It was during the mid 1980’s that scientists first detected the hole in the ozone layer that had appeared over the South Pole. Â These days it doesn’t get that much press, since global warming and melting ice caps have stolen most of the limelight, but the ozone layer hole is still there and is being monitored.
I don’t know who coined the term Ozone Hole but it isn’t strictly correct. Â I suspect it was a journalist wanting to create a scare story, as the word hole implies a complete lack of ozone, which isn’t actually true. Â The hole is in fact an area where the levels of ozone are below a particular level, rather than a complete lack. Â Of course this is still a serious problem, but it isn’t actually a hole.
Nor does the “hole” permanently exist. Â Ozone levels only actually drop significantly during the antarctic spring (August-October).
So what caused the problem then. Â Well, the big culprit that was blamed was the use of Chloroflourocarbons (CFCs) which are chemicals that were thought to be completely harmless when they were invented in the 1920’s. Â Most will remember them as being used in spray cans as a propellant, but they were also used in fridges and in making polystyrene. Â By the late 1970’s however it was discovered they weren’t quite so harmless as first thought. Â The CFC gas molecules were able to rise high into the Earth’s atmosphere, where they hang around until weather conditions cause them to break up the ozone molecules in the Earth’s atmosphere. Â This is what causes the ozone hole.
The reason this made headlines when it was first discovered was because the ozone layer performs the very useful task of blocking much of the ultra violet light from the sun. Â UV light is what causes us to tan in the sun, but too much can cause skin cancer.
In many ways then it was during the 1980’s that the human race finally wised up to what they were doing. Â CFCs were quickly replaced with alternatives (remember those deodorants you had to pump up first – what happened to them?) and of course now everyone is trying to recycle as much as possible, but is it all too little too late now? Â I guess we should count ourselves lucky that the Ozone Hole is other a pretty much uninhabited part of the planet! 😉