Distillations podcast

Deep Dives into Science Stories, Both Serious and Eccentric
April 17, 2018 Environment

Whatever Happened to the Ozone Hole?

An environmental success story.

A group of about 14 Adelie penguins on an iceberg in Antarctica

If you were around in the 1980s, you probably remember the lurking fear of an ominous hole in the sky.  In the middle of the decade, scientists discovered that a giant piece of the ozone layer was disappearing over Antarctica, and the situation threatened us all. The news media jumped on the story. The ozone layer is like the earth’s sunscreen: without it, ultraviolet rays from the sun would cause alarming rates of skin cancer and could even damage marine food chains. And it turns out we were causing the problem.

Today, more than three decades after the initial discovery, the ozone hole in Antarctica is finally on the road to recovery. How did we do it? This environmental success story gives us a glimpse into what happens when scientists, industry, the public, and the government all work together to manage a problem that threatens all of us. Happy Earth Day!


Hosts: Alexis Pedrick and Elisabeth Berry Drago
Senior Producer: Mariel Carr
Producer: Rigoberto Hernandez
Our theme music was composed by Zach Young
Additional music courtesy of the Audio Network

Research Notes

To research this episode we read Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming by Naomi Oreskes and Erik Conway. We read, listened to, and used excerpts from an oral history with chemist Mario Molina that was conducted by the Science History Institute’s Center for Oral History. We also interviewed atmospheric chemist Susan Solomon at MIT in 2016.

These are the archival news clips we used as they appear in the episode:

Dow, David; Quinn, Jane Bryant; Rather, Dan. “Ozone Layer,” CBS Evening News. Aug 15, 1986.
Hager, Robert; Seigenthaler, John. “Ozone Layer,” NBC Evening News. Dec 3, 2000.
Gibson, Charles; Blakemore, Bill. “Environment/Ozone Layer,” ABC Evening News. Aug 22, 2006.
Reasoner, Harry; Stout, Bill. “Supersonic Transport Vs. Concorde,” CBS Evening News. Jan 1, 1969.
Quinn, Jane Bryant; Rather, Dan. “Ozone Layer Depletion,” CBS Evening News. Oct 20, 1986.
Chancellor, John; Neal, Roy. “Special Report (Ozone),” NBC Evening News. Sep 24, 1975. Benton, Nelson; Cronkite, Walter. “Ozone/Fluorocarbons/ National Academy of Sciences Study,” CBS Evening News. Sept 14, 1976. Brokaw, Tom; Hager, Robert. “Assignment Earth (Ozone Layer),” NBC Evening News. Feb 3, 1992.


Whatever Happened to the Ozone Hole?

>>Distillations sound collage>>

CBS Evening News. Aug 15, 1986: Miles above Antarctica a strange and disturbing process has been measured since the late 70s. It is a growing hole in the ozone layer, that gas shroud that screens the earth from the worst dangers of ultraviolet radiation.

Alexis: Hi, I’m Alexis Pedrick.

Lisa: And I’m Lisa Berry Drago, and this is Distillations, coming to you from the Science History Institute.

Alexis: Each episode of Distillations takes a deep dive into a moment of science-related history in order to shed some light on the present. Today we’re talking about the ozone hole, in the first installment of a three-part series about environmental success stories.

Lisa: If you were a kid in the 80s like we were, you probably remember the lurking fear of the ominous hole in the sky. Maybe you didn’t understand it, but if you were like us, it freaked you out.

NBC Evening News. Dec 3, 2000: Without ozone, the sun’s ultraviolet rays would shine through unfiltered, dramatically increasing cases of skin cancer, and eye damage, and damage to the entire food chain.

Alexis: So Lisa, tell me about your childhood and the ozone hole.

Lisa: I remember feeling a lot of guilt about McDonald’s. I think it wasn’t that we were worried about what was inside the container yet, but we were very worried about the Styrofoam containers.

Alexis: Exactly! I think I had that same helpless, scared feeling. I remember doing a lot of projects in school about how to save the environment. But it was always things like, ‘don’t run the water while brushing your teeth.’ But that did not seem to match up with the fact that the hole in the ozone was going to like open up and murder us all. I felt all this panic, it sounds like you felt all this panic, but then it sort of just…like…faded away. Disappear. And people kind of stopped talking about it. And then this happened in 2006:

ABC Evening News. Aug 22, 2006: Some good environmental news tonight, scientists report that the ozone layer in the Earth’s atmosphere seems, finally, to be on the road to recovery.

Bill Blakemore: It’ll begin to decrease, starting about 2018 or so, and by 2070 the ozone hole should be fully recovered.

Alexis: So now it’s 2018, the year the ozone hole is supposed to start closing, at least according to that CBS news clip, and here we are, living our lives…not in a Mad Max film, which is personally how I thought it was going to go.

Lisa: So maybe you’re wondering, how did we go from global freak-out to actually finding a solution? Well, it turns out the ozone hole story is a very good and very rare example of an environmental success story. It gives us a glimpse into what happens when scientists, industry, the public, and the government all work together to manage a problem that threatens everyone.

Alexis: So today we’re going to tell you how to solve any environmental problem in five easy steps. Number one: figure out the problem.

Lisa: Number two: get evidence.

Alexis: Number three: inform the public. Lisa: Number four: get industry onboard Alexis: Number five: implement policy.

Lisa: And we’ll call this one step five and a half: after you’re successful, make sure you continue monitoring the issue and make adjustments and regulations. Easy, right?

Chapter 1: Figure out the problem

Alexis: So we are at step number one: figure out the problem.

Lisa: The ozone hole story all started around in 1970 with a kind of wild idea to make supersonic jets:

CBS Evening News. Jan 1, 1969: Theoretically it will fly faster than any other passenger plane.

Sound effects of Concorde pilot pit: … Concorde 9180…

CBS Evening News. Jan 1, 1969: At nearly three times the speed of sound, eighteen hundred miles an hour.

Lisa: When the idea for these planes was, ahem, in the air, there was some concern that their emissions could damage the ozone layer. In the end it wasn’t a huge issue, but people started thinking about what could hurt the ozone layer, and that led to the discovery that some seemingly innocuous things could actually do it serious harm.

Mario Molina: Spray cans got a bad name at that time.

Alexis: That’s chemist Mario Molina, in an oral history interview conducted by the Science History Institute in 2013. In 1973 Molina was a young post-doc at UC Irvine, working in the chemistry lab of F. Sherwood Rowland. They’d been studying a set of common industrial chemicals called chlorofluorocarbons.

CBS Evening News. Aug 15, 1986: Chlorofluorocarbons, CFC’s, gasses used in a variety of household products, including plastic foams.

CBS Evening News. Oct 20, 1986: 50 years ago, CFC’s were a miracle of modern technology from the DuPont Company, turning the home ice box into a safe and efficient refrigerator.

Lisa: CFCs were used in things like air conditioners, refrigerators, and aerosol cans. Molina and Rowland discovered that CFCs had the potential to destroy the ozone layer, and in 1974 they published a paper in the academic science journal Nature about it. So we already knew that there were CFC’s in the atmosphere. What was new was the idea that the ultraviolet rays from the sun would decompose these CFCs and the resulting chemicals would deplete the ozone. Responses to the articles from scientists familiar with the field were supportive, but there was some backlash from those outside of it.

Molina: Some thought maybe we were exaggerating or just trying to make noise.

It was an unusual thing to talk about: invisible gases, invisible rays, but eventually the media sort of picked it up.

NBC Evening News. Sep 24, 1975: Some scientists have theorized that fluorocarbon gases from spray cans and refrigerants have floated up to the stratosphere to react chemically with ozone. The government has mounted an all- out campaign to prove or disprove the theory.

Alexis: Congress acted quickly.

Lisa: Which sounds crazy, right?!

Alexis: I know. It’s not a combination of words we’re used to hearing anymore. But they took it really seriously and asked the National Academy of Sciences to look into the issue.

CBS Evening News. Sept 14, 1976: The National Academy of Sciences today confirmed that fluorocarbons in aerosol sprays weaken the Earth’s protective ozone layer in the atmosphere. Spray cans, which use fluorocarbon gasses as propellant are the principal offenders in the National Academy report. The report says their use must be regulated and perhaps banned in some cases to protect the earth’s ozone layer.

Alexis: Not surprisingly, there was significant pushback from the CFC industry.

CBS Evening News. Sept 14, 1976: The industry claims that fluorocarbons are an 8 billion dollar a year business that employs more than a million people. The industry also claims that there are no adequate substitutes and that it will take years to research and develop alternatives.

Lisa: They challenged Molina and Rowland’s theory every step of the way. They formed a resistance campaign, and their star witness was a British professor of theoretical mechanics named Richard Scorer. He repeatedly denounced the ozone depletion hype with phrases like “pompous claptrap.” Eventually the LA Times exposed him as being a “scientific hired gun.”

Alexis: In 1977 three federal agencies, the FDA, the EPA, and the Consumer Product Safety Commission, announced they would phase-out and ultimately ban CFC propellants by 1979. But Americans had been watching the news, and they were worried. And they’d already begun phasing them out themselves.

Lisa: It seemed like the problem was under control, until something happened in 1985 that shocked the world. And the chapter of the story that unfolded during our childhoods was about to begin. I am talking about step two: gather your evidence.

Chapter 2: Get evidence (Antarctica)

CBS Evening News. Aug 15, 1986: Scientists are worried by a mysterious massive hole high above the ice.

David Dow: In Antarctica, up to half the ozone is being depleted each year over an area the size of the United States.

CBS Evening News. Aug 15, 1986: (Susan Solomon) Nobody predicted this, it’s kind of like a bomb falling out of the sky.

Lisa: In 1985 the British Antarctic Survey confirmed what their satellites had actually detected years before: there was a massive hole in the ozone above the South Pole.

Alexis: Now, dear listeners, you might be wondering, if it was already detected years before why didn’t we find out about it sooner?

Lisa: Ah, yes. Interesting story: the satellite had been recording ozone levels that were so low that they’d been catalogued as mistakes. But these were not mistakes. The ozone was disappearing over a huge area. Until this point ozone depletion was mostly theoretical. It was something that wouldn’t happen for a long time. But suddenly it was actually happening and scientists leap into action to try to figure it out.

CBS Evening News. Aug 15, 1986: A research team is leaving Los Angeles tonight, bound for the South Pole. Within weeks, scientists will sent balloons into the Antarctic stratosphere in search of a final answer. The ozone hole, a consequence of man or nature.

Susan Solomon: When I saw the British paper I started thinking about what could possibly account for this incredible phenomenon that we just didn’t anticipate at all.We started thinking about, “Hey, could we actually go down there and measure some stuff? Actually figure out whether this chemistry is what’s responsible or not or some other chemistry?”

Lisa: Atmospheric chemist Susan Solomon led the expedition to Antarctica when she was just 30 years old. The 16-person team took the first chemical measurements of the stratosphere on the continent, trying to figure out what was causing the hole. This is Solomon in 1986 on CBS news, before the expedition.

CBS Evening News. Aug 15, 1986: (Susan Solomon) We don’t yet know weather or not what is happening down there has anything to do with mankind. It may be a completely natural phenomenon.

David Dow: It may be, but some scientists, including Solomon, are looking hard at another long debated possibility. Chlorofluorocarbons, CFC’s.

Solomon: Antarctica really is very, very cold so it truly is the coldest place on Earth. You know, they open the door of the airplane and you just think, “Okay, it’s hitting my face and it’s hurting my nose and this air is just so ferocious. Maybe I’ll just stay in my room the whole time, you know?

Lisa: But she didn’t, of course. In fact, Solomon and her team took measurements around the clock, often in extreme conditions.

Solomon: Taking measurements in the dark, going up to the roof, pointing the mirror, almost getting blown off the roof by the strong winds that sometimes came up was pretty exciting stuff.

Alexis: Solomon had theorized that extreme temperatures were partly to blame for the ozone hole. Antarctica is so cold it has clouds in its stratosphere, which is really unusual. The Arctic also has them occasionally, but everywhere else on earth is too dry and warm.

Solomon: I realized they might be driving a very different chemistry there than we have anyplace else in the world. I did some studies of what that chemistry might do and then I wrote a scientific paper presenting the theory that reactions on the polar stratosphere clouds combining with the man-made chlorine that we’ve pumped up over the past decades might be enough to produce the Antarctic ozone hole and that turned out to be the right answer.

Alexis: The expedition found the smoking gun. It proved Mario Molina and Sherry Rowland’s theory. Then two other studies confirmed what Solomon’s team found.

Solomon: Three independent data sets can’t all be getting the wrong answer. At some point it just becomes silly to say that’s not the answer.

Chapter 3: Inform the public

Lisa: Doing the science was only part of the battle. There was another crucial step in solving this problem:

Alexis: Right, letting the public know.

Lisa: It’s so important, but it’s also much more difficult than it sounds. The news moves fast. And science—science goes at it’s own pace.

Solomon: Science wants to make very sure that everything gets properly peer-reviewed and that we really take our time producing an answer that has been checked and

rechecked by other people which is absolutely very, very important. On the other hand even in those days the demand for the information was huge because of the potential importance of it. We immediately got all kinds of requests from reporters and requests to testify. We just tried to do a balancing act.

NBC Evening News. Feb 3, 1992: Today, scientists who recently returned from the Antarctic told Congress that the ozone layer is still disappearing at an alarming rate. Dr. Susan Solomon let the expedition, and today before a House sub-committee reported results.

Solomon in NBC Evening News. Feb 3, 1992: We observed a 35 percent decrease of the total ozone overhead. Three different and independent sets of observation showed this change. I think we will eventually see large-scale depletions of the ozone layer at other latitudes.

Lisa: Solomon, Molina, and Rowland all had to confront the fact that experts in their positions weren’t accustomed to speaking directly to the public or speaking before congress. There was then and there is still now a common idea among scientists that the facts should speak for themselves. But the facts themselves, let alone the methods used to obtain those facts are not always clear or easy to interpret. And on their own they are not always enough to sway public opinion.

Solomon: I did not have then and I don’t have now a good formula for how science deals with that. I think the problem we have is that bad information spreads faster than good information. Bad information doesn’t have to be peer-reviewed so stuff goes flying around the Internet immediately and creates all kinds of misimpressions or fears or misunderstandings that sometimes take many, many years to unravel and sort out.

Alexis: In the 1970s Mario Molina and Sherry Rowland had a hard time navigating how to talk to the public.

Molina: A sort criticism at that time was if you are in academics, you don’t publish in the newspapers. We had a few colleagues that actually did like to publish first in the newspapers. And they were not very highly regarded as scientists, although in society they were better known.

Alexis: But Molina and Rowland felt their findings were important enough they had to break with tradition.

Molina: So that’s when slowly we decided, hey, this looks serious enough. We have to make an effort to learn to communicate with the media. If this is real, we should do something about it.

Alexis: But it was a steep learning curve to figure out how to actually do it. After they published that first article about CFCs, they decided they had to get the story out beyond a peer-reviewed journal that only scientists would read.

Molina: So we sort of naively organized a press conference.

Alexis: They brought in scientists to explain how the atmosphere works. Then others to talk about how measurements that were being taken. But by the time Molina and Rowland explained their findings almost all of the reporters had left.

Molina: Because that’s not the way [laughs] press conferences work with the media. You have to come up with a punch line at the very beginning.

Alexis Even though they weren’t great at it, Susan Solomon thinks Molina was right: talking to the public is crucial.

Solomon: Because nothing happens without public understanding. I think there’s a role for science, there’s a role for technology, but in terms of making a change at a large scale, even when it comes to things like chlorofluorocarbons, public understanding is absolutely critical.

Alexis: So if you use me and Lisa as case studies, the media coverage definitely worked in swaying public opinion.

CBS Evening News. Oct 20, 1986: CFC’s are all around us, and in some surprising places. For example, every time you crumble a Big Mac package you may be venting CFC’s into the atmosphere.

Alexis: Did little three-year old Lisa see this CBS story in 1986? And begin fearing takeout containers?

Lisa: Maybe.

Alexis: We’ll never know for sure, but it seems plausible.

Lisa: It’s not enough to make people understand the consequences of a problem. They need to be able to perceive the problem itself. And luckily, 1980s news footage was showing viewers the problem. They could actually visualize the ozone hole.

CBS Evening News. Aug 15, 1986: In enhanced satellite photos, it appears as a series of colored splotches over the South Pole.

Solomon: The nice thing, in some ways, about the way that the ozone hole unfolded was that people could actually see the images of what was happening and those were very, very powerful. The film clips that you can see of the ozone hole develop and grow are pretty tangible, imaginable.

Chapter 4: Implement policy, get industry onboard.

Alexis: Ok, so people were seeing the problem. We’ve gathered our evidence. Now its time to move on to step four and five. Get industry onboard and implement policy.

Lisa: The U.S., Canada, and Norway had already banned CFCs in aerosol cans back in 1978, so the discovery of the ozone hole in 1985 came as a shock.

CBS Evening News. Oct 20, 1986: Most Americans thought we got rid of the ozone problem years ago, when the government banned the use of chlorofluorocarbons in aerosol sprays. But the problem did not go away, it got worse.

Lisa: At this point CFC use was still growing in Europe and in the Soviet Union and it became clear that this was a global problem in need of a global solution. After Antarctica, policy happened fast. In 1987, almost every country in the world signed on to the Montreal Protocol. The treaty’s purpose was to protect the ozone by phasing out CFCs and other ozone-depleting chemicals. Within 15 years we went from the basic scientific understanding of a problem to implementing policy to address it. The speed of the response was unprecedented.

Alexis: Solomon says that the treaty was so successful because the proposed solutions were practical, not overly idealistic. Industries needed to find replacements for CFCs, and for some things it was really easy. Like electronic chips. Up until this point CFCs were the way to clean them. But there was a surprising and environmental friendly solution.

Solomon: People actually recognized that you could clean some types of chips pretty well with lemon juice. Pretty easy, huh?

Alexis: But other things had more at stake: take for example fire extinguishers. They were made with another ozone-depleting chemical called Halon, and there were no easy substitutes for it. So phasing out these chemicals had to happen more slowly, with help from scientists and economic advisors.

Solomon: Then, the governments could choose, for example, to take longer with the chemicals for fires extinguishers. They could choose to make an exemption for medical asthma inhalers and things like that.

Lisa: Chemical companies like DuPont also had to get on board. And let’s take a second and realize how hard it is for a major industry to shift gears like that. It requires people at every level from stakeholders, and board members to people at the factory floor, to buy into the changes and support them. It’s a huge investment. It’s a huge undertaking. And a change in infrastructure.

Alexis: And on top of that all, these changes had to be industry-wide.

Solomon: Some of the big chemical companies actually had very good scientists working in those companies. And they were huge, in my opinion, at bringing the chemical industry into the discussion in a very fair and positive way. I really wish more industries would do that.

Chapter 5: What does success look like?

Alexis: The Montreal Protocol went into effect on January 1st, 1989, ending a tumultuous decade. But despite the phasing out of CFCs and other ozone-depleting chemicals, the hole over Antarctica continued to grow throughout the 90s and into the 21st century.

Solomon: So in the old days when you’d look at it your heart would kind of sink along with the ozone because it started dropping and then it just dropped like a rock through the whole decade of the ’80s.

Alexis: The paperwork had been signed, but CFCs have a lifespan of 50 to a hundred years.

Solomon: So the chlorofluorocarbons from your grandmother’s refrigerator that she got rid of in 1975, some of it is still in the atmosphere depleting the ozone layer.

Alexis: But the hard work eventually started to pay off. And finally, in 2006:

ABC Evening News. Aug 22, 2006: Some good environmental news tonight, scientists report that the ozone layer in the Earth’s atmosphere seems, finally, to be on the road to recovery. The hopeful update comes two decades after one gutsy woman made the world pay attention to a potentially catastrophic problem.

Lisa: Scientists estimate that the hole will fully close around 2065—eighty years after it was discovered.

Alexis: So the ozone hole story really was an environmental success story. It did involve the five steps: figure out the problem, get evidence, tell the public, get industry onboard, and pass some regulations. But it also needed other things.

Lisa: It really helped that the problem had what Susan Solomon calls the 3 p’s: The problem is personal, it’s perceptible, and the solutions are practical. The ozone hole felt like a personal problem because hair spray cans, refrigerator coolant—all things that were woven into the fabric of everyday life. The problem was perceptible because people were seeing in the news every night. Scientists were reaching out and helping to visualize their data. And the solution, the Montreal Protocol, was very practical. It’s a living document that even has opportunities to reassess and rework the problem every few years.

Alexis: So the hole over Antarctica is closing, yes. But there’s ozone depletion in other places, especially around the equator where a lot more people live. And we got other environmental issues like climate change. Yes it’s only five easy steps but we’d have to be willing to repeat these fives easy steps over and over again and make changes that aren’t just small, personal things like hair spray or refrigerator coolant, but actually huge lifestyle changes on a major scale. It’s actually not as easy as we made it sound.

Lisa: Still, Susan Solomon is relatively optimistic about humanity’s ability to manage severe environmental problems.

Solomon: We’ve done that with the issue of pesticides. We’ve done it pretty well with the issue of smog. We’ve done it with acid rain. We’ve done it with chlorofluorocarbons. I mean, gee, we’ve got quite a string of successes going here, people. I think there’s plenty of reasons for hope from history.

Alexis: Distillations is more than a podcast. We’re also a multimedia magazine.

Lisa: You can find our videos, our blog, and our print stories at Distillations DOT org.

Alexis: And you can also follow the Science History Institute on Facebook, Twitter, and Instagram.

Lisa: This episode was produced by Mariel Carr and Rigo Hernandez.

Alexis: And our theme music was composed by Zach Young.

Lisa: Special thanks to the Science History Institute’s oral history program for sharing the Mario Molina interview. You can find our vast collection of interviews with leading figures in chemistry, chemical engineering, life sciences, and related fields at O-H DOT SIENCE HISTORY DOT ORG.

Lisa: For Distillations I’m Lisa Berry Drago.

Alexis: And I’m Alexis Pedrick.

Both: Thanks for listening!

Photo: Adelie penguins on an iceberg in Antarctica/Wikimedia Commons.

Listen to more episodes

Collage of images related to cancer research

Cancer Virus Hunters: An Interview with Gregory J. Morgan

Seen as outcasts, some persistent scientists went against the grain to study viruses they suspected caused cancer.

Collage of images on blue background

The Ames Test

Environmentalists championed biochemist Bruce Ames for his test’s ability to weed out potential cancer-causing chemicals. Then he seemingly turned his back on them.


Is Ozempic Different?

The weight-loss drug has become well known, but many others have come before, often with horrific results.


    Copy the above HTML to republish this content. We have formatted the material to follow our guidelines, which include our credit requirements. Please review our full list of guidelines for more information. By republishing this content, you agree to our republication requirements.