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Page Number: 65

12 

MASSACHUSETTS v. EPA 

SCALIA, J., dissenting 

stances  in  the  air  near  the  surface  of  the  earth,  not 
higher  in  the  atmosphere. . . . CO2,  by  contrast,  is 
fairly  consistent  in  concentration  throughout  the 
world’s  atmosphere  up  to  approximately  the  lower 
stratosphere.”  Id., at 52926–52927. 

In  other  words,  regulating  the  buildup  of  CO2  and  other 
greenhouse gases in the upper reaches of the atmosphere,
which is alleged to be causing global climate change, is not
akin  to  regulating  the  concentration  of  some  substance 
that is polluting the air. 

We  need  look  no  further  than  the  dictionary  for  confir-
mation  that  this  interpretation  of  “air  pollution”  is  emi-
nently reasonable.  The definition of “pollute,” of course, is 
“[t]o  make  or  render  impure  or  unclean.”    Webster’s  New 
International Dictionary 1910 (2d ed. 1949).  And the first 
three definitions of “air” are as follows: (1) “[t]he invisible, 
odorless,  and  tasteless  mixture  of  gases  which  surrounds 
the earth”; (2) “[t]he body of the earth’s atmosphere; esp.,
the  part  of  it  near  the  earth,  as  distinguished  from  the
upper  rarefied  part”;  (3)  “[a]  portion  of  air  or  of  the  air 
considered  with  respect  to  physical  characteristics  or  as
affecting the senses.”  Id., at 54.  EPA’s conception of “air 
pollution”—focusing on impurities in the “ambient air” “at
ground level or near the surface of the earth”—is perfectly 
consistent with the natural meaning of that term.

In  the  end,  EPA  concluded  that  since  “CAA  authoriza-
tion to regulate is generally based on a finding that an air 
pollutant  causes  or  contributes  to  air  pollution,”  68  Fed.
Reg.  52928,  the  concentrations  of  CO2  and  other  green-
house  gases  allegedly  affecting  the  global  climate  are
beyond  the  scope  of  CAA’s  authorization  to  regulate. 
“[T]he term ‘air pollution’ as used in the regulatory provi-
sions  cannot  be  interpreted  to  encompass  global  climate 
change.” 
Ibid.  Once  again,  the  Court  utterly  fails  to
explain  why  this  interpretation  is  incorrect,  let  alone  so