Chlorofluorocarbons. CFCs.

The word doesn’t roll off the tongue – and it would be safe to say that before the eighties it was not a topic for common conversations at dinner parties. But in the eighties, we all suddenly became experts on CFCs and ozone holes.

Before we understand why, we need to go back to the beginning.

The ‘father of the refrigerator’ was Jacob Perkins who received a patent for a vapor-compression cycle using liquid ammonia in 1835. The liquid chemicals used in a refrigerator are called refrigerants and, to be effective, they need to satisfy several specific criteria including having a low boiling point.

Unfortunately, early refrigerators were appallingly risky because they used dangerous gases that were flammable or toxic or highly reactive – and they sometimes leaked.

Thomas Midgley set out to find a safer option and in 1930 US patent number 1,930,129 was granted for the manufacture of aliphatic fluoro compounds – or what we now refer to as chlorinated fluorocarbon. He demonstrated the effectiveness of his invention when he inhaled a large amount of the gas and then blew out a candle, showing it to be non-toxic and non-flammable. The substance was marketed commercially by Du Pont under the brand name Freon.

Freon and other CFCs soon largely replaced dangerous refrigerants and many other applications were found for the new inert gas with a low boiling point – such as propellants from items as diverse as aerosol cans to asthma inhalers and fire extinguishers.

The Society of Chemical Industry awarded Midgley the Perkin Medal in 1937 for his work with CFCs. And there ends a story of scientific discovery and progression in our society.

Except for a sting in the tail.

Fast forward forty years. James Lovelock used a sensitive instrument he had designed himself to test for the existence of CFCs on the west coast of Ireland. His hypothesis was that the haze in the air was caused by winds that blew pollution from the urban areas. If the haze was caused by pollution, it would contain larger concentrations of synthetic chemicals. CFCs would be part of this mix so he tested for the existence of CFCs. He detected CFCs in the air on hazy days and therefore confirmed its human-made origins.

Case closed.

But as any good scientist, he didn’t just accept the initial results. He kept testing. And the results on clear days did not match his hypothesis. When the air was coming from the Atlantic with not an urban area in site, CFCs should be close to undetectable. They weren’t. On pristine days, Lovelock was still able to detect CFCs. This started Lovelock along a different line of thinking. Were CFCs building up in the atmosphere everywhere?

Lovelock took his instrument on a sea voyage from England to Antarctica and took measurements along the way. Wherever he travelled, he found CFCs. Not a lot – but more than were expected. He found about 0.06 parts per million of CFC-11 in the atmosphere.

He presented his findings at a scientific meeting in 1972 and, while interesting, concluded that the level of CFCs constituted “no conceivable toxic hazard” despite the fact that practically all of the CFC-11 ever manufactured was still present in the atmosphere.

But the wonderful thing about science is that knowledge is cumulative. The dwarf can see further by standing on the shoulders of giants (nanos gigantum humeris insidentes) and two researchers, Sherwood Rowland and Mario Molina, wanted to further research the fate of CFCs in the atmosphere. When Midgley first set out to find a new refrigerant, he was looking for a compound that was inert so there should be no reaction with a CFC and the data from Lovelock basically confirmed that this was the case. That was in the lower troposphere. What happened when CFCs drifted up into the stratosphere?

CFCs would take some time to drift up as they are heavier than air. Air has an average molar mass of 28.97g/mol but CFC-11 comes in at 137.37g/mol. Despite this the atmosphere is a moving, living, dare I say it, breathing environment and gases are mixed together. Rowland and Molina calculated that CFC molecules would, over decades, wind up in the stratosphere where UV radiation would potentially split off chlorine atoms. Each chlorine atom would react immediately with an ozone molecule, they hypothesised, setting off a chain reaction that would destroy thousands of ozone molecules.

Their first paper that linked stratospheric CFCs and ozone depletion was published in 1974. It took twenty-one years but that paper would eventually earn them a shared Nobel Prize.

Rowland and Molina believed that the only solution was to ban the production of all CFCs immediately. Even if that occurred, ozone loss would go on for years. If CFC production continued, the ozone loss would be even greater.

Other scientists conducted further research testing the original hypothesis. Data and information varied with different testing methods and as scientists focused on different areas. Modelling showed varied timelines for different percentages of ozone being destroyed. One thing seemed certain – despite the variations it was clear that CFCs were damaging the environment.

Not surprisingly, there were some that weren’t convinced that a ban on CFCs was the right action. Even less surprisingly, many were engaged in industries that relied on the production and use of CFCs. This was not a small industry. It was estimated that in 1974 industries relying on CFC production generated US$8 billion ($41.2 billion in current terms) and employed 200,000 people.

CFC manufacturers were trying to cast doubt on the scientific validity of the hypothesis in any way they could.

“It is just a hypothesis,” they said.

“There is only flimsy evidence,” they continued.

“There is no proof the molecules would ever reach the stratosphere,” with the seemingly logical argument of the heavier than air weight of CFCs.

“Stratospheric ozone concentrations fluctuate naturally by geography and by season so any detected changes are just natural,” again seemed quite logical as there are natural oscillations.

“CFCs should be regarded as innocent until proven guilty,” was another line.

“812,522 tonnes of CFC compounds were produced in 1974 but the Earth’s atmosphere is 6.3 billion times more massive. How could 0.000000016 per cent of the atmosphere have any negative impact,” was another seemingly plausible argument put forward.

The industry even brought in their own expert to challenge the ozone depleting properties of CFCs with a sponsored speaking tour for Professor Richard Scorer, well-known for his research on pollution.

The fact that CFCs were seen to be such a highly useful class of chemicals and, particularly in refrigerators and air conditioners, no obvious alternatives existed, made it much harder for support of widespread bans. So the world continued to produce CFCs.

The scientific community realised, possibly for the first time, that our activities could impact Earth’s environment on a planetary scale. It didn’t matter where the CFCs were emitted, it was a global problem.

The US was the first to act. On 11 May 1977 the US government announced a timetable for phasing out of CFC in aerosols. Several countries followed suit. The ozone level was also going to be monitored more closely. World production of CFCs started to drop – but then started to grow again. Within ten years, the annual production had surpassed the 1974 level and was still rising. Molina and Rowland were advocating – still – for a total ban on CFC production from all sources. The impact of continued production would not be felt for many years, but they would be felt. Policymakers the world over were lagging with any significant response.

Now jump to 1984 and move to the cold climes of the Antarctic. More specifically the Halley Bay Station of the British Antarctic Survey. The levels of ozone above the Antarctic had been measured for decades yet in 1984 the scientists found that stratospheric ozone above the Antarctic had decreased dramatically. In September, in particular, when conditions were just right for CFCs to cause ozone depletion, the level of ozone was reduced by a massive forty per cent. The results were published in May 1985 specifically in relation to the ozone ‘hole’ above the Antarctic – which was later backed by NASA – and further studies showed that the average ozone level across the rest of the planet had decreased by possibly up to three per cent.

Without the continued protection from the sun’s UV rays that stratospheric ozone offered, skin cancers would start to increase and many organisms would start to suffer genetic damage. If the ozone levels continue to be depleted, life on this planet would cease to be sustainable.

Finally…Finally governments put aside the short-term economic impact and looked at the future of the planet.

When there is the desire, the world can move swiftly to solve a problem. By 1987, the Montreal Protocol was agreed to by 56 countries. CFC production would be cut in half by 1999. Three years later this target was updated when a gathering in London saw 93 countries sign a treaty agreeing to phase out CFCs completely by 2000. Over the next two years more results indicated increasing ozone depletion hence the elimination date for CFCs was moved to 1996.

Today the spray paint and deodorant sitting on shelves is CFC-free. New refrigerators and air conditioners are using alternative refrigerants. The work of Rowland and Molina and countless other scientists was justified and acknowledged by the wider community. With the CFC-ban now in place, atmospheric levels of chlorine are beginning to decline and the ozone level is on the way to recovery. A full recovery is expected by 2070 – almost one hundred years after the impact of CFCs was first discovered. With hindsight it is easy to say we should have acted sooner but the world finally came to an agreement and we are on the way to recovery. The whole story does show how incredibly rapidly we can produce major changes to our atmosphere with seemingly small inputs and how long it can take nature to recover. Remember that ozone only makes up approximately 0.00006 per cent of our atmosphere and its peak concentration occurs at an altitude of 32km above the earth’s surface.

Most importantly the world learned a few lessons and will obviously never repeat the same mistake…or…or is it already doing just that?

I am actually incredibly confused by the approach of governments across the world to ban CFCs. Not because it wasn’t the right thing to do. Not because the evidence wasn’t there. Not because it avoided a cataclysmic event that would end life on this planet as we currently know it.


I am confused because we acted in a relatively short timeframe to resolve a world issue in relation to CFCs, but when a much larger potential threat looms across the planet in the form of climate change, we seem to be ignoring all the lessons from our near-miss with CFCs and continue blindly doing what we have done for over a century. What makes it even worse is that when the negative impact of CFCs was first discovered, one of the hardest issues to resolve was to find a suitable alternative.

With climate change we have the facts, we have the research, we have the data, we have the alternatives but we just don’t seem to have the will. At least governments, in particular Australian governments, don’t seem to have the will.


I could speculate that the US$1 trillion global coal industry and the US$2 trillion oil industry significantly dwarf the size of the CFC industry when it was threatened. I could further speculate that we have seen evidence of sophisticated misinformation campaigns by companies such as Glencore Coal with Project Caesar which used the C|T Group to run a vast, secret communications campaign over a two year timeframe aimed at shifting public and government attitudes towards coal – at a cost of up to £7 million per year.

These reasons do seem somewhat feeble though compared to the threats that climate change is posing to our worldwide US$80 trillion economy and the lives and property that are already being lost. I just can’t see why we aren’t taking urgent and immediate action at every level.

I go back to my first question. Why did we bother to ban CFCs when all it seems to have done is delay the inevitable destruction that we will wreak on our only home?

Why bother fixing one puncture in our car if we are just going to continue to drive with a flat tyre the next time we get a puncture and destroy the rim.



I don’t know why. Does anyone?

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