The Human Age: The World Shaped by Us

by Diane Ackerman

  Even the clouds show our handiwork. Some are wind-smeared contrails left by globe-trotters in airplanes; others darken and spill as a result of factory grit loosed into the air. We’ve banded the crows, we’ve hybridized the trees, we’ve trussed the cliffs, we’ve dammed the rivers. We would supervise the sun if we could. We already harness its rays to power our whims, a feat the gods of ancient mythology would envy.

  Like supreme beings, we now are present everywhere and in everything. We’ve colonized or left our fingerprints on every inch of the planet, from the ocean sediment to the exosphere, the outermost fringe of atmosphere where molecules escape into space, junk careens, and satellites orbit. Nearly all of the wonders we identify with modern life emerged in just the past two centuries, and over the past couple of decades, like a giant boulder racing ahead of a landslide, the human adventure has accelerated at an especially mind-bending pace.

  Every day, we’re more at the helm, navigating from outer space to the inner terraces of body and brain. We are not the same apes flaking tools on the savanna, toting gemlike embers, and stringing a few words together like precious shells. It’s even hard to imagine our mental fantasia from that perspective. Did it feel more spacious or every bit as streamlike? We’re revising the planet and its life forms so fast and indelibly that the natural world from which we sprang—atoms to single cells to mammals to Homo sapiens to dominance—is far from the same wellspring our ancestors knew. Today, instead of adapting to the natural world in which we live, we’ve created a human environment in which we’ve embedded the natural world.

  Our relationship with nature has changed . . . radically, irreversibly, but by no means all for the bad. How we now relate to the land, oceans, animals, and our own bodies is being influenced in all sorts of unexpected ways by myriad advances in manufacturing, medicine, and technology. Many of nature’s mysterious stuck doors have shivered open—human genome, stem cells, other Earth-like planets—widening our eyes. Along the way, our relationship with nature is evolving, rapidly but incrementally, and at times so subtly that we don’t perceive the sonic booms, literally or metaphorically. As we’re redefining our perception of the world surrounding us, and the world inside of us, we’re revising our fundamental ideas about exactly what it means to be human, and also what we deem “natural.” At every level, from wild animals to the microbes that homestead our flesh, from our evolving homes and cities to virtual zoos and webcams, humanity’s unique bond with nature has taken a new direction.

  I began writing this book because I was puzzled by certain questions, such as: Why does the world seem to be racing under our feet? Why is this the first year that Canada geese didn’t migrate from many New England towns, and why have so many white storks stopped migrating in Europe? The world is being ravaged by record heat, drought, and floods—can we fix what we’ve done to the weather? What sort of stewards of the future planet will today’s digital children be? What will it mean to travel when we can go anywhere on our computers, with little cost or effort? With all the medical changes to the human body—including carbon blade legs, bionic fingers, silicon retinas, computer screens worn over one eye with the ability to text by blinking, bionic suits that make it possible to lift colossal weights, and a wonderland of brain enhancers to improve focus, memory, or mood—will adolescents still be asking, “Who am I?” or “What am I?” How will cities, wild animals, and our own biology have changed in fifty years?

  Without meaning to, we’ve created some planetary chaos that threatens our well-being. Yet despite the urgency of reining in climate change and devising safer ways to feed, fuel, and govern our civilization, I’m enormously hopeful. Our new age, for all its sins, is laced with invention. We’ve tripled our life span, reduced childhood mortality, and, for most people, improved the quality of life—from health to daily comforts—to a staggering degree. Our mistakes are legion, but our talent is immeasurable.

  If we could travel back to, say, the Iron Age, few of us would go without packing certain essentials: matches, antibiotics, corrective lenses, compass, knife, shoes, vitamins, pencil and paper, toothbrush, fish hooks, metal pot, flashlight with solar batteries, and an array of other inventions that make life safer. We wouldn’t travel light.

  BLACK MARBLE

  As our spaceship enters the roulette wheel of a new solar system, hope starts building its fragile crystals once again. Disappointment has dogged our travels, but we are nomads with restless minds, and this sun resembles our own middle-aged star. Like ours, it rules a tidy jumble of planets looping in atypical orbits, some unfurling a pageant of seasons, others hard-hearted, monotone, and remote. They’re a strange assortment for siblings, with many small straggling hangers-on, but we’ve encountered odder night-fellows, and variety is their lure. One fizzy giant trails dozens of sycophantic moons; another floats inside a white cocoon. We weave between rocky, hard-boiled worlds, swing by a blimp tugging a retinue of jagged moons, dodge the diffuse rubble of asteroids, skirt a hothouse of acid clouds and phantom light.

  Slowing to a hyperglide, we admire all the dappled colors, mammoth canyons of razor-backed rust, ice-spewing volcanoes, fountains fifty miles high, hydrocarbon lakes, scarlet welts and scourges, drooling oceans of frozen methane, light daggers, magma flows, sulfur rain, and many other intrigues of climate and geology. Yet there’s no sign of living, breathing life forms anywhere. We are such a lonely species. Maybe this solar system will be the harbor where we find others like ourselves, curious, questing beings of unknown ardor or bloom. Life will have whittled them to fit their world, it doesn’t matter how.

  One more planet to survey, and then it’s on to the next port of call.

  On a small water planet flocked over by clouds, sequins sparkle everywhere. Racing toward it with abandon, we give in to its pull, and orbit in step with nightfall shadowing the world, transfixed by the embroidery of gold and white lights—from clusters and ribbons to willful circles and grids. Crafted lights, not natural auroras or lightning, but designed, and too many, too regular, too rare to ignore.

  IN 2003, ABOARD the Space Station, Don Pettit felt his heart pinwheel whenever he viewed Earth’s cities at night. If only everyone could see Earth like this, he thought, they’d marvel at how far we’ve come, and they’d understand what we share. A born tinkerer, he used spare parts he found in the Space Station to photograph the spinning planet with pristine clarity, as if it were sitting still. When he returned home he stitched the photographs together into a video montage, an orbital tour of Earth’s cities at night, which he posted on YouTube. His voice-over identifies each glowing spiderweb as we sail toward it with him, as if we too were peering out of a Space Station window: “Zurich, Switzerland; Milan, Italy; Madrid, Spain.

  “Cities at night are caught in a triangle,” he says with awe tugging at his voice, “between culture, geography, and technology. . . . Cities in Europe display a characteristic network of roads that radiate outwards. . . . London, with a tour down the English coast to Bristol. Cairo, Egypt, with the Nile River seen as a dark shape running south to north, the Pyramids of Giza are well lit at night . . . Tel Aviv on the left, Jerusalem on the right . . .”

  Glowing gold, green, and yellow, the Middle Eastern cities seem especially lustrous. He points out India’s hallmark—village lights dotted over the countryside, softly glowing as through a veil. Then we fly above Manila, where geometrical lights define the waterfront. The dragon-shaped lights of Hong Kong flutter under us, and the southeast tip of South Korea. In the welling darkness of the Korea Strait, a band of dazzling white grains is a fleet of fishing boats shining high-intensity xenon lamps as lures.

  “There’s Tokyo, Brisbane, the San Francisco Bay, Houston,” Pettit notes.

  We don’t intend our cities to be so beautiful from space. They’re humanity’s electric fingerprints on the planet, the chrome-yellow energy that flows through city veins. Dwarfed by the infinite dome of space with its majestic coliseum of stars, we’ve created our own constellations
on the ground and named them after our triumphs, enterprises, myths, and leaders. Copenhagen (“Merchants Harbor”), Amsterdam (“A Dam on the Amstel River”), Ottawa (“Traders”), Bogotá (“Planted Fields”), Cotonou (“Mouth of the River of Death”), Canberra (“Meeting Place”), Fleissenberg (“Castle of Diligence”), Ouagadougou (“Where People Get Honor and Respect”), Athens (City of Athena, Greek goddess of wisdom). We play out our lives amid a festival of lights. The story the lights tell would be unmistakable to any space traveler: some bold life form has crisscrossed the planet with an exuberance of cities, favoring settlements along the coast and beside flowing water, and connecting them all with a labyrinth of brilliantly lit roads, so that even without a map the outlines of the continents loom and you can spot the meandering rivers.

  The silent message of this spectacle is timely, strange, and wonderful. We’ve tattooed the planet with our doings. Our handiwork is visible everywhere, which NASA has captured with graphic poignancy in “Black Marble,” its December 7, 2012, portrait of Earth ablaze at night. A companion to the famous “Blue Marble” photograph of Earth that appeared forty years ago, this radical new self-portrait promises to awaken and inspire us just as mightily.

  On December 7, 1972, the crew of Apollo 17, the last manned lunar mission, shot the “Blue Marble” photograph of the whole Earth floating against the black velvet of space. Africa and Europe were eye-catching under swirling white clouds, but the predominant color was blue. This was the one picture from the Apollo missions that dramatically expanded our way of thinking. It showed us how small the planet is in the vast sprawl of space, how entwined and spontaneous its habitats are. Despite all the wars and hostilities, when viewed from space Earth had no national borders, no military zones, no visible fences. One could see how storm systems swirling above the Amazon might affect the grain yield half a planet away in China. An Indian Ocean hurricane, swirling at the top of the photo, had pummeled India with whirlwinds and floods only two days before. Because it was nearly winter solstice, the white lantern of Antarctica glowed. The entire atmosphere of the planet—all the air we breathe, the sky we fly through, even the ozone layer—was visible as the thinnest rind.

  Released during a time of growing environmental concern, it became an emblem of global consciousness, the most widely distributed photo in human history. It gave us an image to float in the lagoon of the mind’s eye. It helped us embrace something too immense to focus on as a single intricately known and intricately unknown organism. Now we could see Earth in one eye-gulp, the way we gaze on a loved one. We could paste the image into our Homo sapiens family album. Here was a view of every friend, every loved one and acquaintance, every path ever traveled, all together in one place. No wonder it adorned so many college dorm rooms. As the ultimate group portrait, it helped us understand our global kinship and cosmic address. It proclaimed our shared destiny.

  NASA’s new image of city lights, a panorama of the continents emblazoned with pulsating beacons, startles and transforms our gaze once again. Ours is the only planet in our solar system that glitters at night. Earth is 4.5 billion years old, and for eons the nighttime planet was dark. In a little over two hundred years we’ve wired up the world and turned on the lights, as if we signed the planet in luminous ink. In another forty years our scrawl won’t look the same. There are so many of us who find urban life magnetic that our cities no longer simply sprawl—they’ve begun to grow exponentially. Millions of us pack up, leave jobs and neighbors behind, and migrate to the city every year, joining nearly two-thirds of all the people on Earth. In the future, more and more clusters will appear, with even wider lattices and curtains of lights connecting them. Many display our curious tastes and habits. A harlequin thread drawn from Moscow to Vladivostok and dipping into China is the Trans-Siberian Railway. A golden streak through a profound darkness, the Nile River pours between the Aswan Dam and the Mediterranean Sea. A trellis connecting bright dots is the U.S. interstate highway system. The whole continent of Antarctica is still invisible at night. The vast deserts of Mongolia, Africa, Arabia, Australia, and the United States look almost as dark. So, too, teeming jungles in Africa and South America, the colossal arc of the Himalayas, and the rich northern forests of Canada and Russia. But shopping centers and seaports sizzle with light, as if they’re frying electrons. The single brightest spot on the entire planet isn’t Jerusalem or the Pyramids of Giza, though those do sparkle, but a more secular temple of neon, the Las Vegas Strip.

  Newer settlements in the American West tend to be boxy, with streets that bolt north-south and east-west, before trickling into darkness at the fringes of town. In big cities like Tokyo, the crooked, meandering lines of the oldest neighborhoods glow mantis-green from mercury vapor streetlights, while the newer streets wrapped around them shine orange from modern sodium vapor lamps.

  Our shimmering cities tell all (including us) that Earth’s inhabitants are thinkers, builders and rearrangers who like to bunch together in hivelike settlements, and for some reason—bad night vision, primal fear, sheer vanity, to scare predators, or as a form of group adornment—we bedeck them all with garlands of light.

  HANDMADE LANDSCAPES

  Now let’s zoom in closer.

  The Earth isn’t the same when you fly over it at three thousand feet and look for signs of humans. It’s easy to lose your bearings. All the reassuring textures of daily life are lost. Gone are the sensuous details of wild strawberry jam, a vase of well-bred irises with stiff yellow combs, the smell of wild scallions beside the kitchen door. But it’s a grand perch for viewing our tracks on the ground—visible everywhere and just as readable as the three-pronged Y’s etched into the snow by ravens or the cleft hearts stamped by white-tailed deer.

  The landscape looks very different than it did to our forebears, although we still use the sixteenth-century Dutch word (lantscap) to mean the natural scenery of our lives. Peering out of an airplane window, it’s clear how we’ve gradually redefined that rustic idea. No longer does it apply only to such untouched wilderness as Alpine crags, sugared coastlines, or unruly fields of wildflowers. We manufacture new vistas and move so comfortably among them that quite often we confuse them with natural habitats. A field of giant sunflowers in Arizona or an extravagance of lavender in Provence offers a gorgeous naturalistic tapestry, even though both were sewn by human hands.

  From the air, you can see how mountains lounge like sleeping alligators, and roads cut alongside or zigzag around them. Or slice clean through. Some roads curve to avoid, others to arrive, but many are straight and meet at right angles. Where forests blanket the earth, a shaved ribbon of brown scalp appears with implanted electrical towers shaped like stick men.

  We not only bespangle the night, we broadloom the day. In summer, our agriculture rises as long alternating strips of crops, or quilted patchworks of green velour and brown corduroy. Miles of dark circles show where giant pivoting sprinkler systems are mining the water we unlocked deep below ground, which we’re using to irrigate medallions of corn, wheat, alfalfa, or soybeans. Lighter circles linger as the pale shadows of already harvested crops. Evenly spaced rows of pink or white tufts tell of apple and cherry orchards. Among houses and between farms, small fragments of wooded land remain untouched: either the land is too wet, rocky, or hilly to build on, or the locals have set it aside on purpose to protect or use as a park. Either way, it proclaims our presence, just as the canals and clipped golf courses do.

  Where retreating glaciers once dropped boulders and stones, scattering rocks of all sizes along the way, hedgerows border the crops. Farmers first had to unearth the rocks and boulders before they could till the land, and they piled the riprap along the edges of fields, where they were colonized by shrubs and trees that thrive in crevices and trap the drifting snow. On the first warm spring days, all of the snow will have melted from the corrugated brown fields, but not from the rocky white-tipped hedgerows that frame them.

  Where dark veins streak the mountains, coal miner
s have clear-cut forests, shattered several peaks with explosives, scooped up the rubble, dumped it into a valley, and begun excavating. The blocks and crumbles of a stone quarry also stand out, and the terraced ziggurats of a copper mine rise above an emerald green pool.

  Where mirages swim in the Mojave Desert’s flan of caramel light, tens of thousands of mirrors shimmer to the horizon, each one a panel in an immense solar thermal facility. In other deserts around the world, and on every continent, including Antarctica, arrays of sun-catchers sparkle. Oil refineries trail for miles, swarmed over by pump jacks attacking the hard desert floor like metal woodpeckers and locusts.

  Our pointy-nosed boats dot the ports and lakeshores; our tugboats wrangle commercial barges down the blue sinews of rivers. Newly hewn timber looks like rafts of corks floating toward the sawmills. Where marshlands attract flocks of migrating birds, one may also spot the scarlet paisley of our cranberry bogs, and the yellow of the mechanical growers that flood the bogs and then churn the cranberries to loosen them from their vines, corralling the floating fruit in long flexible arms. Red capital T’s are the stigmata of our evaporation ponds, where salt concentrates hard as it’s harvested from seawater, in the process changing the algae and other microorganisms to vivid swirls of psychedelic hues. One sees our dams and harnessed rivers and the long zippers of our railway lines, and even occasional railway roundhouses. There’s the azure blue of our municipal swimming pools, and the grids of towns where we live in thick masses piled one upon the other, with the tallest buildings in the center of a town, and long fingers of shorter buildings pointing away from them. The cooling stacks of our nuclear power plants stare up with the blank eyes of statues. Low false clouds pour from the smokestacks atop steel and iron plants, factories, and power stations.