Good News About the Ozone Layer

The UN scientists who undertook the "Scientific Assessment of Ozone Depletion 2010" have stated that the Montreal protocol of 1987, when 196 countries phased out the use of CFC's has meant that 2010 is really the first year when the thinning of the ozone layer, which led to the "hole" over the Antarctic discovered in the 80's - has not increased, but not yet decreased either. Hopefully this reduced level of CFC's means that the worst of the damage has been prevented. And that a concerted collective effort to curb a pollutant has been (so far) successful.

The CFC's creating the hole in the ozone layer was one of the most famous popular environmental focal points of the 1980's, yet was and still is rather misunderstood by many. It was a tragic tale of a very promising bunch of compounds having the ability to unleash a terrifying chain of events under the right conditions, which would lead to one of the most surprising examples of scientific unforeseen consequences. The hole in the ozone layer was a big concern in the 80 and 90's and led to Montreal being enacted to curb but not fully stop CFC's as well as things like freon and halon fire extinguishers dumping this stuff into the stratospheric ozone layer. As I said it does still remain a not well understood phenomena in parts of the lay population. The hole (it is actually more of a zone of depleted ozone, than a literal hole in the sky.) is sometimes blamed on man made climate change, whilst it is really a different topic altogether. Though the two do have some interlapping points, which really take us on other trajectories elsewhere. Was this why the Daily Star proclaimed that this story "proved" Global warming [their words] was just "hot air"? Many of the comments on the Expresses report of the story seem to confuse the two issues as one. So what is all this ozone malarkey then?

This will be only a summary of what the "ozone thingy" is all about. I mean who the hell am I, a bloody science teacher? About 20 to 30 kilometers up, in the stratosphere there is a diffuse band housing 90 percent of the planets ozone in a layer called the ozone layer. Ozone is essentially 3 chemically linked oxygen molecules, rather than the two linked ones you normally get in atmospheric oxygen. At this height the thinner air allows more UV radiation to saturate the molecules up there. This means that the UV can slice individual oxygen molecules off which attach to other paired up oxygen molecules, creating ozone. This ozone is also chopped up into normal oxygen by UV, which can then have other single molecules latch on and create some more ozone. This effect, with its interactions - also has the useful ability to shield the surface (and all us lot) from the most harmful levels of UV radiation such as UVC and the most dangerous wavelengths of UVB, so we get suntans and plant food, and not cancers and sterilized single celled lifeforms. A natural radiation shield that stops us getting zapped by our own suns less welcoming side. The molecules being chopped and shifted in the layer mean that it is constantly seeing ozone created then destroyed, then created again, all in a level of finely tuned equilibrium, and it is this equilibrium where CFC's do the damage.

CFC's or chlorofluorocarbons (or bromocarbons) were created in the late 19th century for use as refrigerants and propellant gasses and expander aerosols. They were initially seen as the saviour of this kind of chemical product. They took over from stuff that was either flammable or poisonous or both together. CFC's were neither. By using halogens rather than hydrogen bonded to carbon, they didn't burn, and lacked the unpleasant properties of older stuff used fo their new purposes. They were also very stable, well they were down on the ground. In the 1970's and 80's it was noticed (by amongst others James "Gaia Theory" Lovelock and others) that the ozone layer was thinning. It became known that CFC's which had been pumped into the atmosphere for 60 plus years, were themselves starting to degrade by UV bombardment in the upper atmosphere, it had just taken a while to degrade them. Single chlorine and even worse - bromine atoms were energised and broke free where they could interact with the ozone and "steal" the third atom, which could go on to eat into more ozone molecules. It is reckoned that through this and further catalytic reactions, one of these radicals could devour 100 000 ozone molecules, throwing the equilibrium to a sharp deficit of ozone to oxygen produced. Montreal was implemented to prevent the CFC's from overwhelming this layer to an unsalvagable level.

For me if the report singles out that the damage to the layer has been stemmed, then this is a great success story for evidence based scientific assessment and damage limitation of a serious problem. That perhaps a situation caused [unintentionally] by man on the planets ability to sustain life as we know it, can be rectified by reasoned collective action led by scientific methodology to prevent a positive feedback point of no return. It provides hope that a workable solution plan to counter man made climate change (which is different to this phenomena I might add.) is achievable in a reasoned and pertinent timescale. We may get ourselves unwittingly in these scrapes, but we can get out of them if the will is there.

*I'm pretty sure some bright spark somewhere is going to comment that if we aren't all going to get "cooked" by the ozone hole (usually worded "well they used to say that the ozone hole would kill us all.") after all then perhaps it should follow that man made climate change won't be such a big deal after all. Let us remember that it took a concerted effort to remove the CFC's. It didn't magically mend itself. Which I'm sure will be forgotten by the writers of this kind of stuff.