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The Earth's Ozone Layer, Here Today, Gone Tomorrow?

© Kenneth Friedman

If you were asked to name two essentials for life on earth and you answered "oxygen and water," you'd only be part right. Better add ozone to your list. Not the ozone smog that blankets Denver in winter and Los Angeles on bad days; the ozone in a layer about 25 kilometers above the Earth's surface. Mostafa Tolba, executive director of the U. N. Environment Programme, describes it as "thinner than gauze itself and just as delicate."

The problem is, we've been thinning this delicate gauze layer (particularly over the Earth's poles) little by little by releasing chemicals either directly or indirectly into the atmosphere as a result of natural and industrial activity. Chlorine, mostly in chlorofluorocarbons (known as CFCs), and Halon, a fire extinguishing agent, are released directly. Nitrous oxide, carbon monoxide, carbon dioxide and methane are released either naturally or from industrial activity. Once these gases reach the ozone layer, they break it down and expose the Earth to harmful ultraviolet UV-B radiation. Exposure means sunburn, snow blindness, eye damage (cataracts), skin cancer and wrinkled, aged skin. Humans are not the only living things affected by the UV-B; count in animals and plants too. One worry, according to some scientists, is that increased UV-B will harm phytoplankton in the upper ocean layers and affect the entire marine ecosystem.

International concern over the thinning ozone layer led nations to sign an agreement, the 1987 Montreal Protocol, to phase out production and use of CFCs. Not all countries signed, however. India, for example, refused to sign, saying it was unfair for industrialized nations to punish developing nations that had still not raised the economic welfare of their citizens. In other words, it is one thing for the United States to halt production of CFCs, which were used in air conditioners, among other uses, while developing nations still haven't met the demand for such products. Another argument: developed nations can afford more expensive alternative chemicals; developing nations can't.

Continuing studies of ozone depletion have kept nations and scientists hopping. Ozone layer depletion updates in 1990 and 1992 led people to call for a speed up of the cutback on destructive chemicals. A major U.S. CFC manufacturer voluntarily agreed to halt production. Meanwhile, the incidences of skin cancer appear to be increasing and it is common to read and hear summertime warnings that caution against unnecessary exposure to the sun. Who knows what the future will bring.

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