Document ID: ./input/supremecourt_opinions/opinions/23pdf/23a349_0813.pdf
Page Number: 24.0

2 

OHIO v. EPA 

BARRETT, J., dissenting 

evidence.  Applicants therefore cannot satisfy the stringent 
conditions for relief in this posture. 

I 
  I will start by setting the record straight with respect to 
some important background. 
  First, the Court downplays EPA’s statutory role in ensur-
ing  that  States  meet  air-quality  standards.    Ante,  at  2–3.  
The Clean Air Act directs EPA to “establish national ambi-
ent air quality standards (NAAQS) for pollutants at levels 
that will protect public health.”  EPA v. EME Homer City 
Generation, L. P., 572 U. S. 489, 498 (2014); see 42 U. S. C. 
§§7408,  7409.    States  must  create  State  Implementation 
Plans (SIPs) to ensure that their air meets these standards.  
§7410(a)(1).    But  States  also  face  an  externality  problem: 
“Pollutants  generated  by  upwind  sources  are  often  trans-
ported  by  air  currents  . . .  to  downwind  States,”  relieving 
upwind States “of the associated costs” and making it diffi-
cult for downwind States to “maintain satisfactory air qual-
ity.”  EME, 572 U. S., at 496.  So the Act’s Good Neighbor 
Provision requires SIPs to “prohibi[t]” the State’s emissions 
sources from “emitting any air pollutant in amounts which 
will . . . contribute significantly to nonattainment in, or in-
terfere with maintenance by, any other State with respect 
to any [NAAQS].”  §7410(a)(2)(D)(i)(I). 
  Given  the  incentives  of  upwind States  to  underregulate 
the pollution they send downwind, the Act requires EPA to 
determine  whether  a  State  “has  failed  to  submit  an  ade-
quate SIP.”  EME, 572 U. S., at 498; see §7410(c)(1).  If a 
SIP does not prevent the State’s polluters from significantly 
contributing  to  nonattainment  in  downwind  States,  EPA 
“shall”  promulgate  a  Federal  Implementation  Plan  (FIP) 
that does.  §7410(c)(1).  And EPA must stop the State’s sig-
nificant contributions by the statutory deadline for the af-
fected downwind States to achieve compliance.  See Wiscon-
sin  v.  EPA,  938  F. 3d  303,  313–314  (CADC  2019)