An Ocean of Air (24 page)

They are beautiful, these clouds, iridescent like the inside of an abalone shell with hot pinks and purples and shimmering blues, colors that don't belong in the sky. In spring, when the sun has returned after the long polar night, they materialize at sunrise or sunset seemingly out of thin air. In fact, the clouds are there all the time, but it's only as the sun tips over the horizon that it picks them out, shining on them like a spotlight with its final steep rays. And then, suddenly, it's as if the sky is filled with glimmering peacock feathers. The early explorers made exquisite watercolors of the effect. They had no idea how dangerous it would turn out to be.

Many different researchers began to suggest that these high stratospheric clouds might explain the Antarctic ozone hole. Among them was a thirty-year-old theoretician named Susan Solomon, who was working at the National Oceanic and Atmospheric Administration in Boulder, Colorado. Though she was young, Solomon was very talented. She had been
one of the original reviewers of Joe Farman's paper, and when she read it she was immediately horrified. Ever since, the data had nagged at her.

Hunched over her computer, Solomon had tried model after model, accounting for every reaction she could think of in the Antarctic stratosphere. None of them made a hole of this magnitude. Then she began thinking about the clouds. What if they made the difference? Perhaps they somehow "primed" the Antarctic atmosphere during the winter, so that when sunlight returned in spring the destruction could begin.

Cloud surfaces can make a big difference to chemical reactions, especially in somewhere as thin as the stratosphere. For any chemistry to happen in the air, two atoms or molecules have to meet. But up where the air is rarefied, such encounters don't happen very often. What's more, the two, or more, participants in the reaction need to be suitably energized. If they're overly lethargic, nothing much will come of their meeting.

But if any of these chemicals can land on the surface of a cloud, they immediately have many more options. The cloud can act as an introduction agency, both bringing species together and giving them an energy boost to get them going. That's what Solomon found when she began to put clouds into her model.

The key seemed to be in those unreactive "reservoir" species that could bind up chlorine atoms and keep them out of trouble. Throughout the long winter nights, these molecules—chlorine nitrate and hydrochloric acid—could be landing on the surface of clouds and reacting. Work through the sequence of reactions and you end up with chlorine gas, Cl2. This molecule detaches itself from the clouds and awaits the return of sunlight. The first ultraviolet rays that appear with the rising sun split the chlorine gas into its individual, deadly atoms, which rip ravenously through the ozone layer. Suddenly a hole made perfect sense. The only wonder was that it wasn't even worse.

Still, this was only a theory. Around the United States, many other research groups had come to similar conclusions, but they all knew that nobody could be sure until they had more data. Someone would have to go south to Antarctica, to measure the reactions as they happened at the end of the twenty-four-hour darkness of winter and on into the first few weeks of spring.

Solomon was as surprised as anyone to find herself volunteering for the job. She was a theoretician. Her work involved sitting at a computer, not going out into the field. For her first-ever venture into experimental science, she would lead a team of twelve people to the coldest, most hostile place on Earth, in the winter.

She still can't explain why she wanted to go. Perhaps because, in spite of the sedentary nature of her chosen profession, she was captivated by the might of the atmosphere. She loved storms, thunder, lightning—anything that reminded her how powerful nature is, and how puny humans are by comparison.

For whatever reason, a few months later Solomon found herself at the airport in Christchurch, New Zealand, sweltering in her red fur-trimmed parka, clutching her standard-issue canvas bag full of safety gear and survival clothing. Ahead was a hazardous eight-hour flight in a Hercules military transport plane. The pilot arrived for the briefing and regarded the twelve men and one young woman in front of him. "Who's in charge here?" he asked. Solomon raised her hand. The pilot regarded her with some astonishment and then managed to stammer out, "Good for you."

Solomon loved Antarctica from the moment she stepped off the plane. She loved the emptiness, the ferocity, the unforgiving wildness. It wasn't beautiful in the usual, picture-postcard sense. Its beauty was fierce, and Solomon reveled in it.

She had arrived at McMurdo, the main American base, which is the unofficial "capital" of the continent. It was August 1986, the tail end of the austral winter. The influx of summer visitors would not begin for another month or so, when the weather warmed and daylight began to stretch toward twenty-four hours. The only occupants of the base were the people who had been isolated there for the whole winter, who had bonded tightly with each other into established cliques and enmities and tended to regard with suspicion newcomers who would unwittingly take the wrong chair at dinner, or hang their coat on "somebody else's" peg.

Solomon's task was to set up an instrument on the roof of one of the buildings. The idea was to use incoming moonlight to pick out and measure the chemicals floating in the intervening stratosphere. The measuring instrument would be inside the building, but up on the roof would be mirrors that would turn to guide the moonlight down into a channel.

The team had only four months' notice of their journey. They hadn't had time to construct a tracking system to turn the mirrors as the moon journeyed across the sky. Instead, someone had to be on hand, braving temperatures of –40 degrees and the occasional fierce wind that could blow up almost out of nowhere.

One night, Solomon was up on the roof taking her turn when the weather turned cloudy. Without moonlight the instrument was useless. Solomon decided to leave the mirrors and climb back down into the lab for a nap. Perhaps when she returned, the moon would be back. In the laboratory, Solomon curled up in her sleeping bag and fell asleep. She woke to a blizzard, the worst kind of white-out, winds screaming past the building with a ferociousness rarely seen outside the ice. Solomon was aghast. Her mirrors were still on the roof. If they became damaged, the project was over.

Without stopping to think, she climbed back up the wooden ladder onto the roof, bracing her face against the shards of snow that blasted like sand. She flung herself, spread-eagled, onto the roof surface and began to edge her way toward the mirrors, the gusts tugging at her, urging her to fall. But she held onto the mirrors, and the ladder, and managed to scramble back inside.

It was worth it, she says. It was all worth it. Because Solomon's research, and the studies that followed, showed beyond a doubt that high stratospheric ice clouds were indeed doing the damage. Each winter, they took the chlorine reservoirs and activated them, priming the Antarctic air like a grenade. True, this is a problem that is unique to the unoccupied continent of Antarctica; even the Arctic doesn't get cold enough to form stratospheric clouds for long, and there has never been an ozone hole in northern parts. But though you could argue that the Antarctic problem would affect only a few penguins and scientists, the striking image of deadly rays flooding through a hole in the sky turned the ozone tide.

On September 16, 1987, under the auspices of the United Nations Environment Program, twenty-one nations and the European Community signed the famous Montreal Protocol, the first international agreement ever made to restrict the emissions of an environmentally hazardous material. There would be a 50 percent reduction of CFC production by the end of the century.

In March 1988, new analyses of ozone measurements over the United States, Canada, Japan, and northern Europe revealed that, though not as severe as the Antarctic loss, the air was thinning in the north as well. Two weeks later Dupont, the world's largest CFC manufacturer, announced it would cease production.

As the ozone hole continued to deepen and yet more scientific evidence flooded in to link ozone loss to Midgley's CFCs, the targets grew more stringent. In 1990 an amendment signed in London required a complete ban by the end of the century. Two years later in Copenhagen, the rules changed yet again. Now there would be a ban on CFC production and use by 1996.

In 1995, Molina and Rowland were awarded the Nobel prize for their work identifying the dangers of CFCs. The other researchers involved received their share of awards and accolades. Solomon even had a glacier named after her in Antarctica. When she first heard about this by fax she thought it was a joke, and that the glacier had in fact been named after some Antarctic explorer who shared her surname. It was only after she left the fax in her in-tray for a week that she read the small print and realized it was true. She now describes this as her "favorite honor." And all had a personal prize that comes rarely in scientific research: the knowledge that their work has helped save the world.

Midgley's monsters are very long-lived. They will remain in the atmosphere throughout the twenty-first century; you will inhale some of them in every breath you ever take. The ozone hole will continue to appear every spring over Antarctica, too, and will probably get worse before it's
better. In the end, though, some time toward the end of the century, the hole itself will heal, and our protective shield will be back in place.

There is one last sting in this tale. Many people confuse the twin environmental bugbears of the ozone hole and global warming, though they are actually independent problems, each with its own separate cause. And yet there is a sinister connection between them. Global warming makes the tarpaulin water barrier between the troposphere and stratosphere just a little more leaky, so that a warmer world will contain a stratosphere that's slightly more damp. Also, warming in the troposphere means that the stratosphere gets cooler. Put these two together and the conditions become even more favorable to make more stratospheric clouds, not just in Antarctica, but also in the north.

Until now the Arctic has been protected from an ozone hole. The surrounding mountainous landmasses disrupt the air flow, which stops a true vortex from forming, so it's never quite cold enough to make stratospheric clouds for long. But global warming could yet change that. For three months from the end of November 2004, there were more stratospheric clouds over the Arctic than have ever been seen, and they persisted for longer than usual. And in spring 2005, some 50 percent of the ozone layer disappeared overhead. Though this wasn't quite a hole on the Antarctic scale, it has much more chance of reaching inhabited regions. Unlike the tightly isolated Antarctic atmosphere, the northern vortex tends to slew around like a wobbling top; in the same year, it drifted down over northern Europe as far south as Italy.

Perhaps we all need to bear in mind the words of Jim Lovelock, who now fully appreciates the dangers of CFCs. In 1999, approaching his eightieth year, he wrote this:

Our planet is one of exquisite beauty: it is made of the breath, the blood and the bones of our ancestors. We need to recall our ancient sense of the Earth as an organism and revere it again. Gaia has been the guardian of life for all its existence, and we reject her care at our peril.

STARTING SOME SIXTY MILES
above Earth's surface, the air crackles with current. This is a mysterious region of our atmospheric ocean. It is the home of shooting stars and strange dancing jets of light—some long, thin, and blue, which are drawn all the way up from the tops of thunderclouds deep below them; others, gigantic blobs of red with flailing tentacles. Researchers have only recently spotted these weird ultra-high forms of lightning and have given them appropriately whimsical names: elves, sprites, and goblins.

They provide the backdrop to the most important function of this high electrical layer: It is the big brother of the ozone layer, soaking up rays from space so deadly that without it Earth would be lifeless. The first indication that this high electrical region existed at all came from someone who hadn't the slightest clue it was there, but was still hoping with all his heart that it would help him.

DECEMBER
12, 1901
12:30
P.M.

A young man was sitting at a desk in a small building perched on Signal Hill, Newfoundland. Though the room was dusty, the table in front of him bore the highest technology of the time: a curious jumble of leather boxes and shiny gold wires, and a small bronze device that the man had pressed to his ear. He knew, or at least he hoped, that 2,200 miles away in Poldu, Cornwall, a team of workers were cranking up their aerials to broadcast a message to him. But all he could hear was crackles.

Guglielmo Marconi was an unusual mix. His Irish mother, daughter of the wealthy Jameson whiskey family, had run away from home to marry her Italian beau, against whom her parents were implacably opposed. Their antipathy was understandable. Annie was only twenty-one, and Giuseppe Marconi was thirty-eight. Worse still, he was a widower, who already had a son of his own. He was foreign, too, living in some far-off mountainous region that had little to do with the vibrant society circles in which Annie's family habitually moved.

But Annie had been determined. And although Giuseppe had grown a little more distant over the years, she never regretted her elopement. Her first son, Alfonso, was born a year after the marriage; the second, Guglielmo, came a full nine years later, in April 1874. Perhaps because of her husband's increasing remoteness, Guglielmo had all of Annie's heart. According to family legend, among the servants crowding into Annie's room to view the new baby was an old gardener who blurted out, "What big ears he has." Annie is said to have retorted: "He will be able to hear the still, small voice of the air."

Marconi's father was nearly fifty when he was born, and had little patience for mewling infants. Giuseppe's other two sons caused him no trouble. They were quiet and obedient. They submitted to his strict authority with respect. But Guglielmo was in trouble with his father almost from the moment he could talk. At mealtimes, when children were supposed to present themselves punctually, suitably scrubbed, and ready to engage in informed conversation only when called upon to do so, Guglielmo was inclined to arrive late, splattered with mud or dust, and to blurt out whatever new ideas were unaccountably running through his head.