The Atmospheric Ozone Layer Essay Research Paper — страница 4

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changes were major. Since the late 1970s, there has been a slow but steady decrease in global total ozone, even if the major losses over Antarctica is not included. The trend is on the order of -2.7% per year in all seasons with the greater losses occurring in the Northern Hemisphere autumn and winter (greater than 3%) and the least in the Northern Hemisphere summer (1.6%). Surface impacts and political decisions The impacts of a depleted ozone layer on surface organisms depend on their location to increased UV-B radiation. As a rough estimate, many experts suggest that the percentage increase in UV-B radiation affecting surface organisms would be about twice the percentage loss in stratospheric ozone from anthropogenic causes. The most immediate effect on human beings would be

an increase in various skin cancers and skin cancers are increasing. Increases in the evidence of cataracts and interference with the human immunity system are other possible influences. A more serious potential long-term threat is the damage to cell DNA and the genetic structure in not only human beings but in other animals, plants and organisms. With the discovery of the Antarctic ozone hole and the resultant world-wide interest, publicity and concern, a historic meeting occurred in Montreal, Canada in September 1987. For the first time ever, 57 countries and organisations met to make a specific decision to limit the emissions of a series of pollutants which were likely to create major environmental problems affecting the globe in the future. The eventual document adopted on

September 16, 1987 and entitled “The Montreal Protocol”, was signed immediately by 24 countries and since has been ratified by several more. REFERENCES: 1. Jonathan Weiner, “Plant Earth”, New York, Bantam Books, 1986 2. “Atmospheric Ozone, Global Ozone Research and Monitoring Project” (Vol. 16, Geneva 1985 International Organisation of Meteorology) 3. Lydia Dotto and Harold Sciff, “The Ozone War”, Garden City, N.Y., Doubleday, 1978 4. John Gribbin, “The Hole in the Sky”, N.Y., Bantam Books, 1988 5. James G. Titus, “Effect of Changes in Stratospheric Ozone and Global Climate” Vol. 2, United Nations Environmental Programme 6. G. Levi, 1988, “Ozone depletion at the Poles”, Physics Today 7. P. Bowman, 1988, “Global trends in total Ozone”, Science 8.

Hans U. Dutsch, “Vertical Ozone Distribution”, International Centre for Atmospheric Research, Boulder, Colorado