Word: cfcs
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...paraphrase that famous remark about the weather, everyone talks about the ozone layer, but no one does anything about it. Though evidence has mounted that man-made compounds called chlorofluorocarbons (CFCs) are destroying the screen of ozone-enriched air that helps shield the earth from the sun's dangerous radiation, the world's nations have been slow to develop a consensus on how to cope with the problem...
...Montreal Protocol is aimed at reducing CFCs, which are used as coolants in refrigerators and air conditioners and are an important ingredient in aerosols and plastic foams. The pact would limit the use of an ozone- destroying group of fire-suppressant chemicals called halons, which some scientists believe cause as much as 20 times the damage of CFCs. Scientists estimate that overall as much as 7% of the ozone belt, which stretches six to 30 miles above the earth, has already been destroyed. Moreover, researchers have found evidence of "holes" in the shield, including one above Antarctica that approaches...
Representatives from 35 countries met in Montreal last week to hammer out an agreement that would limit man-made damage to the atmosphere's protective ozone layer. As they deliberated, the British journal Nature published a study offering the strongest evidence so far that man-made compounds called chlorofluorocarbons (CFCs) are the culprits. Crofton Farmer, principal author of the study and an atmospheric physicist at the Jet Propulsion Laboratory in Pasadena, Calif., reported that data gathered last year in the Antarctic are "entirely consistent" with the premise that CFCs -- used in refrigeration devices and as ingredients in plastic foams...
...three oxygen atoms, absorbs UV radiation, even the amount that now penetrates the ozone layer can cause skin cancers and has been linked to cataracts. With less ozone, these disorders will increase; with no ozone at all, the UV could be deadly. Scientists have long suspected that decomposing CFCs in the stratosphere release chlorine, which acts as a catalyst, breaking ozone molecules apart. But it was all theory: Could the chemicals rise so high into the atmosphere? Might not the chlorine have come from such natural sources as volcanic eruptions...
...split some of them apart. The single oxygen atoms tend to attach themselves to the remaining molecules, forming an oxygen-atom triplet. The result: a layer, from six to 30 miles up, of ozone-enriched air. Once formed, an ozone molecule is a good absorber of ultraviolet. But when CFCs rise to the ozone layer, sunlight decomposes them, releasing the chlorine they contain. The chlorine is a catalyst, breaking ozone apart without itself being affected. At present, the ozone layer lets enough ultraviolet through to cause sunburn and, in some people, skin cancer. More ultraviolet would increase the effect...