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ENVIRONMENTAL SCIENCE

How humankind can best live within Earth's envi­ronment is the subject of what is loosely called en­vironmental science, the interdisciplinary study of how humanity affects other living organisms and the nonliving physical environment Environmen­tal science encompasses many complex and inter­connected problems involving human numbers, Earth's natural resources, and environmental pollu­tion. Environmental science is interdisciplinary because it uses and combines information from many disciplines: biology (particularly ecology), chemistry, geology, physics, economics, sociology (particularly demographics, the study of population dynamics), natural resources management, and pol­itics.

Every human being lives within a complex community of organisms. One of the principal goals environmental sciences is to identify ways to avoid upsetting the delicate balance of the biological systems that support us. When imbalances do arise, one of the tasks of environmental science is o suggest how to deal with them in the most constructive way possible. For example, destruction of the Earth's ozone shield by industrial chemicals will have a disastrous impact if allowed to continue; pollution of the environment by industrial wastes and over utilization of particular resources such as fresh water and forest trees are other problems of this kind. Environmental scientists are called on to find solutions to all these problems.

The central problem of environmental science, the one that links all others together, is that there are many peo­ple in this picture—and soon there will be many more. In 1950 only eight cities in the world had populations larger than 5 million; the largest was New York, with 12.3 million. By 1990 the largest city, Tokyo-Yokohama, had 20.5 million inhabit­ants, and the combined population of the world's ten largest cities was 143.5 million. By the year 2000 there will be 28 mega cities with populations greater than 8 million, 22 of them in developing countries such as Brazil, India, and Indonesia. (See Chapter 8 for a discussion of developed and devel­oping countries.)

In 1992 the human population of the Earth as a whole passed a significant milestone: 5.4 billion individuals. Since 1650, and probably for much longer, the average global human birth rate has remained nearly constant, at about 30 births per 1000 people per year. The birth rate has declined slightly in recent years (the 1992 value is 26, for example). However, with the spread of bet­ter sanitation and improved nutrition and medical techniques, the death rate has fallen steadily, to an estimated 1992 level of about 9 deaths per 100C people per year. The difference between these two figures amounts to an annual worldwide increase in human population of approximately 1-7 percent. In 1992 this translated to a global increase of 93 mil­lion people, a number equivalent to the total popu­lation of Northern Europe. In just one year this increase compensates numerically for all the lives lost due to all the wars of the 20th century. More than 254,000 people are added to the world's popu­lation each day, about 175 every minute! At this growth rate, the world's population would reach 6.2 billion people by the year 2000—and then increase by almost 1 billion more (the entire world's popula­tion in 1930) during the following 20 years.

All these people consume a lot of food and water, use a great deal of energy and raw materials, and produce much waste. As a group, they also have the potential to solve many, perhaps most, of the problems that arise in an increasingly crowded world. In this book, we delve into the details of how today's styles of living affect the environment within which all future humans must live, and dis­cuss the efforts being mounted to lessen adverse impacts and increase potential benefits.

Despite the vigorous involvement of most de­veloping countries with family planning, popula­tion growth rates cannot be expected Co change very soon, owing to age distribution in developing countries. Three billion people will be added to the world in the next three to four decades, so even if we continue to be concerned about the overpopula­tion problem and even if our solutions are very ef­fective, the coming decades may very well be clouded with tragedy. About 1.2 billion people are now living in extreme poverty, half of them getting less than 80 percent of the minimum calories recommended by the United Nations.

Given the efforts that are under way and con­sidering the direction of growth trends, it is esti­mated that the world population may stabilize by the end of the 21st century. Population experts have made various projections for the population at that time, from almost twice what it is now (about 10.4 billion people) to more than four times our current population (greater than 20 billion people).

No one knows whether the world can support so many people indefinitely. Finding ways for it to do so represents one of the greatest challenges of our times. Among the tasks that we must accom­plish is the development of new ways to feed, clothe, and shelter a world population more than twice as large as the present one without destroying the biological communities that sustain us. The quality of life available to our children and grand-children will depend to a large extent on our ability to achieve this goal.

Success in this effort will require the coopera­tion of all the world's peoples. It will not be enough for the United States, consuming 20 to 40 times as much per person as developing countries, to preach environmental preservation to those same countries. Until the people of developing countries can meet their urgent needs, preserving tropical rain forests will not be a high priority for them, and if we in the United States want to help preserve the trees in the tropics, we must help the /jeo/jL¹ in the tropics,

Envirobrief Choosing Between Poi and Poverty

Africa has been called "the world's toxic dumpsite." African countries are regularly approached by international dealers looking to dispose of American and European waste. Typical of this trade was the 1988 discovery of 8,000 drums of highly toxic waste behind fisherman Sunday Nano's house in the small village of Koko, Nigeria. An Italian disposal Formaldehyde, ethylacetate formaldehyde, and polychlorinated biphenyls (PCBs) in a com­pound behind Nano's house, where the bar­rels popped quietly in the sun, oozing liquid poison and acid fumes.

Nano's nightmare represents a fraction of the 24 million tons of hazardous wastes that were dumped in West Africa alone during 1988. In that same year, Sierra Leone was offered $25 million to take American trash and Guinea-Bissau was scheduled to receive 16 million tons of western waste from a con­sortium of American and European compa­nies in exchange for $120 million pet year for five years—roughly the same as its gross national product. "Deals like these," says the

Environmental groups Greenpeace “force government to make the unfair choice between poison and poverty."