NAKED PLANET : From the Tip of South America to the North Pole, Scientists Are Discovering disturbing New Signs of the Deadly Effects of Ozone Depletion

THE STEEL TOWER STANDS IN A GROVE OF BEECH TREES, overlooking a turquoise lake in southern Chile. Every 10 days, Carlos Rodriguez, a curly-haired man with a nub of a red mustache, dons his quilted forest ranger’s jacket and hikes up the slope, where he unlocks the box perched atop the tower’s galvanized legs. Inside is a compact, stainless-steel air pump. Using sterile rubber gloves, Rodriguez detaches the mechanism’s white mesh filter and seals it in a clear plastic envelope.

Eventually, 8,000 miles away in Idaho Falls, Ida., a chemist will analyze the filter for residues of cadmium, copper, zinc, lead and aluminum. But Rodriguez already knows what the results will be: As usual, the used filter is as spotless as when he installed it. After 10 days anywhere else, the membranes on UNESCO’s air monitors are invariably stained brown. But here, in Chile’s exquisite Torres del Paine National Park, the only thing that penetrates the flawless atmosphere is the lilt of nesting thrushes.

On the gleaming lake below, wild swans drift across reflections of mountain spires hung with glaciers whose startling blue hues-- paine in the language of Chile’s Tehuelche Indians--give the park its name. From this hillside, Rodriguez can see herds of tan guanacos, the giant llamas of the southern Andes, foraging in meadows among flocks of rheas, the South American ostrich. Enormous hares bound past them, pursued by silver foxes. High overhead, Andean condors spiral around the sun.

To Rodriguez, who spent his boyhood fishing for trout in Torres del Paine’s streams, defining this place in terms of some absent industrial molecules seems slightly absurd. Yet he is proud that the monitor shows that this is the cleanest air in the inhabited world--a world in which, he has heard, there is precious little clean air left. Here, nearly at the bottom of the Americas, in Chile’s Ultima Esperanza (“Last Hope”) province, where this slender country fractures into a jumble of craggy fiords and where the only road north must detour through 1,000 empty miles of Argentine pampas, Rodriguez has felt safe from the scourge of so-called progress defiling the rest of the planet.

Until now. Something has changed in this isolated haven where, legend says, God stored all the beauty left over from Creation. Lately, there are hints that nature’s biological clock is overwound. Flamingos arrive a season early; geese breed in autumn instead of spring; egrets lose their migratory bearings altogether and flap erratically around the pampas. Especially puzzling to Rodriguez are the glaciers: Instead of advancing, Torres del Paine’s ice sheets are now receding--40 yards per year, a quarter-mile over the past decade.

No one knows why. Logical explanations have been offered for these and other peculiar phenomena, such as shriveled roses in house gardens or the wave of blindness recently affecting local sheep and rabbits, but scientists say there have not been any proper studies. Yet people in southern Chile increasingly suspect that they’re all connected to a single bleak fact: Human beings who live north of the equator--supposedly among the most intelligent and advanced in history--somehow reached far south and inadvertently ripped a hole in the stratosphere.

“We are paying for something we didn’t cause,” Rodriguez declares glumly, watching Paine’s indigo peaks turn copper under a waning sun he now has begun to fear. Maybe, he says, the inflamed sheep corneas and rabbit cataracts have nothing to do with the ozone hole, as agriculture ministry officials assure them. And maybe the reason it barely snows anymore is really due to global warming, which, he understands, is a different pending disaster altogether. But no one really denies anymore that something actually is new under the sun in this once pristine sanctuary, and the full extent of the damage is still unfolding.

Scientists who have been peering up into the hole since it was discovered seven years ago now generally agree that the atmospheric havoc caused by supposedly friendly chemicals, whose use in air conditioners, spray cans and plastic foam redefined modern life, will take nearly a century to repair. What they can’t yet predict is exactly what will happen during that time to crops, forests, animals and people. In the Earth’s southern oceans, the first warnings already have appeared. Each spring, quantities of dangerous ultraviolet radiation that haven’t reached through the atmosphere to the water’s surface since Creation itself have begun to leak in. It is now clear that life has begun to leak out--specifically, the lives of watery organisms that form the primary link in the food chain that binds us all. Soon, scientists say, this ill fortune will be followed by skin cancers and eye cataracts in humans.

The saga of the disappearing ozone layer now stretches from polar research bases below Chile to Washington, D.C., and New England and on to the North Pole. Even as policy makers attempt to arrest the destruction, new studies keep revealing more evidence of ozone loss--this time, over the densely populated developed world. People with ringside seats at the Antarctic ozone hole have long joked about living at the end of the earth. Now, as they contemplate that phrase’s grim double entendre, it is scant comfort to know that they are not alone.

TWO HUNDRED AND FIFTY MILES BELOW TORRES DEL PAINE, THE road reaches Punta Arenas, the world’s southernmost city. The gabled houses, poplar-lined streets and generally fair-skinned population frequently remind northerners of Maine or Nova Scotia. The single hint of Spanish heritage is the cypress-shaded central plaza with its bronze statue of Ferdinand Magellan, who passed here in 1520 en route to proving he could circumnavigate the world.

Founded as a lonely military outpost at the tip of the South American mainland, Punta Arenas prospered during the last century as a coaling station for ships rounding Cape Horn. But in 1914, when sea lanes shifted 5,000 miles north to the newly dredged Panama Canal, there was little further reason for a city here. That same year, however, record numbers of Croatians were headed for America--anywhere in America. Rumors of gold enticed many to Tierra del Fuego, just across the Straits of Magellan. The big island’s ample moors looked lush compared to the Croatians’ rocky Dalmatian coast homeland. After gold fever cooled, they stayed and became sheep ranchers, and Punta Arenas revived as a wool-exporting port.

At first, the news that the ozone layer, the earth’s protective sunscreen, had been perforated due south of town evoked little attention among Punta Arenas’ 125,000 residents. In these latitudes, an increase in lethal ultraviolet rays was considered just one more piece of bad weather. Nearly constant winds shriek in here from the Atlantic, from the Pacific, down the Andes or up from Antarctica, often simultaneously. Even in midsummer, when the sun shines nearly 20 hours straight, sweaters knit from the thick fleece of Tierra del Fuego sheep remain firmly in fashion.

But the sudden arrival of legions of foreign scientists got everyone’s attention. In August, 1987, in order finally to determine what was devouring the south polar ozone, the U.S. National Aeronautics and Space Administration flew 150 scientists and technicians, mostly American and British, to Punta Arenas. NASA even repaved the airport to accommodate a U-2 spy plane, capable of soaring 70,000 feet into the stratosphere. Re-dubbed the ER-2 and equipped with chemical probes, it was prepared to enter the ozone hole itself.

Obviously, something portentous had provoked all this expense. Yet beyond glimpses of the visitors in restaurants, conferring in English over plates of local mutton or king-crab pizza, few Punta Arenans learned many details. The hangar that housed NASA’s headquarters was off-limits, and little news emerged. Attention focused more on the dollars the NASA folks were spending around town than the reason they’d come.

One local who slipped through the tight security was a pale, rangy electrical engineer, an assistant professor at the city’s Magellan University. Bedrich Magas, who arrived in Chile from Croatia as a boy in 1959, could speak English, and he ingratiated himself with NASA’s Airborne Antarctic Ozone Experiment personnel by arranging to have some precision adapters needed for a laser measuring device machined on 24 hours’ notice.

“Forget it,” he told Dr. Robert Watson, the project director, when asked to submit a bill. Two years earlier, Magas had sailed across the Drake Passage to Antarctica on a university research trip. Seeing the ivory continent, encircled by its ever-changing horizon of floating mountains of ice, had stunned him. Antarctica was simply gorgeous. It was also abounding with humpback whales, south polar skuas the size of eagles, soaring giant petrels, elephant and leopard seals, cormorants and thousands of irresistible penguins.

The capacity for life to flourish in such consummate cold, Magas had learned, is based on an enormous supply of inorganic nutrients, dragged by deep currents from the world’s oceans to the Antarctic, where the waters rise and begin again to circulate northward. Reduced to their simplest components after years at great depths, these nutrients--nitrogen, phosphorus--support trillions of phytoplankton: tiny plants suspended in Antarctic waters. These plankton, in turn, are the main course for transparent, shrimp-like crustaceans called krill. Living in a sea of food, krill multiply into swarms that stretch for miles. Whales and penguins gorge on krill; leopard seals gobble penguins; the krill larvae, which graze on microscopic plants growing on the underside of the ice, are in turn consumed by silverfish, the Antarctic herring that ends up in the bellies of skuas. . . .

Unobscured by the complexity of the tropics, the food web of Antarctica stands conspicuously revealed against its stark white background. As Magas tried to explain in talks he began delivering around Punta Arenas, the whole elegant system would collapse without tiny phytoplankton. And, from what the visiting scientists were finding in the ozone layer, the phytoplankton were now at risk.

NASA had set out to test whether a theory, often ridiculed after it was proposed in 1974, was true after all. F. Sherwood Rowland and Mario Molina, chemists at the University of California in Irvine, had suggested that chlorofluorocarbons (CFCs), man-made chlorine compounds that were indestructible on Earth, were being ripped apart by solar ultraviolet rays when they rose to the stratosphere. The UV radiation, Rowland and Molina contended, would free pure chlorine, which would attack the natural layer of ozone that kept those ultraviolet rays away from earth.

“When that happens,” Magas would tell whomever would listen--scout groups, women’s clubs, crab fishermen, sheep ranchers’ associations--”the trouble really starts.”

Part of the trouble, however, was trying to keep things simple. “Ozone,” he would attempt to explain, projecting a color slide covered with circles and arrows on the wall, “is just a regular oxygen molecule, O2, with an extra oxygen atom, which makes it O3. Cl--free chlorine--steals that atom away. That leaves oxygen, O2 again, and chlorine monoxide, ClO,” he’d say, aware of increasingly blank stares. “Two ClOs then pair together,” he’d press on; “sunlight breaks them up into more oxygen and free chlorine again, and the whole thing starts over. Each chlorine atom ends up wrecking at least 100,000 ozone molecules before some other airborne chemical intercepts it.”

“What about the plankton?” someone would ask.

He was getting to that. First, the latest bad news: If chlorine monoxide showed up over Antarctica, that would prove that the stratospheric chemistry Rowland and Molina had predicted was indeed responsible for the huge new ozone losses--not, as chemical manufacturers were insisting, natural weather processes. The year before, in 1986, a hastily assembled ground experiment by U.S. researchers had first detected ClO above Antarctica. Now, a device slung under the wing of the converted spy plane that flew directly into the ozone hole not only confirmed their observation, but brought back frightening numbers:

NASA had found 500 times more stratospheric chlorine monoxide than was normal at Earth’s mid-latitudes.

As the implications of these figures sank in, Magas had watched apprehension accumulate in the faces of project director Watson and Harvard University’s Jim Anderson, who designed the chlorine detector. A decade earlier, a public fuss in the United States over potential ozone damage from supersonic transport planes and underarm sprays had scuttled plans for an SST fleet and led to a ban of CFCs in aerosol cans. Most people assumed that the problem was solved; unfortunately, the ban neither prohibited CFC sprays in other countries nor stopped companies such as Du Pont, their largest manufacturer, from selling the chemicals for other uses: cleaning electric circuit boards, filling car air conditioners, making insulation or blowing foams for running shoes.

During the 1980s, more chlorofluorocarbons were manufactured than ever. Millions more tons drifted toward the stratosphere, where winds distributed them evenly over the Earth. Then British researcher Joe Farman, after doubting his own data for two years, announced in 1985 that 40% of Antarctica’s ozone appeared to be missing overhead each spring. No one, not even Rowland and Molina, had predicted anything like this. No one was sure why the effects first appeared over unpopulated Antarctica. Some saw this as a blessing: At least nobody was bathing in ultraviolet radiation--except for all those delicate phytoplankton and everything else that depended on them.

But the same chemicals that caused this, Bedrich Magas informed his little Punta Arenas gatherings, were also above Chile. The ozone hole was getting deeper and bigger every year. “We could be next. In fact, we will be,” he told them.

ULTRAVIOLET RAYS DISRUPT DNA, WHICH contains life’s genetic codes. Oddly enough, they also helped to fashion life as we know it--and they created the ozone layer itself. Back when the primordial goo of the Earth’s surface was being pelted with unimpeded ultraviolet radiation from space, at some pivotal instant--perhaps sparked by a jolt of lightning--the first biological molecules formed. These living cells mutated rapidly under the high energy of UV rays, metabolizing inorganic compounds and turning them into new organic ones. Eventually, one of these reacted to carbon dioxide and sunlight in the primitive atmosphere by giving off a new kind of exhaust: oxygen.

Now the ultraviolet rays had a new target. Picking off O2 oxygen molecules, they split them apart. The two single oxygen atoms immediately latched onto nearby O2 molecules, forming O3: ozone. But ultraviolet easily breaks the ozone molecule’s extra atom off, re-forming oxygen; just as quickly, that atom sticks to another pair, forming more ozone until it absorbs more ultraviolet and spins off again.

Gradually, beginning about 10 miles above the surface, a state of equilibrium emerged: Ozone was constantly being created, pulled apart and recombined, thus constantly occupying UV rays so they never reached the ground. This was especially true of mid-range ultraviolet, UV-B, the most dangerous to organisms. As the layer of ozone stabilized, so did the life on Earth it was shielding. Eventually, species evolved that could never have tolerated the former levels of UV-B bombardment. Eventually, one of them was us.

Unfortunately, during the past 60 years, humans managed to undermine the oxygen-ozone balance that has remained relatively constant since soon after life began. Beginning in the 1930s with Freon, the trademark name for the CFCs used in refrigerators, we started dissolving this protective ozone covering by soaking it with chlorine. The same year that NASA proved this, 1987, delegates from 24 nations in Montreal agreed to cut CFC production in half by the end of the century. They also restricted bromine compounds used mainly in fire extinguishers, now known to be even more reactive than chlorine in the stratosphere. It was obvious to most atmospheric scientists, however, that halfway wasn’t enough.

“Think of the atmosphere as a big bathtub, filling from the taps with chemicals while the drain runs extremely slowly,” argued David Doniger, attorney for the Washington-based Natural Resources Defense Council during the lobbying effort in Montreal. “The only way to get chlorine levels down is to turn off the taps and wait 100 years for the tub to drain.”

Until then, he repeated, the only way the hardy CFCs would wear out was by depleting ozone. The more chlorine and bromine that kept escaping into the stratosphere, the longer that would take. And nobody really was sure what would happen to life on Earth in the meantime.

RAY SMITH, AN OPTICAL PHYSICIST AT THE University of California, Santa Barbara, understood the double bind of research. Special interests liked to use research as a delaying tactic. In 1988, it occurred to Smith that 14 years had been lost since Rowland and Molina’s warning. During that time, industry had successfully stalled, demanding more proof before subjecting society to the hardship of doing without air conditioning until alternatives to CFCs could be developed.

Back in the 1970s, Smith had built an instrument to measure UV-B penetration under water. The idea was to learn how ultraviolet radiation affects anchovy eggs and larvae, but after the aerosol ban, government money for ultraviolet research suddenly dried up. With no funding, Smith packed away his instrument. Then the ozone hole appeared and kept growing. At the time, he was studying the impact of coastal weather fronts on phytoplankton with his good friend Barbara Prezelin, a UC Santa Barbara biologist.

“Think of the hole as an ozone front,” Smith would say to her. “If you knew the ultraviolet fluctuations, could you predict biological effects?”

Two years later, in September, 1990, Prezelin and Smith--along with his renovated underwater UV spectroradiometer, four more tons of equipment and a crew of 19--were headed to Chile. They had received a National Science Foundation grant to sail into Antarctica’s Bellingshausen Sea and wait for the ozone hole to open up over them. This occurs every October soon after the beginning of the Antarctic spring, just as the sun rises after six months of darkness. Scientists now realize that frozen particles in polar stratospheric clouds are major culprits, by providing a surface for chlorine atoms to cling to. The energy of the rising springtime sun then releases the chlorine, triggering the deadly reactions. The polar clouds also freeze nitrogen, which in its unfrozen state helps divert chlorine from the ozone. The destruction of the protective ozone shield occurs just as vulnerable young phytoplankton are ready to absorb light to begin the springtime process of photosynthesis.

For 10 days in Punta Arenas they unpacked massive numbers of boxes, recalibrated delicate equipment, fought to get computers through customs and prayed that the navigation gear on their research vessel, the Polar Duke, would get fixed before the spring ozone hole had already closed. In the meantime, Barbara Prezelin kept having to apologize to people for not knowing why their sheep were going blind.

Another project scientist, Deneb Karentz, then of UC San Francisco, had passed through two months earlier and had some long conversations with Bedrich Magas. Magas had learned that Karentz, a marine biologist there to identify phytoplankton and measure radiation dosage, had spent three years studying the genetics of UV damage in human skin cells. Magas was trying to convince Dr. Jaime Abarca, Punta Arenas’ sole dermatologist, that pale-skinned people of European descent like himself were in imminent danger of ozone-induced skin cancer.

He wasn’t having much luck, he confessed. Although Abarca admitted to a recent increase in malignant melanomas, he was not prepared to link anything to ozone depletion. It was far too early to tell--and besides, without knowing how much UV-B radiation was hitting Punta Arenas, it was also impossible. The U.S. National Science Foundation had put UV monitors in Antarctica and on the Argentine side of Tierra del Fuego, but none in Punta Arenas, where most of the people lived. Neither the Argentines nor the Americans had sent them any data--in fact, since NASA left three years ago, they’d received no information at all.

It was obvious that people in Punta Arenas were becoming concerned. Pharmacies were stocking up on sunscreen, and optical shops advertised the latest in sunglasses for children. Greenpeace was funding local environmentalists to collect and send rabbit eyes to a university laboratory for analysis. Newspaper headlines announced that 31 groups had canceled tours to Torres del Paine, fearing the ozone hole. And everyone was complaining about something almost unheard of in this sub-Antarctic climate: sunburn.

AFTER FIVE DAYS OF CROSSING THE DRAKE Passage, Prezelin and Smith awoke to find the Polar Duke pushing through a sea of loose brash ice. Huge icebergs, recently calved from glaciers, had flipped in the water, so the oldest ice now towered above the pilothouse. Thousands of years of pressure had squeezed out air bubbles until light refracting through the frozen water was as undiffused and blue as the polar sky.

In Antarctic ice-core samples, the birth of the industrial revolution could be detected in minute traces of carbon and lead. Subsequent deposits marked the first nuclear explosions. Now the atmosphere was filling with chlorofluorocarbons, and, in a century, its carbon dioxide had increased by a third. Here, in this revealing environment at the bottom of the world, scientists expected to find the first conclusive repercussions from both.

They docked at Palmer Station, a United States scientific base at the edge of a receding glacier on Anvers Island, just off the Antarctic Peninsula. Palmer, a blue clump of prefabricated steel labs and dormitories, houses 43 researchers. Scientists here wondered if the unprecedented absence of an algae bloom along the melting ice edge was due to an increased cloud cover caused by global warming--or something else. Whatever it was, the krill, starved for carbon nutrients, were hardly reproducing. It was early October; the Antarctic dawn had begun, and ozone levels were dropping. Researchers studying nearby breeding colonies of Adelie penguins wore dark glasses and coated their faces with grade-25 sunscreen, but, despite the sun’s low angle on the northern horizon, the blondest among them were already becoming sunburned.

Deneb Karentz and three student assistants had arrived at Palmer two months earlier during the Antarctic night, to prepare cultures of local phytoplankton that the scientists would use as controls during their cruise. Now they were headed south, racing the rising sun to the edge of the pack ice. It was well known that UV-B damaged living cells in laboratories. The discovery of the ozone hole had finally freed up research funds to see what UV-B did in the real world.

For the next six weeks they floated along transect lines hundreds of miles long, suspending water and plankton samples at various depths in polyethylene bags, some shielded with UV filters, some exposed. Among other things, they tested to see if plankton could produce natural sun-block pigments--the microfloral equivalent of a suntan--to resist the increased ultraviolet radiation. With Smith’s underwater spectroradiometer, they also settled an old scientific controversy, proving that UV-B penetrates the ocean--to at least 70 meters, with detectable effects on microorganisms as deep as 35 meters.

Once every minute, they monitored UV at the ocean’s surface. Using a mathematical model Smith devised, corroborated later by a NASA satellite, they calculated the shrinking ozone overhead. The ozone hole, an elongated depression bigger than the United States, was rotating like an invisible propeller every two weeks. Through extraordinary luck, they had three full cycles to measure phytoplankton growth and reproduction with and without the hole. Whenever blizzards didn’t blow and light permitted, they took samples, alternating two-hour shifts on the Polar Duke’s wet, freezing deck. The harvest of data grew.

Every day at 4 a.m., Prezelin and Smith checked the weather, then roused the early shift to get instruments and specimen trays over the side and securely moored. Finally one morning, after she and a graduate student had rammed numbers through her computer all night long, Prezelin told him, “I think we’re seeing it.”

Smith already knew: They all did. Every time the ozone hole passed over, there was an unmistakable trend: Phytoplankton growth faltered. Because no measurements existed before the ozone hole was discovered, they could only guess how much loss had already occurred. Being purposely conservative, they announced phytoplankton production decreases of up to 12% each spring. Privately, they suspected the figures to be significantly higher, but it would take years of interpretation to understand what their findings really implied.

Since the damage began during the phytoplankton’s spring reproduction, would those numbers tumble through the food chain, resulting in even greater percentage losses of krill, penguins and whales? So far, these observations represented just a small fraction of the world’s phytoplankton output. If serious ozone depletion spread beyond Antarctica, would that mean the aquatic equivalent of burning rain forests, depriving the earth not only of food but of even more plant life to convert carbon dioxide back to oxygen?

And the hole was staying open longer and getting deeper. The UV monitor at Palmer Station showed that springtime ultraviolet radiation had doubled since 1970. After six months of darkness, tender organisms were suddenly being awakened by blasts of ultraviolet light beyond what they normally received in midsummer. Karentz and her colleagues had identified eight different sun-blocking compounds in local plants and animals such as starfish and sea urchins. But would the accumulated UV exposure eventually exceed their threshold of tolerance? What would that mean for tender human organisms, such as children in southern Chile?

Across the Drake Passage, Bedrich Magas worried over the same thing. As warm, high-pressure air pushed down over Antarctica, breaking up the annual ozone hole, chunks of the hole drifted north over New Zealand, Australia and South America. Mothers and kindergarten teachers stopped Magas in the streets of Punta Arenas, complaining of children who went outside to play and returned pink as lobsters. A local artist hauled him to her garden to see desiccated rosebuds and the yellowing grapevines in her solarium.

“Did you water them?” he asked.

Of course, she retorted. The artist had also taken one of the odd, double-headed sprigs of lupine that had suddenly appeared in her yard to the Patagonia Institute, a research wing of Magellan University, to show horticulturist Lothar Blunck. Blunck assured her that it was a normal anomaly, not an ozone-hole mutant.

Blunck was getting tired of newspaper portrayals of sheep stumbling into water holes and drowning. He was aware that sporadic viral blindness among livestock wasn’t unknown in the region, albeit maybe not hundreds of cases in a single flock. He didn’t want to contribute to panic over the ozone hole. But for five years now, he had been noticing how certain plants in his greenhouses, such as African violets and cucumbers, increasingly turned yellow. Chile’s economy now depends on its agricultural exports. If these things actually signaled increased ultraviolet radiation, he wondered what it portended for the country.

WHEN SEN. ALBERT GORE JR. WAS AN UNDERgraduate at Harvard, a professor explained the greenhouse effect to him. Twelve years later, when he was elected to Congress, Gore held the first congressional hearings on global warming. Soon he found himself dealing with another atmospheric crisis. “The scientific community has screened more than 300 species of crops,” Alan Teramura, chairman of the University of Maryland botany department, was telling Gore. “Alarmingly, over half seem to be sensitive to UV radiation.”

Even more disturbing, the list included major staples such as peas, beans, cassava, soy, rice and the entire squash family--among which the most susceptible to UV were cucumbers.

For the second time in 1991, the Tennessee senator, now chairman of the Senate Committee on Commerce, Science and Transportation, was holding emergency hearings on ozone depletion. Even before any public announcement of plankton decline in the Antarctic ecosystem, the world had already suffered two ozone-related shocks within a single year. The first, in April, was when William K. Reilly, chief of the Environmental Protection Agency, announced that the ozone layer was disappearing over the United States 300% faster than previously believed. This, he conceded, would add at least 200,000 skin-cancer deaths over the next 50 years.

The second, in October, was a United Nations report that the northern hemisphere’s ozone losses had mysteriously extended into the spring and summer, when the sun’s rays were most direct. The worst possible case for the year 2030 had already come true.

Just one year earlier, nations that had agreed to phase out 50% of offending chemicals by the year 2000 had upped that figure to 100%. Against U.S. resistance, a multimillion-dollar fund was established to help developing countries convert to alternative technologies as they became available. Now, Gore was calling for banning CFCs and destructive bromine compounds by 1996, as European countries had promised.

Even cynics who believed that Albert Gore was simply trying to embarrass President George Bush were having trouble ignoring witnesses such as Alan Teramura. Many strains of rice--the world’s most important food crop--appeared to be nearing their threshold of UV tolerance, the botanist explained. EPA-funded rice studies in the Philippines had also revealed an unsettling twist: As the world’s population increased, more rice paddies were releasing more methane, a greenhouse gas that accelerates global warming. Methane passes through the stems of rice plants as through a conduit; ultraviolet radiation seemed to force rice to develop extra branches, increasing the number of straws that allow methane easy passage. As climate changes affected rice, Teramura suggested, rice, in turn, could aggravate climate change.

Splicing genes from more UV-resistant crops might help keep the world fed, he said. But the research had yet to begin. To engineer new varieties would take 10 to 20 more years--both to find the genetic mechanism for resistance and to breed out flaws the resistant strains might have, such as vulnerability to pests.

A worse problem, Teramura added, was the natural environment. We couldn’t breed entire new forests nor could we protect them with hats, sunglasses and sunscreen. Long-lived plants such as trees may be especially sensitive: Preliminary research on three commercial species of pine suggested they accumulate ultraviolet radiation effects over time, so any damage would appear after UV dosage passed some unknown limit.

From trees to phytoplankton, Teramura concluded, natural diversity will decline, as the balance gradually tips toward species that can endure more ultraviolet. As Dr. Margaret Kripke, head of immunology at the University of Texas’ M.D. Anderson Cancer Center, testified, the same holds for humans.

Although ultraviolet-induced skin cancer mostly afflicts Caucasians, darker pigmentation provides no extra protection for immune cells in the skin. The tendency for some people’s immune systems to be more easily suppressed by ultraviolet light seems to be inherited regardless of race. Little is understood about the increased risk for infectious diseases, although UV is known to trigger the herpes virus, and a new U.N. report warns that in laboratory mice UV seems to activate the AIDS virus. “There are two major public health problems in the world: inadequate nutrition and infectious diseases,” Dr. Kripke said. “Ultraviolet radiation has the potential to affect both.”

IN PUNTA ARENAS, BEDRICH MAgas was finally able to show data from Argentina to the reluctant dermatologist, Dr. Jaime Abarca, indicating that the ozone hole sometimes brushed the tip of South America. The situation had not existed long enough for attributable cancers to appear, but each spring, Abarca realized, his patients were exhibiting increasingly severe non-malignant disorders, such as sun allergies and lupus. Why, he wondered, weren’t researchers from CFC-producing countries such as the United States down here, studying the biggest human population under the ozone hole?

The answer, Margaret Kripke knew, was that the United States was barely funding UV-effects studies at home. She had written senators protesting the dearth of UV research money for biologists and medical investigators, who perhaps weren’t as sophisticated as NASA at lobbying Congress. About 100 times more had been spent on atmospheric studies of ozone depletion than on its biological effects. Lately, she feared that funds would be diverted into finding CFC substitutes, not toward studying human health. “That is shortsighted. The ozone depletion we’ve already caused will be around a long time,” she said. “We need to know what sunscreens to wear. We need to know what we should be looking for.”

NASA, meanwhile, was doing its own looking. For 13 years, Total Ozone Mapping Spectrometer (TOMS) had been orbiting north-south 600 miles above the Earth, its volume of information so overwhelming that data processors failed to notice the ozone hole until British researcher Joe Farman reported it from the ground. In 1991, two more ozone-tracking satellites joined TOMS. Then, last December, a group of scientists, including Sherwood Rowland, who discovered the chlorofluorocarbon-ozone connection, and Harvard’s Jim Anderson, gathered in Bangor, Me., to watch the ER-2, NASA’s converted spy plane, carry Anderson’s chlorine detector and other instruments over the North Pole.

A series of flights had been planned through March. Halfway into the mission, the results were so grim the scientists felt obliged to go public. This time, there was even more chlorine monoxide over northern New England and eastern Canada than they’d found in the Antarctic in 1987. They sent the ER-2 south to the limit of its range, near Jamaica. More chlorine than ever was also over the tropics, where the sun is highest and ultraviolet radiation shines most intensely.

Even more sobering were signs that naturally occurring droplets of sulfuric acid in the mid-latitude atmosphere over the United States and Europe were behaving like the ice crystals of polar stratospheric clouds. The droplets were providing tiny surfaces for chlorine reactions to take place and suppressing the stratosphere’s immune system by tying up nitrogen compounds that retard chlorine’s assault on ozone. As if that weren’t enough, the massive eruption of Mt. Pinatubo in the Philippines had injected 10 times the normal amount of sulfur particles directly into the stratosphere, where they will remain suspended for nearly four years.

During that time, atmospheric chlorine will be nearing its all-time peak, reaching it just after the turn of the century. Efforts to phase out CFCs cannot coax it back to pre-ozone-hole levels until about the year 2075. What will happen, especially during the next decade, is unknown. The dynamics the scientists were studying in the northern hemisphere, Jim Anderson realized, were more subtle and complex than the sledgehammer effect of the concentrated vortex over frigid Antarctica. The northern vortex, buffeted by atmospheric waves along mountain ranges, oozed like an amoeba, sending one lobe over Quebec and Maine, another over Russia. If the vortex remained intact into the spring, enough ozone would be lost to call it a bona fide hole--if not this year, then soon.

The real question, though, involved not the North Pole but the sky above the United States, Europe, Japan and China, where so many people live. Many different reactions at different altitudes--chemistry involving not only chlorine and bromine--were combining to erode ozone. Every molecule in every catalytic reaction held a surprise, and they had yet to study even half of them.

“In some sense,” Anderson observed, “justice is prevailing. The northern hemisphere produced an overwhelming amount of CFCs. The ozone hole opened in a distant place. Now the problem has come home to roost.” By the century’s end, he added, living near Antarctica’s concentrated hole with its occasional passes overhead may be preferable to life under the northern swath of thin, ruptured ozone. The prospect of people hiding from the sunlight was unspeakable to him. But now he and his colleagues were wondering if anyone would be lying on beaches over the next several decades.

In response to the NASA announcements of new ozone loss over the United States, last month President Bush reversed his former stance and announced that “with limited exceptions for servicing certain existing equipment, all production of these substances in the United States will be eliminated by Dec. 31, 1995.”

“We’ve wasted more than a decade,” says Sherwood Rowland. “A lot more industrial CFCs appeared after we’d already banned aerosol sprays.” With no law to compel them otherwise, industry has dawdled in developing clean substitutes. Currently available alternatives, mostly related compounds called HCFCs, while an improvement, still harm ozone and are expensive. Even Rowland’s own university, UC Irvine, recently chose a new central cooling plant that uses CFCs instead of a more benign substitute--which one day will also have to be phased out.

BEDRICH MAGAS, HIS long legs dangling over a cliff at the end of the American continent, gazes at snowcapped islands where the Andes bend eastward and become the Darwin Mountains, named for the explorer who came to Chile to discover the origins of life. The pink, gray and golden dusk is so beautiful that Magas finds it hard to remember that the sky is sick. The hardships the United States will now endure by retrofitting millions of car air conditioners will be nothing, he knows, compared to effecting changes in the developing world. Despite international agreements, salesmen dumping CFC-based compressors and freezers are already in town, making the rounds. But that is not Magas’ real worry.

Humanity’s unintended, unfortunate experiment with the ozone layer is coming to a close, although it will be many years before human beings know if the damage was halted in time. But there are other crises pending, and thus far, no one has heeded the ozone hole’s costly lesson about delaying too long. Across the water on Tierra del Fuego, and throughout the world, oil is being pumped to the last drop, despite years of warnings by Rowland and others that to continue burning fossil fuel risks planetary suicide because of global warming. No government yet dares to dream of phasing out gasoline. This time, Magas wonders, will we really wait until it’s too late?

Recently, for allegedly scaring off developers with his ultraviolet alarms, Magas was publicly branded an “eco-terrorist” by the provincial governor. Now, he supposes, if he takes on global warming, he’ll be scorned as the Prophet of the Apocalypse.

A flock of upland geese flies past, silhouetted by the lingering glow over Cape Horn and Antarctica. “I wish the governor were right,” he says. “I’d rather be wrong about all this. I wish it were all a dream--that all we had to do is awaken, and the world will be right again.”

How Chlorofluorocarbons Destroy Ozone 1. Solar ultraviolet radiation hits chlorofluorocarbon molecules and breaks them apart. 2. A freed chlorine atom destroys an ozone molecule, forming chlorine monoxide and oxygen. 3. Ultraviolet rays break up the chlorine monoxide molecule, releasing the chlorine atom. One chlorine atom can destroy as many as 100,000 ozone molecules.