Extinction of Starlight

This week, we have another special offering—near-future fiction specifically about our atmosphere, courtesy of Arizona State University's Center for Science and the Imagination. Read more about CSI below, but I was excited to share this story from its Overview project, both because it's poignant and thrilling, and because it's about the price we might pay for using technology to indefinitely cool the planet—to embark on permanent planetary geoengineering, basically. It's one of the best fictional treatments about the nitty gritty of geoengineering the future I've ever seen. Enjoy. -the Ed. Now a word from ASU's CSI:

"This story is part of Overview: Stories in the Stratosphere, a collection of science fiction stories, art, and speculative timelines exploring the near future of the stratosphere, published by ASU's Michael G. Bennett, Joey Eschrich, and Ed Finn. From Star Trek and 2001: A Space Odyssey to The Martian, great science fiction stories have shaped how we think about voyages into deep space — but what kinds of gripping confrontations and adventures might unfold in near space, above the clouds? Overview provides several compelling answers to that question, created by renowned science fiction authors, working in collaboration with designers, illustrators, and experts in fields ranging from human spaceflight and signal processing to law and tourism. The book is free to download in EPUB and MOBI formats, as well as through Apple's iBooks Store. Learn more here."

Liftoff was delayed by weather. The sun was bright and the sky was clear, its usual milky aqua, but far above a jetstream was in the way. They'd been waiting six hours.

—Lucy!

Carl was calling from the groundcar.

—We're go. Let's get you to the gondola.

The motor whined as Carl gunned it across the tarmac.

—Jetstream's gone?

—It's shifting. The lower winds will take you clear of it.

The balloon hung above the gondola like a great inverted fig. As it rose into lower air pressures, it would expand into a squat pumpkin shape.

—So, it's your first time into the stratosphere, said Carl.

—I've been up plenty of times.

—Yeah, but everyone says it's different above the tropopause. I wouldn't know.

—Guess I'll find out.

He brought the groundcar to a halt. —You OK?

—Of course. Why wouldn't I be?

He looked at her for a moment. — Safe journey.

—Thanks.

She walked toward the gondola, a cheerful-looking thing with a colorful parafoil. It had been designed for tourism, but that end of the business was slack these days.

Lucy had been on staff for a few years. She'd started on the ground, processing data from Earth observation balloons. Their clients — military, corporate, private — used the balloons in place of orbital satellites. They were cheaper and more maneuverable, gave better resolution and persistent coverage. She'd shied away from the surveillance and battlefield apps and ended up in climate science, monitoring ice shelves, coastlines, vegetation, and so forth. The data went to various agencies and NGOs.

But she'd wanted to be more hands-on. So she got involved with engineering, with implementation, and at last got her pilot certification. Now she took new balloons up for shakedown cruises.

—We are go, Crutzen 4.

—OK, ground. Crutzen 4 is go. Let's get this show on the road.

The airlock snugged shut behind her, and she heard the air compressor and heater start up. She didn't need them now, but she would before long. The tethers released, but she felt nothing. Only when she saw the outside perspective shift did she know she was rising. There was still a small thrill to it.

People and vehicles on the launch pad dwindled beneath her. The pad itself shrank to a small disk in the desert. The buildings around it threw exaggerated dark silhouettes of themselves to the east. Small puffs of cumulus clouds tracked their own black shadows against the dun ground.

— Lucy, it's calm up to about five kilometers. Then you should catch a westerly flow, about fifteen meters per second. You want to stay in that flow for about ten minutes.

She saw the flow on the radar. After a few minutes she felt it take hold and she shunted some gas to maintain altitude. The balloon stabilized and moved east.

Her Ph.D. was in geoengineering, so she understood what they were doing better than most. The story went back before her birth. That the burning of fossil fuels releases carbon dioxide, which in turn traps the sun's infrared and raises the Earth's temperature, wasn't the big news of the twenty-first century, or even the twentieth. The Swedish chemist Svante Arrhenius had pointed it out in the 1890s. The news was that it was no longer theoretical: it was here, and happening faster than anyone had foreseen.

In 2037 the West Antarctic Ice Sheet collapsed. Sea levels rose half a meter. And that was only a fraction of the sheet. Another eight meters' rise was being held back by some unstable buttresses.

The geoengineers wanted to dim the sun. Put aerosols into the stratosphere, they said. Reflect sunlight back into space and lower Earth's temperature. It was cheaper and easier than sequestering the excess CO2, replacing electrical and transportation infrastructure, or reforesting. Even if you did all those things, they'd take many decades. Civilization didn't have that much time.

In 2039 a volcano erupted in Sumatra, sending forty million tons of aerosols into the stratosphere. Global temperatures dropped by one degree Celsius for a year.

It was a compelling proof of concept. Within two years the U.N. had more or less worked out the governance issues, and humankind began injecting synthetic aerosols into the stratosphere.

At first a multinational fleet of some four hundred balloons went up daily, sprayed their payloads, then returned to Earth for more. The aerosol ingredients changed over the years, but included sulfates, titanium, alumina, calcites, and synthetic diamond. It was called the Dust for short.

And it worked. Earth's temperature soon dropped to late-twentieth-century levels.

But it wasn't a fix. It was an emergency stopgap. It didn't remove CO2 from the atmosphere. More still was added every year. The oceans still absorbed CO2, becoming more acidic. There wasn't a living coral reef anywhere on Earth. Large parts of the oceans were deserts of life.

Under the Dust, weather patterns changed. Monsoons failed, bringing famine. Arctic ports refroze, crashing economies. The ozone layer, after decades of recovery, began to thin again. The Dust fell back to Earth after a few years, and had to be replenished continually. No one knew what long-term effects the fallout might have on plant and animal life.

All that was before Lucy was born.

Now, some thirty balloons remained aloft at twenty kilometers for months at a time, tethered to Earth by nanotube hoses which pumped to the balloons the slurry of gases and nanoparticles that was the Dust, at a rate of twenty million tons per year.

So the Earth was cool, but CO2 levels were now above 800 ppm. The original promise, that if the Dust proved harmful it could be stopped and reversed, was no longer true. It now held back forty years' worth of temperature rise — about six degrees Celsius — which, in its absence, would surge quickly back. That was called termination shock, and the consequences were unspeakable.

To the south, distant thunderheads cast long shadows on themselves and on the ground. She was glad the clouds were far away. The balloon could be torn apart in those updrafts.

As she entered the tropopause, the sky grew bluer, a profound hue she'd never seen before. She remembered that ancient Greek had no word for blue, and wondered what Mediterranean profusion, what excess of splendor, had made for that lack. Something like this. No word was equal to it. It was like being truly outside for the first time.

Inevitably, she thought of Hiroshi. Two and a half years, and the pain of loss was still raw.

They'd met at university. He was an assistant professor, she a grad student eighteen years younger. They were married for seven years. Then he killed himself.

He left no note, but she knew his reason. He'd been twelve years old when the Dust started. It inspired him to study geoengineering. In the 60s and 70s he'd been a central voice in many climate decisions.

Hiroshi was a fixer. He was always repairing things around the house. He hated to throw things away. He practiced kintsugi, the art of mending broken ceramics with lacquer. The lacquer was made from the sap of the urushi plant, related to poison ivy, oak, and sumac. It was highly allergenic and dangerous to handle. She would watch him paint the lacquer carefully onto the shards' edges, pressing them together. After they dried, he painted over the seams with gold dust, to beautify the seam, and to honor the breakage, the history of the object.

More than once he'd pointed out the similarity between kintsugi and the Dust.

—We broke the natural carbon cycle. It's not the first time we've broken a global cycle. That would be the nitrogen cycle, when we first fixed it in fertilizers. That's what really enabled the population growth that put us where we are now. So it is our responsibility to care for these systems we have broken.

He went on. — Kintsugi is not … repair in the ordinary sense. It's for special things that are unique, that were made for a purpose. It's to honor their past. There are actually two different words for it, kintsugi and kintsukuroi.

—What is the difference?

He quickly wrote the characters.

—Kin, that part means gold, same in both. But look at these kanji. This one, tsukuroi, means … oh, merely repair. This one, tsugu, means more like … to continue, to renew.

—I don't see the difference.

—No? Well … tsukuroi is … to do the job. Tsugu is to do it with all your soul.

She had risen above the Dust. Ninety-seven percent of Earth's air was beneath her. Air pressure was thirty millibars, temperature -56 C. It was the edge of space. The sky was black. Just above the curvature of Earth's western horizon, the sun blazed upon the fragile blue envelope of atmosphere. This was the view that tourists paid a small fortune for.

—Crutzen 4, come in.

—This is Crutzen 4.

—How are you, Lucy? She recognized Carl's voice.

—All systems nominal.

—Good to know. But how are you, girl?

—Me? She was startled by the question. — I'm fine.

—OK, then. Are you ready to begin stationkeeping?

—Ready.

—On my mark.

—Stationkeeping engaged.

—Ground tracking engaged.

Now, for twelve hours the balloon would strive to hold position while she verified all its instruments. Propellers would hold it steady against lighter winds. Against stronger disturbances, multiband radar watched altitudes above and below the balloon, ready to move up or down to catch a favorable flow.

In the morning she would report in, and then release the gondola from the balloon. A moment of freefall in the thin air, but the parafoil would soon take over and glide it safely to the landing site. The balloon, shortly after, would compact itself and come down under its own parafoil.

— OK, Crutzen 4, we are tracking you. You call if you need anything. I'll be right here.

In his last year Hiroshi became disillusioned, dark. She might have seen what was coming but she didn't.

—If you mitigate risk, even reduce the appearance of risk, people take more risks. Putting the Dust up was the easy part. But you can't do just the easy part. We go on burning fossil fuels, we don't do enough carbon drawdown, emissions are worse than before we started! It would have been better to let the temperature rise and take the consequences.

—Hirochan, no. Billions of people would have suffered. The poorest the most.

—At least we would be serious about it now! Earth is unique. Its purpose is, what do you think? To shelter life, yes? Our purpose should be to continue that purpose.

—Yes. And that's what we're doing. Caring for the system that we altered. Reducing harm.

—I deceived myself into thinking that. But this is not care. This is not respecting the past. This is cutting loose from it. I wonder, even from the start, was it all empty show, to console ourselves for what we knew was lost?

As the sun set, the horizon was a curved line of blood. The reddened light spattered the tops of high clouds. Then, that quickly, it was night. Out of the black sky started thousands of stars, untwinkling. She stared out hungrily.

A faint band of light stretched from one horizon to the other — mottled, sugary, serene, like diamond dust. She knew what it was. It was our galaxy. It was the Milky Way.

She had never seen it before. No one living on Earth now ever saw it. The Dust absorbed just enough light to blot it out, even in the darkest places. That was called extinction of starlight.

For a moment she felt weightless with loss. Tears wet her face. She wept knowing that an entire world was now extinct — the world that had been blessed every night with this subtle glow. For eons it had shone on Australopithecus, Homo erectus, Homo sapiens. Now, under the Dust, it was forgotten, as humanity's brighter lights spangled the Earth like coals — the marks of ten billion mortal souls rushing into an unstable future that demanded one tenuous fix after another — a made world in debt to itself, immiserated. That faint arc of galactic light was, to this world, unimportant—it did not sustain life, it did not give shelter — yet she wept for its loss. To lose it was truly cutting the future loose from the past.

—You gave up, damn you! You gave up and left me behind.

The air compressor and heater hummed.

It would be easy. She could override the safeties on the airlock. She knew how.

But she wouldn't. She couldn't say he was wrong, but she was not there yet. She still believed in the difficult art of continuance.