Document ID: ./input/supremecourt_opinions/opinions/21pdf/20-1530_n758.pdf
Page Number: 77

Cite as:  597 U. S. ____ (2022) 

21 

KAGAN, J., dissenting 

tenant relations.  It is EPA (that’s the Environmental Pro-
tection  Agency,  in  case  the  majority  forgot)  acting  to  ad-
dress the greatest environmental challenge of our time.  So 
too, there is nothing special about the Plan’s “who”: fossil-
fuel-fired  power  plants.   In  Utility  Air,  we  thought  EPA’s 
regulation of churches and schools highly unusual.  See su-
pra, at 18.  But fossil-fuel-fired plants?  Those plants pol-
lute—a lot—and so they have long lived under the watchful
eye of EPA.  That was true even before EPA began regulat-
ing carbon dioxide.  See Train v. Natural Resources Defense 
Council, Inc., 421 U. S. 60, 78 (1975).

Finally, the “how” of generation shifting creates no mis-
match with EPA’s expertise.  As the Plan noted, generation 
shifting has a well-established pedigree as a tool for reduc-
ing  pollution;  even  putting  aside  other  federal  regulation, 
see infra, at 25–26, both state regulators and power plants 
themselves have long used it to attain environmental goals. 
See 80 Fed. Reg. 64664; Brief for Power Company Respond-
ents 47; see also S. Breyer, Regulation and Its Reform 444, 
n. 1 (1982) (citing literature on the subject from the 1970s). 
The technique is, so to speak, a tool in the pollution-control 
toolbox.  And  that  toolbox  is  the  one  EPA  uses.    So  that 
Agency, more than any other, has the desired “comparative 
expertise.”  Ante, at 25.  The majority cannot contest that
point  frontally:  It  knows  that  cap  and  trade  and  similar 
mechanisms are an ordinary part of modern environmental 
regulation.  Instead,  the  majority  protests  that  Congress 
would not have wanted EPA to “dictat[e],” through genera-
tion shifting, the “mix of energy sources nationwide.”  Ante, 
at 26.  But that statement reflects a misunderstanding of
how  the  electricity  market  works.  Every  regulation  of 
facility-
power  plants—even  the  most  conventional, 
specific  controls—“dictat[es]”  the  national  energy  mix  to 
one or another degree.  That result follows because regula-
tions affect costs, and the electrical grid works by taking up