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--\o7 paine \f7 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.