Ozone Depletion

Ozone Depletion

A Case for

"Ignoring the Facts"

Ozone forms a layer of the earth's atmosphere that protects us from the sun's deadly ultraviolet rays. During the last decade there has been a scare set forth by environmental enthusiasts that Chlorofluorocarbons (CFCs) destroy the ozone layer. Although there has been no evidence of any CFC destruction of the ozone layer there is an international stoppage on using CFCs, as well as an executive order set forth by Clinton to limit the sell and use of CFCs in the United States. These bans are unnecessary , since they are merely based on fear and politics. Basing the ban on evidence can not be possible, because there is no factual evidence.

This executive order is not only futile, but ridiculous. Facts are the ozone layer is not depleting due to CFCs or any other manmade chemical. Qualified scientists have proven the whole notion of the ozone layer is not something fixed and finite to be destroyed faster and slower rates. It is simply not a depletable resource like a fossil fuel. The process by which CFCs are supposed to deplete it is highly speculative and has never been observed to take place, and even if it did, the effect would be small compared to what happens naturally.

Ozone is dynamic. It is constantly being created and destroyed, and as long as the sun emits rays the process will continue. Ozone is the Trioxide molecule (O3), which is created by photons radiated from the sun. A normal oxygen molecule (O2) consists of two oxygen atoms, in diatomic form. High energy ultraviolet radiation known as UV-C can split one of these molecules, through a process known as photodissociation, into two free oxygen atoms. These atoms then join with a third oxygen and form ozone. Some ozone is found at ground level, but most occurs in the "Ozone Layer," a concentration of O3 approximately 30 miles above the Earth's surface. Most ozone is produced in the tropics where ultraviolet flux is the strongest.

Ozone is destroyed by chemical reactions that convert the O3 molecule into O2. The reaction that causes this is mostly nitrogen dioxide (produced in part by high altitude cosmic rays), through ultraviolet dissociation by the same UV-C that creates ozone, and also by a less energetic band know as UV-B, which is absorbed in the higher regions of the atmosphere. Every incoming UV-B photon dissociates an oxygen molecule, which is what gives the ozone its ultraviolet screening ability.

The height and thickness of the ozone layer are not always the same, but rather it adjusts automatically to compensate for the moderate incoming ultraviolet flux. That is when ultraviolet flux is greater, it penetrates deeper in turn creating more ozone which in turn blocks more of the incoming photons. Even if the ozone layer suddenly vanished there would still be 20 to 25 miles of oxygen rich atmosphere which would become available for ozone creation.

In 1974 two overly energetic chemists, Rowland and Molina, theorized the same chemical inertness that prevents CFCs from causing corrosion and makes them nontoxic, also would allow the molecules to remain intact as they diffuse throughout the atmosphere. High energy ultraviolet radiation would soon dissociate these particles into free chlorine particles which in turn would react with the ozone molecule to form chlorine monoxide and a normal oxygen molecule, and as a result ozone would be destroyed. This theory becomes more guileful by stating the chlorine monoxide molecule would dissociate and thus a single chlorine molecule can then run amuck in the atmosphere, destroying all ozone molecules.

The theory also overlooks the fact most CFCs released from the surface will never reach the stratosphere. In other words, CFCs do not rise in significant amounts to altitude where UV-C photons can break them apart. Because ozone absorbs the heat directly from the sun's rays, the stratosphere exhibits a thermal inversion effect. That is, as one rises in altitude the air cools until a point is reached where the stratosphere begins and the air begins to warm from this heat absorption. It is at this point a thermal barrier (Tropopause) prevents vertical air movements and the interchange of gases (including CFCs) from reaching the stratosphere. One can see this fact with a typical thunderstorm. The cloud raises rapidly until it reaches the Tropopause where at once it flattens and spreads to form an anvil head. Thus very little air is exchanged across the Tropopause from connective currents. Because of this, CFCs in the stratosphere rapidly decline to only two percent of their surface value. At the same time, less than two percent of UV-C penetrate below the Tropopause. As a result the number of CFC splitting possibly is drastically lower than the hypothesis assumes.

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