Today's decisions will not only determine the options of tomorrow but also write the history of yesterday. We currently have far more knowledge of the world in which we live than did our forbearers. Therefore, we not only have greater opportunities than they did but also are confronted with greater responsibilities than they were because we are no longer an isolated continent but part of an interconnected global society, whether or not we fully understand the idea, whether or not we even like the idea.
If humanity is to survive this century and beyond with any semblance of dignity and well-being, we must both understand and accept that we have a single ecosystem composed of three spheres: the atmosphere (air), lithosphere (the Earth's crust of rock and water), and the biosphere (all life, including us, sandwiched in the middle). And because this magnificent, living system—planet Earth—simultaneously produces, nourishes, and maintains all life, including us, we would be wise to honor it and care for it. If we do not, if we cause too much damage to any one of the "spheres," we will be the authors of our own demise—and that of all of the world's children into everlasting.
I say this because the ocean of air and the ocean of water both have currents that circumnavigate the Earth, and many things ride these currents for better or ill. In 1883, for example, a small Indonesian island in the Indian Ocean, called Krakatoa, was virtually obliterated by enormous volcanic eruptions that sent ash high enough above the Earth to ride the world's air currents for more than a year. This event reduced the amount of sunlight that reached the Earth, which in turn cooled the surrounding climate and affected all life.
Just as it carried the volcanic ash of Krakatoa, air also carries the reproductive spores of fungi and the pollen of various trees and grasses, as well as dust and microscopic organisms. In fact, if not for these air currents that circle the earth, the Amazon forest would starve to death.
The wind-scoured, nearly barren southern Sahara Desert of north Africa feeds the Amazonian forests of South America with mineral-coated dust from the Bodélé Depression, which is the largest source of dust in the world. During the northern hemisphere winter, winds routinely blow across this part of north Africa, where they pick up 700,000 tons of dust on an average day and sweep much of it across the Atlantic. Approximately 20 million tons of this mineral-rich dust fall on the Amazon rainforest and enrich its otherwise nutrient-poor soils. The Bodélé Depression accounts for only 0.2% of the entire Saharan Desert and is only .05% of the size of the Amazon itself.¹ Whereas air currents carry life-giving oxygen, water, and life-sustaining dust, they also transport toxic pollution—a human legacy.
Air—everyone's birthright—can be likened to the key in this Chinese proverb: To every man is given the key to the gates of heaven, and the same key opens the gates of hell. Air is both life-giving oxygen and life-threatening pollution. Although air quality decreases as pollution levels increase, rain and snow scrub many pollutants from the air and deposit them into the soil, where they move through the soil along the flow of groundwater.
Unintentional fragility is imposed on ecosystems of the biosphere through direct and indirect pollution of soil and water. Soil, which is like an exchange membrane between the living components of the biosphere and the nonliving components of the lithosphere, is dynamic and ever changing. Derived from the mechanical and chemical breakdown of rock, soil is built up by plants that live and die in it. It is also enriched by animals that feed on the plants, void their bodily wastes, and eventually die, decay, and return to the soil as organic matter. Soil, the properties of which vary from place to place within landscapes, is by far the most alive and diverse part of a biosphere. In addition, soil micro-organisms are the regulators of most processes that translate into soil productivity.
The soil food web is a prime indicator of a healthy terrestrial ecosystem. But soil processes can be upset by such things as a decrease in the ratio of bacterial to fungal biomass, which alters the fungal/bacterial activity in a way that reduces the number and diversity of protozoa and nematodes, thereby altering their community structure. Such disruptions can lead to a loss of vegetation or even the loss of human health.²
Soil, which is the main terrestrial vessel, receives, collects, and passes to the water airborne, human-caused pollutants. In addition, such pollutants as chemical fertilizers, fungicides, herbicides, insecticides, rodenticides, and so on, are added directly to the soil and through the soil to the water. At times, such pollutants make their way into the air and hence are redistributed more widely over the planet's surface through strong winds, which carry aloft the topsoil following deforestation, desertification, and ecologically unsound farming practices—all of which ultimately affect water.
The great collector of human-caused pollutants, water washes and scrubs them from the air by rain and snow; it leaches them from the soil as it obeys gravity's call, and it carries them in trickle, stream, and river to be concentrated in the ultimate vessel, the combined oceans of the world.³ Because oceans have no outlets whereby pollutants can be flushed, these chemicals continually concentrate—though the inflow of contaminated streams and rivers and the evaporation of water from the ocean's surface to be carried hither and yon by the currents of air in the form of rain. The latter then collects more pollutants on its journey back to the ocean, which can only compound the on-going cycle and affect such ancient beings as the coelacanth in the vast, aquatic portion of the lithosphere.
The coelacanth (pronounced "SEAL-a-canth") is a rare fish that has survived deep in the Earth's seas almost unchanged for million of years. The first coelacanth was caught in a deep-water gillnet set for sharks about 600 feet down off the mouth of the Chalumna River, in southeastern Africa in 1938. This individual, given the generic named Latimeria in honor of naturalist Marjorie Courtenay Latimer, represented the only surviving species of coelacanths—a lineage of fishes that originated in the Devonian period, about 380 million years ago, but was thought to have become extinct in the Upper Cretaceous period, some 80 million years ago, which is the date of the youngest fossil. How could this lineage of fishes have survived all that time without leaving a trace of its existence? Since 1938, however, others have been caught in deep water off the Comoros Islands, which lie between the coast of southeastern Africa and the northwestern tip of Madagascar.
On September 18, 1997, the wife of Mark V. Erdmann, an author of one of the recent articles about coelacanths in Indonesia, saw a coelacanth in Sulawesi (Celebes), Indonesia, being wheeled across a fish market on a cart. Eardmann's wife only had time to photograph the fish before it was sold. Then, on July 30, 1998, Sulawesi fishermen dragged up a 4 1/2-foot-long, 65-pound coelacanth, which they had caught in a gill net set for sharks about 400 feet down off the young volcanic island of Manado Tua, north Sulawesi. Manado Tua is known to have submarine caves at about the same depth as those that occur on the Comoros Islands, 6,000 mile away.
Today, humans are threatening the coelacanth through the chemical pollution of its deep-sea habitat. Given an estimated 500 individuals in the total population around the Comoros Islands, coupled with the species' low rate of reproduction (it bears live young), there is cause for concern. A team of scientists at the Virginia Institute of Marine Science in Gloucester found high levels of DDT and PCBs in the tissues of frozen specimens taken from the population off the Comoros Islands. "It's a very scary situation," said John A. Musick, who headed the study at the institute. "It's even more alarming because if we lose the coelacanths, we're not losing a species, or a genus, or a family. We're losing a superorder—the last member of a species that dominated the world's ecology for millions of years." The loss of a superorder is, to scientists, the loss of a gigantic branch from the tree of life, the tree of evolution.
Some ancient species, such as opossums, are unlikely to become extinct because they meet Nature's criteria for persistence. In addition, they live in environments that vary so much from day to day, month to month, and year to year that they're unlikely to meet anything in the future they have not already survived in the past. Another category of organisms, however, called "living fossils," is in much greater danger of extinction.
"Living fossils," like the coelacanth, are so called because they represent the only surviving species of a taxonomic group that was once considerably richer. The notion of a living fossil has an air of doom about it, as though they are living on borrowed time, a holdover from a more aristocratic era. Indeed, some are living thus, either because they are rigidly adapted to narrowly specific habitats threatened with drastic modification or because the species themselves are simply disappearing into extinction.
In the game of survival, the coelacanth has three ominous strikes against it: it is the only surviving species of a taxonomic group that was once considerably richer; it has not changed in millions of years; and it is adapted to a specific habitat now threatened by human-caused pollution and exploited by human intrusion.
The continued survival of the coelacanth, after 380 million years of history in the deep sea, is suddenly threatened by major changes in its environment.⁴ These changes have been created by an upstart species that has been around for only five to eight million years—us. What does it say about us, the human species, if we destroy the biophysical integrity of the coelacanth's habitat and its patterns of self-maintenance to the point of its extinction?
In the case of the coelacanth, it means that a whole, major line of evolution will suddenly disappear—forever. It means that all living individuals in the species, each one of which is the culmination of a 380-million-year chain of genetic experiments, will cease to be. Such a pointless loss is, to me, unconscionable.
We humans also have dramatic, unforeseen impacts on terrestrial areas of our biosphere. To illustrate, let's consider Easter Island, which is a tiny, 43-square-mile piece of land in the South Pacific, 2400 miles off the coast of South America. The island's oldest pollen dates go back some 30,000 years, long before the first people arrived. At that time, based on the pollen record, the island was forested with now-extinct, giant Jubaea palms.
Polynesians settled on the island around the year 1200—800 years ago. They began to gradually clear the land for agriculture and cut trees to build canoes. The island, while small, was relatively fertile, the sea teemed with fish, and the people flourished. The population rose to about 3,000 or 4,000, and probably remained relatively stable. Eventually, trees were felled and cut into log lengths to transport and erect hundreds of stone statues, or moai, some of which are roughly 32 feet high and weigh as much as 85 tons.
Deforestation, which began shortly after the first people arrived, was almost complete by 500 years later—1700. The pollen record that trees did not grow back to replace those cut. When the Europeans discovered Easter Island in 1722, it was treeless and in a state of decline. Nevertheless, the Dutch explorer Jacob Roggeveen and the commanders of his three ships described the island as "exceedingly fruitful, producing bananas, potatoes, sugar-cane of remarkable thickness, and many other kinds of fruits of the earth. . . . " If the soil was rich enough for these plants, why then did the trees not grow back?
Not surprisingly, the Polynesians brought rat stowaways with them in their boats. As the human population expanded, and the people were busy cutting down trees, the rat population was keeping pace with its human counterparts. In so doing, the rats ate more and more of the palm nuts, which prevented growth of new trees. The effects of drought, wind, and soil erosion could also have accelerated the island's deforestation. In addition, both people and rats exploited many of the island's other resources, such as its abundance of birds' eggs. The downward spiral had begun.
Deforestation meant there were no trees available to build canoes for fishing. Soil erosion led to reduced crop yields. And eggs of the sooty tern were probably exploited to the point it discouraged the birds from nesting on the island.
Fewer fish, eggs, and crops inevitably led to a shortage of food. Hunger, in turn, eventually brought the civilization to the brink of collapse. Today, all that remains of the original culture of Easter Island are the coastal statues that once stood upright on specially built platforms. Others lie abandoned between the volcanic quarries of their origin and their planned destinations, and still others remain unfinished in the quarries.⁵
As we humans attack the biosphere in our living, through such things as deforestation, desertification, overfishing the oceans, and burning fossil fuels, we alter how the biosphere relates to both the atmosphere and the lithosphere. In doing so, we are changing the interactions among the three spheres—a change mediated through the myriad self-reinforcing feedback loops of the global climate.
For example, overexploiting the large, predatory, marine fishes, such as tuna, allows the populations of smaller, plankton-feeding fishes to proliferate in numbers sufficient to dramatically reduce the amount of phytoplankton and thus the ocean's ability to absorb atmospheric carbon dioxide, thereby increasing global warming. In turn, warming oceans affect the major wind patterns, which affect the direction of ocean currents, which then shift the dynamics of the biosphere through such things as increased areas of drought and their prolonged duration.
Drought slows an area's vegetative growth, which diminishes its ability to absorb atmospheric carbon dioxide, thereby augmenting the rise in global temperatures that warms the lithosphere—melting glaciers and increasing ocean temperatures, both of which raise the level of the world's oceans, one be adding water and the other by expanding the existing water.
Moreover, while the vegetation in North America annually absorbs millions of tons of atmospheric carbon dioxide, it does not keep up with the prodigious emissions of the planet-warming gas produced by automobiles, power plants, and the manufacturing of cement.⁶ Because we humans do little to curb out materialistic appetites and our burgeoning population, our behavior further increases the atmospheric temperature, which affects the lithosphere and so the biosphere and thus the atmoshere in a never-ending, self-reinforcing feedback loop that is negative with respect to the best quality of life as we know it.
Clearly, we humans directly affect air and both directly and indirectly affect soil and water. If, for example, we choose to clean the world's air, we will automatically cleanse the soil and water to some extent because airborne pollutants will no longer exist to be extracted by rain and snow. If we then choose to treat the soil in such a way that we can grow what we desire without the use of artificial chemicals and if we stop using the soil as a dumping ground for toxic wastes and avoid overly intensive agriculture, the soil can once again purify water by filtering it. If we then stop dumping waste effluents into ditches, streams, rivers, estuaries, and oceans they can begin to cleanse and regain healthy condition.
With clean and healthy air, soil, and water, we can also have clear, safe sunlight with which to power the Earth and, with the eventual repair of the ozone shield, a more benign—and perhaps predictable—climate in which to live. In addition, effective population control can tailor human society to fit within the world's biophysical carrying capacity.
A population in balance with its habitat will reduce demands on the Earth's resources. With reduced competition for resources can come the cooperation and coordination that will allow our landscapes to provide the maximum possible biodiversity. Protecting biodiversity translates into the gift of choice, which in turn translates into hope and dignity for all generations.
If we do everything outlined here except clean the air, we will still pollute the entire Earth. Clean air is the absolute bottom line for social-environmental sustainability and, therefore, human survival. Without clean air, we will eventually destroy ourselves—either by genocide or indirect suicide—because our habitat is comprised. By "habitat," I mean the three, interactive spheres, which continually affect one another through their reciprocal, self-reinforcing feedback loops.
The discussion of the Bodélé Depression is based on: I. Koren, Y. Kaufman, R. Washington, M. Todd, Y. Rudich, J. Vanderlei Martins, and D. Rosenfeld. 2006. The Bodélé Depression: A Single Spot in the Sahara That Provides Most of the Mineral Dust to the Amazon Forest. Environmental Research Letters 1:1-5.
Elaine R. Ingham. 1995. Organisms in the soil: the functions of bacteria, fungi, protozoa, nematodes, and arthropods. Natural Resource News. 5:10-12, 16-17.
Chris Maser. 1995. The humble ditch. Resurgence 172:38-40.
Discussion of the coelacanth is based on: (1) Rare Fish Faces Extinction. 1989. Corvallis Gazette-Times, Corvallis, OR. October 4; (2) Peter Forey. 1998. A home from home for coelacanths. Nature 395:319-320; and (3) Mark V. Erdmann, Roy L. Caldwell, and M. Kasim Moosa. 1998. Indonesian 'King of the Sea' discovered. Nature 395:335.
The discussion of Easter Island is based on: (1) Michael Kiefer. 1989. Fall of the Garden of Eden. International Wildlife, July-August:38-43; (2) Terry L. Hunt and Carl P. Lipo. 2006. Late Colonization of Easter Island. Science 311:1603-1606; and (3) Terry L. Hunt. 2007. Rethinking Easter Island's Ecological Catastrophe. Journal of Archaeological Science 34:485-502.
S. Perkins. 2007. Falling Behind. Science News. 172:34342.
©chris maser 2007. All rights reserved.