Memo to the Supreme Court: Study Highlights Clean Air Act’s Focus on CO2 as Climate Pollutant

A new study reveals that lawmakers who crafted the Clean Air Act in 1970 were aware of carbon dioxide's role as a pollutant.
The Supreme Court is seen on Feb. 21 in Washington, as the court hears arguments challenging the Biden administration

Among the many obstacles to enacting federal limits on climate pollution, none has been more daunting than the Supreme Court. This is where the Obama administration’s efforts to regulate power plant emissions failed, and the Biden administration’s attempts will likely end up.

A forthcoming study aims to inform how courts consider challenges to these regulations by establishing that the lawmakers who shaped the Clean Air Act in 1970 were aware that carbon dioxide was considered an air pollutant and intended to limit its emissions.

The research, expected to be published in the journal Ecology Law Quarterly, delves into congressional archives to uncover what it calls a “wide-ranging and largely forgotten conversation between leading scientists, federal agency administrators, members of Congress,” and senior staff under Presidents Lyndon Johnson and Richard Nixon. This conversation detailed widely accepted science showing that carbon dioxide pollution from fossil fuels was accumulating in the atmosphere and would eventually warm the global climate.

The findings could have important implications in light of a legal doctrine the Supreme Court established when it struck down the Obama administration’s power plant rules, said Naomi Oreskes, a history of science professor at Harvard University and the study’s lead author. The “major questions” doctrine asserts that when courts hear challenges to regulations with broad economic and political implications, they ought to consider lawmakers’ original intent and the broader context in which legislation was passed.

“The Supreme Court has implied that there’s no way that the Clean Air Act could really have been intended to apply to carbon dioxide because Congress just didn’t really know about this issue at that time,” Oreskes said. “We think that our evidence shows that that is false.”

The work began in 2013 after Oreskes arrived at Harvard. A call from a colleague prompted the question of what Congress knew about climate science in the 1960s as it was developing Clean Air Act legislation. She had already co-authored the book Merchants of Doubt, about the efforts of industry-funded scientists to cast doubt about the risks of tobacco and global warming and was familiar with the work of scientists studying climate change in the 1950s. “What I didn’t know,” she said, “was how much they had communicated that, particularly to Congress.”

Oreskes hired a researcher to start looking, and what they found surprised her. The evidence included articles cataloged by the staff of the act’s chief architect, proceedings of scientific conferences attended by members of Congress, and correspondence with constituents and scientific advisers to Johnson and Nixon. The material included documents from both environmental champions and other prominent members of Congress.

“These were people really at the center of power,” Oreskes said.

Naomi Oreskes, a history of science professor at Harvard University, speaks at the World Economic Forum Annual Meeting in Switzerland on Jan. 18. Credit: World Economic Forum/Sandra Blaser
Naomi Oreskes a history of science professor at Harvard University speaks at the World Economic Forum Annual Meeting in Switzerland on Jan 18 Credit World Economic ForumSandra Blaser

When Sen. Edmund Muskie, a Maine Democrat, introduced the Clean Air Act of 1970, he warned his colleagues that unchecked air pollution would continue to “threaten irreversible atmospheric and climatic changes.” The new research shows that his staff had collected reports establishing the science behind his statement. He and other senators had attended a 1966 conference featuring discussion of carbon dioxide as a pollutant. At that conference, Wisconsin Sen. Gaylord Nelson warned about carbon dioxide pollution from fossil fuel combustion, which he said “is believed to have drastic effects on climate.”

The paper also cites a 1969 letter to Sen. Henry “Scoop” Jackson of Washington from a constituent who had watched the poet Allen Ginsberg warning of melting polar ice caps and widespread global flooding on the Merv Griffin Show. The constituent was skeptical of the message, called Ginsberg “one of America’s premier kooks” and sought a correction of the record from the senator: “After all, quite a few million people watch this show, people of widely varying degrees of intelligence, and the possibility of this sort of charge—even from an Allen Ginsberg—being accepted even in part, is dangerous.”

Jackson then sent the letter to presidential science advisor Lee DuBridge, who responded by detailing the latest science, which showed that while there was uncertainty about the effects of increased levels of carbon dioxide, the greenhouse gas effect was real and a product of fossil fuel combustion.

“We just felt that strengthens the argument that this is not some little siloed scientific thing,” Oreskes said of the episode. “It’s not just a few geeky experts.”

The new paper is not the first to assert that climate science was well established by the mid-1960s and that congressional leaders were aware of it. Other work, including some cited in the study, has shown that hearings on Clean Air Act amendments explicitly addressed global climate change.

The new work adds breadth and depth to this body of evidence, said Michael Burger, executive director of the Sabin Center for Climate Change Law at Columbia Law School.

In a landmark 2007 decision, the Supreme Court held that the Clean Air Act authorizes the Environmental Protection Agency to regulate carbon dioxide as a pollutant. However, even that ruling claimed that climate science was in its “infancy” when Congress enacted the key provisions in 1970.

The ruling, known as Massachusetts v. EPA, quickly became a target for some political conservatives. Project 2025, a conservative playbook for a next Republican administration, calls for undoing the EPA “endangerment” findings the ruling enabled, though Donald Trump has sought to distance himself from Project 2025 as he campaigns for reelection. The Trump administration reportedly considered such a move in its final days but opted against it.

Michael Oppenheimer, a professor of geosciences and international affairs at Princeton University, said the new study could be “of critical importance” if the Supreme Court were to hear a challenge to Massachusetts v. EPA.

The authors published their paper in a law journal, rather than one focused on history or science, because they hope it will shape future legal challenges and court decisions, Oreskes said.

While several legal and policy experts praised the work for its additions to the history, some questioned how much influence it will have on the Supreme Court’s rightwing majority.

“Unfortunately there’s a big question mark as to how much weight the court will, in any individual instance, place on actual history as opposed to select history that supports the ultimate conclusion that they favor,” Burger said. “One of the big criticisms of the major questions doctrine and the current majority’s use of history is that it does tend to be quite selective.”

He added that the current challenge to the Biden administration’s power plant regulations does not focus on whether the EPA has authority to regulate carbon dioxide but on unrelated, technical questions about which technologies can be used to limit pollution.

What the new research should do, Burger said, is conclusively refute the notion that the EPA cannot regulate carbon dioxide.

“The argument that the Clean Air Act for some reason should not include the regulation of greenhouse gases is simply wrong,” Burger said.

Original Story at insideclimatenews.org

Trending News

COP29 Ends Amidst Criticism Over Loopholes and Disunity


The United Nations’ 29th Conference of the Parties (COP29) concluded with widespread criticism over perceived loopholes and a lack of unity among participating nations. Environmental experts and activists expressed concerns that the agreements reached may be insufficient to address the escalating climate crisis.



Despite initial optimism, the conference, held in Bonn, Germany, was marked by intense debates and disagreements. Key issues included carbon emission reduction targets and financial commitments to developing countries. Many attendees felt these discussions fell short of meaningful progress. Learn more about the UN’s climate change efforts here.



A significant point of contention was the establishment of clear guidelines for monitoring and reporting emissions. Critics argue that the absence of stringent measures allows countries to exploit loopholes, undermining global efforts to curb climate change. The lack of consensus on this issue highlights the challenges in achieving cohesive international action.



Some developing nations voiced frustration over inadequate financial support from wealthier countries, which they argue is essential for implementing sustainable practices and mitigating climate impacts. This financial gap remains a major obstacle, fueling discontent and hampering collaborative efforts. Explore the Green Climate Fund’s role in supporting climate action.



Meanwhile, environmental groups emphasized the need for immediate and robust action, warning that delays could have catastrophic implications. They called for greater transparency and accountability in future agreements, urging nations to prioritize the planet’s health over economic interests.



As COP29 ends, the international community faces the challenge of bridging divides and enhancing cooperation to effectively combat climate change. Stakeholders are now looking ahead to future conferences, hoping for more decisive action and unity.

Mississippi River Faces Persistent Saltwater Intrusion, Region Seeks Long-Term Solutions



For the third consecutive year, the Mississippi River is experiencing significant saltwater intrusion, prompting local communities and environmental experts to search for sustainable solutions. This recurring issue arises as the river’s flow decreases, allowing saltwater to move upstream and threaten drinking water supplies. The U.S. Army Corps of Engineers is actively involved in addressing this problem, employing temporary measures like saltwater barriers to mitigate the impact on affected areas.



Saltwater infiltration poses serious risks to public health and agriculture, as freshwater sources become compromised. The situation is exacerbated by prolonged periods of drought, which have reduced freshwater flow in the Mississippi River. According to the National Weather Service, drought conditions have worsened due to climate change, increasing the frequency and severity of saltwater intrusion events.



Local authorities are collaborating with federal agencies to explore permanent solutions. Among the proposed strategies are enhanced levee systems and improved water management techniques. The U.S. Army Corps of Engineers is evaluating the feasibility of long-term infrastructure projects to prevent further saltwater encroachment. Additionally, community leaders are advocating for increased funding to support these initiatives and safeguard the region’s water resources.



The impact of saltwater intrusion extends beyond drinking water concerns, affecting local ecosystems and agricultural productivity. Farmers in the region have reported crop damage due to elevated salinity levels in irrigation water. The Natural Resources Conservation Service is working with farmers to implement adaptive practices, such as planting salt-tolerant crops and improving soil management techniques.



As the Mississippi River continues to face challenges from saltwater intrusion, stakeholders emphasize the importance of collaborative efforts and innovative solutions. The ongoing threat underscores the need for comprehensive planning and investment to protect one of America’s most vital waterways from the impacts of climate change and environmental stressors.



Environmental activists have raised concerns over the fossil fuel sector’s significant impact on COP29, the latest United Nations Climate Change Conference. Activists argue that the industry’s presence diverts focus from critical climate actions.



The conference, designed to promote global climate agreements, faces criticism for allowing fossil fuel companies to participate extensively. Environmental groups claim these companies undermine efforts to reduce carbon emissions and transition to renewable energy sources.



According to Climate Action Network, fossil fuel representatives have increased their lobbying activities, aiming to weaken climate policies. These industries allegedly influence negotiations, leading to watered-down commitments that fail to address the urgency of climate change effectively.



Experts suggest that the influence of these companies stems from financial contributions and longstanding relationships with decision-makers. Critics argue that this affects the conference’s ability to enforce meaningful climate change regulations.



During the event, several protests highlighted the need for transparency and a stronger focus on sustainable energy solutions. Activists are calling for increased participation of renewable energy stakeholders in future conferences.



The controversy surrounding fossil fuel involvement at COP29 underscores the ongoing challenge of balancing industrial interests with the global imperative to combat climate change.