I've heard that AC is responsible for the hole in the ozone layer

Whilst not true there is an element of truth in this story. Up until about fifteen years ago only luxury cars had AC in Britain; some Mercedes, BMW's, Jaguars, and the top models of the popular makes, such as the Ford Granada/Scorpio and the Vauxhall Senators. Rolls Royce had a nice system and cars that would otherwise be extremely hot and uncomfortable such as Ferrari, Lamborghini and Porsche had to have AC. Not only cars of course, over twenty years ago on the top-of-the-range Volvo lorries, AC was not even an option – it was a standard fitment. Many farm tractors and most combine-harvesters were also so fitted. They used a system much the same as today but the difference was they used a refrigerant popularly known as Freon.

Freon is a trade name but is properly called R12 and it is this refrigerant, which is a CFC, and the mis-use of it by the AC technicians of the day that is partly responsible for the problems in the ionosphere. This refrigerant (invented around 1932) was not only used in AC of course, every domestic refrigerator and freezer all over the world was filled with R12 as was every shop frig or freezer and also the walk-in chillers that butchers have and the huge coldstores that farmers use and the vast freezer warehouses that the processors and the supermarkets use. Food safety legislation over recent decades has forced the use of refrigeration into many areas of shops where they previously used just the display counters, one has only to notice the large number of chill cabinets in shops for cakes and sandwiches and cheese and milk and drinks and - the list is endless. Additionally there is now a large number of refrigerated lorries on the road where chilled or frozen food must by law be kept to set temperatures during delivery: take a look when you are next driving on a motorway and first look at the number of Tesco/Asda/Morrison/Sainsbury/etc lorries you see - almost every one is a reefer (refrig), then look at the number of similar artics used by the supplier companies, I'm sure you will be amazed at the extent of refrigeration in transport. Almost every application where refrigeration was needed you would find R12 or another similar refrigerant of the same family of CFC's, the use of it world-wide was huge. Every frig we the general public scrapped would have been broken up by the rag-and-bone man to recover the steel and copper and the R12 allowed to escape.

Hindsight is a wonderful thing and if we were able to put the clock back I'm sure that things would have been done differently, but, up until the mid '80s the best knowledge available said that the release of R12 into the atmosphere was safe. In those days, if there was a problem in the system, the refrigerant was released as not only was it thought to be safe to do so, it was relatively cheap and therefore the customer would benefit from a completely new charge of refrigerant with no possible contamination. One cannot blame the local Sainsburys for what was done on their behalf by the technicians of the day; with the knowledge available then they were doing what was thought right at the time. Now that we know that over a long period of time CFC’s break down and eventually damage the ionosphere most refrigeration is handled by a different family of gasses, thought to be safer! When a refrigeration or an AC system develops a fault the refrigerant is recovered and recycled - we have moved on.

R12 is now only used in the UK in AC in cars built before 1993 which have not been recharged since 2001 but it is not completely dead and buried however - although no longer used in car AC systems it is still widely used by Medicine and also by the Military (among other things it is used to cool the warhead in missiles I believe).

Whilst there is no change in the theory that CFC's are mostly responsible for the hole in the ozone layer new research in 2007 at NASA's Jet Propulsion Laboratory in Pasadena is showing that the breakdown of the chrorine molecule (dichlorine peroxide) was extremely low in the wavelengths available in the stratosphere and as such atmospheric scientists are saying that they now don't quite understand how ozone holes came into being. Nevertheless CFC's are still the main suspect for the problem.


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