Friday, September 14, 2007

The Ozone Layer

The ozone layer is essential for protecting society from harmful UV radiation by acting as a filter. However, this protective layer has been thinning due to three main sources: human activity, natural sources, and volcanoes. Human activity is responsible for the most damage to the ozone layer, thus, society should recognize that much can be done to prevent ozone layer damage.
In 1985, in a region over Antarctica, the yearly polar vortex had caused the ozone layer to deplete so greatly, that it could be classified as a hole. In 1996, this hole was large enough to cover Antarctica.
The depletion of the ozone layer does not come without problems. Scientific research has suggested the probability that increased UV-B radiation as a result of the thinning ozone layer leads to increased cases of skin cancer, immuno-suppression, cataracts, and “snowblindness” due to radiation damage of the DNA. Additionally, experiments have shown a correlation between increased UV radiation and crop damage due to UV radiation damaging the plants DNA. Some scientists, however, feel that this will not be a problem in the future due to the possibility of breeding UV resistant crops and plants.
When the topic of the ozone layer arises, many people immediately think of the hole over Antarctica, but few know why the hole is actually there. In 1985, British scientists discovered this hole. A special condition exists in Antarctica that accelerates the depletion of the ozone layer. Every Arctic winter, a polar vortex forms over Antarctica. A polar vortex is a swirling mass of very cold, stagnant air surrounded by strong westerly winds.Since there is an absence of sun during Arctic winters, the air becomes incredibly cold and the formation of ice clouds occurs. When the sun returns in the spring, the light shining on the nitrogen oxide filled ice particles activates the formation of chlorine. This excess of ozone destroying chlorine rapidly accelerates the depletion of the ozone layer. Finally, when the polar vortex breaks up, the rapid dissolution decreases. It is evident that the effects of the polar vortex are dramatic.For about two month every southern spring, the total ozone declines by about 60% over most of Antarctica.
Many national governments and agencies recognized the problem of ozone depletion, and therefore, united in 1987 to sign the Montreal Protocol. This agreement was implemented to decrease CFC levels in order to help protect the thinning ozone layer.
Clearly, ozone depletion is a dangerous problem due to possible disease outbreaks and famine as a result of increased UV-B radiation. However, society can collectively attempt to combat this problem by relatively simple means such as education and the practice of “ozone smart behavior. For if society acts now, future generations will be handed a safe and healthy planet.

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