That hole in the ozone layer

It’s the 1980s, and Antarctic research wasn’t feeling all that loved. Research stations had been set up in the late 1950s in a wave of Cold War enthusiasm. But a few decades on and people were starting to wonder what the point was.

As one scientist with the British Antarctic service, Joe Farnam, described it in a British Library record of their work, there was a general sense that scientists had been down there measuring stuff for decades, and maybe they didn’t need to bother any more: “You know, an awful lot of people say, oh, you’ve measured this for so many years, do you really need to keep on doing it?  Well, what can you say? I mean you can’t say, oh, but keep doing it for another twenty years, you’ll find an ozone hole [laughs].” 

But they did keep measuring.

And they did find a hole in the ozone layer.

Kinda of.

[NOTE: the story of the ozone layer isn’t, by everyone’s definition, part of the history of climate change. But their stories intersect a bit, so I hope you’ll excuse me the slight deviation. If you want an explainer on the distinction between the ozone layer and global warming, Nasa has a great one.]

Let’s wind back a bit, and say a bit about WTF ozone is anyway. Normally, it exists as a pale blue gas, but if you can get cold enough to solidify, it turns dark blue, finally violet-black. It’s a form of oxygen – O3, compared to the standard O2, because it’s made up of three oxygen atoms. It whiffs a bit – a bit like chlorine – and was first found in 1785 when a Dutch chemist, Martinus van Marum, was messing about shooting electricity above water, and found it created something a bit stinky. A few decades later, German-Swiss chemist Christian Friedrich Schönbein noticed a similar stench after a bolt of lightening and, after successfully isolating the chemical in 1839, named it ozone after the Greek word ozein meaning ‘to smell’.

The thing we call the ozone layer was discovered in 1913 by French physicists Charles Fabry and Henri Buisson as they tried to work out why radiation sent out by the sun was different from the radiation that ended up on Earth. Something must be absorbing the missing ultraviolet radiation. British meteorologist GMB Dobson, while exploring how meteors travelled through the atmosphere, worked out that there must be a layer that’s especially hot, and figured out this was the sun’s ultraviolet radiation heating up ozone. He developed an instrument for measuring ozone – the Dobsonmeter – and, working between the 1920s and 1950s, set up a network of ozone monitoring stations around the planet.

This layer of ozone is pretty important to our ability to live on Earth. It’s often gets discussed in terms of saving us from cancer. That’s part of it, but not all. The ultraviolet radiation the ozone absorbs could harm animals too, and can reduce crop yields. If we lost the ozone layer entirely, ultraviolet radiation could steralise the Earth's surface. (If you want an intro the chemistry of the ozone layer, there’s a great Nasa booklet).

For a lot of the 19th and 20th centuries people seemed to think ozone was good for you – you sometimes read about people being sent to the seaside to breathe the ozone in old books. But if anything, today, we should be aware that it's a reasonably harmful pollutant. A major component of smog, ozone gets created when sunlight sparks chemical reactions with nitrogen oxides (e.g. from cars) and can cause major damage to lungs and plants. On the ground = bad. Up in the sky = yay, useful!

Concerns that we might be damaging the ozone layer started in the 1970s – could the exhaust from spaceships harm the make up of the stratosphere? That’d put a shitter on the Space Race.

But it soon turned out that the main danger was a lot more prosaic – hairspray, fridges and shaving cream. In 1974, chemists Mario Molina and Sherwood Rowland published a paper in Nature on the theatre that chlorofluorocarbon (CFC) gases could have on ozone. Not long before, James Lovelock had developed an apparatus for measuring CFCs, and established that these exclusively man-made gases had already spread globally throughout the atmosphere. Molina's and Rowland's research led to some restrictions on CFCs, and some further research. They also got the Nobel Prize in 1995, but that’s rushing a bit ahead of ourselves.

Nasa researcher Pawan Bhartia started working on the ozone layer in 1977. As he describes it, when they got satellites to study the ozone layer (satellites named Nimbus-4, Harry Potter fans) in 1970, it was mainly just ‘curiosity driven research’ – something just for the sake of knowing. By the time Nimbus-7 was launched in October 1978, it was a hot topic, and there was a lot of political pressure on scientists to get a better sense of what was going on up there. Should we be banning CFCs, or was this Molina and Rowland stuff just scaring us all unnecessarily?

The real shock came in 1985 though, with the discovery of an especially thin patch in the ozone layer – the thing we’d now call the hole.

And this is the point I should let you know there’s isn’t really a hole, as such. (The Earth’s not really round either, sorry.) It is maybe better described as a bit of a graze, or just a slight thinning.

Who exactly we can credit with dreaming up the phrase ‘a hole in the ozone layer’ is unclear. According to Joe Farnam, it turned up in the pages of the Washington Post, possibly via a Nasa press release, and no one really owned up to coining it. According to other reports though, it was Sherwood Rowland.

Whatever the history of the term, it stuck, and we can probably thank that anonymous Nasa press officer/ Prof Rowland for such a powerful metaphor. If we follow the idea that metaphors structure our thinking, it’s easy to see how a hole invites us to actively try to fix something. In contrast, we think of a graze as gradually healing itself, or a thinning patch of hair as irreversible.

Back to the discovery of this ‘hole’.

Nasa satellites weren’t the only people interested in the topic. A load of scientific bases had been set up in the Antarctic in the 1950s, as part of the International Geophysical Year, and one of the things they measured was ozone. By the 1980s, the justification for keeping these research stations was getting more and more shaky, especially with the context of massive government cuts back in the UK. As Joe Farnam describes it, there was a general sense that scientists had been down there measuring stuff for decades, and why would they need to keep on doing it. There wasn’t a universal acceptance of a need for on-going, continued data collection: “You know, an awful lot of people say, oh, you’ve measured this for so many years, do you really need to keep on doing it?  Well, what can you say? I mean you can’t say, oh, but keep doing it for another twenty years, you’ll find an ozone hole [laughs].” 

When, in the early 1980s, Farnam and his team started reading a drastic drop in ozone levels about the south pole, their first instinct was to blame the equipment. Surely the experiment was wrong? By they tried again, and got the same results came up.

After a few years of further research and careful analysis, the team were eventually convinced not only of the thinning of the ozone layer, but that it had been caused by CFCs. Deciding they must publish as soon as possible, the team popped a paper in the post to Nature on Christmas Eve. It was far from settled though – these sorts of extreme claims always inspire push back – and the head of Farnam’s division tried to suppress the paper, writing to the Met Office that he was worried that it'd just lead to embarrassment if it all turned out to be an error.

Around the same time, satellite data from Nasa also spotted this ‘hole’ and, in the words of Pawan Bhartia “all hell broke loose, particularly in the media”. One campaigner described it to Newsweek as “like AIDs from the sky" (arguably, a much less helpful metaphor than describing it as a hole).

Bhartia was slightly surprised by the impact the research had: “the significant ozone loss was not happening in areas where people were living. It was occurring mostly over Antarctica. There are penguins there, but no human beings, and it happens for only two months a year. Regardless, it had a huge impact on people.”

By 1987, there was an international agreement to phase out the production of substances harmful to the ozone layer, aka, the Montreal Protocol.

The Montreal Protocol was unusually successful for a global agreement. People signed up for it – lots of people, and reasonably fast. And then it didn’t all fall apart when a new President was elected or anything either. CFCs didn’t disappear entirely, or overnight, but they have greatly reduced, and it seems to be making a big difference to the ozone layer. Research last year that the hole had shrunk by more than 1.7 million square miles since the turn of the millennium and could be ‘healed’ by 2050, a change they could put down to the success of the Montreal Protocol. As New York Times puts it, it was the little treaty that could.

Why? We should remember that people had been building up for it for a while – Nasa already felt it was a hot topic. The data that popped up from the Antarctic base and the satellite was crucial, and it ended up turning up on the world stage with some drama, but it wasn’t entirely out of the blue. It’s not as simple a case as Nature published a paper and Nasa ran a press conference and BOOM global policy. Things are never that simple.

There’s a theory that Reagan allowed it to pass because he had skin cancer, or he just loved nature. Several people also argue that it wasn’t that hard to shift from CFCs – at least compared to the challenge we have in terms of quitting oil – and companies could sell products labelled ozone friendly, helping customers to feel good about themselves and, ultimately, boost sales of stuff no one needed in the first place. Plus the PR gods were aligned – rightly or wrongly, the media and public were spooked by this idea of a hole in our atmosphere. And on the topic of PR, never discount the power of saying something causes cancer.

Humanity’s ability to spot the hole in the ozone layer and work together do something about it is often touted as a sort of inspirational case study for climate change action. We should remember that for all that both issues involve stuff in polar regions and apparently-invisible harm humans are doing to stuff up in the sky, they are slightly different issues, and the problem of climate change is much bigger and more complex. Still, it’s inspiring, it’s interesting, and there are similarities. It’s a story people interested in climate action should at least know.