In the Supreme Court of the United States
COMMONWEALTH OF MASSACHUSETTS, ET AL., PETITIONERS
ENVIRONMENTAL PROTECTION AGENCY, ET AL.
ON PETITION FOR A WRIT OF CERTIORARI
TO THE UNITED STATES COURT OF APPEALS
FOR THE DISTRICT OF COLUMBIA CIRCUIT
BRIEF FOR THE FEDERAL RESPONDENT
PAUL D. CLEMENT
Counsel of Record
SUE ELLEN WOOLDRIDGE
Assistant Attorney General
JON M. LIPSHULTZ
Department of Justice
Washington, D.C. 20530-0001
ANN R. KLEE
Washington, D.C. 20460
1. Whether, in this challenge to the denial by the Environmental Protection Agency of petitioners' rule making petition, petitioners adequately established standing-i.e., that their alleged injuries were caused by the denial of the rulemaking petition and would be redressed by a judicial decision in their favor in this case.
2. Whether the court of appeals correctly deter mined that EPA lawfully exercised its discretion in denying petitioners' rulemaking petition seeking regulation of carbon dioxide and other greenhouse gas emissions from mobile sources (such as cars and light trucks) under Section 202(a)(1) of the Clean Air Act, 42 U.S.C. 7521(a)(1), where, among other things, EPA believed pertinent scientific and technological issues could be better analyzed after the completion of ongoing studies.
3. Whether EPA correctly determined that the Clean Air Act does not in any event give it authority to regulate greenhouse gas emissions for the purpose of addressing concerns about global climate change.
In the Supreme Court of the United States
COMMONWEALTH OF MASSACHUSETTS, ET AL., PETITIONERS
ENVIRONMENTAL PROTECTION AGENCY, ET AL.
ON PETITION FOR A WRIT OF CERTIORARI
TO THE UNITED STATES COURT OF APPEALS
FOR THE DISTRICT OF COLUMBIA CIRCUIT
BRIEF FOR THE FEDERAL RESPONDENT
The opinion of the court of appeals (Pet. App. A1-A58) is reported at 415 F.3d 50. The decision of the Environ mental Protection Agency (Pet. App. A59-A97) is published at 68 Fed. Reg. 52,922.
The judgment of the court of appeals was entered on July 15, 2005. Petitions for rehearing were denied on De cember 2, 2005 (Pet. App. A94-A98 ). The petition for a writ of certiorari was filed on March 2, 2006. The jurisdiction of this Court is invoked under 28 U.S.C. 1254(1).
Petitioners seek review of a decision of the court of ap peals upholding the denial by the Environmental Protection Agency (EPA) of a rulemaking petition seeking regulation of emissions of carbon dioxide and three other greenhouse gases from new motor vehicles under the Clean Air Act (CAA), 42 U.S.C. 7401 et seq. In denying the petition, EPA first determined that it did not have authority under the CAA to regulate emissions of greenhouse gases to address concerns about climate change. See Pet. App. A59-A93. The Agency further explained that even if it had the requi site regulatory authority, it would still deny the rulemaking petition for a number of other reasons, including its desire to have the benefit of ongoing scientific and technical stud ies before making a regulatory decision of such complexity and potential effect. Id. at A80-A87. Numerous petitioners challenged the denial of the rulemaking petition, but the court of appeals denied their petitions for review. See id. at A1-A58.
1. Sections 108 and 109 of Title I of the CAA, 42 U.S.C. 7408-7409, authorize EPA to set national ambient air qual ity standards (NAAQS) for air pollutants that cause or con tribute to air pollution that may reasonably be anticipated to endanger public health or welfare and that are emitted by numerous or diverse sources. Section 110 of the CAA, 42 U.S.C. 7410, establishes a federal-state partnership for meeting NAAQS in local air quality control regions through state implementation plans.
While most of the provisions in Title I of the CAA focus on stationary sources of air pollution, Title II of the Act establishes a regulatory framework for federal control of pollution from motor vehicles and other mobile sources. See CAA Sections 202-250, 42 U.S.C. 7521-7590. This case specifically involves Section 202(a)(1) of the CAA, 42 U.S.C. 7521(a)(1), which authorizes EPA to "prescribe * * * standards applicable to the emission of any air pollutant from any class or classes of new motor vehicles or new mo tor vehicle engines, which in [EPA's] judgment cause, or contribute to, air pollution which may reasonably be antici pated to endanger public health or welfare."
Section 302 of the Act, 42 U.S.C. 7602, sets forth general definitions applicable to the CAA as a whole. Section 302(g), 42 U.S.C. 7602(g), defines "air pollutant" as "any air pollution agent or combination of such agents, including any physical, chemical, biological, [or] radioactive * * * sub stance or matter which is emitted into or otherwise enters the ambient air[,]" including any precursors to the forma tion of such air pollutant. "[E]ffects on welfare" is defined to include "effects on soils, water, crops, vegetation, man made materials, animals, wildlife, weather, visibility, and climate, and damage to * * * property, and hazards to transportation, as well as effects on economic values and on personal comfort and well-being." 42 U.S.C. 7602(h).
2. On October 20, 1999, the International Center for Technology Assessment and several other parties filed a rulemaking petition asking EPA to regulate emissions of carbon dioxide, methane, nitrous oxide, and hydrofluorocarbons from new motor vehicles. The petition alleged that emissions of those "greenhouse gas[es]" from motor vehicles contributed to global climate change, satis fied the criteria for regulation under Section 202(a)(1) of the Act, 42 U.S.C. 7521(a)(1), and would be feasible for EPA to regulate. See Pet. App. A59-A63. After soliciting and considering approximately 50,000 public comments, see id. at A63, EPA issued a written decision denying the peti tion. Id.at A59-A93.
EPA first concluded that Congress did not provide it with authority in the CAA to regulate carbon dioxide and other greenhouse gases to address concerns about global climate change. Pet. App. A67, A68-A79. EPA explained that it must be cautious about "using broadly worded statu tory authority to regulate in areas raising unusually signifi cant economic and political issues when Congress has spe cifically addressed those areas in other statutes." Id. at A68 (citing FDA v. Brown & Williamson Tobacco Corp., 529 U.S. 120 (2000)). In that regard, EPA noted that the only provisions of the Act that specifically mention carbon dioxide or "global warming" are non-regulatory in nature, and pointed out that when Congress elsewhere wanted to address an analogous type of global environmental is sue-stratospheric ozone depletion-it added an entirely new set of provisions to the CAA specifically tailored to that problem and its international dimensions. Id. at A70-A72. EPA further noted that Congress had enacted non-CAA legislation in recent years specifically directed to climate change, and had rejected numerous attempts to give EPA authority to regulate greenhouse gas emissions to address climate change. Id. at A75. For those and other reasons, EPA determined that the CAA, read as a whole, did not provide the Agency with authority to promulgate the type of regulation sought by petitioners. Id. at A78.
EPA also explained why, even if it had the requisite CAA regulatory authority, it would deny the rulemaking petition. Based in large part on its review of a 2001 report on global climate change by the National Research Council (NRC), EPA identified numerous areas of scientific uncer tainty involving the mechanisms of climate change, its po tential effects on human health and the environment, and the means by which such issues can most effectively be ad dressed. Pet. App. A82-A84. Noting NRC's conclusion that "[t]he understanding of the relationships between weather/ climate and human health is in its infancy and therefore the health consequences of climate change are poorly under stood," EPA found that "[s]ubstantial scientific uncertain ties limit our ability to assess each of these factors and to separate out those changes resulting from natural variabil ity from those that are directly the result of increases in anthropogenic [greenhouse gases]." Id. at A84; see id. at A83 (the "science of climate change is extraordinarily com plex and still evolving"). EPA explained that "[u]ntil more is understood about the causes, extent and significance of climate change and the potential options for addressing it, EPA believes it is inappropriate to regulate [greenhouse gas] emissions from motor vehicles." Id. at A86. EPA identified a variety of ongoing efforts that were then under way to further investigate the areas of scientific and techni cal uncertainty, and explained its view that "establishing [greenhouse gas] emission standards for U.S. motor vehi cles at this time would require EPA to make scientific and technical judgments without the benefit of the studies being developed to reduce uncertainties and advance technolo gies." Id. at A85.
EPA also explained that any effort by it to regulate greenhouse gas emissions from motor vehicles at this time would necessarily raise other important legal and policy concerns, such as possible interference with foreign policy considerations including the United States' negotiations with developing nations. Pet. App. A86. In addition, since at present "the only practical way to reduce tailpipe emis sions of [carbon dioxide] is to improve fuel economy," id. at A79, a regulation directed to that end would present prob lems of coordination and inconsistency with the statutory scheme of the Energy Policy and Conservation Act (EPCA), 49 U.S.C. 32901-32919, which authorizes the De partment of Transportation (DOT) to set fuel economy standards. Pet. App. A79-A80, A86-A87.1
3. Numerous petitions for review of EPA's denial of the rulemaking petition were filed in the D.C. Circuit. On July 15, 2005, the court of appeals decided the consolidated case in EPA's favor, finding that the challenges to EPA's action should be denied. Pet. App. A1-A58.2 Judge Randolph filed the judgment of the court, but each of the three judges on the panel filed a separate opinion adopting a distinct analysis.
a. EPA challenged petitioners' standing to bring this case, arguing that petitioners had failed to show causation (i.e., that their alleged injuries were caused by EPA's deci sion not to regulate emissions of greenhouse gases from new motor vehicles) and redressability (i.e., that their al leged injuries could be redressed by a judicial decision in their favor in this case). Judge Randolph stated that the declarations submitted by petitioners "'support each ele ment' of standing" sufficiently to survive a summary judg ment motion. Pet. App. A8 (quoting Sierra Club v. EPA, 292 F.3d 895, 899 (D.C. Cir. 2002)). But he observed that the record also "contains a wealth of * * * 'other evi dence,' and some of it contradicts petitioners' claim that greenhouse gas emissions from new motor vehicles have caused or will cause a significant change in the global cli mate." Id. at A9. He concluded that, in that unusual situa tion, the court should "proceed to the merits with respect to EPA's alternative decision not to regulate on the grounds, among others, that the effect of greenhouse gases on cli mate is unclear and that models used to predict climate change might not be accurate." Ibid. See id. at A9-A10; Steel Co. v. Citizens for a Better Env't, 523 U.S. 83, 97 n.2 (1998) (discussing permissibility of proceeding to the merits before resolving statutory standing issues).
Judge Sentelle concluded that petitioners did not have standing. In his view, they had "alleged and shown no harm particularized to themselves," Pet. App. A17, but in stead had merely shown that "[e]mission of certain gases that the EPA is not regulating may cause an increase in the temperature of the earth," that "[t]his is harmful to human ity at large," and that "[p]etitioners are or represent seg ments of humanity at large," id. at A18. In Judge Sentelle's view, that "would appear to be neither more nor less than the sort of general harm eschewed as insufficient to make out an Article III controversy by the Supreme Court and lower courts." Ibid. Nonetheless, because his preferred resolution of the case (dismissal for lack of jurisdiction) was different from the resolutions urged respectively by Judge Randolph (denial of the petition for review) and Judge Tatel (grant of the petition for review) and thus would have prevented issuance of any judgment commanding a major ity of the court, Judge Sentelle accepted as law of the case the view of Judges Randolph and Tatel that the court had jurisdiction to issue a judgment and then "join[ed] Judge Randolph in the issuance of a judgment closest to that which [Judge Sentelle himself] would issue." Id. at A20.
Judge Tatel, alone of the panel members, concluded that petitioners had shown that they had standing in this case. In his view, the declarations submitted by Massachusetts adequately established that global warming would cost the State a particularized "loss of land within its sovereign boundaries" as sea levels rise. Pet. App. A27. He con cluded that, with respect to causation, other declarations adequately established "that global warming is chiefly trig gered by human-caused [greenhouse gas] emissions." Id. at A28. With respect to redressability, he found that a dec laration submitted by petitioners adequately established that regulating greenhouse gas emissions from motor vehi cles in the United States "would . . . delay and moderate many of the adverse impacts of global warming." Id. at A29. He also noted that another declaration asserted that a decision by EPA to regulate greenhouse gases would lead to improved technologies, which would in time be required by other countries around the world. Ibid. Finally, he stated that no factual disputes on those issues had to be resolved, because EPA did not cite or otherwise advance any record evidence in support of contrary findings. Id. at A30.
b. On the merits, Judge Randolph stated that he would merely "assume arguendo that EPA has statutory author ity to regulate greenhouse gases from new motor vehicles," Pet. App. A10, but that the petition for review should none theless be denied because the Administrator "properly ex ercised his discretion * * * in denying the petition for rulemaking," id. at A15. He noted the substantial uncer tainty in the "current understanding of how the climate system varies naturally and reacts to emissions of green house gases," an uncertainty that "is compounded by the possibility for error inherent in the assumptions necessary to predict future climate change." Id. at A12. He also noted that, because Section 202(a)(1) "directs the Adminis trator to regulate emissions that 'in his judgment' 'may reasonably be anticipated to endanger public health or wel fare," it "gives the Administrator considerable discretion" to take into account not only "scientific evidence" but also what may be called "policy judgments." Id. at A13. He concluded that, especially given that the rulemaking peti tion required EPA to "resolve issues 'on the frontiers of scientific knowledge,'" the "EPA Administrator properly exercised his discretion under § 202(a)(1) in denying the petition for rulemaking." Id. at A15 (quoting Environmen tal Def. Fund v. EPA, 598 F.2d 62, 82 (D.C. Cir. 1978)).
As noted above, Judge Sentelle did not address the mer its of EPA's denial of the petition for rulemaking in his opinion.
Judge Tatel dissented. Pet. App. A21-A58. In his view, EPA had erred in concluding that it had no statutory au thority to regulate greenhouse gas emissions from motor vehicles-an issue on which neither of the other panel members expressed an opinion. Id. at A31-A42. Judge Tatel also stated that EPA had erred in concluding that, even if it did have that regulatory authority, it would none theless decline to make an "endangerment" finding here. In his view, Section 202(a)(1) authorizes the EPA Adminis trator, in determining whether a pollutant "in his judgment cause[s], or contribute[s] to, air pollution which may reason ably be anticipated to endanger public health or welfare," only "to determin[e] whether the statutory standard for endangerment has been met." Id. at A46. Moreover, Judge Tatel concluded that the scientific uncertainties associated with global warming, see id. at A50-A54, the overlapping responsibilities of the Department of Transportation in setting fuel economy standards, see id. at A55, and the po tential for interference with the United States' ongoing negotiations with other nations, see id. at A56, did not jus tify EPA's action.
4. The court of appeals denied a petition for rehearing en banc. See Pet. App. A94-A97. Judge Tatel filed an opin ion dissenting from the denial of rehearing en banc, in which Judge Rogers joined. See id. at A95-A98. Judge Griffith also would have granted the petition for rehearing en banc, but he did not join Judge Tatel's dissent from the denial of that petition. Id. at A95.
Petitioners argue that the Clean Air Act required EPA to embark on the extraordinarily complex and scientifically uncertain task of addressing the global issue of greenhouse gas emissions by regulating mobile sources of such emis sions in the United States. Although the court of appeals did not itself reach a firm conclusion regarding petitioners' standing, petitioners failed to make the necessary showing of causation and redressability to satisfy Article III stand ing requirements. On the merits, EPA reasonably con cluded that regulation of greenhouse gases by means of vehicle emissions standards is neither authorized by the Clean Air Act nor an appropriate exercise of agency au thority at the present time and on the existing record. The judgment of the court of appeals upholding that deci sion-which is supported by separate opinions of the panel members rather than a single majority opinion and thus would provide a particularly poor vehicle for review-does not conflict with any decision of this Court or any other court of appeals. Further review is not warranted.
1. As a threshold matter, petitioners lack standing to bring their challenge. "In every federal case, the party bringing the suit must establish standing to prosecute the action." Elk Grove Unified Sch. Dist. v. Newdow, 542 U.S. 1, 11 (2004). In addition to a showing of "injury in fact," the plaintiff must establish causation and redressability. The plaintiff must show that there is "a causal connection be tween the injury and the conduct complained of," so that the plaintiff's injury is "fairly . . . trace[able] to the chal lenged action of the defendant, and not . . . th[e] result [of] the independent action of some third party not before the court." Lujan v. Defenders of Wildlife, 504 U.S. 555, 560 (1992) (quoting Simon v. Eastern Ky. Welfare Rights Org., 426 U.S. 26, 41-42 (1976)). The plaintiff must also show that it is "'likely,' as opposed to merely 'speculative,' that the injury will be 'redressed by a favorable decision.'" Id. at 561 (also quoting Simon).
Petitioners in this case failed to establish either causa tion or redressability. As Judge Tatel explained, the rele vant particularized injury asserted in the declarations sub mitted by petitioners was that of the Commonwealth of Massachusetts, which asserted that greenhouse gas emis sions would lead to global warming, which would cause ris ing sea levels, which in turn "would lead both to permanent loss of coastal land and to more frequent and severe storm surge flooding events along the coast." Pet. App. A27 (in ternal quotation marks omitted). Thus, to establish causa tion and redressability, petitioners had to do more than show that global warming, generally, would cause the al leged injury. Rather, they had to show that the subject of their rulemaking petition-greenhouse gas emissions from new motor vehicles in the United States-would, at least to a material extent, cause them the alleged injury.3 In addi- tion, they had to show that a successful resolution of this case-a decision by EPA to impose emission standards on such new motor vehicles-would, to a material extent, re dress that injury.
The declarations that petitioners submitted are insuffi cient to make those showings. Judge Tatel cited, as the best evidence of causation, a declaration asserting that global warming, chiefly triggered by anthropogenic green house gas emissions, was increasing the sea level, with "the U.S. transportation sector (mainly automobiles) . . . re sponsible for about 7% of global fossil fuel emissions." Pet. App. A28 (citation omitted). Similarly, with respect to redressability, Judge Tatel cited a declaration asserting that "[a]chievable reductions in emissions of [carbon diox ide] and other [greenhouse gases] from U.S. motor vehicles would . . . delay and moderate many of the adverse im pacts of global warming." Id. at A28-A29.
In light of the speculative nature of petitioner's theories, petitioners failed to establish that the injuries they allege from global warming are traceable to greenhouse gas emis sions from new vehicles in the United States-rather than to greenhouse gas emissions from other sources in the United States, greenhouse gas emissions from vehicles or other sources elsewhere in the world, or entirely different factors-and that a decision to require regulation of emis sions of greenhouse gases from new motor vehicles in the United States would redress their injuries. Petitioners allege only an indirect injury from vehicular emissions of greenhouse gases in the United States; they assert that such emissions will cause global warming, which in turn will cause sea levels to rise, which in turn will, in the case of Massachusetts, damage its coastal property. As this Court has explained, "indirectness of injury, while not necessarily fatal to standing, may make it substantially more difficult * * * to establish that * * * the asserted injury was the consequence of the defendants' actions, or that prospective relief will remove the harm." Simon, 426 U.S. at 44-45 (in ternal quotation marks and citation omitted). In this case, as in Simon, "[s]peculative inferences are necessary to con nect [petitioners'] injury to the challenged actions," id. at 45, and a "federal court, properly cognizant of the Art. III limitation upon its jurisdiction, must require more than [petitioners] have shown before proceeding to the merits." Id. at 46.
Indeed, petitioners' standing allegations rest on specu lation at two levels. First, petitioners' standing argument depends on their claim that greenhouse gases emitted by new motor vehicles in the United States alone are sufficient to cause, at least in material part, the injuries that they allege will occur from global warming. Petitioners' declara tions, however, address the alleged causation of global warming by greenhouse gases emitted from many different sources and from many different countries throughout the world. Their declarations do not establish that the subject matter of this case-emissions of greenhouse gases by new motor vehicles in the United States-causes or meaning fully contributes to their injuries.
Second, petitioners' standing argument depends on the proposition that EPA, if it adopted standards to limit emis sions of greenhouse gases from new vehicles in the United States, could limit such emissions sufficiently to have an appreciable effect on global warming and, ultimately, on the degree of injury petitioners allegedly would suffer. Petition ers' declarations do not establish that a mere reduction in greenhouse gas emissions from new vehicles in the United States would be sufficient to eliminate or meaningfully re duce the harm that they allege they will suffer from global warming. Indeed, EPA concluded that it would not "be either effective or appropriate for EPA to establish [green house gas] standards for motor vehicles at this time." Pet. App. A82 (emphasis added).
In concluding that petitioners had shown causation and redressability, Judge Tatel relied principally on the state ment in one declaration that "[a]chievable reductions in emissions of [carbon dioxide] and other greenhouse gases from U.S. motor vehicles would . . . delay and moderate many of the adverse impacts of global warming." Pet. App. A28-A29. That conclusory statement was taken from the declarant's summary of his findings, but the balance of the declaration did not address the question of whether, or the extent to which, reductions in greenhouse gas emissions from new motor vehicles in this country alone would "delay and moderate" the injuries alleged by petitioners. To the contrary, the declarant's conclusion that EPA regulation of automobile emissions would redress the alleged harm ap pears to be based on his claim that, if EPA acts, then for eign governments will eventually take similar steps. See Pet. C.A. Standing App. 220 (para. 32) ("If the U.S. takes steps to reduce motor vehicle emissions, other countries are very likely to take similar actions regarding their own mo tor vehicles using technology developed in response to the U.S. program."). According to the declarant, "[w]ith such efforts, accompanied by progress in limiting other emis sions, it would be much more likely that the extent of cli mate change could ultimately be limited to levels that would avoid the most serious impacts of global warming." Ibid.4 In short, petitioners' theory is that redress of their alleged injuries would result only from a chain of causation begin ning with EPA regulation, which would cause advances in technology, which would cause decisions by other countries similarly to limit vehicle emissions, which would cause an effect on global climate, and which would finally result in a redress of petitioners' alleged injuries. Such a chain of cau sation, involving coordinated actions by entirely independ ent third-party governments around the world, is far too speculative to support standing. See ASARCO Inc. v. Kadish, 490 U.S. 605, 615 (1989) (Opinion of Kennedy, J.) (plaintiffs could not establish standing because whether their "claims of economic injury would be redressed by a favorable decision in this case depends on the unfettered choices made by independent actors * * * whose exercise of broad and legitimate discretion the courts cannot pre sume either to control or to predict"); Allen v. Wright, 468 U.S. 737, 759 (1984) ("chain of causation" is "far too weak for the chain as a whole to sustain * * * standing," where it depended on actions of "numerous third parties" making "independent decisions").
In short, petitioners have failed to make the necessary showings of causation and redressability. The problem is not that there is a factual dispute raised by the declarations submitted by petitioners. Rather, the problem is that peti tioners have failed adequately to present proof of causation and redressability, and therefore that they lack standing to bring this challenge.
2. On the merits, the court of appeals correctly upheld EPA's decision. Section 202(a)(1) of the Act, 42 U.S.C. 7521(a)(1), expressly conditions the establishment of motor vehicle emissions standards on a discretionary exercise of the Agency's "judgment" as to whether air pollution related to motor vehicle emissions "may reasonably be anticipated" to endanger public health or welfare. Because that provi sion expressly invokes the Administrator's "judgment," it provides EPA with substantial discretion in deciding whether and when an endangerment finding can or should be made in the first instance. Here, the Agency identified a variety of sensible and appropriate reasons-including the complex and highly uncertain nature of the scientific record and the Agency's desire to have the benefit of ongo ing research-for its conclusion that even if it had authority to regulate greenhouse gas emissions from motor vehicles, an endangerment finding would be inappropriate at this time. That conclusion reflects a reasonable exercise of the Agency's discretion.
a. As the full D.C. Circuit explained 30 years ago in Ethyl Corp. v. EPA, 541 F.2d 1, 20 n.37 (en banc), cert. de nied, 426 U.S. 941 (1976), the "express provision for admin istrative discretion via the 'judgment' phrase [in CAA sec tion 202(a)(1)] is necessary" precisely because that section requires EPA to initiate regulation once it makes a deter mination of "endangerment" to health or welfare. 541 F.2d at 20 n.37. Numerous other decisions stress EPA's discre tion in deciding whether to make similar types of threshold regulatory determinations under similarly structured pro visions of the CAA. See, e.g., Her Majesty the Queen in Right of Ont. v. EPA, 912 F.2d 1525, 1533-1535 (D.C. Cir. 1990) (EPA has discretion whether and when to make the threshold finding as to whether or not there is "reason to believe" that emissions from sources in the United States are causing a health or welfare endangerment in another country under Section 115(a) of the Act, 42 U.S.C. 7415(a)).5 In particular, courts have recognized that EPA may prop erly defer making an endangerment determination while it waits for additional scientific and technical studies to be completed. Her Majesty the Queen, 912 F.2d at 1533-1534.
b. More generally, courts have long recognized that agencies are entitled to particular deference in deciding whether to grant rulemaking petitions.6 As the D.C. Circuit
has stated, "[i]t is only in the rarest and most compelling of circumstances that this court has acted to overturn an agency judgment not to institute a rulemaking." WWHT, Inc. v. FCC, 656 F.2d 807, 818 (1981). Agencies have lim ited resources and therefore must have the latitude to set priorities among possible initiatives and to decide how any particular policy objective may best be pursued. See id. at 817 (recognizing that "[a]n agency's discretionary decision not to regulate a given activity is inevitably based, in large measure, on factors not inherently susceptible to judicial resolution-e.g., internal management considerations as to budget and personnel; evaluations of its own competence; weighing of competing policies within a broad statutory framework.") (quoting NRDC v. SEC, 606 F.2d 1031, 1046 (D.C. Cir. 1971)). Accordingly, the D.C. Circuit has tradi tionally described its role in reviewing denials of rule making petitions as "limited to ensuring that the agency has adequately explained the facts and policy concerns it relied on, and that the facts have some basis in the record." National Ass'n of Regulatory Util. Comm'rs v. DOE, 851 F.2d 1424, 1430 (D.C. Cir. 1988) (internal quotation marks and citation omitted).
c. Against that background, the facts and policy con cerns articulated by EPA were sufficient to sustain its deci sion that a finding of endangerment regarding greenhouse gas emissions from motor vehicles was not appropriate at this time. As Judge Randolph explained, EPA properly relied on an authoritative analysis by the NRC, an entity of the National Academy of Sciences, and that report sup ported the Agency's view that any decision whether or not to regulate in this area would be better made after further research was conducted into critical areas of current scien tific uncertainty. See Pet. App. A11-A13, A83-A85. In addi tion, EPA's decision properly took into account other legal and policy implications of any decision to initiate regulatory action at this time.7
d. Petitioners incorrectly assert (Pet. 14-15) that it was impermissible for EPA to conclude that an "endangerment" finding was inappropriate at the present time based on the existing scientific uncertainty and the other factors men tioned by EPA. In essence, petitioners argue that in acting on a petition to initiate rulemaking under Section 202(a)(1), EPA must make an express finding that endangerment is either present or absent, and may deny such a petition only if it makes the latter finding in definitive fashion. There is no precedential or statutory support for petitioners' posi tion. As discussed above, cases such as Ethyl and Her Maj esty the Queen make clear that EPA has significant discre tion in making the judgments related to an endangerment finding under CAA Section 202(a)(1) and similar provisions. That discretion is particularly pronounced in cases such as this, which to a significant degree involve the more prelimi nary question of when it is appropriate to make an endan germent finding. See, e.g., WWHT, Inc., 656 F.2d at 817.8
Moreover, such an approach would, in effect, deprive EPA of its statutory authority to exercise its "judgment" on the threshold determination of when it is appropriate to make an endangerment finding. In so doing, it would also effectively cede control over EPA's limited resources to anyone who submits a petition for rulemaking, and it would illogically force EPA to make regulatory decisions even when it reasonably viewed existing data as unreliable, un certain, or inconclusive.
e. Petitioners are mistaken in suggesting (Pet. 14-16) that the CAA itself precludes EPA from considering the state of scientific uncertainty and other relevant factors in making the threshold determination of whether it is now appropriate to make an endangerment finding. Section 202(a)(1) simply states that any regulation in this area is conditioned on an exercise of EPA's "judgment," and it does not in any way cabin the Agency's discretion-proce dural or substantive-to decide how to make that judgment most effectively.9 In the absence of any such statutory con straints, EPA has discretion to make the threshold deter mination of whether the scientific record is sufficiently well developed to begin the regulatory process. See Her Maj esty the Queen, 912 F.2d at 1533-1535 (upholding EPA's discretion to await the development of further information on potential remedial measures before making an endan germent finding under Section 115 of the CAA, 42 U.S.C. 7415, dealing with international air pollution); Professional Drivers Council v. Bureau of Motor Carrier Safety, 706 F.2d 1216, 1222 & n.19 (D.C. Cir. 1983) (agencies may per missibly defer decision whether or not to regulate for a variety of reasons within their "special expertise," including whether "the scientific state of the art [is] such that suffi cient data are not yet available on which to premise ade quate regulations") (emphasis omitted) (quoting NRDC v. SEC, 606 F.2d at 1046).10 EPA's decision is thus consistent with the statute, applicable precedent, and with the more general rule that courts should refrain from imposing rule making requirements on agencies that go beyond those im posed by Congress. See Vermont Yankee Nuclear Power Corp. v. NRDC, 435 U.S. 519 (1978).
f. Petitioners correctly point out (Pet. 15) that the D.C. Circuit's decision in Ethyl endorsed the notion that EPA's broad discretion under Section 202 of the Act could support a judgment to regulate, even if the record before the Agency evidences some scientific uncertainty, when the Agency deems such a course to be appropriate. See Ethyl, 541 F.2d at 27-28. Petitioners err, however, in arguing that because the Agency may permissibly proceed with regula tion even in the face of some uncertainty, it must do so even when it has the type of legitimate policy concerns present here. Instead, EPA has the discretion to make reasonable determinations in the first instance whether or not to pro ceed in the face of scientific uncertainty. The Agency's con clusion that an endangerment determination is not appro priate at this time was more than amply explained and sup ported by the record, and was properly upheld by the court of appeals.
3. Petitioners also argue that review is warranted to consider whether EPA correctly determined that it did not have authority under Section 202(a) of the Clean Air Act to regulate greenhouse gas emissions from vehicles for the purpose of addressing concerns about global climate change.
a. That issue was not decided by the court of appeals, see Pet. App. A10 n.1, and it has never been addressed by any other court of appeals. This Court rarely addresses a legal question without the benefit of any prior decisions by the lower courts. See, e.g., Yee v. City of Escondido, 503 U.S. 519, 538 (1992); Lytle v. Household Mfg., Inc., 494 U.S. 545, 552 n.3 (1990). No basis supports taking such an ex ceptional course here, because the court of appeals cor rectly denied the petitions for review on the grounds dis cussed above. Moreover, while regulation of greenhouse gas emissions from new motor vehicles would present the Agency with issues of quite extraordinary magnitude and would conflict with a key component of the CAA regulatory system, EPA's determination that it had no authority under the Act to institute such regulation is limited to the specific context of greenhouse gases and is unlikely to have a signif icant effect in other contexts.
b. In any event, EPA's conclusion that it did not have regulatory authority to regulate vehicular greenhouse gas emissions to address the problem of global warming re flects a reasonable interpretation of the CAA and is consis tent with applicable precedent. As this Court has fre quently instructed, statutes must be read as a whole "since the meaning of statutory language, plain or not, depends on context." King v. St. Vincent's Hosp., 502 U.S. 215, 221 (1991); see, e.g., FDA v. Brown & Williamson Tobacco Corp., 529 U.S. 120, 132-133 (2000); Gustafson v. Alloyd Co., 513 U.S. 561, 569, 575 (1995); McCarthy v. Bronson, 500 U.S. 136, 139 (1991). Here, as was true of tobacco regu lation in Brown & Williamson, there are persuasive rea sons to conclude that the CAA, when read as a whole, does not confer authority on EPA to regulate emissions of green house gases to address concerns about global climate change.
Nothing in the CAA indicates Congress's intent to regu late greenhouse gases for purposes of addressing global warming, and all indications that are present suggest that Congress intended a non-regulatory approach to those is sues at this time. See Pet. App. A70-A71, A74-A75; see also id. at A71-A72 (noting Congress's distinctive approach, not merely making use of EPA's ordinary regulatory provi sions, to address the global atmospheric issue of strato spheric ozone depletion). The NAAQS system-the CAA's primary tool for regulating pervasive air pollutants-is based on state-by-state analyses of compliance with na tional standards, and the Act imposes distinct regulatory regimes on attainment and nonattainment areas. See CAA Sections 110, 172 et seq., 42 U.S.C. 7410, 7502 et seq. That system would serve no logical purpose in regulating carbon dioxide and other greenhouse gases, concentrations of which are not generally subject to substantial local or state- by-state variation but are instead global in nature. Pet. App. A71-A73. If petitioners were correct, "any [carbon dioxide] standard that might be established would in effect be a worldwide ambient air quality standard, not a national standard-the entire world would either be in compliance or out of compliance," id. at A73, thus rendering the impor tant statutory distinction between attainment and non attainment areas meaningless. Id. at A73-A74. Effectively increasing fuel economy standards would be the only way EPA could attempt to limit vehicle emissions of carbon di oxide, but such EPA regulation would conflict with the sep arate statutory scheme that Congress carefully developed and expressly crafted to address fuel economy standards, under which a division of the Department of Transportation is responsible for such standards. See id. at A79-A80.11
In short, EPA reasonably concluded that the CAA does not confer authority on EPA to regulate greenhouse gas emissions to address global climate change. See Pet. App. A78. Section 202(a)(1) authorizes EPA only to regulate "any air pollutant," and "air pollutant" is in turn defined as "any air pollution agent or combination of such agents, in cluding any physical, chemical, biological, radioactive * * * substance or matter which is emitted into or other wise enters the ambient air." 42 U.S.C. 7602(g). Under that definition, "a substance does not meet the CAA defini tion of 'air pollutant' simply because it is a 'physical, chemi cal, biological, radioactive * * * substance or matter which is emitted into or otherwise enters the ambient air.' It must also be an 'air pollution agent'" in order to be regu lated under Section 202(a)(1). Pet. App. A79 n.3. For the reasons discussed above, EPA reasonably concluded that "the term 'air pollution' as used in the regulatory provisions [of the CAA] cannot be interpreted to encompass global climate change." Id. at A78. Therefore, carbon dioxide and other greenhouse gases "are not 'agents' of air pollution and do not satisfy the CAA Section 302(g) definition of 'air pollutant' for purposes of" the CAA's regulatory provisions, including Section 202(a)(1). Ibid.12
4. Finally, petitioners err in contending (Pet. 22-26) that further review is warranted because of the asserted urgency of the environmental issues involved. EPA has never contested that global climate change is an important issue worthy of focused attention, both in the United States and abroad. In fact, the Agency detailed in its decision in this case a variety of efforts that the federal government is currently undertaking to "effectively and efficiently ad dress the climate change issue over the long term." Pet. App. A82; see id. at A82-A93. Those efforts, and others that could follow as the numerous scientific and factual questions involved in the issue of global warming are clari fied further, are better tailored to address this quintes sentially multinational issue than is the ill-suited regulatory machinery of the CAA, which could attack only a small and isolated part of it.
The petition for a writ of certiorari should be denied.
PAUL D. CLEMENT
SUE ELLEN WOOLDRIDGE
Assistant Attorney General
JON M. LIPSHULTZ
ANN R. KLEE
1 In EPCA, Congress set the corporate average fuel economy (CAFE) standard for "passenger automobile[s]" (a term that includes a variety of vehicles carrying up to 10 passengers). 49 U.S.C. 32901(a)(16), 32902(b). Congress also provided that any DOT action increasing (or significantly decreasing) the stringency of the standard be subject to congressional review and potential disapproval. 49 U.S.C. 32902(c). Moreover, Congress designed EPCA to allow automobile manufacturers substantial flexibility in meeting CAFE standards through credit banking and borrowing provisions. 49 U.S.C. 32903.
2 Several of the petitions for review attempted to challenge the memorandum by EPA's General Counsel that was cited in EPA's deci sion. See Pet. App. A6. Judge Randolph rejected those challenges, on the ground that the memorandum was not final agency action subject to judicial review. Ibid. Neither Judge Sentelle nor Judge Tatel dis sented from that disposition or otherwise discussed it.
3 Under Section 202(a)(1), EPA may regulate only new motor vehicles and cannot impose controls on existing vehicles. Therefore, petitioners have the burden of showing that regulation of new motor vehicles would provide redress for their alleged injury.
4 Judge Tatel also relied on another declaration that made essentially the same point. See Pet. App. A29 (quoting statement in declaration that "establishing emissions standards for pollutants that contribute to global warming would lead to investment in developing improved technologies to reduce those emissions from motor vehicles, and * * * successful technologies would gradually be mandated by other coun tries around the world").
5 See New York Pub. Interest Research Group v. Whitman, 321 F.3d 316, 330-331 (2d Cir. 2003) (EPA has discretion whether or not to make the threshold "determination" regarding deficiencies in state operating permit programs under Section 502(i) of the Act, 42 U.S.C. 7661a(i)); NRDC v. Thomas, 885 F.2d 1067, 1073-1075 (2d Cir. 1989) (EPA has discretion in exercising its "judgment" as to whether emissions of hazardous air pollutants "may reasonably be anticipated" to result in certain types of illnesses under then-existing version of CAA Section 112(a)(1), 42 U.S.C. 7412(a)(1) (1988)); Environmental Def. Fund v. Thomas, 870 F.2d 892, 898-899 (2d Cir.) (EPA has discretion to make the threshold "judgment" as to when it is "appropriate" to issue revised NAAQS under Section 109 of the Act, 42 U.S.C. 7409), cert. denied, 493 U.S. 991 (1989).
6 See, e.g., Midwest Indep. Transmission Sys. Operator, Inc. v. FERC, 388 F.3d 903, 910-911 (D.C. Cir. 2004) ("[W]e will overturn an agency's decision not to initiate a rulemaking only for compelling cause, such as plain error of law or a fundamental change in the factual pre mises previously considered by the agency.") (internal quotation marks and citation omitted); National Mining Ass'n v. DOI, 70 F.3d 1345, 1352 (D.C. Cir. 1995) ("[A]n agency's refusal to initiate a rulemaking is evaluated with deference so broad as to make the process akin to non- reviewability.") (internal quotation marks and citation omitted); Timpinaro v. SEC, 2 F.3d 453, 461 (D.C. Cir. 1993) (such challenges will be granted "only in the rarest and most compelling of circumstances") (internal quotation marks and citations omitted); General Motors Corp. v. National Highway Traffic Safety Admin., 898 F.2d 165, 169 (D.C. Cir. 1990) (judicial review is "especially narrow" in cases that involve challenges to the denial of a petition for rulemaking); American Horse Prot. Ass'n v. Lyng, 812 F.2d 1, 4-6 (D.C. Cir. 1987) (denials of rule making petitions are entitled to the "high end" of deference).
7 See Pet. App. A13-A14 (discussing possible effects on United States foreign policy, the Agency's concern about initiating a "piecemeal" regulatory approach to these issues, and the concern that any effort by EPA to limit carbon dioxide emissions through the imposition of more stringent fuel economy standards would conflict with the Department of Transportation's regulation of fuel economy under EPCA).
8 Neither Whitman v. American Trucking Ass'ns, 531 U.S. 457 (2001), nor Union Electric Co. v. EPA, 427 U.S. 246 (1976), supports petitioners' argument. See Pet. 8, 14. Those cases involved the extent to which costs can be considered by EPA in setting a NAAQS or ap proving a state implementation plan, respectively. This case, by con trast, involves the distinct threshold question of what factors EPA may permissibly take into account in deciding when and whether to make an "endangerment" determination, not merely the factors to be consulted once EPA has decided to make such a determination.
9 Nor does Section 202(a)(1) expressly address rulemaking petitions at all. By contrast, in other parts of the Act, where Congress has intended to prescribe aspects of the process EPA must follow in re sponding to such petitions, it has done so expressly. See, e.g., 42 U.S.C. 7412(b)(3) and (4) (specifying timing and other requirements for consideration of petitions to modify the CAA list of hazardous pollut ants and agency responses thereto); 42 U.S.C. 7661d(b)(2) (specifying the process for presentation and consideration of petitions to EPA to object to state CAA operating permits).
10 See Sierra Club v. Thomas, 828 F.2d 783, 798 (D.C. Cir. 1987) (denying an "unreasonable delay" claim and explaining that because EPA decisions about whether to regulate under the CAA "often involve complex scientific, technological, and policy questions," the Agency "must be afforded the amount of time necessary to analyze such questions so that it can reach considered results in a final rulemaking that will not be arbitrary and capricious or an abuse of discretion").
11 As the court of appeals noted, the rulemaking petition made "no suggestion" as to how emissions of the three greenhouse gases other than carbon dioxide that were the subject of the rulemaking petition might be reduced from motor vehicles. See Pet. App. A14.
12 Petitioners and the dissenting judge below thus err in contending that EPA has disregarded the Act's "plain" text. Pet. App. A33; see Pet. 18. They erroneously assume that the definition of "air pollutant" necessarily encompasses any "physical, chemical, biological, radioactive * * * substance or matter which is emitted into or otherwise enters the ambient air," see Pet. App. A32 (citing 42 U.S.C. 7602(g), but EPA has rejected that view, and has instead authoritatively construed the definitional provision's reference to "air pollution agent" to have independent meaning and effect. See id. at A78-A79 & n.3. That reasonable interpretation of the ambiguous statutory definition is entitled to deference under Chevron U.S.A. Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984).