american electric power et al connecticut et argued april decided june massachusetts epa held clean air act authorizes federal regulation emissions carbon dioxide greenhouse gases environmental protection agency epa misread act denied rulemaking petition seeking controls greenhouse gas emissions new motor vehicles response epa commenced rulemaking act set limits greenhouse gas emissions new modified existing fired power plants pursuant settlement finalized march epa committed issuing final rule may lawsuits considered began well epa initiated efforts regulate greenhouse gases two groups plaintiffs respondents filed separate complaints federal district five major electric power companies petitioners one group plaintiffs included eight new york city second joined three nonprofit land trusts according complaint defendants largest emitters carbon dioxide nation contributing global warming plaintiffs asserted defendants emissions substantially unreasonably interfered public rights violation federal common law interstate nuisance alternative state tort law plaintiffs ask decree setting emissions defendant initial cap reduced annually district dismissed suits presenting nonjusticiable political questions second circuit reversed threshold questions circuit held suits barred political question doctrine plaintiffs adequately alleged article iii standing merits held plaintiffs stated claim federal common law nuisance relying decisions holding may maintain suits abate air water pollution produced industry see illinois milwaukee milwaukee determined clean air act displace federal common law held second circuit exercise jurisdiction affirmed equally divided clean air act epa action act authorizes displace federal right seek abatement emissions fired power plants pp since erie tompkins recognized federal general common law new federal common law emerged subjects national concern dealing air water ambient interstate aspects federal common law milwaukee decisions predating erie compatible emerging distinction general common law new federal common law approved federal suits brought one state abate pollution emanating another state see missouri illinois plaintiffs contend right maintain suit follows cases recognition subject meet federal law governance necessarily mean federal courts create controlling law need address question whether absent clean air act epa actions authorizes plaintiffs state federal claim curtailment greenhouse gas emissions contribution global warming claim displaced federal legislation authorizing epa regulate emissions pp hen congress addresses question previously governed decision rested federal common law need unusual exercise federal courts disappears milwaukee illinois milwaukee ii legislative displacement federal common law require sort evidence clear manifest congressional purpose demanded preemption state law rather test simply whether statute speak directly question issue mobil oil higginbotham massachusetts made plain emissions carbon dioxide qualify air pollution subject regulation clean air act equally plain act speaks directly emissions carbon dioxide defendants plants act directs epa establish emissions standards categories stationary sources administrator judgment caus contribut significantly air pollution may reasonably anticipated endanger public health welfare epa lists category must establish performance standards emission pollutants new modified sources within category relevant must regulate existing sources within category act also provides multiple avenues enforcement epa set emissions limits particular pollutant source pollution private parties may petition rulemaking matter epa response reviewable federal see act thus provides means seek limits emissions carbon dioxide domestic power plants relief plaintiffs seek invoking federal common law room parallel track pp rejects plaintiffs argument second circuit holding federal common law displaced epa actually exercises regulatory authority setting emissions standards defendants plants relevant question displacement purposes whether field occupied whether occupied particular manner milwaukee ii clean air act less exercise legislature considered judgment concerning air pollution regulation permits emissions epa acts critical point congress delegated epa decision whether regulate emissions power plants delegation displaces federal common law plaintiffs case dissatisfied outcome epa forthcoming rulemaking recourse seek appeals review ultimately petition certiorari act prescribed order decisionmaking first expert agency federal judges yet another reason resist setting emissions standards judicial decree federal tort law appropriate amount regulation particular greenhouse sector requires informed assessment competing interests clean air act entrusts complex balancing epa first instance combination state regulators expert agency surely better equipped job federal judges lack scientific economic technological resources agency utilize coping issues order plaintiffs proposal federal judges determine first instance amount emissions unreasonable level reduction necessary reconciled congress scheme pp plaintiffs also sought relief state nuisance law second circuit reach claims held federal common law governed light holding clean air act displaces federal common law availability vel non state lawsuit depends inter alia preemptive effect federal act none parties briefed preemption otherwise addressed availability claim state nuisance law matter left consideration remand pp reversed remanded ginsburg delivered opinion roberts scalia kennedy breyer kagan joined alito filed opinion concurring part concurring judgment thomas joined sotomayor took part consideration decision case american electric power company et petitioners connecticut et al writ certiorari appeals second circuit june justice ginsburg delivered opinion address opinion question whether plaintiffs several city new york three private land trusts maintain federal common law public nuisance claims emitters four private power companies federal tennessee valley authority relief plaintiffs ask decree setting emissions defendant initial cap reduced annually clean air act environmental protection agency action act authorizes hold displace claims plaintiffs seek pursue massachusetts epa held clean air act et authorizes federal regulation emissions carbon dioxide greenhouse gases aturally present atmosphere also emitted human activities greenhouse gases named trap heat otherwise escape earth atmosphere thus form greenhouse effect helps keep earth warm enough life fed reg massachusetts held environmental protection agency epa misread clean air act denied rulemaking petition seeking controls greenhouse gas emissions new motor vehicles greenhouse gases determined qualify air pollutant within meaning governing clean air act provision quoting therefore within epa regulatory ken epa authority set greenhouse gas emission standards offered reasoned explanation failing concluded agency acted accordance law denied requested rulemaking quoting responding decision massachusetts epa greenhouse gas regulation december agency concluded greenhouse gas emissions motor vehicles cause contribute air pollution may reasonably anticipated endanger public health welfare act regulatory trigger fed reg agency observed atmospheric greenhouse gas concentrations elevated essentially unprecedented levels almost entirely due anthropogenic emissions mean global temperatures agency continued demonstrate unambiguous warming trend last years particularly past years ibid acknowledging scientists agreed causes consequences rise global temperatures epa concluded compelling evidence supported attribution observed climate change anthropogenic emissions greenhouse gases consequent dangers greenhouse gas emissions epa determined included increases deaths coastal inundation erosion caused melting icecaps rising sea levels frequent intense hurricanes floods extreme weather events cause death destroy infrastructure drought due reductions mountain snowpack shifting precipitation patterns destruction ecosystems supporting animals plants potentially significant disruptions food production epa department transportation subsequently issued joint final rule regulating emissions vehicles see fed reg initiated joint rulemaking covering vehicles see epa also began phasing requirements new modified ajor greenhouse gas emitting facilities use best available control technology fed reg epa commenced rulemaking act set limits greenhouse gas emissions new modified existing fired power plants pursuant settlement finalized march epa committed issuing proposed rule july final rule may see fed reg reply brief tennessee valley authority ii lawsuits consider began well epa initiated efforts regulate greenhouse gases described july two groups plaintiffs filed separate complaints southern district new york five major electric power companies first group plaintiffs included eight new york city second joined three nonprofit land groups respondents defendants petitioners four private tennessee valley authority federally owned corporation operates fired power plants several according complaints defendants five largest emitters carbon dioxide app collective annual emissions million tons constitute percent emissions domestic electric power sector percent emissions domestic human activities percent anthropogenic emissions worldwide app pet cert contributing global warming plaintiffs asserted defendants emissions created substantial unreasonable interference public rights violation federal common law interstate nuisance alternative state tort law app new york city alleged public lands infrastructure health risk climate change app trusts urged climate change destroy habitats animals rare species trees plants land trusts owned conserved app plaintiffs sought injunctive relief requiring defendant cap carbon dioxide emissions reduce specified percentage year least decade app district dismissed suits presenting political questions citing baker carr second circuit reversed threshold questions appeals held suits barred political question doctrine plaintiffs adequately alleged article iii standing turning merits second circuit held plaintiffs stated claim federal common law nuisance determination relied dominantly series decisions holding may maintain suits abate air water pollution produced industry see illinois milwaukee milwaukee recognizing right illinois sue federal district abate discharge sewage lake michigan appeals determined clean air act displace federal common law milwaukee illinois milwaukee ii held congress displaced federal common law right action recognized milwaukee adopting amendments clean water act et seq legislation installed regulatory program supervised expert administrative agency deal comprehensively interstate water pollution legislation prohibited discharge pollutants waters without permit proper permitting authority milwaukee ii citing time second circuit decision contrast epa yet promulgated rule regulating greenhouse gases fact thought dispositive epa completes rulemaking process reasoned speculate whether hypothetical regulation greenhouse gases clean air act fact directly issue raised plaintiffs granted certiorari iii petitioners contend federal courts lack adjudicate case four members hold least plaintiffs article iii standing massachusetts permitted state challenge epa refusal regulate greenhouse gas emissions threshold obstacle bars four members adhering dissenting opinion massachusetts regarding decision distinguishable hold none plaintiffs article iii standing therefore affirm equally divided second circuit exercise jurisdiction proceed merits see nye iv federal general common law erie tompkins famously recognized wake erie however keener understanding developed see generally friendly praise erie new federal common law rev erie le ft left thus required federal courts follow state decisions matters substantive law appropriately cognizable erie also sparked emergence federal decisional law areas national concern new federal common law addresses subjects within national legislative power congress directed basic scheme constitution demands environmental protection undoubtedly area within national legislative power one federal courts may fill statutory interstices necessary even fashion federal law stated milwaukee deal air water ambient interstate aspects federal common law decisions predating erie compatible distinction emerging decision general common law specialized federal common law friendly supra approved federal common law suits brought one state abate pollution emanating another state see missouri illinois permitting suit missouri enjoin chicago discharging untreated sewage interstate waters new jersey city new york ordering new york city stop dumping garbage new jersey coast georgia tennessee copper ordering private copper companies curtail discharges tennessee caused harm georgia see also milwaukee decision upholding suit illinois abate sewage discharges lake michigan plaintiffs contend right maintain suit follows inexorably line decisions recognition subject meet federal law governance however necessarily mean federal courts create controlling law absent demonstrated need federal rule decision taken prudent course adopt ing readymade body state law federal rule decision congress strikes different accommodation kimbell foods see bank america nat trust sav assn parnell borrowing law particular state inappropriate remains mindful creative power akin vested congress see missouri illinois fact must decide mean course takes place legislature cf standard oil holding federal law determines whether government secure indemnity company whose truck injured soldier declining impose indemnity absent action congress primary often exclusive arbiter federal fiscal affairs cases plaintiffs heavily rely permitted sue challenge activity harmful citizens health welfare yet decided whether private citizens land trusts political subdivisions new york city state may invoke federal common law nuisance abate pollution ever held state may sue abate manner pollution originating outside borders defendants argue considerations scale complexity distinguish global warming bounded pollution giving rise past federal nuisance suits greenhouse gases emitted become well mixed atmosphere fed reg emissions new jersey may contribute flooding new york emissions china cf brief petitioners plaintiffs hand contend equitable remedy largest emitters carbon dioxide order beyond judicial competence see brief respondents open space et al recognized public nuisance law like common law generally adapts changing scientific factual circumstances missouri adjudicating claim though concern nuisance simple kind known older common law see also duhme fdic jackson concurring federal courts free apply traditional technique decision fashioning federal common law need address parties dispute regard academic question whether absence clean air act epa actions act authorizes plaintiffs state federal common law claim curtailment greenhouse gas emissions contribution global warming claim displaced federal legislation authorizing epa regulate emissions hen congress addresses question previously governed decision rested federal common law explained need unusual exercise federal courts disappears milwaukee ii holding amendments clean water act displaced nuisance claim recognized milwaukee legislative displacement federal common law require sort evidence clear manifest congressional purpose demanded preemption state law ue regard presuppositions embracing federal system promoter democracy quoting san diego building trades council garmon enter calculus primarily office congress federal courts prescribe national policy areas special federal interest tva hill test whether congressional legislation excludes declaration federal common law simply whether statute speak directly question issue mobil oil higginbotham see milwaukee ii county oneida oneida indian nation hold clean air act epa actions authorizes displace federal common law right seek abatement emissions fired power plants massachusetts made plain emissions carbon dioxide qualify air pollution subject regulation act think equally plain act speaks directly emissions carbon dioxide defendants plants section act directs epa administrator list categories stationary sources judgment caus contribut significantly air may reasonably anticipated endanger public health welfare epa lists category agency must establish standards performance emission pollutants new modified sources within category see also relevant requires regulation existing sources within existing sources epa issues emissions guidelines see compliance guidelines subject federal oversight issue performance standards stationary sources within jurisdiction act provides multiple avenues enforcement see county oneida reach remedial provisions important determination whether statute displaces federal common law epa may delegate enforcement authority agency retains power monitor regulated sources impose administrative penalties noncompliance commence civil actions polluters federal specified circumstances act criminal penalties person knowingly violates emissions standards issued see act provides private enforcement epa fail enforce emissions limits regulated sources act permits person bring civil enforcement action federal epa set emissions limits particular source pollution private parties may petition rulemaking matter epa response reviewable federal see massachusetts earlier noted see supra epa currently engaged rulemaking set standards greenhouse gas emissions fired power plants settle litigation brought group included majority plaintiffs case agency agreed complete rulemaking may fed reg act thus provides means seek limits emissions carbon dioxide domestic power plants relief plaintiffs seek invoking federal common law see room parallel track plaintiffs argue second circuit held federal common law displaced epa actually exercises regulatory authority sets standards governing emissions defendants plants disagree sewage discharges issue milwaukee ii overlook subject effluent limits set epa displacing statute point source discharge water pollution prohibited unless covered permit emphasis deleted milwaukee ii made clear however relevant question purposes displacement whether field occupied whether occupied particular manner necessity congress different regulatory regimes address different problems congress hardly preemptively prohibit every discharge carbon dioxide unless covered permit emit carbon dioxide merely breathing clean air act less exercise legislature considered judgment concerning regulation air pollution permits emissions epa acts see middlesex county sewerage authority national sea clammers finding displacement although congress allowed continued dumping sludge prior certain date critical point congress delegated epa decision whether regulate emissions power plants delegation displaces federal common law indeed epa decline regulate emissions altogether conclusion ongoing rulemaking federal courts warrant employ federal common law nuisance upset agency expert determination epa judgment hasten add escape judicial review federal courts earlier observed see supra review agency action final rule declining take action ensure compliance statute congress enacted noted see supra clean air act directs epa establish emissions standards categories stationary sources administrator judgment caus significantly air pollution may reasonably anticipated endanger public health welfare use word explained massachusetts roving license ignore statutory text direction exercise discretion within defined statutory limits ibid epa may decline regulate emissions power plants refusal act arbitrary capricious abuse discretion otherwise accordance law plaintiffs case dissatisfied outcome epa forthcoming rulemaking recourse federal law seek appeals review ultimately petition certiorari indeed prescribed order decisionmaking first decider act expert administrative agency second federal judges yet another reason resist setting emissions standards judicial decree federal tort law appropriate amount regulation particular greenhouse sector prescribed vacuum questions national international policy informed assessment competing interests required along environmental benefit potentially achievable nation energy needs possibility economic disruption must weigh balance clean air act entrusts complex balancing epa first instance combination state regulators standard performance epa sets must tak account cost achieving emissions reduction nonair quality health environmental impact energy requirements see also epa may permit state plans deviate generally applicable emissions standards upon demonstration costs epa may distinguish among classes types sizes stationary sources apportioning responsibility emissions reductions see also agency may waive compliance emission limits permit facility test drive innovative technological system yet adequately demonstrated act envisions extensive cooperation federal state authorities see generally permitting state take first cut determining best achieve epa emissions standards within domain see altogether fitting congress designated agency epa best suited serve primary regulator greenhouse gas emissions expert agency surely better equipped job individual district judges issuing ad hoc injunctions federal judges lack scientific economic technological resources agency utilize coping issues order see generally chevron natural resources defense council judges may commission scientific studies convene groups experts advice issue rules procedures inviting input interested person seek counsel regulators defendants located rather judges confined record comprising evidence parties present moreover federal district judges sitting sole adjudicators lack authority render precedential decisions binding judges even members notwithstanding disabilities plaintiffs propose individual federal judges determine first instance amount emissions unreasonable app decide level reduction practical feasible economically viable app determinations made defendants named two lawsuits launched plaintiffs similar suits mounted counsel new york city estimated thousands hundreds tens defendants fitting description large contributors emissions tr oral arg judgments plaintiffs commit federal judges suits filed federal district reconciled decisionmaking scheme congress enacted second circuit erred hold ruling federal judges may set limits greenhouse gas emissions face law empowering epa set limits subject judicial review ensure action arbitrary capricious otherwise accordance law plaintiffs also sought relief state law particular law state defendants operate power plants see app second circuit reach state law claims held federal common law governed see international paper ouellette case resolved reference federal common law state common law preempted light holding clean air act displaces federal common law availability vel non state lawsuit depends inter alia preemptive effect federal act holding clean water act preclude aggrieved individuals bringing nuisance claim pursuant law source state none parties briefed preemption otherwise addressed availability claim state nuisance law therefore leave matter open consideration remand reasons stated reverse judgment second circuit remand case proceedings consistent opinion ordered justice sotomayor took part consideration decision case american electric power company et petitioners connecticut et al writ certiorari appeals second circuit june justice alito justice thomas joins concurring part concurring judgment concur judgment agree displacement analysis assumption make sake argument party contends otherwise interpretation clean air act et adopted majority massachusetts epa correct footnotes addition carbon dioxide primary greenhouse gases emitted human activities include methane nitrous oxide hydrofluorocarbons perfluorocarbons sulfur hexafluoride fed reg views opposing epa see dawidoff civil heretic times magazine march caution endorses particular view complicated issues related emissions climate change california connecticut iowa new jersey new york rhode island vermont wisconsin although new jersey wisconsin longer participating brief respondents connecticut et al open space institute open space conservancy audubon society new hampshire american electric power company wholly owned subsidiary southern company xcel energy cinergy corporation addition renewing political question argument made petitioners assert additional threshold obstacle seek dismissal prudential bar adjudication generalized grievances purportedly distinct article iii bar see brief tennessee valley authority brief petitioners exception epa may employ existing stationary sources pollutant question regulated national ambient air quality standard program hazardous air pollutants program see