Tackling climate change in the USA: Obama’s Clean Power Plan

By Katarina Hovden and Wybe Th. Douma



Obama announced his Clean Power Plan on 3 August 2015. It aims at tackling greenhouse gas emissions from power plants in the USA. The legal basis for the plan is Section 111(d) of theClean Air Act (CAA), which requires the Environmental Protection Agency (EPA) to set limits on air pollutants generally and on the emissions of air pollutants from particular sources such as power plants, and gives states (and tribes) the power to choose how to meet those targets. In this brief dossier, some background information on the way in which the EPA got involved in tackling climate change is offered, followed by more detail on the current Plan and on the likelihood of it facing legal challenge.


The reluctant start of EPA’s involvement with climate change

The duty to regulate air pollutants that can "reasonably be anticipated to endanger public health or welfare" was present in the CAA from its start, but for a long time the EPA was reluctant to use this power where climate change was concerned. In 2003, the EPA denied a petition to regulate greenhouse gas emissions from motor vehicles, in spite of the fact that the transportation sector forms one of the largest sources of greenhouse gas emissions in the US. The EPA did so because in its view, it did not have authority under the Clean Air Act to regulate CO2 and other greenhouse gases for climate change purposes. Even if it would have this authority, the EPA added, it had discretion to defer a decision until more research was done on the causes, extent and significance of climate change and the potential options for addressing it. Setting GHG emission standards for motor vehicles was not appropriate at that moment in time, it argued.

In the case Massachusetts et al. v EPA et al. (549 U.S. 497 (2007)), the US Supreme Court found in a 5-4 verdict on 2 April 2007 that the EPA decision was incorrect because "greenhouse gases fit well within the CAA’s capacious definition of air pollutant", and because the EPA’s rationale for not regulating was inadequate. This Supreme Court decision opened the door for EPA’s 2009 ‘endangerment finding’ (explaining that science shows that greenhouse gases endanger both the public health and the public welfare of current and future generations) and EPA regulation of carbon dioxide-emitting sources. Following this finding, the EPA issued its 2010 and 2012 rules on the fuel economy and greenhouse gas emissions of cars and light-duty trucks. The latest rules call for a strong decrease in greenhouse gas emissions. With the climate change aspects of transport being regulated, this left the other largest source of greenhouse gas emissions to be tackled: the US power industry. This is what the Clean Power Plant intends to do in the following manner.


The Clean Power Plan

The Clean Power Plan applies to fossil fuel-fired electric generating units (coal, oil and natural gas-fired units). The Plan is composed of three parts:

-          Existing power plants must emit 32 percent less CO2 from 2005 levels by 2025;

-          Power plants that are built in the future must produce ca. half the rate of pollution produced by existing power plants;

-          States must draft emission reduction plans in 2016, finalising their plans by 2018. States are given flexibility to decide how to meet their targets, and they may do so using renewable energy sources.

In announcing the Clean Power Plan, Obama referred to the Pope’s encyclical and noted that taking action on climate change is a moral obligation. Moreover, the benefits that can be expected from implementing the Plan would include: public health benefits (such as reducing premature deaths from power plant emissions by 90% in 2030 compared to 2005), creating thousands of jobs, driving more aggressive investment in clean energy technologies, saving the average American family nearly $85 on their annual energy bill in 2030 and saving consumers a total of $155 billion from 2020-2030.

Power plants currently account for a third of US emissions of CO2. The Clean Power Plan is expected to help the US to meet its Intended Nationally Determined Contribution (INDC), submitted ahead of the Paris talks at the UNFCCC's COP21, where the US has pledged a 26-28% overall emissions reduction from 2005 levels by 2025.


Reactions to the plan

Despite the positive attention that the Plan has received, in particular for the signal that it sends to the international community in the build up to COP21, others have commented that it does not go far enough for the US to be able to meet its INDC. 

Domestically, moreover, Obama has had to face fierce opposition from lawyers and lobbyists, who expressed their intent to challenge the Plan before the Supreme Court as soon as Obama made his announcement. They are expected to argue, inter alia, that the EPA has overstepped the powers it has been conferred through the Clean Air Act. That strategy proved to be successful recently, in another 5-4 US Supreme Court decision (Michigan et al v Environmental Protection Agency et al, 29 June 2015) concerning the EPA’s rules on mercury, arsenic and other toxins. The US Supreme Court struck down the EPA’s rules, which had set limits on the amount of such toxins that power plants could emit into the air, lakes and rivers. It held that they were prohibitively expensive and amounted to government overreach.

Given this recent Supreme Court decision, and the previous cases against legislation adopted under the Clean Air Act, it is likely that Obama’s Clean Power Plan will be the topic of further legal action in the USA. The costs and benefits of tackling climate change in the manner foreseen in the plan could very well be a decisive factor for the outcome of such legal action.



Clean Air Act, § 111(d); U.S. Code § 7412(n)(1)(A)

Massachusetts et al v EPA et al (549 U.S. 497 (2007))

Michigan et al v EPA et al (29 June 2015)

Fact Sheet: President Obama to Announce Historic Carbon Pollution Standards for Power Plants, White House Press Office 3 August 2015

Overview of the Clean Power Plan: Cutting Carbon Pollution from Power Plants, EPA Factsheet

Mr. Mass v. EPA: An Interview with the Man Who Put Climate Change on America's Legal Map, Yale Climate Connections 30 September 2010

Supreme Court Blocks Obama's Limits on Power Plants, NY Times 29 June 2015

Move to Fight Obama's Climate Plan Started Early, NY Times 3 August 2015

Obama Issues Landmark Climate Change Rule, Politico 3 August 2015

European Industry Hopes to Profit from Obama's New Climate Plan, EUobserver 3 August 2015

Obama Clean Power Plan Welcomed- But won't Avoid Dangerous Warming, The Guardian 4 August 2015