life, too, and gradually adapt to eat them. Armadillos will return to burrow in the cleansed soil, among the rotting remains of buried pipe.
Unattended oil drums, pumps, pipes, towers, valves, and bolts will deteriorate at the weakest points, their joints. “Flanges, rivets,” says Fred Newhouse. “There are a jillion in a refinery.” Until they go, collapsing the metal walls, pigeons that already love to nest atop refinery towers will speed the corruption of carbon steel with their guano, and rattlesnakes will nest in the vacant structures below. As beavers dam the streams that trickle into Galveston Bay, some areas will flood. Houston is generally too warm for a freeze-thaw cycle, but its deltaic clay soils undergo formidable swell-shrink bouts as rains come and go. With no more foundation repairmen to shore up the cracks, in less than a century downtown buildings will start leaning.
During that same time, the Ship Channel will have silted back into its former Buffalo Bayou self. Over the next millennium, it and the other old Brazos channels will periodically fill, flood, undermine the shopping malls, car dealerships, and entrance ramps—and, building by tall building, bring down Houston’s skyline.
As for the Brazos itself: Today, 20 miles down the coast from Texas City, just below Galveston Island and just past the venomous plumes rising from Chocolate Bayou, the Brazos de Dios (“Arms of God”) River wanders around a pair of marshy national wildlife refuges, drops an island’s worth of silt, and joins the Gulf of Mexico. For thousands of years, it has shared a delta, and sometimes a mouth, with the Colorado and the San Bernard rivers. Their channels have interbraided so often that the correct answer to which is which is temporary at best.
Much of the surrounding land, barely three feet above sea level, is dense canebrake and old bottomland forest stands of live oaks, ashes, elms, and native pecans, spared years ago by sugarcane plantations for cattle shade. “Old” here means only a century or two, because clay soils repel root penetration, so that mature trees tend to list until the next hurricane knocks them over. Hung with wild grapevines and beards of Spanish moss, these woods are seldom visited by humans, who are dissuaded by poison ivy and black snakes, and also by golden orb weaver spiders big as a human hand, which string viscous webs the size of small trampolines between tree trunks. There are enough mosquitoes to belie any notion that their survival would be threatened when evolving microbes finally bring down the world’s mountain ranges of scrap tires.
As a result, these neglected woods are inviting habitats for cuckoos, woodpeckers, and wading birds such as ibises, sandhill cranes, and roseate spoonbills. Cottontail and marsh rabbits attract barn owls and bald eagles, and each spring thousands of returning passerine birds, including scarlet and summer tanagers in fabulous breeding plumage, flop into these trees after a long gulf crossing.
The deep clays below their perches accumulated back when the Brazos flooded—back before a dozen dams and diversions and a pair of canals siphoned its water to Galveston and Texas City. But it will flood again. Un- tended dams silt up fast. Within a century without humans, the Brazos will spill over all of them, one by one.
It may not even have to wait that long. Not only is the Gulf of Mexico, whose water is even warmer than the ocean’s, creeping inland, but all along the Texas coast for the past century, the ground has been lowered to receive it. When oil, gas, or groundwater is pumped from beneath the surface, land settles into the space it occupied. Subsidence has lowered parts of Galveston 10 feet. An upscale subdivision in Baytown, north of Texas City, dropped so low that it drowned during Hurricane Alicia in 1983 and is now a wetlands nature preserve. Little of the Gulf Coast is more than three feet above sea level, and parts of Houston actually dip below it.
Lower the land, raise the seas, add hurricanes far stronger than midsize, Category 3 Alicia, and even before its dams go, the Brazos gets to do again what it did for 80,000 years: like its sister to the east, the Mississippi, it will flood its entire delta, starting up where the prairie ends. Flood the enormous city that oil built, all the way down to the coast. Swallow the San Bernard and overlap the Colorado, fanning a sheet of water across hundreds of miles of coastline. Galveston Island’s 17-foot seawall won’t be much help. Petroleum tanks along the Ship Channel will be submerged; flare towers, catalytic crackers, and fractionating columns, like downtown Houston buildings, will poke out of brackish floodwaters, their foundations rotting while they wait for the waters to recede.
Having rearranged things yet again, the Brazos will choose a new course to the sea—a shorter one, because the sea will be nearer. New bottomlands will form, higher up, and eventually new hardwoods will appear (assuming that Chinese tallow trees, whose waterproof seeds should make them permanent colonizers, share the riparian space with them). Texas City will be missing; hydrocarbons leaching out of its drowned petrochemical plants will swirl and dissipate in the currents, with a few heavy-end crude residues dumped as oil globules on the new inland shores, eventually to be eaten.
Below the surface, the oxidizing metal parts of chemical alley will provide a place for Galveston oysters to attach. Silt and oyster shells will slowly bury them, and will then be buried themselves. Within a few million years, enough layers will amass to compress shells into limestone, which will bear an odd, intermittent rusty streak flecked with sparkling traces of nickel, molybdenum, niobium, and chromium. Millions of years after that, someone or something might have the knowledge and tools to recognize the signal of stainless steel. Nothing, however, will remain to suggest that its original form once stood tall over a place called Texas, and breathed fire into the sky.
CHAPTER 11
The World Without Farms
1. The Woods
WHEN WE THINK civilization, we usually picture a city. Small wonder: we’ve gawked at buildings ever since we started raising towers and temples, like Jericho’s. As architecture soared skyward and marched outward, it was unlike anything the planet had ever known. Only beehives or ant mounds, on a far humbler scale, matched our urban density and complexity. Suddenly, we were no longer nomads cobbling ephemeral nests out of sticks and mud, like birds or beavers. We were building homes to last, which meant we were staying in one place. The word
Yet it was the farm that begat the city. Our transcendental leap to sowing crops and herding critters— actually controlling other living things— was even more world-shaking than our consummate hunting skill. Instead of simply gathering plants or killing animals just prior to eating them, we now choreographed their existence, coaxing them to grow more reliably and far more abundantly.
Since a few farmers could feed many, and since intensified food production meant intensified people production, suddenly there were a lot of humans free to do things other than gather or grow meals. With the possible exception of Cro-Magnon cave artists, who may have been so esteemed for their talents that they were relieved of other duties, until agriculture arrived, food-finding was the only occupation for humans on this planet.
Agriculture let us settle down, and settlement led to urbanity. Yet, imposing as skylines are, farmlands have much more impact. Nearly 12 percent of the planet’s landmass is cultivated, compared to about 3 percent occupied by towns and cities. When grazing land is included, the amount of Earthly terrain dedicated to human food production is more than one-third of the world’s land surface.
If we suddenly stopped plowing, planting, fertilizing, fumigating, and harvesting; if we ceased fattening goats, sheep, cows, swine, poultry, rabbits, Andean guinea pigs, iguanas, and alligators, would those lands return to their former, pre-agro-pastoral state? Do we even know what that was?
For an idea of how the land on which we’ve toiled might or might not recover from us, we can begin in two Englands—one old, one New.
In any New England woods south of Maine’s boreal wilderness, within five minutes you see it. A forester’s or ecologist’s trained eye notices it just by spotting a stand of big white pine, which only grow in such uniform density in a former cleared field. Or they spot clusters of hardwoods— beech, maples, oaks—of similar age, which sprouted in the shade of a now-missing stand of white pines that were cut or blown away in a hurricane, leaving
