December 20, 2019

Justice John Paul Stevens: An appreciation

John C. Dernbach

Justice John Paul Stevens served on the U.S. Supreme Court from 1975 until he retired in 2010. Stevens died on July 16, 2019, at the age of 99. Appointed by Republican President Gerald Ford, he charted a more independent course over his long Supreme Court career. While he wrote opinions on a wide variety of legal issues, some of the most important involved environmental law.

One measure of his influence is his role in key environmental cases. Professors J.B. Ruhl and Jim Salzman have polled environmental professionals about the most important environmental cases of all time. The top two, they wrote in the Environmental Forum, are Chevron v. Natural Resources Defense Council, 467 U.S. 837 (1984), and Massachusetts v. EPA, 549 U.S. 497 (2007), respectively. Justice Stevens wrote the majority opinion in both. The third-ranked case is Rapanos v. United States, 547 U.S. 715 (2006), in which Stevens wrote the dissenting opinion. A common theme in these and other Stevens opinions is his willingness to defer to environmental agencies—but only when they faithfully implement the statutes they are charged with administering.

Chevron v. NRDC

In Chevron, the Supreme Court upheld a 1981 U.S. Environmental Protection Agency (EPA) regulation under the Clean Air Act that contained a plant-wide definition of “stationary source.” The regulation embodies a “bubble concept,” treating a facility with multiple pollution sources as a single source, and thus allowing the facility to modify its operation without needing a permit so long as total emissions from the facility do not increase.

The Chevron case, of course, is known more for its articulation of a two-part test for judicial review of an agency’s construction of the legislation it administers. The Chevron test requires courts first to “give effect to the unambiguously expressed intent of Congress,” and, where Congress has not directly addressed the issue, requires courts to defer to an agency’s reasonable construction of a statutory provision.

The Court first concluded that Congress had not directly addressed the “bubble concept” in the Clean Air Act. The Court then determined that the regulation was “entitled to deference: the regulatory scheme is technical and complex, the agency considered the matter in a detailed and reasonable fashion, and the decision involves reconciling conflicting policies.” Chevron has had enormous influence; according to a 2014 study, “it is the most cited administrative law decision of all time.” C. Walker, Most Cited Supreme Court Administrative Law Decisions, Yale J. on Reg. (Oct. 9, 2014), available at (last visited Dec. 3, 2019).

Massachusetts v. EPA

EPA has authority under section 202(a)(1) of the Clean Air Act, 42 U.S.C. § 7521(a)(1), to regulate any air pollutant from motor vehicles that “may reasonably be anticipated to endanger public health or welfare.” Massachusetts v. EPA was a challenge to EPA’s rejection of a petition to regulate greenhouse gas emissions from motor vehicles under the Clean Air Act. In a 5–4 majority opinion authored by Justice Stevens, the Court held that greenhouse gases are “air pollutants” under the Act. The Court also rejected other reasons given by George W. Bush’s EPA for not regulating greenhouse gases from motor vehicles (e.g., existence of voluntary programs, interference with the president’s foreign affairs power), because they were not anchored in section 202(a)(1). The Court remanded the matter to EPA to decide whether greenhouse gases meet the “cause or contribute” standard in section 202(a)(1).

The case may be understood as a reflection of the Court’s concern about the politicization of law and science concerning climate change that occurred during the George W. Bush administration, under which EPA decided not to regulate greenhouse gases from motor vehicles. “The harms associated with climate change are serious and well recognized,” the Court said in its analysis of whether Massachusetts had standing, acknowledging “the existence of a causal connection between man-made greenhouse gas emissions and global warming.” The Court gave no deference to EPA’s refusal to decide and obliged EPA to decide the question on the basis of the Clean Air Act alone. As Professors Jody Freeman and Adrian Vermeule have argued, the Court simply forced EPA to apply its expertise and do its job. J. Freeman & A. Vermeule, Massachusetts v. EPA: From Politics to Expertise, 2007 Sup. Ct. Rev. 51, 76 (2007).

The Court’s holding made the statute available to reduce greenhouse gas emissions from both mobile and stationary sources, even in the absence of new federal climate change legislation. In 2009, EPA issued an endangerment finding under section 202(a)(1). Then, after comprehensive federal legislation to address climate change failed to pass Congress in 2009 and 2010, EPA (and, for vehicles, the National Highway Traffic Safety Administration) adopted regulations to reduce greenhouse gas emissions from existing stationary sources, new stationary sources, light duty vehicles, and heavy duty vehicles. All of these regulations (but not the endangerment finding) are now subject to attempted rollbacks by the Trump administration.

Rapanos v. United States

In Rapanos, the Supreme Court limited the ability of the U.S. Army Corps of Engineers to regulate the filling of wetlands as “waters of the United States” under the Clean Water Act. The case was a challenge to the application of regulations that the Corps had long administered. The Court articulated two different legal tests for regulating wetlands not adjacent to navigable waters, neither of which commanded a majority. These are whether these wetlands have a “continuous surface connection with the water, making it difficult to determine where the water ends and the wetland begins” (Scalia and three other Justices), and whether these wetlands have a substantial chemical, physical, or biological nexus to navigable waters (Kennedy).

Justice Stevens, in dissent (with three other Justices), would have simply applied and upheld regulations that reflected “more than 30 years of practice” by the Corps. Rejecting the “creative criticisms” offered by Scalia and Kennedy, he described the then-existing regulations as “a quintessential example of the Executive’s reasonable interpretation of a statutory provision,” citing Chevron.


The issues of deference and climate change continue to be both significant and controversial. In Kisor v. Wilkie, 139 S. Ct. 2400 (2019), the Court narrowly upheld the principle in Auer v. Robbins, 519 U.S. 452 (1997), that courts should generally defer to agencies’ interpretations of their own regulations. This principle, of course, is a cousin to that in Chevron. Many of the challenges to the Trump administration’s rollbacks on climate change regulation under the Clean Air Act will likely be decided by the Supreme Court. On both issues, Justice Stevens laid down markers that will be hard to ignore.

John C. Dernbach

John C. Dernbach is Commonwealth Professor of Environmental Law and Sustainability at Widener University Commonwealth Law School and director of its Environmental Law and Sustainability Center.