 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-in-
Charge, 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 heat-
trapping 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 several steps. 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 policy-
based 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-than-
perfectly 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 peer-
reviewed 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 decision-
makers 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-by-
case, 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 (N 2 O), 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 motor-
vehicle-related petitioner. Nor has any non-motor-vehicle-
related petitioner shown an injury-in-fact resulting from EPA’s
inclusion of these two gases in the six-gas amalgam of “well-
mixed 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 e-
mails 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 motor-
vehicle 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 fuel-
economy 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 non-
criteria 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 pollutant-
specific: 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 gas-
exclusive 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 regionally-
focused 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 gas-
exclusive 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 ‘visibility-
impairing 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 pollutant-
specific, 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 gas-
emitting 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-a-
time” 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.
