Document ID: ./input/supremecourt_opinions/opinions/21pdf/20-1530_n758.pdf
Page Number: 59

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

3 

KAGAN, J., dissenting 

American  Elec.  Power,  564  U. S.,  at  416–417;  Massachu-
setts,  549  U. S.,  at  528–532.    EPA  thus  serves  as  the  Na-
tion’s  “primary  regulator  of  greenhouse  gas  emissions.” 
American  Elec.  Power,  564  U. S.,  at  428.    And  among  the
most significant of the entities it regulates are fossil-fuel-
fired (mainly coal- and natural-gas-fired) power plants.  To-
day,  those  electricity-producing  plants  are  responsible  for
about one quarter of the Nation’s greenhouse gas emissions. 
See EPA, Sources of Greenhouse Gas Emissions (Apr. 14, 
2022),  https://www.epa.gov/ghgemissions/sources-greenhouse-
gas-emissions.  Curbing that output is a necessary part of 
any effective approach for addressing climate change.

To  carry  out  its  Section  111  responsibility,  EPA  issued 
the Clean Power Plan in 2015.  The premise of the Plan—
which  no  one  really  disputes—was  that  operational  im-
provements at the individual-plant level would either “lead
to only small emission reductions” or would cost far more 
than  a  readily  available  regulatory  alternative.  80  Fed. 
Reg. 64727–64728 (2015).  That alternative—which fossil-
fuel-fired plants were “already using to reduce their [carbon
dioxide]  emissions”  in “a  cost  effective  manner”—is  called 
generation shifting.  Id., at 64728, 64769.  As the Court ex-
plains, the term refers to ways of shifting electricity gener-
ation from higher emitting sources to lower emitting ones—
more  specifically,  from  coal-fired  to  natural-gas-fired 
sources, and from both to renewable sources like solar and 
wind.  See ante, at 8.  A power company (like the many sup-
porting  EPA  here)  might  divert  its  own  resources  to  a 
cleaner source, or might participate in a cap-and-trade sys-
tem with other companies to achieve the same emissions-
reduction goals. 

This  Court  has  obstructed  EPA’s  effort  from  the  begin-
ning.  Right  after  the  Obama  administration  issued  the 
Clean  Power  Plan,  the  Court  stayed  its  implementation.
That action was unprecedented: Never before had the Court 
stayed a regulation then under review in the lower courts.