rules. But our review in this case

is limited to four EPA decisions: the Endangerment Finding, the

Tailpipe Rule, and the Timing and Tailoring Rules. We thus lack

jurisdiction over the SIP-related rules. Moreover, challenges to

these rules are currently pending in at least two separate cases

before this court. See Utility Air Regulatory Group v. EPA, No.

11-1037 (consolidating various challenges); Texas v. EPA, No.

10-1425 (challenge brought by Texas). We decline Industry

Petitioners’ invitation to rule on the merits of cases which are

properly before different panels.

VIII.

For the foregoing reasons, we dismiss all petitions for

review of the Timing and Tailoring Rules, and deny the

remainder of the petitions.

So ordered.