Analog SFF, April 2007

by Dell Magazine Authors

  Her palm throbbed. She yearned to reply, but what was the point? This wasn't about reason. It was about power—and she had none here. She wasn't getting out of this place, certainly not if she didn't play ball.

  She had misjudged this man. He was no drone, and that was no blessing.

  "That's what awaits you,” the President said, “if you don't own what you've done. We can prevent that, if you will work with us. You can consider it mutual assistance, if you're so inclined. You can also consider it a plea bargain, if you're inclined that way."

  "My term is ‘extortion,’ Mr. President."

  "Your attitude is your problem, Ms. Peale. The choice is there before you. I can give you time to think it over, but not much.” He motioned to the Secret Service. “Take her to the holding area."

  Two of the agents took her in hand, leading her toward the door. As one opened it, she turned over her shoulder. “I don't need that time. I've decided.” She saw Burleigh scowl, and the agents’ grip on her stiffened. She nearly reconsidered before going on. “I'm ready to work here."

  She had the satisfaction of seeing the President's jaw drop, meager consolation that it was. He was going to take this course, with or without her. Her choice was between the invisible martyrdom of refusal, or working within this project, mitigating its abuses as much as she could. That was a worthy goal—and she didn't have the nerve to try the alternative.

  Burleigh quickly gestured to the agents to turn her loose. Once they did, she finished her sentence. “But I'll need some guarantee that I won't have the overlay of Mr. Lodish held over my head."

  The President grew guarded again, and Lucinda much preferred him that way. “What guarantee?"

  Lucinda rolled her shoulders to get circulation back into hard-gripped arms, and strode halfway across the oval room. “If that procedure was a crime, as you allege, then I think a Presidential pardon is in order. In writing, with your signature, and in my hand before I leave this office."

  "You're asking rather a lot, Doctor."

  "Under the circumstances, I'm asking rather little, compared to what I'll be giving you.” Like my soul.

  Burleigh's eyes drifted downward as he thought. Finally, he turned to his computer. “Very well.” Lucinda felt a spurt of triumph, and got ready to name her next conditions. “But,” he continued, “let me make all the terms clear."

  "I have rather more to say."

  "Not now, you don't. You are not going to have freedom of communication or movement while under our auspices. You'll be working in a secure federal facility, probably here at the Mount, at least at the start. You aren't going to tell people where you are or what you're doing without our explicit permission. You won't be communicating anything to anyone outside without our permission, and oversight. Do you understand?"

  "You're talking about censoring my letters, my e-mail, everything. That comes as no surprise."

  "It shouldn't,” Burleigh said, very matter of fact. “A Second World War project would have acted similarly."

  Put that way, it almost sounded reasonable. Still, it meant severing herself from her regular life. Home, family, friends ... Josh, whatever he was to her. Even poor Ben: he'd have no place here. Josh might have to take him in. She might not see him for a long time. Either of them.

  What would Josh have told her to do here? He had said overlay was too powerful to leave to people eager to use it. But he had said that when she about to challenge the system, not work inside it. She wanted him here to guide her, and knew it was impossible.

  "I ... accept those restrictions, sir."

  "And will you sign an agreement along those lines?” Burleigh saw her balk. “If you're expecting that pardon—"

  "I know what deal I'm negotiating, sir.” Lucinda needed to wrest away his upper hand. “Will you be keeping Dr. O'Doul and Kate Barber here as well?"

  "O'Doul, yes. Barber, we don't need. Her skills aren't that vital."

  "Can I see her before she goes?"

  "She's ... already out of the Mount. Now, that signature."

  Lucinda knew the President was dissembling. Kate had refused him, and probably wasn't headed home. She wanted to cheer, or rail, or throw his words back in his face. She did none of those, with an act of inhibition that was already becoming second nature. She knew her limits here.

  "Our signatures, you mean,” she said. “I think you should draw up those papers."

  He bent over the keyboard, and hammered away fast. Not giving her time to back out, she guessed. Let him think she might, for whatever psychological edge it might grant her.

  And Lucinda did wish, intensely, desperately, that she could back out. Pavel might have made common cause with the President willingly. So might Nancy, who had been so adamant on not aiding acts of reprisal. But it was her here, not them: one small irony, adrift in the oceanic nightmare of the last few days.

  She had done this before. She worked under Dr. Petrusky's de facto control of the Berkeley program. If she could stand that, for a while, she could stand this, for a while. But when she couldn't stand Berkeley any longer, she had the choice of leaving. She wouldn't have that here.

  One year, she told herself. Burleigh could not last forever. The country would not stand what he would do. They'd stop this, maybe by sheer mass of outcry, surely no later than the November election. If he held one.

  Lucinda screwed her eyes shut. She would drive herself insane if she dwelt on such thoughts. One year, she repeated. I can endure one year.

  "Is there a problem, Doctor?"

  Her eyes blinked open, a shimmer of tears fogging her vision. “It's catching up to me,” she said, not looking at the President. “All the people I've lost; all the ... things."

  A printer began humming. “We have to look ahead,” Burleigh said. “What's past will not return, ever."

  Lucinda Peale stared at a bare stretch of the curved wall. That's what I'm afraid of.

  Copyright (c) 2007 Shane Tourtellotte

  (EDITOR'S NOTE: Earlier stories of the overlay project include “Acts of Conscience” [March 2005] and “A New Man” [October 2003].)

  * * * *

  "Everything is open to questioning. This does not mean all answers are equally valid."—Kelvin Throop

  [Back to Table of Contents]

  SCIENCE FACT: THE ICE AGE THAT WASN'T by Richard A. Lovett

  How our ancestors may have held the ice at bay.

  Anyone who pays attention to the news knows that the Earth is warming. As I write this, the latest report is that the rate of ice flow from Greenland's glaciers has doubled in the past decade. But by the time you read it, the only certainty is that this will be old news.

  The main question is the extent to which humans have caused this warming. The Earth, the conventional wisdom goes, is rebounding from an ice age, but in the past 150 or 200 years, we have accelerated the pace as a byproduct of our use of fossil fuels. Prior to that, we were puny creatures incapable of affecting the global environment, and it is only modern technology that changed this.

  But is that true? Not the modern technology part—few Analog readers would disagree that we have the ability to geoengineer the Earth on a large scale, and that the future will give us ever greater power. “Our leverage [over climate] keeps growing as our science gets better,” David Keith, of the University of Calgary, put it at the Fall 2005 meeting of the American Geophysical Union.

  But until recently, climate had a much more obvious effect on us than we had on it. Harvey Weiss, an archaeologist from Yale University, goes so far as to argue that civilization was created in reaction to a climate fluctuation that occurred about 8,200 years ago. He bases this argument on the fact that humans have been on the planet a long time, but it was only then, in ancient Mesopotamia (today's Iraq), that they began banding together into anything more complex than scattered tribes and villages.

  "The biggest question in Mesopotamian archaeology is why there even is a Mesopotamian archeology,” he said at a 2003 geophysics
meeting. That's because, at first glance, Mesopotamia isn't the most inviting place. It's a desolate area “that looks like what you see on CNN every night. Bleak, dismal, and parched, only watered where the Euphrates has its course.” It can be farmed, but only at the cost of a lot of work, building and maintaining irrigation canals. Cooperating to do this was obviously a boost to civilization—but why bother?

  Weiss argues that the answer lay in the aforementioned climate change: an abrupt cold shift and drought that lasted 200-300 years.[1] This forced people to migrate to the water, where they had to work together to learn irrigation. By the time the climate moderated, civilization was established.

  [Footnote 1: Geophysicists can identify such things by numerous means, one of which is cataloguing pollen residues in sediments. Changes in pollen types reveal changes in climate.]

  Sara Parcak, of the University of Cambridge, believes that another abrupt shift, about 4,200 years ago, produced droughts that contributed to the collapse of Egypt's once-powerful Old Kingdom. Similarly, many archaeologists believe that drying climate in the American Southwest may have forced the Anasazi to abandon the cliff dwellings that delight today's tourists. More recently, a series of wet decades in the early twentieth century lured farmers to places as unlikely as California's Mojave Desert and the sagebrush steppes of eastern Oregon, where ghost towns still dot the land. And in early 2006, South African scientists calculated that global warming would eliminate a sizeable percentage of the continent's arid-region creeks by the end of this century—a potential catastrophe for some of the world's poorest countries.

  * * * *

  Swamp Gas

  But dependent as humans were (and are) on weather, were our distant ancestors really too weak to make an impact?

  Not so, says William F. Ruddiman, a retired professor from the University of Virginia. That's because 12,000 years ago, they discovered agriculture. And within a few thousand years, that gave them so much (unintended) power over climate that the Earth wouldn't be “naturally” warming without them.

  Ruddiman begins by noting that ice ages are caused by variations in the Earth's orbit that alter the amount of sunlight reaching Canada, Siberia, and Alaska during the brief arctic summer. During high sunlight cycles, there's enough warmth to melt the previous winter's snows. During cold ones, there isn't, and snow gradually accumulates into glaciers.

  These orbital variations occur in three well-understood cycles.

  1. A 41,000-year variation in the tilt of the Earth's axis. Discovered in the 1840s by French astronomer Urbain Leverrier, this is produced by the gravity of the outer planets and causes the tilt to vary from 22.2 degrees to 24.5 degrees. That changes the angle of the midsummer sun by 2.3 degrees—small, but enough to significantly affect snow melting in the far north. Right now, we're in the middle of the range, at 23 1/2 degrees, but we're heading toward the cold end.

  2. A 26,000-year precession of the Earth's orbit around the sun.[2] Basically, this is like a top wobbling on its axis. The angle of the Earth's tilt doesn't change (except for the small variation noted above), but the direction slowly shifts. If the Earth's orbit were circular, this wouldn't matter. But it's elliptical, which means that sometimes the arctic summer comes when the Earth is closest to the sun, sometimes when it's farthest. Again, the effect is small but significant. In the first case we get warm summers and lots of melting.[3] In the other, we get cooler summers and less melting. And guess what: For the last several thousand years, we've been heading for the cold-summer end of this cycle, too.

  [Footnote 2: This was also discovered in the nineteenth century by French mathematician Jean le Rond d'Alembert.]

  [Footnote 3: We also get colder winters, but that's not as important.]

  3. A 100,000-year variation in the eccentricity of the Earth's orbit.[4] In some ways, this is most important because it exaggerates the effect of the precession cycles, making them more pronounced when the Earth's orbit is least circular. This one is also shifting toward its colder realm.

  [Footnote 4: This is yet another discovery of Leverrier's. Those nineteenth-century French astronomers were busy folk!]

  During the heart of the most recent ice age, 20,000 years ago, all three cycles combined to plunge the planet into the icehouse. By 11,000 years ago, when the glaciers were in full retreat, solar radiation reached a glacier-melting peak. Afterward, glaciers continued to melt (just as summer days continue to get hotter after June 21, the longest day of the year), but solar energy has been steadily decreasing: a trend that normally would lead into the next cold cycle.

  All of this is reinforced by changes in the Earth's atmosphere, particularly regarding two important “greenhouse” gases, methane and carbon dioxide.

  Greenhouse gases are ones that trap atmospheric heat. Carbon dioxide (CO2) is the most plentiful, but molecule for molecule, methane (CH4) is a good deal more powerful.

  We can trace the levels of these gases back for thousands of years by measuring their concentrations in air bubbles trapped in arctic and Antarctic ice. At the time Ruddiman proposed his theory, scientists had used cores from Russia's Vostok station in Antarctica to do this for the past 400,000 years.

  These cores reveal that during eras when the Northern Hemisphere receives weaker summer sunlight (i.e., ice ages), methane is lower. In eras when solar energy is higher in the arctic, methane increases.

  This makes sense because methane is produced when vegetation decays beneath swamps and marshes. Many of these marshes are in the arctic, where, if the sun is weak, they're locked up in permafrost. If it is strong, permafrost melts, and swamps and marshes expand.

  But that's only one factor. Another, probably more important, lies in Africa, China, and Eurasia.

  It's long been known that these areas were a lot wetter 11,000 years ago than today. It's a fact attested to by dry lake valleys in the Sahara and huge reserves of groundwater in regions that see virtually no rain today.

  Ruddiman argues that it is not by coincidence that these lakes existed when the northern summers were at their strongest. Even at moderate latitudes north of the equator (such as the Sahara and large areas in southern Eurasia), he says that summer sunlight was eight percent more intense than today. That produced stronger thunderstorms, a wetter climate, and lots of marshes, as well as lakes.

  All of this appears to have been the case throughout the last several million years: Methane levels fluctuate with the 100,000-, 41,000-, and 22,000-year sunlight cycles, peaking when the northern summers are strongest and declining when they weaken.

  This pattern means that the atmosphere's methane level should have reached a peak 11,000 years ago and been dropping ever since. And that's exactly what happened until 5,000 years ago. Then something went awry, and it began to rise.

  "You have to throw 395,000 years of history out the window to come up with a natural explanation for this,” Ruddiman said when he unveiled his theory in a lecture at the 2003 fall meeting of the American Geophysical Union.[5] “Something has overridden the natural system."

  [Footnote 5: I first encountered Ruddiman at that lecture. A technical version of his hypothesis was published shortly after in Climatic Change, 61(3), December 2003, pp. 261-93. Now he's back with his thesis neatly packaged in a book, Plows, Plagues & Petroleum, which is must reading for anyone seriously interested in climate theory. This article is based largely on the lecture, with additional details drawn from the book, which also lays out a great deal of background material and the thought processes that led to his hypothesis—all at a level that is easily accessible to lay readers. Highly recommended.]

  His not-so-natural alternative? Five thousand years ago was just about when people started creating artificial marshes to grow rice in Southeast Asia. Weeds, stems, and rice roots decomposing in these paddies would have released considerable amounts of methane. Since then, rice farming has continued to expand. As far back as 2,000 years ago, rice farmers had already used up the flat land of the valleys and were beginning
to build the hillside terraces we see today, increasing their methane releases with each new terrace.[6]

  [Footnote 6: Other activities also produce methane, including the rearing of domestic animals. In the last quarter of the twentieth century, human-caused releases rose sharply, but a new study in the November 23, 2006 issue of Geophysical Research Letters has found that there has been no additional rise since late 1998. Most likely this good news is the result of improved maintenance at natural gas pipelines, said the study authors, who included Sherwood Rowland of the University of California, Irvine, co-winner of the 1995 Nobel for discovering the link between ozone depletion and chlo]

  The result is that preindustrial methane levels were about the same as those 11,000 years ago, when African and Eurasian thundershowers were at their highest and marshlands were spreading behind retreating glaciers. That's about 25 percent higher than they were at the time the trend reversed and 60 percent higher than would be expected if the “normal” cycle had persisted.

  The current level is about 1750 parts per billion. That may not sound like much (carbon dioxide levels are more than 200 times higher), but methane is a powerful enough greenhouse gas (twenty times as powerful as carbon dioxide, according to the website of Oak Ridge National Laboratory) that this is enough to play a major role.

  * * * *

  Wrong-Way CO2

  Atmospheric concentrations of carbon dioxide have shown a similar deviation. Antarctic ice cores reveal that CO2 levels fluctuate on natural cycles of 22,000, 41,000, and 100,000 years. The reasons aren't well understood, but the pattern is quite evident, especially for the 100,000-year cycle, which has thrice produced 80 ppm (40 percent) oscillations in the past 350,000 years.

  One theory is that carbon dioxide is affected by the extent of pack ice in the oceans. That's because the ice reduces the amount of water coming into contact with the air, thereby reducing the rate at which carbon dioxide can be transferred from the atmosphere to the oceans. Less ice equals more CO2 removal, which means a gradual decline in atmospheric CO2 between ice ages. Another theory is that big ice sheets affect ocean circulation patterns in ways that produce a similar effect.