One of the paleontologists spoke from the fringes of the group. “And the life-forms would have less oxygen to drive fast metabolisms like ours.”
Stan nodded. “And of course, with less land area, there’d be less chance of evolving these.” He held up ten wriggling fingers.
“Huh!” Elena Gorshkov commented, shaking her head. Several arguments erupted at the periphery as the scientists disputed amiably. Nielsen was tapping away at the miniplaque on his lap, probably looking for refutations.
Good, Stan thought. These were bright people, and he liked watching them toss ideas about like volleyballs. Too bad he had to keep his most pressing scientific quandaries secret from them. To know such things as he did, and withhold them from his peers… it felt shameful to Stan. ›,
“Aha,” Nielsen said. “I just found an interesting paper on continental weathering that supports what Stan says. Here. I’ll pipe it to the rest of you.”
People drew plaques and readers from their pockets and unfolded them to receive the document, drawn from some corner of the net by Nielsen’s quick-and-dirty ferret program. Distracted from his recent desire to leave, Stan too began reaching for his wallet display.
At that moment, though, his watch gave a tiny, throbbing jolt to his left wrist, just sharp enough to get his attention — the rhythm urgent.
While the chatter of excited discussion swelled again, Stan excused himself as if heading for the men’s room. Along the way he popped a micro-pickup from the watch and put it in his ear.
“Speak,” he said to the luminous dial.
“Stan.” It was the tinny voice of Mohotunga Bailie, his assistant, and it carried overtones of fear. “Get back. Right quick.” That was all. The carrier tone cut off abruptly.
Stan felt a chill, mixed thoroughly with sudden pangs of guilt. The taniwha — has it gone out of control? Oh Lord, I shouldn’t have left them alone!
But even as he thought it, he knew in his heart that Beta couldn’t have gotten away so suddenly. The physics just weren’t there for such a happenstance… not from the stable configurations of just an hour ago!
Then it must be one of the beams. This time we must have hit a city. How many died? Oh God, can you forgive us? Can anyone?
With pale, shaking hands he plunged outside where the pearly arctic twilight stretched around two thirds of the horizon. The aurora borealis made flickering, ionized curtains above the Greenland ice sheet. Stan half stumbled, half ran to his little four-wheeled scooter and kicked the starter, sending its balloon tires whining across the glittering moraine, spewing gravel behind it.
All the way back to the Tangoparu shelter, his mind was filled with dire imaginings of what could have put those dread tones in his stolid assistant’s voice. Then he crossed a hillock and the dome itself came into view, along with the big, olive-drab helicopter, parked just beyond. Stan’s heart did another flip-flop.
It wasn’t a problem with Beta after all, he realized suddenly. At least not directly. This was quite another type of calamity.
NATO, he realized, recognizing the uniforms of the armed men patrolling the shelter’s perimeter. Lord love a duck… I never thought I’d see those colors again. I’d forgotten they were still in business.
He knew only one reason the big armed aircraft would have come all this way at such a time of night, bringing soldiers to the door of his laboratory. And it surely wasn’t a social call.
They’ve found us, he realized, knowing he had only seconds to decide what to do.
□ Piano-Forbes: 2.5 billion
World Watch: 6.0 billion
Rocks-Runyon: 10.0 billion
These estimates of the Earth’s maximum sustainable human population were all made before 1990,. as the world’s attention began shifting from ideologies and nationalism toward matters of ecological survival. The three appraisals at first sight seem utterly at odds. Yet all were based on the same raw data.
In fact, their differences lie primarily in how each defined the word “sustainable.”
To Piano and Forbes, it meant a system lasting at least as long as ancient China had — several thousand years — that would provide all human children with education, basic amenities, and per capita energy use equal to half the consumption of circa 1980 Americans. A sustainable human population would use carbon-based fuels only as fast as vegetation recycled them and would set aside enough wilderness to preserve the natural genome.
These criteria proved impossible to maintain for long periods at population levels exceeding 2.5 billion.*
World Watch used looser constraints for their estimate. For instance, while “American” consumption levels were still seen as spendthrift, the authors did not call for rationing fossil fuels. Food was their critical concern, and although they failed to foresee many important negative and positive trends (e.g., greenhouse desertification vs. self-fertilizing maize) their major difference with Piano-Forbes arose from projecting “sustainability” only a hundred years or so at a stretch.
The Rocks-Runyon model has proven the most accurate one, in the simple sense that it correctly predicted we could (with difficulty) feed ten billion by the year 2040. It also clearly asks the least for the human future. Bare survival was its criterion — muddling through, with little worry spared for even a hundred years, let alone thousands of years, down the road.
And indeed, there are those who argue we shouldn’t be concerned so far ahead. After all, science progresses. Perhaps those generations will invent new solutions to make the problems we leave them seem academic.
Perhaps our descendants will be able to take care of themselves.
’These figures are challenged by groups promoting space colonization, who project that lunar and asteroidal resources, with limitless solar power, would permit Piano-Forbes life-styles for ten to twenty billion humans, sustainable for all foreseeable time. Their favorite analogy is Columbus’s discovery of the New World. The flaw in such schemes, however, is the initial investment needed before wealth from space can bring prosperity down to Earth. Governments and peoples, already living hand to mouth, will hardly put so much into projects whose bounty might profit their grandchildren, but not themselves.
• MANTLE
There was only one entrance to the deep cave complex. When armed men in blue helmets rained from the sky on jet-assisted parafoils, they had to hunt and thrash through the jungle for a time before they found that hidden opening. Then, silently, they began repelling down the shadowy chimney.
Sepak Takraw awakened to the sound of blaring alarms and at first thought it was only another Gazer run… whatever those were. The Kiwis working for George Hutton had remained closemouthed about the essential purpose of the gravity scans, though clearly they had to do with the Earth’s deepest interior. Whatever the Tangoparu techs were doing here in New Guinea, they sure took their work godawfully seriously — as if the world would end if they made one bleeding mistake!
Sepak had finally moved his sleeping roll up to a cleft in a narrow, extinct watercourse, because of the noise they made each time their big resonator thing fired up, sending bells and whoops echoing through the deep galleries. This time, however, when he stumbled toward the lighted chamber rubbing his eyes, he suddenly stopped and stared down at a scene of utter chaos. Had the New Zealanders finally done it this time, with all their noise? Invoked Tu, the Maori god of war?
They were dashing about like addled bowerbirds, and the bright cylindrical resonator swung wildly within its gimbaled cage as armed men swarmed into the hall. Sepak slipped into the shadows and kept very still. George bloody Hutton. What’ve you got me into! The government can’t be this upset over us keeping a few caves secret for a while!