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The EPA’s Regulatory Power: Set to Shrink or Grow?

On February 24, 2014, the Supreme Court heard oral arguments lasting an unusually long 97 minutes in United Air Regulatory Group v. Environmental Protection Agency.1 The case involves six consolidated petitions from both state and industry groups challenging an EPA finding that regulating greenhouse gas emissions from new motor vehicles would also trigger the duty to set up permitting requirements for stationary sources of emissions as well. The petitioners allege that these rules are arbitrary and capricious and based on an improper construction of the Clean Air Act (the “CAA”).2

This case comes after the hotly-debated 2007 Massachusetts v. EPA, in which the Supreme Court found that EPA has the authority to regulate emissions from tailpipes.3 The Court in 2007 further found that “greenhouse gases fit well within the CAA’s capacious definition of an air pollutant.”4 In United Air Regulatory Group, the issue relates to the EPA’s use of the 2007 holding to extend its regulatory power in monitoring greenhouse gases to cover stationary sources of emissions.

Mr. Keisler argued on behalf of the private party petitioners and took a fall back position that the Court does not need to interpret the CAA if it goes with the argument posited in the American Chemistry Council’s brief. His argument was that the Prevention of Significant Deterioration (“PSD”) Program is exclusively focused on emissions with area-based air quality impact, not on “globally undifferentiated phenomena.”5  Keisler argued that the language of CAA Section 7471 limits the PSD program to “emissions limitations and other measures as may be necessary to prevent significant deterioration of air quality in each region . . . .,“ and concluded that this language refers to regionally-defined effects on the air that people breathe.6

Texas Solicitor General Jonathan Mitchell argued for the state petitioners, advancing the traditional claims of agency overreach and the correct balance between bright-line rules and discretionary standards.  Mitchell argued that an ‘air pollutant’ under the CAA is not everything that is unambiguously airborne.7 Mitchell further posited that the EPA has allowed the term “air pollutant” to be flexible for decades and that the EPA has insisted that ‘air pollutant’ can mean different things in different parts of the CAA.8 Therefore, Mitchell said, the term ‘air pollutant’ in relation to motor vehicle emissions does not necessarily refer to the same air pollutants in the context of stationary source emissions.

Finally, United States Solicitor General Donald Verilli argued on behalf of the EPA. Verilli took the floor framing this as an environmental case – a somewhat unusual step considering the negative implications due to various sociopolitical views on environmental issues. Verilli argued that greenhouse gases “pose the same threat to public health and welfare when they are emitted from a power plant as when they are emitted from the tailpipe of a car.”9 Solicitor General Verilli made the case that the EPA’s interpretation is reasonable and addresses the urgent need to curb emissions. Verilli also claimed there have to be plausible alternative interpretations of the CAA for there to really be an issue – in this case, reading “any pollutant” to exclude greenhouse gases is not plausible.10

Commentators are still unsure how the Court will decide. On one side, the Court may go with a very narrow holding stating that the EPA does not have the general authority to change the statute, but in this case, changing the CAA to encompass greenhouse gas emissions from stationary sources is permissible.11 Conversely, the Court might agree that a ruling on whether greenhouse gas emissions are ‘air pollutants’ for purposes of the CAA will eventually be necessary and may use this case to make a final ruling on the subject.

Either way, there are two things to consider moving forward:  First, can states regulate greenhouse gas emissions on their own if the Court finds EPA is not authorized to do so? And secondly, will Congress need to amend the CAA to include greenhouse gases as air pollutants if the EPA is to regulate greenhouse gases in the future? The answers to these questions will have significant political and economic implications.


-Christina Bonanni is a General Member on MJEAL. She can be reached at


The views and opinions expressed in this blog are those of the authors only and do not reflect the official policy or position of the Michigan Journal of Environmental and Administrative Law or the University of Michigan.

1. Oral Argument, Utility Air Regulatory Group v. Environmental Protection Agency, No. 12-1146 (2014), available at; see also: American Bar Association: Preview of the United States Supreme Court Cases; Utility Air Regulatory Group v. EPA,

2. See id.

3. Massachusetts v. EPA, 549 U.S. 497 (2007).

4. Massachusetts v. EPA, 549 U.S. at 528-29.

5.   Oral Argument, Utility Air Regulatory Group v. Environmental Protection Agency, (2014) (No. 12-1146), available at:; Transcript of Oral Argument, Utility Air Regulatory Group v. Environmental Protection Agency, (2014) (No. 12-1146), available at:

6. Transcript of oral argument, supra note 5 at 13, lines 16-23.

7. Transcript of oral argument, supra note 5 at 37, lines 9-14.

8. Transcript of oral argument, supra note 5 at 40, lines 5-7.

9.  Transcript of oral argument, supra note 5 at 45, lines 21-24.

10. Transcript of oral argument, supra note 5 at 77-78, lines 21-25.

11. See, e.g., Richard Frank, Deconstructing Today’s U.S. Supreme Court Arguments in Utility Air Regulatory Group: The EPA Could Well Lose This Challenge to Its Greenhouse Gas Reduction Efforts, Legal Planet of Berkeley Law/UCLA Law (Feb. 24 2014)

1 Comment

  1. Carmine

    Pollution is pollution from whatever source. The intent is to protect the environment. The EPA ruling and hold should stand.

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