Caliban

“This is a real-time view of our world as it is today,” Grieg’s voice announced from the far side of the now solid-seeming globe. “We came to a waterless world with an unbreathable atmosphere. We gave it water and oxygen. Every drop of water in those oceans, we caused to be there. Every breath of oxygen in the air is there because we remade this world. We unlocked water from the rocks and soil and imported comets and ice meteors from the outer reaches of this star system. We put plant life in the sea and on the land and gave this world breathable air. We made this world bloom. But now the bloom is off the rose.

“Next you will see Inferno as it will be, if we merely rely on our own abilities, using just our own terraforming stations and technology, if we go on as we have been. First, to make it easy to observe, I will remove the atmosphere, cloud cover, and the day-night cycle.” Suddenly the half-lit globe was fully illuminated, and the storms and haze vanished. The hologram had seemed like a real world up to that moment, but, stripped of darkness and cloud, it was suddenly nothing more than a highly accurate map, a detailed globe. Quite irrationally Alvar felt a pang of loss even then. Something lovely that had been was suddenly gone, and he knew, beyond doubt, that the surviving image of the world would grow uglier still. “Now let me add a few supplementary graphics,” Grieg’s voice said. A series of bar charts and other displays appeared around the globe, showing the state of the forests, the sea and land biomass, temperatures, atmospheric gases, and other information.

“I will run the simulation forward at the rate of one standard year every ten seconds,” Grieg said, “and I will keep the western hemisphere positioned so you can watch the fate of Hades.” A white dot appeared at the appropriate position on the edge of the Great Bay. “That is Hades’s location.”

The governor spoke no more, but instead let the simglobe tell its own tale, partly in direct images, partly in readouts and graphic displays.

It was the oceans that died first. The predators at the top of the food chain overbred and all but wiped out the mid-chain species, the fish and other creatures that fed on each other and on the various species of plankton, and were in turn eaten by the high-end predators. Their food supply wiped out, the high-end predators died out as well.

With no controls on their reproduction, the plankton and algae in the ocean were next. They reproduced out of all control and the oceans bloomed a sickly, ghastly green. Then the seas turned brown as the algae died as well, having overrun their own food supply and absorbed virtually every molecule of carbon dioxide. With no animal life in the ocean, plant life everywhere,’ on land and sea, was starved for carbon dioxide. The loss of the greenhouse gas meant Inferno could retain less and less heat. The planet began to grow colder.

Alvar watched, an unwilling witness to the forthcoming doom of his own world, watched as the planet Inferno was strangled by ice. Water, water was the key. No living world could survive without it, but it could do no good-and could do great damage-if it was in the wrong state, in the wrong place. Now it was the ice cap that was the problem. The line on the chart displayed the size of the northern ice cap, but Alvar could see the cap itself growing. The ice advanced, and the northern forests fell before it, the great stands of trees dying in the too-cold, carbon-dioxide-starved air. With the atmosphere’ s oxygen content far too high, and drought conditions taking hold, forest fires exploded everywhere, even as the ice pushed southward.

The white ice reflected back far more heat and light than the forests, and the planetary cooling trend locked itself in, strengthened itself, reinforced itself.

But the cooling was not universal: Alvar could see that. As the forest died and the ice advanced and the overall planetary temperature dropped, local temperatures dropped in some areas and rose in others. Wind patterns shifted. Storms grew more violent. Semipermanent snow hurricanes lodged themselves here and there along the southern coast of Terra Grande, while Purgatory became semitropical. But still the ice advanced, creeping farther and farther south, locking up more and more water in snow and ice, water that should have flowed back into the southern ocean.

The sea levels dropped. The oceans of Inferno, never very deep to begin with, receded at incredible speed as the ice grew ever deeper in the north. Islands began to appear out of the southern ocean. Still the waters drew back, until the Great Bay revealed its true form as a drowned crater. Now it was a circular sea, surrounded on all sides by land.

The ice mass continued to advance, and the city of Hades vanished under the snow and ice.