Книга: The Human Age

Wild Heart, Anthropocene Mind

Wild Heart, Anthropocene Mind

Knee-deep in the blizzard of 1978, when wind-whipped sails of snow tacked across Lake Cayuga, and the streets looked like a toboggan run, I was a student in upstate New York. Despite the weather, classes met, and scientists with souls luminous as watch dials were talking about nuclear winter, the likely changes in Earth’s climate in the aftermath of a nuclear war: the sun white cotton in a perishable sky, dust clouds thickening over the Earth, plants forgetting how to green, summer beginning at twenty below zero, and then the seasons failing all living things. It seemed a possible scenario, since in Washington and Moscow, politicians were outdaring each other with playground bravado. This was the first time I’d heard my elders suggesting that we were now capable of unraveling the whole atmosphere shrouding Earth, and I was both wonder-struck and worried.

Only moments before, in geological time, we were speechless shadows on the savanna, foragers and hunters of small game. How had we become such a planetary threat? As the lectures and snow squalls ebbed, we students seemed small radiant forms in a vast white madness.

A quarter of a century later, Nobel laureate Paul Crutzen (who discovered the hole in the ozone layer and first introduced the idea of nuclear winter) stepped onto the world stage again, arguing that we’ve become such powerful agents of planetary change that we need to rename the geological age in which we live. Elite scientists from many nations agreed, and a distinguished panel at the Geological Society of London (the official arbiter of the geologic time scale) began weighing the evidence and working to update the name of our epoch from its rocky designation, Holocene (“Recent Whole”), to one that recognizes, for the first time, our unparalleled dominion over the whole planet, Anthropocene—the Human Age.[2]

By international agreement, geologists divide Earth’s environmental history into phases, based on ruling empires of rock, ocean, and life; it’s similar to how we use “Elizabethan” and other royal dynasties to denote periods of human history. Deep ice cores in the Antarctic tell us of ancient atmospheres, fossil remains reveal ancient oceans and life forms, and more is written in silt and cataloged in stone. Previous periods, like the Jurassic, which we identify with dinosaurs, lasted millions of years, and we sometimes cleave them into smaller units, as changing epochs and eras slide into view. Each one adds a thread, however thin, to the tapestry. How wide a stripe will we leave in the fossil record?

PEOPLE WHO ARE recognizably human have walked the Earth for roughly two hundred thousand years. During those millennia, we survived by continuously adapting to our fickle environment. We braved harsh weathers and punishing landscapes, and feared animals much fiercer than we were, bowing to nature, whose spell overwhelmed us, whose magnificence humbled us, and around which we anxiously rigged our lives. After a passage of time too long to fully imagine, and too many impression-mad lives to tally, we began rebelling against the forces of nature. We grew handy, resourceful, flexible, clever, cooperative. We captured fire, chipped tools, hewed spears and needles, coined language and spent it everywhere we roamed. And then we began multiplying at breathtaking speed.

In the year 1000 BC, the entire world population was just 1 million. By AD 1000 it was 300 million. In 1500, it had grown to 500 million. Since then we’ve started reproducing exponentially. The world population has quadrupled since 1870. According to the BBC News website, when I was born, on October 7, 1948, I became the 2,490,398,416th person alive on Earth and the 75,528,527,432nd person to have lived since history began.[3] In the Middle Ages, we were still able to count people in millions. Today there are 7 billion of us. As the biologist E. O. Wilson says, “The pattern of human population growth in the twentieth century was more bacterial than primate.” According to Wilson, the human biomass is now a hundred times greater than that of any other large animal species that has ever existed on Earth.[4] In our cities 3.2 billion people crowd together, and urban planners predict that by the year 2050 nearly two-thirds of the world’s projected 10 billion people will be city-dwellers.

By the end of this decade, the history of planet Earth will be rewritten, textbooks will slip out of date, and teachers will need to unveil a bold, exciting, and possibly disturbing new reality. During our brief sojourn on Earth, thanks to exhilarating technologies, fossil fuel use, agriculture, and ballooning populations, the human race has become the single dominant force of change on the planet. For one species radically to alter the entire natural world is almost unprecedented in all of Earth’s 4.5-billion-year history.

The only other time it happened was billions of years ago, before anything like golden-shouldered parakeets or marine iguanas, when the atmosphere was a poisonous brew and a time-traveling human would have needed to wear a gas mask. Then only spongy colonies of one-celled, blue-green algae blanketed the shallows, dining on water and sunlight, and pumping torrents of oxygen—their version of flatulence—into the atmosphere. Gradually, the air and ocean seethed with oxygen, the sky sweetened, and Earth welcomed creatures with lungs. It’s a humbling thought, but one life form’s excrement is another’s tonic. For nearly five billion years, life ticked and tocked through an immensity of bold experiments, which the algae’s recreation of the planet made possible, including all sorts of leaves and tongues, pedigrees and tribes, from Venus flytraps to humans. Then, improbably for origins so mundane, in roughly the last two or three hundred years, humans have become the second species to dramatically alter the natural world from earth to sky.

Humans have always been hopped-up, restless, busy bodies. During the past 11,700 years, a mere blink of time since the glaciers retreated at the end of the last ice age, we invented the pearls of Agriculture, Writing, and Science. We traveled in all directions, followed the long hands of rivers, crossed snow kingdoms, scaled dizzying clefts and gorges, trekked to remote islands and the poles, plunged to ocean depths haunted by fish lit like luminarias and jellies with golden eyes. Under a worship of stars, we trimmed fires and strung lanterns all across the darkness. We framed Oz-like cities, voyaged off our home planet, and golfed on the moon. We dreamt up a wizardry of industrial and medical marvels. We may not have shuffled the continents, but we’ve erased and redrawn their outlines with cities, agriculture, and climate change. We’ve blocked and rerouted rivers, depositing thick sediments of new land. We’ve leveled forests, scraped and paved the earth. We’ve subdued 75 percent of the land surface—preserving some pockets as “wilderness,” denaturing vast tracts for our businesses and homes, and homogenizing a third of the world’s ice-free land through farming. We’ve lopped off the tops of mountains to dig craters and quarries for mining. It’s as if aliens appeared with megamallets and laser chisels and started resculpting every continent to better suit them. We’ve turned the landscape into another form of architecture; we’ve made the planet our sandbox.

When it comes to Earth’s life forms we’ve been especially busy. We and our domestic animals now make up 90 percent of all the mammal biomass on Earth; in the year 1000, we and our animals were only 2 percent. As for wild species, we’ve redistributed plants and animals to different parts of the world, daring them to evolve new habits, revise their bodies, or go extinct. They’ve done all three. In the process, we’re deciding what species will ultimately share the planet with us.

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.