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How Human Civilization Is Ransacking the Earth
Groaning under the strain
In every part of the earth, natural systems that have sustained themselves from time immemorial are groaning under the strain of human civilization. The basic elements of life on Earth that we take for granted – forests, fish in the oceans, water to drink – are rapidly being consumed by humanity’s voracious demands.
We regulate the flow of about two-thirds of the earth’s rivers, and many of the greatest rivers – the Colorado, Yellow, Yangtze, Ganges, Nile – no longer reach the sea during parts of the year. Massive inland water bodies, such as the Aral Sea and Lake Chad, have virtually disappeared. Much of the world’s agriculture, including the wheat-growing states of the Midwest, rely on underground aquifers that are being used up at unsustainable rates. It has been forecast that, by midcentury, as much as three quarters of the earth’s population could face freshwater scarcity.
Similarly, we are insatiably exhausting the bounty of the earth’s natural terrain. Half of the world’s tropical and temperate forests have disappeared, along with about half the wetlands and a third of the mangroves. At the current rate of deforestation, roughly an acre a second, half of what still remains of the Amazon rainforest will be gone within thirty years.
Even the topsoil that we rely on for cultivation of crops is rapidly being depleted. Like aquifers, topsoil naturally regenerates itself, but at a rate of about a centimeter every two hundred years. Meanwhile, in the United States we are using it up at ten times the rate of replenishment; in Europe seventeen times; in China fifty-seven times. This has already led to a significant loss of productivity on nearly a third of the world’s arable land.
Much of this loss has been masked by the use of manufactured nitrogen fertilizer which has become so widespread that – astonishingly – more than half of all nitrogen atoms in green plant material now come from artificial fertilizer rather than the earth’s own ecosystem.
This has created a new problem as nitrogen runoff drains into the oceans, causing uncontrolled algae blooms that consume the water’s oxygen, leaving none for any other life. More than four hundred of these “dead zones” have emerged in coastal waters around the world, some extending in size to over twenty thousand square miles.
Not even the furthest regions of the oceans have escaped humanity’s depredations. As a result of industrialized fishing, the oceans have lost over 90% of large fish such as tuna and swordfish. If overfishing continues unchecked, it’s expected that catches around the world will be down 30-60% by midcentury. An international team of ocean experts, reporting in 2013 on the state of the oceans, could barely mask their desperation at what they call a “dismal outlook,” calling for urgent global action “if we are to avoid tipping us further, and irreversibly, onto the despair side of the hope/despair balance.”
Towards the Sixth Extinction
Pushed out of their natural habitats, hunted down and poisoned by our pollutants, the nonhuman animals with whom we share the earth are reeling along with the rest of the planet. A 2008 report announced that populations of all vertebrates – mammals, birds, reptiles, amphibians and fish – had declined on average by a third over the past four decades.
Perhaps even more disquieting is the rate at which human activity is driving species to extinction. There have been five times in the history of life on Earth when a global catastrophe caused a mass extinction of species. Scientists now recognize that the onslaught of humanity is causing the sixth of these catastrophic extinction events, driving species into oblivion at a rate a thousand times faster than would be natural. Between thirty and fifty percent of all vertebrate species are threatened with extinction this century.
The arrival of the Anthropocene
Many prominent scientists have concluded that humanity has now emerged as its own force of nature. The scope of human impact is so enormous, and will affect the distant future of the earth to such a degree, that they are describing our modern period as a new geological epoch called the Anthropocene. “Human activities,” writes a leading scientist, “have become so pervasive and profound that they rival the great forces of Nature and are pushing the Earth into planetary terra incognita… The phenomenon of global change represents a profound shift in the relationship between humans and the rest of nature.”
Excerpted from The Patterning Instinct, Chapter 20 | Consuming the Earth In the Modern Era
Peter M. Vitousek et al., "Human Domination of Earth's Ecosystems," Science 277 (25 July, 1997): 494–99.
Johan Rockström et al., "A Safe Operating Space for Humanity," Nature 461, no. 24 (September 2009): 472–75.
Jane Lubchenco, "Entering the Century of the Environment: A New Social Contract for Science," Science 279 (1998): 491–97.
Will Steffen, Paul J Crutzen, and John R McNeill, "The Anthropocene: Are Humans Now Overwhelming the Great Forces of Nature," Ambio: A Journal of the Human Environment 36, no. 8 (2007): 614–21.