Document ID: ./input/supremecourt_opinions/opinions/21pdf/20-1530_n758.pdf
Page Number: 65.0

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

9 

KAGAN, J., dissenting 

the majority mean when it says that “[a]s a matter of defi-
nitional  possibilities,  generation  shifting  can  be  described 
as a ‘system’ ”?  Ante, at 28 (emphasis added; citation and 
some internal quotation marks omitted).  Rarely has a stat-
utory term so clearly applied. 

Other statutory provisions confirm the point.  The Clean 
Air Act’s acid rain provision, for example, describes a cap-
and-trade program as an “emission allocation and transfer 
system.”  §7651(b) (emphasis added).  So a “system,” accord-
ing to the statute’s own usage, includes the kind of cap-and-
trade mechanism that the Clean Power Plan relied on.  And 
in a somewhat different way, the NAAQS provision shows 
that Section 111 encompasses such a regulatory technique.  
Under  that  provision,  cap-and-trade  schemes  qualify  as
“control measures, means, or techniques” that state plans 
may  use  to  reduce  emissions.    §7410(a)(2)(A).    That  lan-
guage,  of  course,  does  not  use  the  word  “system.”    But  in 
specifying  that  cap  and  trade  is  allowable  under  the 
NAAQS program, the provision supports the same conclu-
sion here—because Section 111 directs EPA to use “a pro-
cedure  similar  to  that  provided  by  [the  NAAQS].”
§7411(d)(1).  The majority discounts the relevance of both
those provisions on the ground that they contemplate trad-
ing systems only “as a means of complying with an already 
established emissions limit.”  Ante, at 29 (emphasis in orig-
inal).  That is a distinction, to be sure.  But to begin, it is 
far  less  of  one  than  the  majority  thinks:  In  arguing  that 
EPA’s  claim  of  authority  here  would  allow  it  to  take  the
emissions limit as low as it wants, the majority ignores the 
varied constraints surrounding the “best system” language. 
See supra, at 7.  And still more important for interpretive
purposes,  the  distinction  appears  only  in  the  majority’s
opinion,  not  in  any  statutory  language.    That  text,  to  the 
contrary,  says  to  EPA:  Do  as  you  would  do  under  the 
NAAQS  and  Acid  Rain  programs—go  ahead  and  use  cap 
and trade.