Ozone problem improving according to nationai study Gradual repair could begin by the turn of the century By PAUL RAEBURN AP Science Editor NEW YORK Worldwide emissions of the two worst ozone-destroying chemicals are slowing sooner than researchers had expected, and the gradual repair of Earth's battered ozone layer could begin by 2000, a study says. A 1987 treaty banning the chemicals and aggressive efforts by industry to find replacements will lead to a decline in emissions of the two chlorofluorocar bons by the end of the decade, researchers predicted. "It's a beautiful case study of environmental action," said the study's principal author, James W. Elkins of the National Oceanic and Atmospheric Administra tion. "Industry has moved more quickly than scien tists or government thought." It will still be a century, however, before the ozone layer returns to normal, researchers said. Elkin and his colleagues found that emissions of two chlorofluorocarbons CFC-11 and CFC-12 had slowed to a growth rate of about 1 percent per year, down from a peak of 5 percent per year in the 1980 s, Elkins said. The findings will appear Thursday in Nature, a Brit ish scientific journal. CFC-11 and CFC-12 are used mostly in aerosol cans and air conditioners, especially auto air conditioners, and to produce plastic foam, Elkins said. The good news comes as NASA satellite data is indicating that the stratospheric ozone layer that shields the Earth from cancer-causing ultraviolet radiation has GOOD SHEPHERD LUTHERAN CHURCH (Missouri Synod) 851 N. Science Park Rd. 9:00 am Student Bible Class 10:30 Worship Student Luncheon, noon Sunday, August 29 We pick up students at the HUB at 10:05 am Donald A. Cario, Pastor 234-8177 4,4444•1 JODON'S w .STABLES EAST * ip ßiding Instruction i . •Horses Boarded * Next to Wal-Mart • 237-8769 Are You a Penn Stater? =Collegian FE' Information Systems Majors dropped to its lowest levels ever. "The ozone levels are at or below what they were last year, and last year was a record low level," said James Gleason of NASA's Goddard Space Flight Center in Greenbelt, Md. He said that even with the peak in emissions of chlorofluorocarbons by 2000, it will take about a century for the ozone layer to recover to what it was before ozone-destroying chemicals began to be widely used in the 1960 s and 19705. That's because chlorine persists for a long time in the atmosphere, he said. "The ozone depletion from the chlorine will continue until the chlorine is removed from the atmosphere," Gleason- said. "All we've done is slowed down the destruction. We are still going to have Antarctic ozone holes until the next century," Elkins said. Ozone molecules absorb some of the sun's harmful ultraviolet radiation before it reaches the Earth's surface, making life on Earth possible. Chlorine breaks up ozone molecules into atoms of oxygen, which do not absorb ultraviolet radiation. Each chlorine atom triggers a cascading cycle that can destroy up to 100,000 ozone molecules, Elkins said. Elkins and his colleagues measured chlorine levels at various locations in the United States, Antarctica and elsewhere. They compared the findings with data from the DuPont chemical company on worldwide chlorofluorocarbon production, and found that the two sets of data matched, confirming the findings, he said. 'MEI 11•11111 MOM 2 MEDIUM 1-TOPPING PIZZAS Not Valid With Dominator GUARANTEED: 30 MINUTES OR FREE Valid at participating stores only. Not valid with any other offer, or special. Prices may vary. Customer pays sales tax where applicable. Delivery areas limited to ensure safe driving. Our drivers carry less than $20.00. Cash value 1/20$. Our drivers are not penalized for late deliveries. 1993 Domino's Pizza, Inc. EXPIRES: 8-31-93 PSU NORTH 237-1414 SOUTH 234-5655 PRESENTING .... 5.11.1. T. NIT At the Shandygaff Come and check out the FUN ! DY -DOUBLES $10.98 : See why Information Technology and Financial Services make a great match... Aetna's Internal Audit Department offers an exceptional professional development program. As an Information Technology Auditor, you will work with top management on system development reviews, technical audits, and special consulting projects. A position in Internal Audit can lead to other key positions at Aetna within 3-5 years. Aetna was recently named by FORTUNE magazine and The Wall Street Journal as one of America's most admired companies. Our /Etna Aetna is an Equal Opportunity, Affirmative Action Employer Political battles By DEBORAH SEWARD Associated Press Writer MOSCOW Boris Yeltsin who denied charges that Vice promised that his battle with political President Alexander Rutskoi secretly opponents would heat up in Sep- squirreled money into a Swiss bank tember, but the fight already has account. exploded into a nasty corruption The Renaissance Fund's presi scandal that is damaging both the dent, Alexander Korovnikov, accused J•tK)i)Need something to do this weekend? Find it in the Col = • ion Weekend Section! outstanding compensation, benefits and training programs were major reasons why. We are looking for individuals with proven analytical ability, effective communication skills, initiative, flexibility, and creativity to join our large staff of audit professionals at our corporate headquarters in Hartford, Connecticut. Interviews will be held We'd like to learn more Friday, October 8, 1993. about you and your expectations. in Russia begin to heat up president and his foes. Starring in yesterday's episode was the head of an influential charity fund The Daily Collegian Thursday, Aug. 26, 1993- Yeltsin's supporters of smearing Rutskoi, a staunch opponent of the Russian president, with phony evidence. Korovnikov said the tactics used by Yeltsin and his supporters were "reminiscent of the methods which were used under Stalin's repres- sions." Submit your Interview Request Form or resume to the Career Development & Placement Center by August 31, 1993. Or send it directly to: Aetna, Andy Anderson, Director, 151 Farmington Ave. RW3H, Hartford, CT 06156 Information Session will be held October 7, 1993.
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