GENEVA (AP) A combination of manmade chemicals and volcanic gases caused unprecedented destruction of the protective ozone layer over large parts of the globe the past year, a U,N. environment agency said Friday. The World MeteoroLogical Organization said ozone levels over northern Europe, Russia and Canada last winter and spring were 12 percent below the seasonal aver age, "an occurrence never before observed in more than 35 years of continuous ozone observations." "Statistically one could expect such low values only once in 100 years," said Dr. Rumen Bojkov, a weather expert with the organization. The Geneva-based agency also reported extremely high depletion rates for ozone over the South Pole and southern Argentina and Chile. The ozone layer shields the Earth against the sun's damaging rays. Its depletion has been tied to increased incidents of skin cancer and vulnerability to disease and bLindness. lt's depletion has also been linked to reduced crop yields and damage to marine food chains. When evidence of ozone depLetion emerged in the l970s, it was concentrated over the Antarctic during its spring period of September and October. However, scientists are increasingly reporting significant ozone decreases all year round and in all latitudes except the tropics. The meteorological organization re leased its latest findings on the eve of a U.N.sponsored meeting aimed at agreeing to faster targets for phasing out ozone consuming chemicals. The conference opens Tuesday in Copenhagen, Denmark, and ends with a ministerial session Nov. 23-25. It is expected to ban chlorofluorocarbons, or CFCs, by the start of 1996 - five years earlier than originally planned CFCs are used in refrigeration, air conditioners and aerosols. However, there is more controversy over phase-out targets for other substances like hydrofluorocarbons, developed as an alternative to CFCs but now also said to destroy ozone, and methyl bromide, used as a pesticide and fumigant. "Implementing these decisions is a matter of urgency since our observations have proven that we are indeed running out of time," said Godwin Obasi, head of the meteorlogical group. The report was based on data from 140 ground stations and satellites. It said that ozone amounts over most of the northern hemisphere were "exceptionalLy low compared to long-term averages" during last winter and spring. Average vaLues in January were 20 percent below normal over northern Europe and down 16 percent over Canada. They were 15 percent below normal over Russia in February and March, it said. Over the South Pole, ozone destruction of up to 65 percent was reported in the second half of September and early October. For nearly four weeks ozone sounding stations in Antarctica reported their lowest-ever daily values, it said. "Scientists also observed that for a few days in early October permanentLy inhabited areas of southern Argentina and south ern Chile were covered with an ozone layer containing only 50 percent of normal ozone amounts," it said. SAN FRANCISCO (AP) - A satellite has found worrisome hints that the Antarctic hole in Earth's ozone layer may suck in and destroy ozone from elsewhere, scientists said. Measurements by the $740 million Upper Atmosphere Research Satellite also showed the chemical stage is set for ozone destruction months before the hole actually develops each year above the South Pole, said Carl Reber , project scientist at NASA's Goddard Space Flight Center in Maryland. Those observations provide overwhelming evidence that industrial pollutants known as chlorofluorocarbons, or CFCs, are responsible for the gap in the ozone shield over Antarctica, Reber and other researchers said Thursday during the American Geophysical Union 's fall meeting. Ozone at low altitudes is a component of smog. But in the stratosphere natural ozone helps shield the planet from the sun's ultraviolet radiation, which can cause skin cancer and cataracts, damage the immune system and harm plant growth . When the sun first rises over Antarctica each spring, fall in the Northern Hemisphere, a hole forms in the ozone layer over the icy continent. The satellite's measurements show concentrations of chlorine compounds in the stratosphere closely match worldwide emissions of CFCs, which are used as refrigerant and in some industrial processes, said Ralph Cicerone, an atmospheric chemist at the University of California, Irvine.* What the Environmentalist don't want you to see. OCR Scan Saginaw News. April 15, 1993 WASHINGTON - After_nearly a decade of headlines and handwringing about erosion of the Earth's protective ozone layer, the problem appears to be well on the way to solution, As a result of the Montreal Protocol , an international treaty obliging signatory countries to phase out ozone-destroying chemicals, scientists expect the threat of ozone destruction to peak in just seven years. In 2000, according to the latest scientific estimates, the ozone layer should start slowly getting thicker and better able to block the sun's harmful ultraviolet rays. In fact, researchers say , the problem appears to be heading toward solution before they can find any solid evidence that serious harm was or is being done. This hopeful trend - at variance with the dark scenarios of environmental doom that were pronounced after discovery of the Antarctic ozone hole in the 1980s - is supported by not only by growing scientific evidence but even by scientists in the environmental movement. "The current and projected levels of ozone depletion do not appear to represent a catastrophe," said Michael Oppenheimer an atmospheric scientist with the Environmental Defense Fund, "But I'm flabbergasted that we let it go this Far before taking action. It was a potentially very serious problem." Richard Stolarski , an atmospheric scientist at NASA's Goddard Space Flight Center agreed: "I happen not to be of ' the disaster school, It's a serious concern but we can't show that anything really catastrophic has happened yet, Or that anything catastrophic will happen in the future." Attempts to detect the most feared effect of ozone depletion increased bombardment of the Earth's surface by ultraviolet rays - have Failed to turn up any evidence of increased ultraviolet influx outside the Antarctic region during the few weeks each year that the ozone hole is open. IF there has been any increase in ultraviolet rays, researchers say, it is too small to measure against a background oF normal ultraviolet levels. Given the expected improvements in the ozone layer, even the ozone hole eventually could stop opening. Already scientists see signs that the hole is not likely to grow much bigger than it has. Even when the problem reaches its worst in 2000, scientists expect summertime ozone losses over temperate zones to be about 6 percent, double what they are now Because each percentage point of ozone loss theoretically leads to an increase in ultraviolet intensity oF 1.3 percentage points, the potential increase in ultraviolet levels would be about 8 percent. Scientists calculate that the increased ultraviolet exposure a Washingtonian would get in midsummer then will be the equivalent of moving south about 200 miles this summer to North Carolina. Latitude is crucial because, like time of day and season, it affects the amount of atmosphere that ultraviolet rays must pass through to reach the ground. When the sun is directly overhead, for example, its light penetrates one thickness of atmosphere, but when it is on the horizon, its rays take a slanting path roughly equivalent to 40 thicknesses, and 40 times as much ozone. This is key to understanding why , even though ozone depletion is worst in late winter (ozone is reduced by 8 to 10 percent), less ultraviolet gets through than in summer when the ozone loss is milder . Sun angle is so low in winter that the ultraviolet rays pass through more ozone then than during summer when there is less depletion. (Over the tropics, where sun angle is high all year long, there has been no observed ozone depletion.) "One reason we haven't seen any increase in UV is that we didn't start taking good data long ago," said Stolarski, who nearly 20 years ago was among the first researchers to assert that the ozone layer could be damaged if certain chemicals - especially chlorine - traveled high enough in the atmosphere . Because of natural fluctuations in ultraviolet, it is impossible to detect a trend in a short period of data collection. "The amount of increase that the theory says we could be getting from ozone depletion is smaller than the error of our best measuring instruments," said John E. Frederick, an atmospheric physicist at the University of Chicago . "People get all excited about a few-percent change in UV . but it's nothing to get a 20 percent increase naturally , ', Frederick said' "If an increase of 20 percent were going to be so damaging, there should be no life in Florida, ' , where ultraviolet always exceeded the allegedly dangerous levels once forecaSt for more northerly latitudes. Stolarski, Frederick and other atmospheric scientists say that even if there were good ultraviolet measurements going back many years, they still might not show an increase because other factors such as increased cloudiness (one of the predicted effects of global warming) and air pollution (including pollution by ozone in the lower atmosphere) might shield the ground, compensating for the lost upper-atmosphere ozone. That, in fact, was a conclusion of one of the most exhaustive studies of. the ozone problem ever undertaken, an effort in which nearly 150 scientists from 28 countries collaborated under the auspices of five American, British and United Nations agencies. "The decreases in UV-B (the damaging form of UV) caused by increases in (air pollution) since the industrial revolution probably exceed the increases due to ozone depletion," according to the group's latest report in 1991, If any of this comes as a surprise, it may be because most of the mass media coverage of this complex issue has focused on cries of alarm by environmentalists who feared a worst-case scenario in which the planet's protective ozone layer would be thinned enough to let in . massive amounts of solar radiation. If the ozone shield did not exist, the surface of the Earth would be virtually uninhabitable . The amount of ultraviolet that reaches the top of Earth' s atmosphere would be lethal to most forms of life if. it penetrated to the ground. The world responded to the environmentalist case. The main threats to the ozone, synthetic chemicals called chlorofluorocarbons used chiefly as refrigerants, solvents. foam- blowing gas, and once as spray-can propellants, are being phased out faster than originally projected. So well are the corrective measures proceeding that scientists who have been looking for effects of ozone depletion say it may not be possible to document any before the massive injection of synthetic chemicals into the atmosphere fades away, ending humanity's in advertent experiment in perturbing Earth 's atmosphere . Nevertheless, debate over various facets of the subject is likely to continue.