More Problems With the FJC Science Manual for Federal Judges

A close look at the FJC's revisionist history of policy responses to ozone depletion

Class is in

Note: The annual subscription for THB increases to $100 on June 1. Lock in your support at a lower level!

Last month I documented how the Reference Manual on Scientific Evidence (4th ed., 2025)¹ included a chapter on climate change that was written by authors whose work supports climate litigation, and, even worse, was ghost written by a plaintiff’s attorney in climate cases. The Manual — published by the Federal Judicial Center (FJC) in partnership with National Academies of Science, Engineering, and Medicine (NASEM) — is supposed to offer a balanced treatment of the myriad complexities where science meets the legal system, as a reference for federal judges.

Today, I return to the FJC Manual to discuss another of its chapters: How Science Works, which underlies the entire volume. The chapter appears to be telling judges “how science works” in a manner supportive of the climate chapter’s characterization of climate litigation.

In her critique of the How Science Works chapter, Jessica Weinkle takes issue with how the chapter presents scientific consensus as the basis of policy action and legal judgment, a form of the “linear model” of science and policy:

By making consensus reporting a necessary precursor to action and an inevitable outcome of scientific research, the linear model circumscribes messy but legitimate democratic decision-making processes. Chapter 2 literally waves away the “twists and turns” that enabled success and, in so doing, positions itself as the world champion of scientific consensus reports- like those produced by NASEM. The implication is that decision-makers need only fall in line with the reasoning and worldviews of scientists.

The fable is false, cliché-ridden, and, in today’s age, utterly tone-deaf. Nonetheless, the FJC-NASEM powers that be saw it fit to feature it in the latest Reference Manual.

Throughout, the How Science Works chapter uses the experience of the 1974 discovery that chlorofluorocarbons (CFCs) deplete the ozone layer and its aftermath to illustrate how science “worked exactly as it ought” in policy and legal settings.

The chapter argues that in the case of ozone depletion, scientific research marched inexorably toward consensus, overcame industry-supported “merchants of doubt,” consensus motivated policy action, and crucially, informed legal action based on science that was beyond question.

In reality, all of this is wrong.² This post explains why.

Let’s begin my detailed critique of the retelling of the ozone story in How Science Works, with a long excerpt from the chapter:

[Mario] Molina and [Sherwood] Rowland published an article [in 1974] putting forth the hypothesis that CFCs deplete our protective ozone layer, but their evidence did not come from an experiment or even any new observations. Instead, the pair brought together measurements collected by other researchers, calculations, and established knowledge about basic and atmospheric chemistry, arguing that if all these other ideas and estimates were true, a logical outcome is that CFCs pose a threat to the ozone layer. Later, experiments were performed that suggested the chemical reactions that Rowland and Molina reasoned should happen actually did happen. Other scientists incorporated these ideas into their models of the atmosphere and made predictions about what should be observed if Rowland and Molina’s hypothesis were correct. Still other groups collected atmospheric evidence to test the predictions made by the models. Meanwhile, the CFC industry backed another scientist to oppose the hypothesis, and Rowland and Molina checked some of the old measurements on which they had based their hypothesis and found them to be inaccurate. After correcting those numbers, models were updated, compared, and updated again. More data were collected and eventually, eight years after the hypothesis was first published, researchers discovered a thinning of the ozone layer over Antarctica much more extreme than expected. This led to more revisions of the hypothesis, a few additional twists and turns, and eventually a Nobel Prize, the Montreal Protocol, which phased out CFC production, and today, a recovering ozone layer. Concurrently, ozone depletion has made its way into the courts as established science. For example, the National Resource Defense Council (NRDC) brought suit against the Environmental Protection Agency (EPA) for making decisions that violated the Montreal Protocol. The NRDC was found to have standing because of the increased risk of skin cancer that NRDC members would experience as a result of ozone destruction. Ozone depletion was treated as a fact in that case, reflecting the scientific consensus on the issue.

There are at least four major problems with this retelling of the ozone depletion experience.

Problem 1: Policy Action Occurred as Science Became Less Certain and More Contested

The FJC Manual tells a story of steadily accumulating scientific evidence converging on consensus, despite a few “twists and turns.” In the decade after Molina and Rowland’s seminal 1974 paper, authoritatve scientific assessments moved away from a widely-shared consensus on the threat of ozone depletion.

The chapter states:

“While the complex and iterative processes that went into establishing depletion of the ozone layer by CFCs are commonplace in science, the speed with which societal and political action followed scientific consensus in this case may be unusual.”

The real lesson is that political action came well before consensus.

A 1976 NAS (National Academy of Sciences) report confirmed the Molina-Rowland finding and projected 15–18% ozone depletion over a century — lending support to the 1978 U.S. aerosol ban.

But successive NAS assessments revised that estimate steadily downward:

• A 1979 NAS report projected 11–16% century-scale decline;

• A 1982 NAS assessment reduced that to 5–9%;

• And a 1983 NAS update projected just 2–4%.

These assessments reflected legitimate views of many leading scientists and they were invoked by those wanting to slow down continued tightening of regulations. As the Christian Science Monitor noted in March 1984:

“This successive downgrading of what some scientists had called a significant danger suggests that the United States acted more out of fear than foresight in banning the suspect chemicals. . . To begin with, the issue is not at all clear-cut scientifically. . . At no point has any expert claimed to have substantial proof that CFCs do, in fact, threaten the ozone layer. Even those experts most strongly in favor of banning the chemicals have urged this as a matter of prudence, not as a response to a clearly established hazard.”

The real lesson here — one not shared with federal judges — is that significant policy action took place from 1974 to 1984 despite the uncertainties and lack of a strong scientific consensus on the risks of significant ozone depletion.

Problem 2: The FJC Chapter Rearranges the Timeline

Did science used to work without consensus? Mentions of the word “consensus” across the four editions of the FJC Reference Manual on Scientific Evidence. Data courtesy Jessica Weinkle.

The FJC Manual works hard to spin a tale of policy driven by consensus and, to do so, mistakenly recounts the historical timeline. The chapter argues, incorrectly,

“eight years after the [Molina and Rowland] hypothesis was first published, researchers discovered a thinning of the ozone layer over Antarctica.”

Molina and Rowland published in June 1974. Eight years later is 1982. But the Farman, Gardiner, and Shanklin Nature paper documenting the thinning of the ozone layer over Antarctica — popularized as the “ozone hole” — was in 1985, eleven years after Molina and Rowland.

The three-year discrepancy matters enormously to the Chapter’s story because of what happened in those three years.

The Vienna Convention for the Protection of the Ozone Layer — the foundational international agreement that set the stage for the Montreal Protocol — was signed on March 22, 1985 —and negotiated during an extended period of scientific debate and uncertainty, and crucially, before the discovery of the ozone hole was announced or popularized.

The real lesson here is that meaningful policy action took place in the face of considerable scientific disagreement over the magnitude and timing of the effects of CFCs on the ozone layer.

The 1985 ozone hole paper may have added momentum to the adoption of the 1987 Montreal Protocol under the Vienna Convention — Though it is worth noting that the U.S. EPA explained when proposing a rule to comply with the Montreal Protocol that, “the Agency has de facto assumed that the ozone hole is not related to CFCs and halons.”

The accurate lesson to take from the ozone experience is that substantial policy action took place in the United States and internationally from 1975 to 1985, a decade during which there was little consensus on the observed and projected effects of CFCs on the ozone layer.

The FJC manual is a bit too clever in its summary the timeline of events, explaining that policy success start with research that led to

“more revisions of the [1974] hypothesis, a few additional twists and turns, and eventually a Nobel Prize, the Montreal Protocol, which phased out CFC production, and today, a recovering ozone layer.”

Again, the chapter plays fast and loose with the timeline. The Montreal Protocol, which initiated negotiations toward a full phase out of CFCs, was agreed to in 1987. Molina and Rowland were awarded the Nobel Prize in Chemistry in 1995. The chapter implies the opposite.

The recovery of the ozone layer is underway, but detection of the effects of phasing out CFCs is slow and uneven, and detection of recovery in many places beyond Antarctica is not yet expected. On the 30^th anniversary of the Montreal Protocol, a group of atmospheric chemists asked, Is global ozone recovering? and they answered:

“The clearest signs of increasing ozone, so far, are seen in the upper stratosphere and for total ozone columns above Antarctica in spring. These two regions had also seen the largest ozone depletions in the past. Total column ozone at most latitudes, however, does not show clear increases yet. This is not unexpected, because the removal of chlorine and bromine from the stratosphere is three to four times slower than their previous increase. Detecting significant increases in total column ozone, therefore, will require much more time than the detection of its previous decline.”

The nuance matters. In the ozone case, policy action needed to occur well before the effects of policy implementation could possibly be detected, which would have to wait many decades. That means that agreement on policy is far more likely when actions have multiple justifications, and not just science.

Problem 3: Industry’s Role Was Actually Essential to Political Action

The FJC retelling of the ozone experience suggests simplistic industry opposition to the findings of Molina and Rowland in 1974: “the CFC industry backed another scientist to oppose the hypothesis.”

The scientist is Richard Scorer, who was an accomplished atmospheric scientist and professor at Imperial College London. He participated in a U.S. speaking tour in 1975, sponsored by a chemical industry PR group, calling the ozone depletion hypothesis “pompous claptrap.”

The FJC chapter uses Scorer to suggest how judges can evaluate experts based on their supposed positioning with respect to a consensus. Scientists who disagree with a consensus are likely to be industry shills. Not mentioned was the fact that Scorer’s industry-backed tour occured in the months after the original ozone depletion hypothesis was put forward, long before there was anything resembling a consensus.

The chapter explicitly generalizes its argument to “issues such as climate change and tobacco exposure.” Industry is reduced to a cartoonish roll of supporting “merchants of doubt,” a concept cited explicitly in the chapter, and connected to tobacco and climate change.

The chapter’s account of the role of industry in the ozone case is limited to the 1975 PR campaign, intimating that industry was opposed to policy action throughout. That is highly misleading.

DuPont — the world’s leading CFC producer with roughly 25% global market share — had identified HFC-134a as a Freon replacement by 1976 and patented the manufacturing process by 1980. By the time of the Montreal Protocol negotiations, DuPont was already interested in alternatives because their original CFC patents were due to expire. DuPont had filed more than 20 patents for CFC alternatives and its Freon division head explained the company’s interests: “There is an opportunity for a billion-pound market out there.” DuPont announced in 1988 that it would phase out CFC production entirely.

One reason why agreement was reached on the Montreal Protocol was that the availability of technological substitutes for CFCs helped to align the interests of environmental groups, governments, and industry around a shared outcome. There is a lesson here as well — As Karen Litfin explains in Ozone Discourses:

“Without regulation there could be no substitutes but, at least in the minds of many, without the promise of substitutes there could be no regulation.”

The technological chicken and the regulatory egg offered a lesson worth sharing with the judges, as it emphasizes the role of technology as a key factor in connections of science and policy.

The 1975 Scorer episode highlighted in the FJC chapter was a sideshow and ultimately inconsequential. The DuPont patent strategy that began in 1976 was a crucial factor in how technological innovation helped to connect policy action with scientific understandings.

The chapter emphasizes a sideshow and ignores the lesson that industry often plays a central role in both science and science in policy. That role is of course not always positive, but it is not always negative either. Judges should have been exposed to these complexities in the Reference Manual.

Problem 4: The Retelling Spins a Lawsuit as A Positive Lesson

The FJC Manual’s retelling of the ozone story concludes with a supposed lesson for those using lawsuits based on science:

“[T]he National (sic)³ Resource Defense Council (NRDC) brought suit against the Environmental Protection Agency (EPA) for making decisions that violated the Montreal Protocol. The NRDC was found to have standing because of the increased risk of skin cancer that NRDC members would experience as a result of ozone destruction. Ozone depletion was treated as a fact in that case, reflecting the scientific consensus on the issue.”

This is wrong on multiple counts.

Most importantly: NRDC lost this case on its merits — specifically, the court rules that international agreements under the Montreal Protocol are not U.S. law — and this is not shared in the chapter. Science did not compel a verdict in favor of the plaintiffs. In fact, the case turned on legal matters and scientific consensus was not relevant to the outcome. None of this is shared in the FJC Manual, which instead tells judges, “ozone depletion has made its way into the courts as established science.”

The lesson of the NRDC vs. EPA case highlighted in the chapter is that science does not compel legal outcomes.

What a Broader Look at the STS/STP Literature Would Have Told Judges Instead

The revisionist history of ozone depletion suggests a tidy story:

Science → Consensus → Policy → Courts → Outcomes

The FJC Manual selectively invokes some of the literature of science and technology studies (STS), but neglects some of the most important traditions in that literature that would have offered a very different perspective for Federal judges.

For example, Silvio Funtowicz and Jerome Ravetz developed the concept of “post-normal science” specifically for situations where “facts are uncertain, values in dispute, stakes high and decisions urgent” — the conditions that often characterize science in litigatio. Funtowiz and Ravetz argue that in such situations ordinary markers of scientific quality are least reliable and the most important decisions are made not after consensus is achieved, but in the presence of irreducible uncertainty, conflict, and ignorance.

The ozone case is a textbook example of post-normal science. Meaningful action occurred well before consensus was established and, in fact, while authoritative risk estimates were declining. Explaining post-normal science would have helped judges to understand this reality rather than telling them that consensus leads action.

In another example, Daniel Sarewitz argues that more science does not necessarily resolve environmental controversies — it can exacerbate them by supplying contesting parties with their own bodies of legitimate facts, an “excess of objectivity.” The successive NAS revisions of the ozone depletion estimate are a perfect illustration: improving science produced declining risk estimates that opponents of regulation used to argue for inaction, while proponents argued that the remaining uncertainty justified precaution.

Sarewitz’s framework would equip judges to recognize this dynamic — and to understand that their role is not simply to identify which side has the scientific consensus, but to weigh evidence and make legal judgments even when the science is unsettled. In fact, uncertainty can underpin action, as happened in the ozone case.

This literature — and much more — are absent from the How Science Works chapter.

The issues in the How Science Works chapter are significant, and taken together with the problems of the climate chapter, suggest that the FJC and NASEM should be asked by Congress to explain how the corruption of the FJC Manual happened and what steps will be put in place to ensure that it does not happen again.

Before you do anything else —> Please click that “❤️ Like.” More likes means more readers of THB. Thanks!

Comments welcomed!

THB exists because of its paid subscribers. Please consider upgrading and join in on the discussion. Thank you.

Announcement: The annual subscription for new subscribers to THB is increasing to $100 on 1 June 2026! Lock in your support at a lower level, at a price that will never increase!

1. See Jessica Weinkle’s post on the origins of the manual.

2. Bona fides: I have studied ozone case — the science, the policy, and the politics — across my entire career. As an undergraduate in the late 1980s, I was a FORTRAN programmer in the Atmospheric Chemistry Division of the National Center for Atmospheric Research, during the thick of the ozone negotiations. I got to observe world-leading scientists doing research that was central to the negotiations, which sparked my interest in how science connects to policy. Later, I discussed the case of ozone depletion in my dissertation, peer reviewed papers (e.g., here), in The Climate Fix, and here at THB.

3. The organization is the Natural Resources Defense Council — not the “National Resource Defense Council.”