LISTEN LIVE: Loading...



How the world came together to save the ozone layer

In this image, from September 2006, the Antarctic ozone hole was equal to the record single-day largest area of 11.4 million square miles (29.5 million square kilometres), reached on Sept. 9, 2000. Satellite instruments monitor the ozone layer, and we use their data to create the images that depict the amount of ozone. The blue and purple colours are where there is the least ozone, and the greens, yellows, and reds are where there is more ozone. (Photo by: Universal History Archive/ Universal Images Group via Getty Images)
In this image, from September 2006, the Antarctic ozone hole was equal to the record single-day largest area of 11.4 million square miles (29.5 million square kilometres), reached on Sept. 9, 2000. Satellite instruments monitor the ozone layer, and we use their data to create the images that depict the amount of ozone. The blue and purple colours are where there is the least ozone, and the greens, yellows, and reds are where there is more ozone. (Photo by: Universal History Archive/ Universal Images Group via Getty Images)

Sign up for the On Point newsletter here

In the 1980s, the world came together to ban CFCs, commonly used chemicals that were destroying the atmosphere’s ozone layer.

"The disaster was in terms of food. Crops that couldn't be grown," Paul Newman says. "How do you raise crops for the few billion people on the planet if you've got so much, you know, sterilizing UV radiation pouring in on the earth?"

Countries rallied and signed the 1987 Montreal Protocol, a treaty which marked the end of CFCs. Can we use that template to help end climate change?

Today, On Point: Fixing the ozone layer and lessons for solving the climate crisis.


Paul Newman, chief scientist for Earth Sciences at NASA's Goddard Space Flight Center. Co-chair of the scientific assessment panel to the Montreal Protocol.

David Victor, professor of innovation and public policy at the School of Global Policy and Strategy at UC San Diego. Co-director of the Deep Decarbonization Initiative.  Author of Fixing the Climate: Strategies for an Uncertain World and Making Climate Policy Work.

Transcript: How the world banned CFCs

MEGHNA CHAKRABARTI: This one’s for you, all you children of the 80s. You’re my people. All that big hair, spandex, those scrunchies, some absolutely epic music. And, unfortunately, this:

MICHAEL RESNICK: I’m Dr. Michael Resnick, with some bad news about the ozone. This medical news update is brought to you by Advil, Advanced medicine for pain. The ozone layer shields the earth from the sun's ultraviolet rays. But a recent report concluded that this layer is thinning rapidly due to trace gases. Primarily, CFCs in consumer products.

CHAKRABARTI: You probably remember that. I do. The sudden realization that the ozone layer was in danger – something most of us had never even heard of prior to 1985. Skin cancer rates were going to skyrocket. Ecosystems would collapse. It was an existential threat – one so urgent, I was one of those 10-year-olds who refused to crush a piece of Styrofoam for fear of releasing more CFCs into the air.

The story, though, starts even further back. With two scientists, Sherwood Rowland and Mario Molina at the University of California, Irvine.

SHERWOOD ROWLAND: This started back in 1972, 1973 with curiosity on the part of a laboratory chemist – namely me – about what would happen to the CFC gases which had just been discovered as being present in the atmosphere essentially everywhere. ... So when Mario Molina joined my research group in 1973 --

MARIO MOLINA: We decided to ask a question about some chemicals that were being released to the environment that we realized that they could pose a serious global environmental problem.

CHAKRABARTI: Chlorofluorocarbons or CFCs. First developed in the 1920s, and by midcentury, used almost everywhere. In aerosol sprays, as blowing agents for foams and packing materials, as solvents, and refrigerants. Molina and Rowland discovered these chemicals could reach the upper atmosphere and destroy the ozone layer which provides vital protection from excess ultraviolet radiation from the sun. They published their results in 1974. Not much happened. But they knew this was serious. Rowland’s wife Joan spoke about this in a PBS documentary:

JOAN ROWLAND: [Sherwood], who is my husband — a very good husband, I might add — came home one night and I was in bed reading and I said, how’s the work going? And he said, it’s going really well. The only trouble is, I think it’s the end of the world.

Rowland decided to take action. He advocated loudly, and publicly throughout the 1970s.

ROWLAND: To avoid these hazards, man cannot continue his ever-increasing use of these chemicals. Instead we must rapidly reduce the amounts of these materials released into the atmosphere.

It wasn’t long before other scientists validated their findings. And in 1985 a team of British scientists including Jonathan Shanklin discovered something alarming: a giant hole in the ozone over Antarctica. Here's Shanklin from a Nature podcast:

NEWSCASTER: Each spring, over Antarctica a hole in the ozone develops ... Satellites photo show that a hole opens for a few months during Antarctica’s springtime.

SHANKLIN: It was very clear when we first looked at the data that we’ve got an ozone decline and I think that’s probably the term we used – a decline in ozone above the Antarctic – and it wasn’t really until you got the satellite images that you could see oh, there’s a hole there.

Soon after, the United States sent a team to Antarctica, led by Susan Solomon of the National Oceanic and Atmospheric Administration.

SUSAN SOLOMON: From the time when the ozone hole was discovered in 1985 to, say, 1987, you went from a situation where you first had one station measuring total ozone, showing something strange. And that's that was an intense period of activity for many of us in the science community. And we were able to measure a host of important chemicals that were all related to this to the chemical perturbations I've been talking about. And they all pointed the same way.

CHAKRABARTI: It was pointing the way to the manmade destruction of the ozone later. So, faced with impending catastrophe, countries around the world took action. In 1987 more than 30 countries signed The Montreal Protocol, an international treaty which focused on phasing out harmful CFCs.

It was an historic agreement. To this day, the most successful international environmental treaty, ever, as noted by then secretary of state George Shultz to PBS.

GEORGE SHULTZ: When it was all done and the Montreal Protocol was signed, I remember President Reagan saying, “What a magnificent achievement.”

CHAKRABARTI: It was a first step, but it wasn’t long before all the countries in the world had signed on. An environmental and diplomatic success. Signed 35 years ago, The Montreal Protocol did what it set out to do – countries eliminated CFCs and the ozone layer is on the road to recovery.

And now, the ozone layer is on track to recover.

UN REPORT: In a new report, a UN-backed scientific panel confirmed that the phase-out of nearly 99% of banned ozone-depleting substances has succeeded in safeguarding the ozone layer, leading to notable recovery of the ozone layer in the upper stratosphere and decreased human exposure to harmful ultraviolet rays from the sun.

Interview Highlights

On first reports of the hole in the ozone layer

Paul Newman: "The first reports of the ozone hole occurred in 1985, and we listened to John Shankland just a minute ago. His colleagues, Joe Farman, Brian Gardiner and John showed that ozone was going down fast. Now, here at NASA, we had satellite images of it, but we were puzzled by these very, very low values we were seeing from the satellite measurements. And like all scientists, we didn't want to put those data out there because we thought we've done something wrong. But ... once we saw the Farman, Gardiner and Shanklin results from Halley Station in Antarctica, we knew that we were seeing these values.

"And it was amazingly a depletion of ozone that was continental in scale. It's just an astonishing thing to see it falling so rapidly in the station data, but then to see that it was continental in scale. Now, at the time I was just a young scientist here at NASA's Goddard, and I began to work with folks about what could be the possible cause. And, you know, there were actually three theories early on. Was it manmade chlorofluorocarbons that could be causing it? There was a theory about the solar cycle. Could it be variations in the sun? Could it be some natural, near logical variation that could be causing it? We didn't know that in 1985.

"And so at that time, I think it was actually a little bit frightening. You know, were we really destroying our ozone layer? I mean, the measurements showing up through 1984, were going down really fast over Antarctica. I got to admit, you know, it was a few sleepless nights I had there, you know, working hard on the science. But you really don't know at that point."

Could the depletion of the ozone layer have caused an end to life on earth as we know it?

Paul Newman: "Well, yeah. We use UV radiation to sterilize things. Fortunately, we have an ozone layer that screens that solar radiation. That's an amazing thing. It's a fundamental critical gas to life on the Earth's surface. So if ozone is depleted, UV radiation goes up. Not only to get faster sunburns, more skin cancer, more cataracts, but crop yields began to go down. And that actually to me was one of the frightening aspects. What if you can't feed the planet?"

On the groundwork for the Montreal Protocol

Paul Newman: "There was some groundwork that had been laid. The Vienna Convention was signed in 1985, now the Vienna Convention, and it was a really important agreement. It basically identified ozone depletion as a problem. We needed to protect the ozone layer and it established what's called the Ozone Secretariat. This is a managerial organization for countries that were interested in this, and that Secretariat began to hold regular meetings of countries. And the third thing it did, it established a scientific framework. The idea of science scientists collecting from around the world to work on things was new. Before that, the United States had done their reports, the UK had done their reports, the Russians had done their reports.

"Nobody did this internationally. So it was a big step forward to do these international results. The second thing was there was a series of books that were written in 1985, and it's called Atmospheric Ozone, in 1985, and it's a huge set of volumes. And this really collected all the science together and fundamentally showed that ozone depletion was a problem.

"Now, the ozone hole came along and actually it turns out that the problem was a heck of a lot worse than what we were predicting in this collective scientific wisdom, these volumes in atmospheric ozone, 1986. So we found out that the problem was worse than we thought, but the science of ozone depletion was solid enough where the countries of the world figured, we better do something now."

On the common use of CFCs

Paul Newman: "CFCs were used in everything. You already mentioned the foam containers you put your hamburgers in, but it was also used in building insulation. It was used in refrigerators; it was used in air conditioners. You went to the supermarket and your food is cold because they had CFC running those refrigeration units there, all the trucks carrying around, delivering frozen foods and everything. They're all using CFC. Boy, when I was a young man, I had a car. It had an air conditioner I used.

"It was really, really widely used on a huge number of things. So changing was a big deal. The one thing that they had going for them is there were a number of technologies that were available to replace CFC. That was a big, big plus. ... You could use a different kind of gas to create your foam insulation. So that was the really positive aspect. Now, not everything ... had replacement technologies at the time. But I think the technologists, policymakers knew that if they implemented some rules, that engineers and technologists would begin to change how we did things as an industrial society. And in fact, that's exactly what happened."

On comparing the hole in the ozone layer to climate change

Paul Newman: "Climate feels a lot like ozone. It's a lot of science, huge consensus, kind of growing pressure to do something about it, not entirely clear what to do. It's very similar to the early days of the ozone policy discussions. I think the other reason is that the ozone accords, which are so successful and at the time were already known to be likely to be quite successful.

"They were really the model, people thought they were the model for what we were trying to do with climate change. And so the model ended up kind of going wrong and not being applied in the right way. But I think that this is a really, really important discussion to be having today, not just because the ozone layer is getting better, but because climate change is still there, and we need good models."

On public opinion on climate change

David Victor: "All these international agreements basically don't have enforcement mechanisms. They have some enforcement mechanisms here and there on the side. But what really enforces them is public opinion, public concern. And here I think there are some really interesting parallels that resonate. There's a massive public concern about climate change, not across the political spectrum, but a lot of the political spectrum.

"So you see a growing number of firms and governments that know they have to do something about this. They have to go find alternatives. They're doing exactly what happened in the Montreal Protocol in the early days, the ozone layer, which is we're doing the easy things first. So we're switching to renewables where they're less expensive already and other things that we're investing in new technologies. ... But that experimentation is underway right now, and a really big motivator for the experimentation is this concern that if you don't do things right by public opinion, that you're going to be shut out of the market or worse."

On tackling climate change

David Victor: "I'd say two things. First, passion is incredibly important. That's what forces change in the industrial system. But most focus that passion on finding solutions, because the more progress we make in finding solution in industrial solutions, then the more rapidly we can ratchet forward these commitments. That's the real, the really important lesson from the Montreal Protocol.

"As it was science along with that finding practical solutions. The other thing I'd say is we're making progress. 15 years ago we were on track for four or five degrees Celsius of warming in this century. Now we're on track for two and a half degrees. That's still a whole lot of climate change, but it's not four or five, and that's the real measure of progress. And by that metric, I think it's actually pretty impressive how well we're doing, and we have to do obviously a lot better."

This program aired on January 31, 2023.


Hilary McQuilkin Producer, On Point
Hilary McQuilkin is a producer for On Point.


Meghna Chakrabarti Twitter Host, On Point
Meghna Chakrabarti is the host of On Point.



Listen Live