The Human Age Read Free

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 evolvenew 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,