We all know about the ozone layer don't we? It's the thing that stops us all
getting skin cancer from exposure to ultraviolet light isn't it?
And we all know that back in the 80's, when damaging the environment was all the rage,
we managed to fill the atmosphere with chemicals that blasted a massive continent-sized hole in
the ozone layer and our scientists had to explain to our politicians that if we didn't stop doing
that then they and their children would die along with most other organic life forms on the planet.
That seemed to do the trick. Our politicians all agreed to ban the chemicals that were
causing the problem. The chemical companies all found a safer alternative to use instead. The
hole in the ozone layer went away, and all life on Earth was saved. The end.
Hello and welcome to Just Have a Think. If only life was as simple as I just described it, eh?
What I said was partly true to be fair. Scientists really did identify the chemicals that were
causing the ozone problem and politicians really did work together to get them banned. But the rest
of it isn't quite as cut and dried as I made out. Let's rewind a bit and take another look.
Ozone is a gas made up of three oxygen atoms. The majority of it can be found in our planet's
Stratosphere which is an atmospheric layer that starts about eight miles above the surface and
goes right up to about 30 miles high. The really handy thing about ozone is that it absorbs the
harmful ultraviolet radiation reaching our planet from the sun. If the ozone layer wasn't there then
the sun's rays would effectively sterilize the planet and all life forms would get fried. And
that would be inconvenient! By an unfortunate twist of fate, way back in the early part of
the 20th century, some very clever engineers discovered that they could replace extremely toxic
gases like ammonia and methyl chloride in first generation refrigerators and air conditioners
with a new class of gases that were apparently completely harmless to living things. Those same
gases made excellent propellants in things like aerosols because they could be pressurized into
containers and would expand rapidly on exposure to the air. That's exactly what you want if
you're spraying your armpits or freshening up your lounge or zapping some bugs or any number of other
applications where a rapid jet of atomized fluid is required. And it turns out there were an awful
lot of applications, not just in domestic homes but in all sorts of industries too.
These new wonder-gases were called chlorofluorocarbons or CFCs. As the name suggests
they contain chlorine. And it just so happens that chlorine reacts very readily with ozone.
The world wasn't aware of that at the time though, so as far as we knew there was no need
to be particularly careful about the way we filled up our cooling systems or aerosol cans with CFCs,
or how we disposed of the units when they reached the end of their operational lifetimes.
The result of that collective ignorance was the release of truly industrial quantities of
chlorofluorocarbons up into our atmosphere for several decades. Meanwhile, down at the South
Pole, as winter approaches each year a very strong wind starts to revolve around the vast continent
of Antarctica. It's a polar vortex just like the one that Northern Hemisphere weather people
are always telling us about above the North Pole during the winter time up here. And as
Antarctic winter temperatures drop down to about 78 degrees Celsius below freezing very specific
cloud formations begin to bubble up in the polar Stratosphere which are, unsurprisingly, called
polar stratospheric clouds. Those conditions are typically still there right into late winter and
early spring as the Sun starts coming back around to add its UV rays into the mix.
So what's that got to do with CFCs then? Well it turns out that the Antarctic polar vortex
and polar stratospheric clouds are really good at trapping in large concentrations
of those CFC gases which can then be broken down by the strengthening springtime sunlight.
The liberated chlorine is then free to steal one of the atoms from ozone molecules,
leaving behind oxygen which doesn't absorb UV light. That reaction keeps happening as long as
those atmospheric conditions prevail until the ozone eventually disappears completely. So each
winter a larger and larger ozone hole was forming above Antarctica. As the seasons progressed into
spring and summer the polar vortex would break down, the ozone depleted air would
drift away to form part of the general planetary atmosphere, and the hole would close up again.
The ozone depletion didn't go away though, it just got more spread out. Our 1980s scientists
discovered this localized phenomenon during scientific research expeditions to the South
Pole. They also found that one chlorine atom can destroy a hundred thousand ozone molecules
and that CFCs can survive in the atmosphere for more than a hundred years. So it was pretty clear
that if immediate action wasn't taken on a global scale the entire planet's atmosphere was at risk
of ozone depletion within decades. All of that led to the historic Montreal Agreement of 1987, which
banned the use of CFC gases and which has now been signed by every single nation on the planet.
Within the space of only four years the entire global chemical industry had switched from
chlorofluorocarbons to hydrofluorocarbons or HFCs, which contain no chlorine and don't destroy the
ozone layer. There was a slight further wrinkle when we discovered that HFCs are an extremely
powerful greenhouse gas, so in 2015 the Montreal Agreement was updated with something called the
Kigali Amendment which led to the phase out of HFCs as well, but thank goodness the initial
problem was discovered when it was and dealt with quickly because even now, decades later,
those long-lived CFCs from the 20th century are still present in our atmosphere and they're
still being released from very old scrapped refrigerators and other CFC filled containers
in badly managed landfills. So even after more than 30 years we still see a very large ozone hole
forming over Antarctica every winter. Imagine what state we'd be in now if our politicians
had failed to act back then! This analysis, published by the U.S National Oceanic and
Atmospheric Administration or NOAA in September 2022, tells us that the overall concentration of
ozone depleting substances in the mid-latitudes has now fallen by more than 50 percent. But the
report also finds that the pace of reduction over Antarctica has been much slower with only
a 26% decline to date. NOAA's global monitoring laboratory senior scientist, Stephen Montzka,
said "It's great to see this progress. At the same time it's a bit humbling to realize that science
is still a long way from being able to claim that the issue of ozone depletion is behind us." Which
I guess reiterates just how important it was that the world took urgent action when it did. So,
how come our government acted immediately and effectively 35 years ago when they were alerted
to the medium and long-term consequences of releasing chlorofluorocarbons into the atmosphere
but didn't act in the same way 35 years ago when they were alerted to the medium and long-term
consequences of releasing greenhouse gases into the atmosphere... "that the Earth is warming by
an amount which is too large to be a chance fluctuation represents a very strong case in
my opinion that the greenhouse effect has been detected and it is changing our climate now"...
after all the science of accelerated atmospheric warming due to human emissions of greenhouse gases
is just as clear and uncomplicated as the science of ozone layer depletion. It can be
measured and quantified just as easily, and its effects are just as scientifically demonstrable.
Well firstly, the consequence of ozone depletion was very easy for us all to
understand. The perception in the collective public psyche at the time was that without an
ozone layer we'd all get skin cancer. It was an immediate and very tangible existential threat.
And of course as soon as you mention cancer people tend to stand up and demand action.
Secondly, governments could see that the problem was global not local and
that unless all nations applied the same remedy the problem just wouldn't go away.
Thirdly, and probably most significantly, it was easy for industry to find alternatives to
CFCs. That meant that manufacturers were able to almost seamlessly move from the old gas to
the new replacement with virtually no upheaval and no threat to their long-term business model.
By contrast, a warming atmosphere was a much harder concept to convey to people back in
the 80's... "because the effects occupy more than a human generation there is a tendency
to say that they are not our problem. Of course then they are nobody's problem"...
there was no perception of an immediate threat like skin cancer. Instead it required the ability
and willingness to think ahead logically to a far-flung future time, perhaps as far away
as their 2020s, when the runaway effects of climate change would really start to kick in.
And that simply wasn't close enough to home to motivate the public into action.
That public inertia wasn't helped by the fact that our governments simply couldn't agree on
the global nature of the predicament or the scale of action required to fix the problem.
But arguably the biggest difference was that, unlike the relatively easy fix of swapping
out one refrigerant gas for another inside the same machines on the same production lines to
repair the ozone layer, reversing climate change required the rapid phase out of fossil fuels and
a huge ramp up of low carbon alternatives like hydropower, geothermal, nuclear and renewables
like wind and solar combined with a global move away from internal combustion engine vehicles
and towards electrically powered replacements. And that scenario was simply not acceptable to
the people who ran the fossil fuel industry. So we got all the false reporting, PR campaigns, billion
dollar political lobbying, and professional denialism that are now so well documented. If
you've got access to the BBC's iPlayer then I'd urge you to have a look at their recent
three-part documentary on the subject. And if you want an especially comedic potted history of just
how insane the fossil fuel propaganda machine was and still is, then you can click up there
to watch Rollie Williams' video all about it for his channel Climate Town. It's well worth a watch!
So our Global hooliganism continues, and the conditions that make our little planetary
playground safe continue to worsen. As the cliche goes, it's very much like a lumberjack using
his favourite chainsaw to chop off the branch he's standing on - it's just not a smart move!
Before I go I just want to give a big shout out to a brilliant new YouTube channel called
Planet Proof, which casts a critical eye over the brands that we use in our everyday lives to assess
how well or otherwise they're taking their climate and environmental responsibilities. The videos are
extremely well researched and very professionally produced so I recommend you check them out.
Getting a new channel up and running on YouTube is not an easy thing to do nowadays, so if you
can give them your support by subscribing to their channel, I'm sure they'd be very grateful.
That's it for this week though. A massive thank you, as always,
to our fantastic Patreon supporters who help me maintain the channel's Independence and keep all
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very much for watching. Have a great week, and remember to just have a think. See you next week