Further: Beyond the Threshold Read Online Free PDF Page B

immediately assumes the destruction came at man’s own hand. For contemporary viewers, there was little doubt that Armageddon would be nuclear.
    Growing up in the shadow of the Impact, for me death was always expected from above. Fictions about extinction-level events, asteroids the size of moons striking Earth, were common when I was young.
    Each culture throughout history, I suppose, has always chosen its own apocalypse, its own end of the world to fear. All of them, as it happens, were wrong. Man was responsible, in the end, but he did it on purpose .
    “As a site for long-term habitation,” the escort explained, “Earth simply became too erratic.”
    We were riding a moving sidewalk down a broad avenue. Buildings rose on either side, in strange and unlikely forms, while oddly configured air-vehicles filled the skies. There were other pedestrians around us, but I was still too distracted to pay them much attention. I felt a deep sense of vertigo, with mountains and oceans looming far overhead, indistinct in the blue sky like a ghostly moon seen by daylight, and had to resist the temptation to wrap my arms around a post or a tree and hold on for dear life.
    “Changes to the planet’s environment, resulting from widespread deforestation and urbanization, the introduction of pollutants to the atmosphere, and so on, compounded to unbalance the climatological system, such that Earth’s weather patterns became increasingly unpredictable, the variations swift and violent.”
    I’d seen erratic weather and the results of climate change firsthand. Long before I was born, the sea levels rose high enough that the waters swallowed whole nations. When the sea reclaimed the flatlands, the Dutch became homeless. A flotilla of seagoing vessels followed the court of King Pieter on his decommissioned cruise liner for years. In the late 21C, with the death of his father, the heir apparent King Christian had purchased a number of castoff NASA reusable launch vehicles and migrated to Ceres, the largest rock in the asteroid belt, which he claimed as the new Dutch homeland. They were a strange, foul-smelling crew, the Dutch belters, but they always threw the best parties, and always had the best stuff to smoke.
    “So then…what?” I asked, shaking my head. “Environmental changes destroyed the planet?”
    I glanced at the silver eagle on my shoulder that regarded me with a metallic expression of confusion.
    “Destroyed?” it repeated. “Well, no, of course not. The planet could have continued to exist quite happily—erratic weather patterns or no. The problem came in that the inhabitants of the planet found it increasingly problematic to remain. When continued warming caused the destabilization of methane hydrate deposits at the bottom of the ocean, the gigatons of methane released increased surface temperatures to levels higher than any seen on Earth in four billion years.”
    I shuddered. I was a student at the university when the rainforests began to catch fire, but I’d always hoped that we’d somehow be able to reverse the trend. Apparently, I was wrong.
    “The planet was abandoned for some time, I’m afraid,” the escort continued, “the inhabitants migrating through flatspace to neighboring worlds and colonies. There was some considerable nostalgia for Original Earth, though. And Sol remained at the center of human space. So eventually, sentiment was such that funds were raised to rehabilitate the ancient cradle of humanity. One proposal was to terraform the planet, resetting the ecosystem and starting over from scratch. That was rejected as too time-consuming by the impatient investors. Instead, it was decided to dismantle and reconstruct Earth into a planetary-scale megastructure.”
    I looked at the unearthly buildings lining the boulevard, the landscape curving up at the limits of vision in every direction.
    “So, this is Earth?” I turned in a wide circle, stubbing my toe on the surface of the moving sidewalk,