Create a new account

It's simple, and free.

Ozone Depletion The Earth's upper atmosphere cont

The Earth's upper atmosphere contains an ozone layer which shields the planet from the sun's ultraviolet rays. This layer extends from approximately 18 to 30 miles above the Earth's surface. The ozone is considered to be "good ozone," as distinguished from the "bad ozone" which is a principal ingredient of smog. It precludes many of the harmful consequences of ultraviolet radiation. In humans, these effects can range from skin cancers to immune diseases to eye cataracts. Accordingly, the discovery of a 40% drop in springtime ozone levels high above Antarctica in 1985 caused widespread concern. Additional investigations found that the Antarctic ozone hole was not an isolated phenomenon. Springtime measurements of stratospheric ozone over southern New Zealand have shown reductions by as much as 20% below values measured before 1979; moreover, satellite observations have detected dramatic overall declines in the concentration of stratospheric ozone around the globe.

Scientists soon deduced the cause. For years there had been some speculation as to what would become of the millions of pounds of chlorofluorocarbons (CFC) that were then being produced by industry. It was found that these chemicalswhich serve as refrigerants, aerosol propellants, and foamblowing agentseventually accumulate in the Earth's stratospheric ozone layer. There, they are degraded by ultraviolet radiation. The resulting reactive byproducts (i.e., chlorine ions) then attack and destroy ozone molecules.

Moreover, it was found that the magnitude of the problem was increasing. In 1987, industry produced nearly 2 billion pounds of CFCs worldwide. In response to both the growing environmental threat, as well as the pleas of the science community and the environmentalists, the governments of the world's nations gathered to discuss possible solutions. The result was an international treaty called the Montreal Protocol.

...

Page 1 of 2 Next >

More on Ozone Depletion The Earth's upper atmosphere cont...

Loading...
APA     MLA     Chicago
Ozone Depletion The Earth's upper atmosphere cont. (1969, December 31). In LotsofEssays.com. Retrieved 00:38, March 29, 2024, from https://www.lotsofessays.com/viewpaper/1704126.html