Perihelion Summer

by Greg Egan

  Arun said, “I think you’ve just invented a new food rating scheme, but it could do with some refinement. Do you mean two fillings, two root canals, or two extractions?”

  There was a brief cacophony as everyone’s phones buzzed and beeped, not quite all at once and with different choices of alert tones.

  In the control room, the map from JPL was waiting for them on the console. The landscape had shrunk to two tiny blobs: Taraxippus A and B at their closest approaches to the Earth, pinned down to within a few thousand kilometers. The heavier hole would come first, on 16 March, and the lighter one three days later.

  “Seventy-two million kilometers for A, seventy-five for B,” Jožka read.

  Aaron gave a strangled cheer that turned into a sob. “That’s nothing!” He looked to Yuki for confirmation. “Inverse cube law makes that eight times stronger than the solar tides, but these fuckers weigh ten times less, so that brings it down to less than solar.”

  Yuki embraced him. “That’s right, babe.”

  Matt closed his eyes and tried to share in their jubilation. The millions of people who’d stayed by the shores would not drown, or face a crushing exodus in the scrabble to find higher ground. He should have felt ecstatic. But if seventy million kilometers was more than enough to rule out a Biblical deluge, he’d seen too many simulations not to dread what was coming next, in the fine print.

  When he opened his eyes, Jožka’s finger was poised to tap a link in the corner of the screen, but she’d been waiting for everyone to signal their readiness.

  He said, “Go ahead.”

  The second map showed the Earth’s new orbit in the aftermath of the encounter, overlaid on the old one. The Taraxippoi would not have time to drag the planet far from its current position, so the two curves continued to pass through almost the same point in mid-March, and six months later in mid-September. The black holes wouldn’t even change the Earth’s speed much: most of the deceleration induced by the tug of their gravity as they approached from behind would be regained once they overtook the planet and began to pull it forward instead.

  What they would do, though, as they passed by on the outer side of the orbit, was turn the Earth’s velocity vector to point a little farther away from the sun. And by forcing it to veer off the road this way they were letting it do all the damage itself: the effect of that slight change in direction would build up over time, long after they were gone. So although the old and new orbits agreed in March and September, in June the planet would be 7 percent farther from the sun, and in December 10 percent closer.

  Aaron spent a minute parsing the new map, but it was well-annotated, so there wasn’t much chance of misreading it. “Our summers get hotter, and our winters colder. Right?”

  Matt said, “Yes.”

  “And the opposite in the northern hemisphere,” Aaron reasoned. “But by how much?” Yuki must have taught him how to calculate the tides, but apparently she’d spared him the Stefan-Boltzmann law.

  Jožka said, “It’s going to take some serious climate modeling to answer that properly, but as a crude rule of thumb you can halve the fractional change in the distance and apply it to the Earth’s average temperature above absolute zero, which is two hundred and ninety degrees. So maybe ten degrees Celsius colder in June, and fifteen degrees warmer in December.”

  Aaron nodded soberly. “All right. So . . . five degrees warmer on average?”

  Matt said, “I think you mean two and a half, but it will probably be a bit less, on average. We speed up when we’re closer to the sun, so we spend more time farther away.”

  “Okay. Two degrees, then?”

  “That sounds right,” Matt conceded. “But remember, it’s just an average.”

  Aaron was undaunted. “We knew two degrees was coming down the track! So maybe now that it’s happening earlier, that will motivate people to get serious. This could be a good thing, in the long run. The Ghost of Climate Future to shake us up before it’s too late!”

  Matt glanced at Yuki, wondering if he should leave it to her to break the news gently, but he couldn’t see how it would help to drip-feed the unpleasantness.

  He said, “This is not going to be the same as two degrees of global warming. Our summers will be hotter, our winters will be colder—they’re not going to split the difference. And when it’s fifteen degrees hotter in December—which means ten in some places, and twenty in others—the fact that it’s colder in June won’t help; most things that break from one extreme are not going to repair themselves when they’re slammed just as hard in the opposite direction. Crops are going to fail, forests will die, reefs will vanish, fisheries will collapse . . . and not by the end of the century. Some within a decade. Some within a year.”

  Aaron went quiet, and Matt felt a twinge of guilt for speaking so bluntly. But if they’d been spared the horror of a tidal inundation that might have killed half a billion people in a day, the only real reprieve would come if they wasted no time preparing for the slow motion equivalent. From March, the Earth would be following a new path: that was beyond doubt now. And everyone needed to start looking for the best way to survive the change.

  PART TWO

  7

  Matt arrived at the client’s house just as the blizzard hit. He parked the van in the street and ran for the door, but even when he reached the veranda he found the wind blowing in on him obliquely, with gusts powerful enough to carry the lighter pieces of hail with it.

  He rang the doorbell and waited, hunched into his jacket. An elderly man opened the door a crack.

  Matt shouted over the wind, “Mr. Carmichael?”

  The man nodded and motioned him in; Matt squeezed through into the hall.

  “I thought you’d cancel the job, in this weather,” Mr. Carmichael said.

  “I can still do the ceiling insulation,” Matt assured him. “The double glazing and the lagging for the water pipes might have to wait.”

  “The pipes burst this morning! I’m going to have to get a plumber in.”

  “I’m sorry to hear that.” Matt followed him through the house to the laundry, where the hatch to the ceiling was located, and where the supplier had left the insulation panels stacked against the wall. “I’ll just get my ladder from the van.”

  “No, I’ve got one in the garage.” Mr. Carmichael gestured at a side door. “Just through there. It’ll save you going outside again.”

  “Thank you.”

  Up in the roof space, the wind rattled the tiles and insinuated itself through the gaps between them to crisscross the gloom with unpredictable planes of icy air. But the job itself was routine; there were no exposed electrical wires, and no halogen lamps in the ceiling to set fire to anything that trapped their heat. Without Arun helping it took twice as long to maneuver each panel through the hatch, but Matt lost himself in the work and treated the wind as background music. Ninety minutes later, he was done.

  “Can I get you a cup of tea?” Mr. Carmichael offered as Matt folded the ladder. “I still have plenty of water; I filled up some containers before I shut off the mains.”

  Matt glanced out the window; he had no more appointments until the next day, and it probably wasn’t safe yet on the roads.

  “Thanks, that’s kind of you.”

  They sat at a table in the kitchen. “Are you on your own here?” Matt asked. It was a huge house, with at least four bedrooms.

  “My wife died last year.”

  “I’m sorry. Do you have any family around?”

  “My daughter’s overseas.” Mr. Carmichael frowned, perhaps taking the question as a slight on his independence. “The weather’s going to be a nuisance, but people have lived with winters like this for centuries, in other places: Manitoba, Mongolia. And they’re saying the summer won’t be much worse than it used to be in Kuwait.”

  Matt hoped that would be true. “Do you know what the temperature is right now in Dili?”

  Mr. Carmichael shook his head. Matt didn’t either, but when he took
out his phone the answer didn’t disappoint him. “Twenty-two degrees,” he read. “With light rain clearing.”

  “Sounds nice, but in six months it will be a bit of a sauna, won’t it?”

  Matt said, “To put it mildly.” He hesitated, unsure of the signals he was getting, but he pressed ahead. “Have you heard of the Seasonal Sharing Scheme?”

  “No.”

  “If you sign up, you get to spend your winters with a family in the tropics, where it’s likely to be balmy. Then in the summers you host the same family down here—where it won’t be pleasant, but at least it’s survivable with aircon.”

  Mr. Carmichael said, “I’ve heard of that, but I thought it was closed now. I mean, you could fit all of Darwin and Townsville into the spare rooms of Sydney, so it’s no surprise they got more offers than they needed.”

  Matt suspected that the government subsidy also helped, but it seemed uncharitable to mention that. “The in-country scheme is booked out,” he agreed, “but I’m talking about people in the countries to the north. PNG, East Timor, Indonesia.”

  “I thought they were going to China.”

  “China’s taking some seasonal migrants, but it’s hardly got room for everyone.”

  “Well, nor have we. Isn’t there some quota that the prime minister announced?”

  Matt said, “Two hundred thousand people. But this would be on top of that.”

  “On top of it?” Mr. Carmichael eyed Matt leerily. “You’re trying to find some kind of loophole?”

  “The quotas are for permanent migrants,” Matt explained. “With triple S, families just take turns hosting each other. No one gets new citizenship.”

  “So how would they support themselves here?”

  “Employment, if possible. But we’re hoping some people will be in a position to bring food with them—maybe nuts, legumes, that kind of thing. Agriculture’s going to be crazy everywhere, but the equatorial zone might stay productive through the southern winter, when we sure as hell won’t be growing anything outdoors.” Matt looked to the window; the blizzard was showing no signs of abating. He took out a card. “Anyway, this is the website if you think you’re interested.”

  He held the card out, but Mr. Carmichael didn’t take it. Matt put it on the table and rose to his feet.

  Mr. Carmichael said, “I’d rather know the contact details for your supervisor. I don’t expect to get a political spiel from a government contractor.”

  “I’m sorry if I offended you.” Matt had thought the man’s demeanor had been cautious; he’d missed the slide into outright hostility. “But I’m not a government contractor, I’m a volunteer.” The same federal scheme that sent out the insulation to every pensioner would also pay for tradespeople to come and install it, eventually, but it would probably have been September by the time that happened.

  “So who’s your supervisor?” Mr. Carmichael demanded.

  “You are,” Matt replied. “When I signed up on the website, the software checked my qualifications and police clearance; there are no other humans involved. If you want to give me a negative review, go ahead, but if you claim there’s a problem with the installation, the system will send someone to check that.” He walked into the hall. “I take it you don’t want me back to do the glazing when the weather clears up, so I’ll cancel that at my end so the site will let you submit a new request.”

  Outside, Matt sat in the van, waiting for the visibility to improve, wondering if it was worth giving in and paying black market prices for snow tires.

  His phone beeped. It was the Insulation Army app, letting him know that he’d been suspended for “offensive language toward a client.” He laughed wearily. He’d always hung up on cold-calling charities, so maybe this was his punishment for the hypocrisy of thinking he was entitled to ask people he’d never met to consider billeting strangers.

  When the snow stopped falling and the wind died down, he drove home as slowly as a nervous L-plater, still wary of his limited experience with the road conditions. He found the house empty except for his mother in the kitchen, preparing dinner.

  “Can I help with anything?” he asked.

  “You could cut those up,” she said, pointing to a collection of sickly vegetables she’d placed on the countertop.

  Matt found a knife and started chopping. He hoped she wasn’t just humoring him, making use of his stunted crop; since Selena had moved in the freezer was well-stocked, and even the current price of imported vegetables hadn’t yet moved beyond reach of a lawyer’s salary.

  When his mother had no more jobs for him, he went out to check on his Rube Goldberg greenhouse. The mesh screen that protected the wind turbine was glistening; it was steep enough that snow just slid off it, but it still acquired a fine coating of ice. Matt spent ten minutes scraping it with a wire brush; it wasn’t worth wasting power on the heating element.

  The building itself relied on more artificial heat and light than a Murmansk grow house, so he slipped inside as quickly as he could to avoid letting too much warmth escape. He hadn’t been able to get hold of the same sensors Arun and Yuki had used for the Mandjet’s garden, so he had to inspect every plant by eye. But the weather seemed to have killed off every living creature in the air and the soil, and there was nothing left to either help or hinder his efforts. He might as well have been growing these carrots and eggplants in a cave on the moon.

  When he returned to the house, Selena and his father were home, and everyone was about to sit down to dinner in front of the television news. The lead “story” was a propaganda piece: a government-supplied video showing off the billion dollars’ worth of drones that the black-shirted goons of the Border Force had acquired to police the empty northern cities throughout the summer, lest anyone from closer to the equator creep in and find what would surely have been marginal respite. “The quotas we’ve set for climate migrants are the most generous in the world,” the minister for Home Affairs read from her autocue. “But we cannot and will not allow our sovereignty to be undermined in the name of some false idea of compassion.” When the speech moved on to hint at the need for vigilance against the risk of a military incursion, Matt struggled to keep himself from bursting out laughing. Most of the top brass in Southeast Asia had enriched themselves sufficiently to buy their way into Russia or China, but even the lower-ranked officers would have no reason to take the initiative. A soon-to-be-barren continent that barely stretched twenty degrees below the Tropic of Capricorn simply wasn’t worth invading.

  Everyone chewed their food in silence, until the stock market prices brought Matt’s father to life. “See!” he crowed triumphantly. “It really didn’t matter about the vineyard, in the end. Whatever we’d invested in, it would have tanked just the same.”

  “Except for snow tires,” Matt suggested.

  “What did Arun’s parents invest in?” Matt’s mother asked. “It must have done well, if they could afford new houses in Cairns and Launceston.”

  “They invested in being surgeons for thirty years,” Matt replied. He glanced at Selena, hoping she might inject some sanity into the conversation, but she was lost in her own thoughts.

  “They can’t have just kept their money in the bank, though. And if they’d put it into local real estate they would have lost it all.”

  “Do you want me to phone him up and ask?” Matt offered, deadpan.

  His mother frowned. “No, I’m sure he’s busy with the boat. But next time you’re talking . . .”

  Matt collected up the plates and took them to the kitchen so he could wash the dishes. He was pretty sure the family could survive the winter, with or without him. But if the summer went badly—if the city hit 60 degrees, desalination couldn’t keep up with demand, and imported food became unaffordable or simply couldn’t make it through the equatorial zone—then his presence alone would be useless. He couldn’t jury-rig a suburban house into a self-sustaining space habitat, exploiting every ray of sunlight, recycling every drop of sweat. If the summer w
ent badly, the only thing to do would be to get them all onto the Mandjet. And if he wasn’t already on board himself, there’d be no guarantee it would be possible.

  He went to his room and phoned Arun.

  “How’s Perth?” Arun asked.

  “Siberian. Where are you now?”

  “A bit south of Broome.”

  “Can you wait for me there? Just a day or two.”

  “Sure.”

  “I think I’ll need to hitchhike. How are you guys doing?”

  “Everything’s fine. But the baby flies miss you so much.”

  “Fuck off.” Matt found the Town Beach boat ramp on a map and sent the coordinates.

  Arun said, “See you in a couple of days.”

  8

  When Matt thanked the truck driver and walked into Broome, it looked as if someone had started to build a film set for a remake of Bran Nue Dae, then realized that shooting it in Winnipeg wasn’t such a good idea. The trunks and branches of the dead palm trees and boabs might have been fiberglass props, waiting to have foliage glued on, and beneath the dull, overcast sky every building with a wide veranda or a touch of bamboo had the air of an impostor, desperately in need of some cinematic magic to make it more convincingly tropical. People walked the streets with their eyes cast down, wrapped up against the chill in repurposed clothing; Matt was quite sure that none of the scarves on view had started their lives that way. Maybe there’d be a few weeks in September when everyone could dress for the beach again, before they had to be bused south to escape the inferno.

  His phone had had no signal since Carnarvon, but as soon as he had a clear view of the water he could see the Mandjet in the middle of Roebuck Bay, maybe a kilometer away. He thought of paying a local boat owner to ferry him out, but he decided to sit and wait for a while, and after an hour or so he spotted the runabout heading toward him.

  “Welcome back!” Arun shouted as he approached the beach. “Third time lucky. I was starting to get worried.”