The discovery of the Ozone Hole is announced - May 16th, 1985

On this day in 1985, the discovery of the Antarctic ozone hole was first reported in the scientific journal Nature. 

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Episode Transcript

Speaker 1 (00:00):
This Day in History Class is a production of iHeartRadio.
Hello and Welcome to This Day in History Class, a
show that demystifies history one day at a time. I'm
Gabe Lucier, and in this episode, we're talking about how

(00:23):
a scary discovery ultimately led to one of the greatest
environmental success stories of the modern age. The day was
May sixteenth, nineteen eighty five. The discovery of the Antarctic

(00:44):
ozone hole was first reported in the scientific journal Nature.
The landmark paper was written by three scientists from the
British Antarctic Survey, Joe Farman, Brian Gardner and Jonathan Shanklin.
Using a device called adopsin spectro photometer, the team had

(01:04):
been able to analyze the amount of ozone over the
South Pole, and the results were not good. The ozone
levels they detected were abnormally low in recent years, indicating
severe damage to the Earth's atmosphere and a palpable risk
to everyone who lived within it. Ozone, also known as trioxygen,

(01:26):
is an inorganic molecule that absorbs ultraviolet radiation. It's mostly
found in the planet's stratosphere, a layer of the atmosphere
between four and thirty miles above the surface. The part
of the stratosphere with the highest concentration of ozone gas
is called the ozone layer, and it acts as a

(01:47):
kind of invisible shield for the planet. That's because it
absorbs nearly all of the Sun's medium frequency UV rays,
harmful radiation that would otherwise reach the Earth's surface and
do serious damage to plants, animals, and humans. Put simply,
without the filtering effects of the ozone layer, life on

(02:09):
Earth would not be possible. That grim reality was likely
top of mind for the three scientists who found a
hole in the ozone layer. The organization they worked for,
the British Antarctic Survey, had been monitoring the ozone layer
since the late nineteen fifties, but no one realized it
was thinning until decades later. Farman, Gardener, and Shanklin finally

(02:34):
discovered the problem after noticing a drop in ozone concentrations
above Antarctica over the course of several years. They compared
the measurements of recent years with those of decades past
and found that ozone values had actually been dropping steadily
since the mid nineteen seventies. The team's conclusion was that

(02:55):
something in the stratosphere was destroying the ozone and had
an alarm rate too. According to the data, the Antarctic
ozone hole had formed in less than a decade and
was growing larger each year. The speed of the ozone
depletion pointed to human activity as the culprit, and thanks
to prior research, the bas scientists had a pretty good

(03:18):
idea of where to lay the blame. A decade earlier,
in nineteen seventy four, scientists Mario Molina and F. Sherry
Roland published a paper theorizing that chlorofluorocarbons, or CFCs, could
be harmful to Earth's ozone layer. The chemicals in question
had always been considered harmless. In fact, they were widely

(03:41):
used in all kinds of household appliances and products. Molina
and Roland suggested there was a hidden environmental danger to CFCs,
but at the time few people believed them. Large corporations
aggressively disputed the claims, insisting their products weren't harmful to
the environment. Some scientists contested the claims as well, while

(04:03):
others minimized them, claiming that if there was ozone depletion,
it would be minor and would only worsen over the
course of centuries, if not longer. Once the idea of
caution had been fully tossed aside, the use of CFCs
grew exponentially, and so too did the damage to the
ozone layer. Products with CFCs were sold all over the world,

(04:28):
and when those products were used, the chlorofluorocarbons they contained
were released into the atmosphere. The chemicals would then get
trapped in clouds which form over the Antarctic during polar winter.
Then when sunlight returned each spring, the rays would trigger
catalytic reactions in the airborne CFCs, and a small amount

(04:49):
of ozone would be burnt up in the process. The
accumulation and destruction of ozone and CFCs was a cycle
that played out each year, but when humans began releasing
more CFCs than ever before, we started burning off ozone
at a faster rate than it could be replenished. In fact,
it was later determined that those springtime reactions between the

(05:11):
mid nineteen seventies and eighties had destroyed ozone at a
rate of about one percent per day. The BSA's findings
were published in the Nature Scientific Journal in May of
nineteen eighty five. Not only did the team's paper present
evidence of the ozone hole's existence. It also suggested a
link to CFCs. NASA backed those claims a few months later,

(05:35):
after one of its atmospheric scientists captured satellite imagery that
clearly showed the ozone hole. Other researchers later confirmed that
CFCs were indeed responsible for the annual depletion of ozone.
The news came as vindication for the work of scientists
Molina and Roland, both of whom were eventually awarded the

(05:55):
nineteen ninety five Nobel Prize in Chemistry. Still, for everyone
else on the planet, confirmation of a gaping hole in
the ozone layer was pretty bad news. The ozone depletion
was happening much faster than anyone could have guessed, and
the bigger the whole grew, the more dangerous it would
become due to the increased levels of radiation that would

(06:17):
pass through it. Scientists projected that if the whole were
allowed to grow unchecked, there would be a drastic rise
in skin cancer and cataracts, as well as a severe
disruption of plant growth and a steep decline in marine
life reproduction. The threat of rampant disease and dwindling food
sources spurred the international community to take action in a

(06:40):
way rarely seen before or since. The uncharacteristically proactive response
was likely due to the relative ease with which the
problem could be solved. All we had to do was
stop producing and using CFCs, of far simpler prospect than
giving up something like fossil fuels, for instance. It was

(07:01):
so feasible, in fact, that just two years after ozone
depletion was brought to the world's attention, forty six nations
pledged to phase out the substances known to cause it.
The agreement was called the Montreal Protocol, and it included
steps to control, reduce, and eventually eliminate the production and
use of CFCs and other ozone depleting chemicals. Former UN

(07:26):
Secretary General Kofi Annon famously described the protocol as quote
the single most successful international agreement to date, and all
these years later, it's hard to argue with him. The
Montreal Protocol was ultimately signed by all one hundred and
ninety seven members of the United Nations, making it the

(07:47):
first treaty in the organization's history to be adopted unanimously.
As a result of that worldwide cooperation, scientists now predict
that the ozone layer will return to its pre nineteen
eighty levels before the end of the twenty first century.
It'll take that long for the ozone layer to replenish
itself because CFCs tend to have a rather long lifespan,

(08:10):
with some persisting in the atmosphere for up to one
hundred and fifty years. So even though ninety eight percent
of ozone depleting chemicals were phased out of production by
two thousand and nine, there are plenty of older ones
still up there destroying ozone. As we speak in the
grand scheme of things, one hundred years is a pretty

(08:31):
rapid recovery. But don't forget that century long healing process
is in response to a wound that only took humans
about a decade to self inflict. That unbalanced equation is
a big reason why experts are so concerned about climate change.
Humans have been contributing to global warming for far longer

(08:51):
than it took us to punch a hole in the
ozone layer, and we haven't been nearly as resolute about
changing our harmful behavior. The to that problem, if it's
not too late already, will be much more difficult than
finding alternatives to CFC's but if the Montreal Protocol teaches
us anything it's that where there's a will, there's a way.

(09:14):
That said the clock is ticking, so here's hoping we
find that will sooner rather than later. I'm Gabe Bluesier
and hopefully you now know a little more about history
today than you did yesterday. If you'd like to keep
up with the show, you can follow us on Twitter, Facebook,
and Instagram at TDI HC Show, and if you have

(09:38):
any comments or suggestions, you can always send them my
way by writing to This Day at iHeartMedia dot com.
Thanks to Chandler Mays and Ben Hackett for producing the show,
and thanks to you for listening. I'll see you back
here again tomorrow for another day in History Class