Kengfoo -
You’ve asked an important question because, as you know, we need to keep the ozone layer because it protects living things from deadly ultraviolet radiation.
Actually, it’s really easy to make ozone. Ozone is produced naturally when sunlight shines on air. It is produced by a chemical reaction in which several molecules of oxygen react with each other. But this reaction only takes place when there’s sunlight. So as long as it’s sunny, ozone will constantly be produced. The reason that we have problems with the ozone layer is that some chemicals like chloroflourocarbons (CFCs; for example, the freon from your freezer or air conditioner) trigger reactions that destroy ozone.. So we have one reaction that makes ozone and one that destroys it. The net ozone level depends on how fast the creation and destruction reactions occur.When pollutants speed up the destruction reactions, the ozone level drops.
At the North and South poles, the way that the Earth rotates causes it to be dark practically all the time in the winter (and light during the summer). So during the winter there is ozone being destroyed but not being made, making a temporary "hole" in the ozone layer. But once summer comes around and it’s sunny all the time, new ozone will be made, and the hole goes away. Of course the ozone level doesn’t quite get back as high as it used to, so long as there are still pollutants up there destroying it.
The key point here is that we don’t need to do anything at all to recover the ozone layer. It will recover by itself, once we quit doing things to destroy it. Full recovery can be slow, because the CFCs last many years in the upper atmosphere.
Mike & Tamara
(published on 10/22/2007)
