Most people have heard about ozone depletion, and a majority probably also know that it is a gaseous layer in our atmosphere that prevents harmful solar radiation from reaching the surface of our planet. But how many people know what it really is, how it is created, and how it is destroyed? It would seem that this would be the logical place to start, when wanting to understand ozone depletion.
Normally, oxygen doesn’t exist as single atoms. It is highly reactive and will readily bond with other atoms. “Free oxygen” consists of two oxygen atoms bonded together in a form that is fairly stable. Ozone is made up of three oxygen atoms bonded together, and as such, is again unstable.
In order to create ozone in the laboratory, energy is passed through oxygen, which separates some of the oxygen molecules and provides the energy to bind the single atoms to other oxygen molecules, forming ozone. The smell commonly associated with an electrical arc is caused by the formation of ozone.
Since ozone is much more unstable than oxygen molecules, it easily breaks down to reform as oxygen.
Interestingly enough, high in our atmosphere where sunlight is unimpeded by such things as dust, the sunlight produces ozone by providing the energy needed. This is where there are some common misunderstandings.
For instance, have you heard of the “ozone hole” that is supposed to exist over Antarctica? Well, truth is that there is no ‘hole’. Every year, during the south polar summer when sunlight is streaming to the Earth most directly in that area, and for the greatest amount of time, ozone is created. Each winter when there is a decided lack of direct sunlight, the amount of ozone diminishes. So by spring each year, there is a thinning of the ozone, most especially over the pole itself, since it gets the most fluctuation in the sunlight coming in. This is what is usually referred to as a hole. It isn’t a hole, but a normal thinning of the ozone layer in that location, which is built back up during summer, provided there are no contaminants such as volcanic dust from eruptions, that block a portion of the sunlight.
So what is the big fervor over CFC’s or Chloro-Floro-Carbons? CFC’s bind with oxygen far more easily than oxygen binds with oxygen. So as oxygen molecules are broken apart, if there are CFC’s in the upper atmosphere, they bind with the free oxygen atoms, making them unavailable for the formation of ozone. Here is another misunderstanding, though.
CFC’s don’t solely come from man, and in order for them to affect the ozone layer, they must somehow get into the extreme upper atmosphere. Freon, a commonly used refrigerant through most of the world, though it was banned long ago in the US, contains CFC’s, and was long considered a major culprit in destroying the ozone layer. However, scientists were hard pressed to explain how Freon got so far up into the atmosphere.
The actual answer came from scientists in the study of volcanoes. It seems that volcanic eruptions produce large quantities of CFC’s. It is not uncommon for a moderate eruption to send these CFC’s 12 miles or even much more, into the atmosphere. So we now know that much of the CFC’s found in the upper atmosphere came from volcanoes, rather than from man. (There are on average 12 to 17 volcanic eruptions on Earth every year, and about half of those can be considered moderate or above.)
Does this mean that man should start using Freon again? No, it doesn’t. CFC’s are toxic to plant and animal life. The most decidedly should not be allowed to pollute our lower atmosphere and the air that we breathe. However, at the same time, we shouldn’t rush to the conclusion that CFC’s made by man are causing a depletion in the ozone layer. The evidence says otherwise.
Man’s arrogance and overwhelming belief in his own power enables him to think that he is so strong as to cause what repeatedly turn out to be natural phenomenon. The earth and sun have been creating and destroying ozone for billions of years. One can only hope that one day man will have the wisdom to understand that while he plays a role on this planet, his is neither an indispensable one, nor one that is greater than the planet and stars.
To mankind as a whole, I’d say this: Cherish the Earth and be good to it, but do so humbly and not with the arrogance to pretend that your place in the scheme of this is far greater than it is, or ever has been.
