Black and white photo looking up the steps of the U.S. Supreme Court building
Credit: Thomas Hawk/Flickr, CC BY-NC 2.0

The United States has a strong tradition of investing in and trusting the best available science to inform regulations that govern natural resources protection, restoration, and management. Lately, however, the Supreme Court seems to have other ideas. In two recent decisions, the court, with environmental protections seemingly in its crosshairs, has sidestepped the checks and balances in our customary lawmaking process and cut sound science—and scientists—out of the equation.

In its May decision in Sackett v. Environmental Protection Agency (EPA), the court scaled back protections for wetlands under the Clean Water Act (CWA) to their smallest in decades. The majority opinion invented out of whole cloth a new and narrow test to determine which wetlands are protected, ignoring scientific consensus and even the explicit intent of Congress when it wrote the law. To conform with the Sackett decision, the EPA has now amended the science-based rule it finalized earlier in 2023, replacing it with the high court’s restrictive interpretation.

With a silent Congress and activist court, environmental protections are evaporating as federal rules designed by scientists are overridden.

Similarly, in its 2022 decision in West Virginia v. EPA, the majority opinion curtailed the ability of the EPA to address atmospheric carbon dioxide under the Clean Air Act (CAA). The decision was made not on the basis of scientific expertise, but rather by invoking the so-called major questions doctrine, which as Justice Elena Kagan noted in her dissent, the court has never explicitly invoked.

Involving scientists has traditionally been a hallmark of crafting and implementing successful environmental legislation. However, with a silent Congress and activist court, environmental protections are evaporating as federal rules designed by scientists are overridden. This troubling trend not only endangers public and environmental health but risks the perceived value and role of science in environmental management. Moreover, cutting science and scientists out of rulemaking undermines trust in scientists working to better understand our environment and our impacts on it.

We contend that scientists, as part of their personal commitment to scientific advancement, must pay attention to how their research and insights are—or are not—being reasonably applied by governing institutions that so heavily influence how we all live in the world. And we encourage them to get involved in the policymaking process to ensure that science is central in environmental legislation.

Trusting the Best Available Science

In 1972, Congress explicitly set an objective for the CWA to “restore and maintain the chemical, physical, and biological integrity of the Nation’s waters,” empowering the EPA and U.S. Army Corps of Engineers to use the best available science as the basis for promulgating rules and enforcing the law. Similarly, in 1970, when Congress directed the EPA to regulate air pollution via the CAA, it expected that the agency’s scientific experts would define which pollutants were most problematic and develop an approach to their regulation.

The EPA has robust and well-established mechanisms by which it gathers the best available science. The agency employs scores of scientists who work to understand the environment and synthesize knowledge to guide policymaking and enforcement, and it analyzes and deploys research conducted by other agencies and scientists around the world. At Congress’s direction, the EPA also convenes a Science Advisory Board to provide external input and an independent review of science, and it welcomes written commentary and feedback at public meetings and listening sessions as part of the required public comment process.

These mechanisms are not without limitations. If Congress realizes its intent with a law was unclear or thinks an agency has gone too far with its rulemaking, Congress can amend the law, or the agency can be challenged in court. In fact, the CWA and the CAA have been challenged many times, with each instance generating new guidance about enforcement.

When those challenges occur, the courts have a long tradition of deference to the scientific and technical expertise that exists in the agencies tasked with day-to-day implementation of laws. This deference has typically strengthened modern environmental regulations, allowing the best available science to inform regulations. Courts must be mindful, though, to distinguish responsible deference to scientific and technical expertise from deference to political positions.

The CWA and Sackett v. EPA

The question of which waters, and particularly which wetlands, are protected by the Clean Water Act has been among the most litigated environmental issues at the Supreme Court.

The question of which waters, and particularly which wetlands, are protected by the CWA has been among the most litigated environmental issues at the Supreme Court. A series of back-and-forth decisions have yielded shifting enforcement. Although debates have been contentious, two principles have held: (1) Scientists and agencies have been central in the rulemaking process, and (2) the courts have exercised judicial restraint and respect for scientific judgment. Unfortunately, these did not persist in the Sackett decision, which abandons both judicial precedent and scientific consensus.

In Sackett, the plaintiffs began filling a wetland on their property near Priest Lake, Idaho, with gravel in preparation for construction of a home without first obtaining a permit to fill the wetland. The EPA ordered work halted, claiming the unpermitted work was a violation of the CWA.

View from above of part of a lake and lakeshore with mountains in the background
Priest Lake, Idaho. Credit: Pecky Cox/Wikimedia, CC BY-SA 4.0

In a decision in 2021, the U.S. Court of Appeals of the 9th Circuit ruled that the wetland in question, roughly 90 meters from the lake and separated from it by a berm, was protected by the CWA and required a permit to fill. The 9th Circuit’s perspective was consistent with several past rulings by the Supreme Court, recent rulemaking efforts, and enforcement decisions that have been in place since 1986. The ruling was also consistent with scientific understanding, which indicates that wetlands provide innumerable benefits to the physical, chemical, and biological health of nearby waters based on their connectivity not only on the surface but also through the subsurface (e.g., via groundwater flowing under a road or a berm).

However, the majority opinion in 2023, authored by Justice Samuel Alito, invents the requirement of adjoinment for protection of a wetland under the CWA, meaning a wetland must share a “continuous surface connection” with a stream, river, lake, or other surface water that is broadly understood to be protected. This contrasts with the earlier precedent that a wetland need only be adjacent to (and likely to affect the water quality of) a larger body.

The standard established in Sackett sets stricter bounds for protection than those in rules proposed by the Obama, Trump, and Biden administrations. And in no prior agency rule, scientific report, opinion from a scientific agency, or recommendation from the Science Advisory Board has the notion of adjoinment been proposed.

In concurring opinions, several justices agreed that the CWA’s jurisdiction is not unlimited but disagreed with the wholesale reimagining of the test for protection. These concurring opinions argued that the majority’s interpretation does not meet the plain language reading of the law and pointed out that the court could have issued a much narrower decision that gave relief to the Sacketts but kept the system of deference to agency scientific and technical expertise in place.

Thus, the majority’s decision appears less motivated by science and more so by political desires to dismantle protections afforded under the CWA.

And dismantle it does.

Sackett’s Environmental Implications

In the wake of the Sackett decision, federal protections for America’s wetlands are at their smallest and weakest in decades.

In the wake of this decision, federal protections for America’s wetlands are at their smallest and weakest in decades. Federal rules are the only protections for wetlands in about half of the states, leaving a substantial portion of the United States’ remaining wetlands—and the benefits they produce, such as flood control, aquatic habitat, and improved water quality—vulnerable to destruction.

Just how many wetlands might be affected by the new decision and rule? The federal government has declined to make estimates at the national scale, but some data exist and offer glimpses regionally. In one recent study of New York’s wetlands, for example, researchers found that fewer than half are located within 100 feet (~30 meters) of waterways. And in a study of the extensively drained midwestern Wabash River Basin, only about 17% of current wetlands (or about 3% of the historical wetland acres in the region, where 80% have been lost since Europeans arrived) are within 100 feet of waterways.

In both studies, 100 feet was used as the narrowest interpretation of prior CWA rules, although this interpretation was still much broader than the Sackett criterion for adjoinment via a continuous surface connection. With the more stringent requirement, only a fraction of these wetlands would be left with federal protections, representing the largest loss of wetland protections since they have been federally regulated.

West Virginia and the Emerging Major Questions Doctrine

At issue in West Virginia was the EPA’s proposed regulation, under the CAA, of greenhouse gas emissions from power plants as part of a set of Obama era rules called the Clean Power Plan (CPP). The CPP included a combination of “within the fence” requirements (i.e., processes deployed at power plants to limit emissions) and “beyond the fence” requirements (i.e., requirements to shift production to alternative energy sources). The case did not center on the science of climate change or the basic ability of the EPA to regulate greenhouse gas emissions (already established in Massachusetts v. EPA), but instead on Congress’s perceived intent in adopting the CAA.

The EPA contended—and dissenting justices agreed—that the agency was explicitly directed in the CAA to implement the “best system of emission reduction” from power-generating plants and stationary sources. Yet the plaintiffs, including several states and coal companies, won the day, arguing that the EPA was overreaching. As a result, the EPA’s tool kit to regulate greenhouse gas emissions has been substantially reduced, at a time when climate change impacts are more apparent and the need for action is more urgent than ever.

In siding with the plaintiffs in West Virginia, the court’s majority sidestepped technical expertise and scientific consensus supporting the need for increased regulation of emissions.

In addition to mitigating carbon emissions, the CPP would have reduced related sulfur dioxide and nitrous oxide emissions, and it was projected to avoid thousands of premature deaths each year and yield billions of dollars in net benefits. In siding with the plaintiffs, however, the court’s majority sidestepped technical expertise and scientific consensus supporting the need for increased regulation of emissions, applying a broad interpretation of the major questions doctrine to the EPA’s regulation of greenhouse gases from power plants.

The major questions doctrine is an emerging judicial principle positing that federal agencies must have clear congressional authorization to implement rules or make major decisions that will have major political or economic effects. The doctrine suggests that although the courts and Congress may defer to agencies for less significant decisions, laws should not be interpreted to presume the same deference for major decisions, unless Congress grants an agency that power using “exceedingly clear language.” This approach stands in stark contrast to the Chevron doctrine (established in 1984 in Chevron v. Natural Resources Defense Council), in which deference is given to agency interpretations of congressional laws like the CAA and CWA.

The emergence of the major questions doctrine as a response to the standard of agency deference creates a political vehicle for major cutbacks in environmental protections and the roles of scientific information and expertise in driving those protections. In West Virginia and Sackett, despite well-established laws and regulations seemingly within the scope of those laws, the court has rolled back proposed regulations (West Virginia) or created a new test with no basis in science or in the legislation (Sackett).

In Sackett especially, the court failed to follow its own directive under the major questions doctrine, neglecting the exceedingly clear language that Congress did use when it explicitly added mention of “adjacent wetlands” to the CWA’s protections in 1977.

Scientists Must Be at the Table

Lacking a clear definition of what might constitute a “major question” and with our present polarized Congress unlikely to implement comprehensive updates of federal environmental regulations to clarify their intents—even as we face emerging threats not conceived of when the regulations were drafted—additional environmental protections may be on the chopping block.

We need Congress to end its steadfast silence on the CWA and CAA and on the erosion of environmental protections. In doing so, it can reassert that scientists must play roles in the design and implementation of environmental regulations. Without congressional action, we expect replication of the court’s line of thinking, further divorcing these regulations from the best available science and endangering the health of communities and ecosystems. So what can scientists do?

Scientists’ primary role remains knowledge production. Americans invest in science through federal agencies, public universities, and taxpayer-funded research to expand our understanding of the world. Implicit in the agreement is that this science provides reliable, trustworthy, unbiased information upon which regulatory decisions on how best to manage natural resources sustainably and improve lives should be based.

The Sackett and West Virginia cases offer powerful examples of why scientists need to understand how their research is (or isn’t) being put to good use.

In addition to producing knowledge, scientists can further serve society by more directly supporting decisionmaking. The Sackett and West Virginia cases offer powerful examples of why scientists need to understand how their research is (or isn’t) being put to good use and why we need a culture shift toward engaging in the policy process.

Helping members of Congress understand potential consequences of—and how legislators’ intent may not be reflected in—judicial decisions is one path to change. Scientists can ensure that Congress has access to the best available science by, for example, writing white papers and reaching out to representatives to provide briefings on the current state of the science related to key issues. These briefings may be most effective when legislation is being proposed or debated, providing expertise when it is most timely.

We also encourage scientists to engage with their professional organizations on policy work. Recent court decisions and agency rulemaking have prompted joint statements from a host of scientific organizations, providing intellectual weight and clear, unified positions on issues that may have more influence than a collection of individually authored statements. Examples of ways to get involved include through society policy programs (e.g., AGU’s Policy Action Center), collaborating on amicus briefs authored on behalf of scientific organizations (e.g., this amicus brief filed by 12 national and international scientific societies in Sackett), and working with professional societies to brief communities on critical issues (e.g., the Society for Freshwater Science’s resource page created during the 2019–2020 rulemaking to revise the definition of waters of the United States).

Another avenue for involvement is the EPA’s Science Advisory Board, which has a host of committees and panels that provide scientific input on a broad range of topics. These committees enable direct engagement between scientists and the EPA, and they regularly weigh in on proposed rules and decisions.

The U.S. public expects scientists to be at the table when environmental regulations are being drafted and enforced. Lately, the Supreme Court has bypassed this vital role and prioritized political goals over environmental and public health. The court’s sweeping decisions emphasize the urgency for scientists to engage in environmental policy and regulation at local, state, and federal levels.

Author Information

Adam S. Ward (, Department of Biological and Ecological Engineering, Oregon State University, Corvallis; and Adell Amos, School of Law, University of Oregon, Eugene

Citation: Ward, A. S., and A. Amos (2023), The Supreme Court is bypassing science—We can’t ignore it, Eos, 104, Published on 6 September 2023.
This article does not represent the opinion of AGU, Eos, or any of its affiliates. It is solely the opinion of the author(s).
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