On October 10, Environmental Protection Agency (EPA) Administrator Scott Pruitt signed a Notice of Proposed Rulemaking (NPRM) to repeal the Clean Power Plan (CPP), one of the Obama Administration’s central policies to reduce greenhouse gas emissions. The CPP would have required states to collectively reduce greenhouse gas emissions from existing power plants by about 32 percent, relative to 2005 emissions, by the year 2030. In an executive order issued on March 28, 2017, President Trump called on all executive departments and agencies to review existing regulations that “burden” domestic energy industries. The President specifically pointed to the CPP as requiring review. In the proposal released Tuesday, the EPA indicated it would repeal the CPP completely, although the agency will consider options for replacement. The repeal of the CPP is the most recent reversal of environmental policy in a series of deregulatory actions by the EPA, and has brought more attention to the legal basis for these policies and the legal consequences of undoing them.

The EPA was created in 1970 to enforce the Clean Air Act, passed by Congress that same year. The Clean Air Act has since evolved to reflect the most up-to-date science and emerging air quality problems, and the role of the EPA has evolved with it. In 2009, the responsibility of the EPA was expanded through its Endangerment Finding, which recognized the real and potential harms of greenhouse gases and determined that the agency was obligated to regulate them. The Endangerment Finding served as the foundation for the Obama Administration’s agenda to combat climate change, including the Clean Power Plan, although the legal grounding for the finding was, in fact, ten years in the making by its finalization in 2009.

Indeed, a group of renewable energy and environmental organizations got together in 1999 to petition the EPA to include greenhouse gas emissions from vehicles under the regulatory authority of the Clean Air Act. That petition initiated years of litigation that culminated in Massachusetts v. EPA, decided by the Supreme Court in 2007. In Massachusetts, the court ruled that greenhouse gases fit the definition of “air pollutant” under the Clean Air Act, and ordered the EPA to assess the harms of greenhouse gas emissions from motor vehicles. From this ruling, the Endangerment Finding was born.

The Endangerment Finding consists of two parts. First, that six greenhouse gases, including carbon dioxide, endanger the public health and well-being of current and future generations. Second, that the greenhouse gas emissions from motor vehicles, specifically, endanger public health and well-being. The Endangerment Finding relies on a large body of scientific research, much of it from the Intergovernmental Panel on Climate Change, the U.S. Global Climate Research Program, and the National Research Council, and went through extensive public comment before its finalization.

The Endangerment Finding has been repeatedly tested—and upheld—in court. In 2012, the U.S. Court of Appeals for the District of Columbia Circuit issued a strong defense of the Endangerment Finding in Coalition for Responsible Regulation v. EPA. The court ruled that the Endangerment Finding was fair, that the EPA’s interpretation of the Clean Air Act in this case was “unambiguously correct,” and that the “Tailoring” Rule, allowing the EPA to regulate greenhouse gas emissions from certain “stationary sources,” should stand. The Supreme Court made a similar decision on stationary sources in Utility Air Regulatory Group v. EPA in 2014. In this case, the court issued a complicated ruling that ultimately maintained the EPA’s authority to regulate greenhouse gas emissions from stationary sources clearly named in the Clean Air Act, including power plants.

The Endangerment Finding is not itself a regulation. Rather, it establishes a legal obligation for the EPA to regulate greenhouses gases, complicating the process of deregulation. If the EPA reverses rules aimed at mitigating greenhouse gas emissions, the agency can be sued for avoiding its responsibilities under the Clean Air Act. Under the current framework, the EPA can only legally repeal greenhouse gas regulations, such as the Clean Power Plan, by offering a replacement. The Endangerment Finding makes no recommendation on the form or forcefulness of regulations.

If EPA Administrator Pruitt wants to negate the agency’s obligation to regulate greenhouse gases, there are two options, both unlikely. First, the EPA could reverse the Endangerment Finding. The second option would be for Congress to amend the Clean Air Act.

The EPA has received several petitions to reconsider the Endangerment Finding. The Competitive Enterprise Institute, a conservative think tank, filed such a petition as recently as 2017. So far, the EPA has denied all petitions. The finding and its supporting documents, including an 11-volume response to public comments, comprise hundreds of pages and took years to write. Reversing the finding would require an equally thorough rebuttal of the scientific consensus on human-caused climate change.

Alternatively, Congress could amend the Clean Air Act to declassify carbon dioxide as an “air pollutant,” excluding it from regulation. But amending the Clean Air Act is similarly unlikely since the law has not been amended since 1990.

If instead, Pruitt repeals regulations and replaces them with more industry-friendly versions, as he is expected to do, this implicitly acknowledges that greenhouse gas emissions are a problem. Many conservative allies of the current administration want Pruitt to deny climate change from his position as EPA Administrator. However, doing so would contradict the EPA’s stance and potentially ensnare Pruitt in legal troubles. In his confirmation hearing, Pruitt acknowledged the Endangerment Finding, saying, “It is there, and it needs to be enforced and respected. There is nothing that I know that would cause it to be reviewed.”

It seems likely that the Endangerment Finding will remain intact, given the significant challenges to overturning it. However, exactly how the EPA interprets the finding may change. Many of the Obama Administration’s environmental policies, including the Clean Power Plan, were trapped in litigation before taking effect. Now, efforts to deregulate will face legal opposition from environmental advocates. This back-and-forth ultimately amounts to a loss for the environment, as regulations, weak and strong, continue to be mired in litigation.


Author: Beatrix Scolari