Population Growth

The Vital Revolution

Ronald Freedman

• Editorial: Routledge
• Año: 2017
• ISBN:
  9781351497886
• Edición: 1
• Categoría: Scienze sociali
• Categoría: Demografia

The population of the modern world continues to grow at a rate unprecedented in human history. How are we to explain this massive increase in the number of living people? What is its consequence, now and for the future? How have populations changed in size and structure since the advent of industrial technology? Can we predict the population trends in developing countries? These and many other significant questions are dealt with in a persuasive yet accessible manner in Ronald Freedman's pivotal "Population Growth".Modern population trends are unique in historical perspective; describing them as part of a "vital revolution" is not an exaggeration. The more popular term "population explosion" is less accurate because it refers to only one aspect of the current situation - the unprecedented growth rates. In the last two centuries other important trends have developed, also without precedent in all of the previous millennia of human history. While the size of population growth is very important in itself, the essays in this volume demonstrate that many other aspects of structure and change in populations are equally important.In readable, non-technical language, these collected essays analyze the most important modern trends in world population. The essays include comprehensive discussions of population theory, analyses of population trends, and prospects in the United States and surveys of population trends in other major areas of the world. As a survey of current population problems, this book will be a library staple for those involved in international development programs, sociologists, family planning workers, and everyone concerned with the contemporary vital revolution in population.

Chapter 1

THE POPULATION OF THE WORLD: RECENT TRENDS AND PROSPECTS

Philip M. Hauser

Knowledge about population in the past, the present, and the future enables a person to see himself as an element in world population. It provides perspective of one’s self in relation to fellow men in the same manner that astronomy provides one with perspective about this earth as an element in the solar system, the galaxy and the universe. Four numbers summarizing the population history of the world help to provide such a perspective.

Although the first complete census of mankind has yet to be taken, it is possible to reconstruct, within reasonable error limits, the estimated population of the world from the end of the Neolithic period (the new Stone Age) in Europe (8000–7000 B.C.). World population at that time is estimated to have been some ten million, and perhaps was as low as five million. At the beginning of the Christian Era the population of the world probably numbered between 200 and 300 million. At the beginning of the Modern Era (1650) world population had reached about 500 million. In 1962 world population totaled three billion. A relatively simple analysis of these numbers discloses that an enormous increase in the rate of world population growth has occurred, especially during the past three centuries.

Man or very close kin to man has been on the face of the earth for perhaps two million years. Although it is not known exactly when Homo sapiens, the present version of man, first appeared, he was much in evidence in Europe something like 25,000 to 30,000 years ago. It is estimated that for the some six hundred thousand years of the Paleolithic Age (the old Stone Age) population growth perhaps approximated .02 per thousand per year. During the three centuries of the Modern Era, population growth increased from about 4 per thousand to 10 per thousand per year during the interwar years. The rate of world population growth continued to accelerate after World War II, so that in 1963 it approximated 20 per 1000 per year.

In the course of man’s inhabitation of this globe, then, his rate of population growth has increased from about 2 per cent per millennium to 2 per cent per year, a thousand-fold increase in growth rate.

If man’s precursors prior to the old Stone Age are ignored, it has been estimated that since the beginning of that era there have been perhaps 77 billion births. Of this number only 12 billion, or less than 16 per cent of the total, occurred during the approximately 8000 years en-compassing the Neolithic period and history up to the middle of the seventeenth century. Some 23 billion births, or 30 per cent of the total, occurred during the three centuries of the Modern Era. Of the total number of persons that have ever been born, according to these estimates, about 4 per cent, therefore, are now living.

Population data prior to the Modern Era are admittedly speculative as are, also, the inferences and conclusions which are drawn. But they provide a reasonably sound perspective and permit a very firm conclusion–namely, that whatever the precise numbers may be, there can be no doubt that in his habitation of this planet, man has experienced tremendous acceleration in his rate of growth.

This conclusion is supported by placing in perspective the present rate of world population increase, estimated by the United Nations as approximating 2 per cent per year. Although 2 per cent per year may seem like a small return on investment to persons fortunate enough to have funds out at interest, it turns out to be a truly astonishing rate of world population growth. For example, to produce the present population of the world, about three billion, one dozen persons increasing at the rate of 2 per cent per year would have required only 976 years. Yet Homo sapiens alone has been on this earth at least twenty-five to thirty thousand years and some form of man perhaps as long as two million years. Similarly, the same one dozen persons reproducing at the rate of 2 per cent per year since the beginning of the Christian Era could by 1962 have had 300 million descendants for each one actually present on the face of the earth.

Further appreciation of the meaning of a 2 per cent rate of increase per year is gained by observing the population that this growth rate would produce in the future. With an initial population of three billion, the present rate of world population growth would give a population of fifty billion in 142 years. This is the highest estimate of the population-carrying capacity of the globe ever calculated by a responsible scholar. This estimate, by geochemist Harrison Brown, is based on two extreme assumptions: first, that solar or nuclear energy will be developed to a point where the cost of power is so low that it approximates zero. Under this condition it would be possible to obtain the “things” we need from rock, sea, and air to support a population of this size indefinitely. The second assumption is that mankind would be content to forego not only meat, as the Hindu has already done, but also vegetables, and be content to subsist on food products from “algae farms and yeast factories.”

A continuation of the 2 per cent rate of world population growth from the present population of about three billion would provide enough people, in lock step, to reach from the earth to the sun in 237 years. It would give one person for every square foot of land surface on the globe, including mountains, deserts and the arctic wastes, in about six and one-half centuries. It would generate a population which would weigh as much as the earth itself in 1,566 years. These periods of time may seem long when measured by the length of the individual lifetime, but they are but small intervals of time measured in the time perspective of the evolutionary development of man.

Projections of this type, of course, are not to be interpreted as predictions. They merely help to indicate the meaning of the present rate of growth. They also permit another firm conclusion–namely, that the present rate of world population growth cannot possibly persist for very long into the future. As a matter of fact, in the long run, given a finite globe and excluding the possibilities of ex-porting human population to outer space, any rate of population growth would in time saturate the globe and exhaust space itself. In the long run, man will necessarily be faced with the problem of restricting his rate of increase to maintain some balance between his numbers and the finite dimensions of this planet.

It is possible quickly to summarize the remarkable acceleration of his growth rate which man has experienced. It took most of the millennia of man’s habitation of this planet to produce a population as great as one billion persons simultaneously alive. This population was not achieved until approximately 1850. To produce a population of two billion persons simultaneously alive required only an additional seventy-five years, for this number was achieved by 1925. To reach a population of three billion persons required only an additional thirty-seven years, for this was the total in 1962. Continuation of the trend would produce a fourth billion in about fifteen years and a fifth billion in less than an additional ten years.

Analyses of this type have led the student of population, the demographer, to use emotional and unscientific language on occasion to describe population developments. Such a phrase as “the population explosion” is admittedly non-scientific language, but it serves to emphasize the dramatic increase in man’s rate of growth and to call attention to its many implications.

Why has the rate of world population growth increased so greatly? The answer may be found by analyzing the great differences in rates of population growth among the continental regions of the world and examining the reasons for these differences. Although the data are subject to error, it is possible to reproduce with reasonable accuracy the populations of the continents over the three centuries of the Modern Era.

Examination of these data discloses that for the three centuries between 1650 and 1950 the population of the world as a whole increased fivefold, from about 500 million to about 2.5 billion. The population of Europe (including Asiatic U.S.S.R.), however, increased almost sixfold. The population of Northern America (north of the Rio Grande) increased 168-fold, from about 1 to 168 million. The population of Latin America (south of the Rio Grande) increased about 23-fold, from about 7 to 163 million. Oceania increased more than sixfold, from about 2 to 13 million; Asia, showing a fivefold increase, grew at a rate close to the average for the world, of which it constitutes the greatest portion. In contrast, Africa, the slowest-growing region of the world, merely doubled its population during these three centuries, increasing from about 100 to about 200 million. The regions which experienced the most rapid growth during the three centuries of the Modern Era were Europe and the areas of European settlement. The population of Europe and the areas of European settlement combined increased about sevenfold; the areas of European settlement alone, the Americas and Oceania, increased eight- to nine-fold between 1650 and 1950.

Why did the rate of population growth increase so spectacularly in Europe and areas of European settlement? The answer is to be found of course in the technological, economic, and social developments within these regions during the Modern Era. Acceleration in growth rate may be traced to the impact of the many technological, economic, and social changes which are summarized by the expressions the “agricultural revolution,” the “technological revolution,” the “commercial revolution,” and the “industrial revolution,” climaxed by the “scientific revolution.” The profound changes in man’s way of life and in the social order generated by these developments produced the “demographic revolution.” More specifically, the combination of developments accelerated the rate of population growth because it brought about a sharp and unprecedented decline in death rates, with a corresponding great increase in average length of life.

Precise information is not available, but in all probability the expectation of life at birth in Egypt, Greece, and Rome around the beginning of the Christian Era was probably not above thirty years. During the first half century of the Modern Era, 1650 to 1700, life expectation at birth in Western Europe and North America was at a level of about thirty-three years, and probably had not changed much during the preceding three or four centuries. By 1900 death rates had declined to a point where expectation of life at birth in Western Europe and North America had increased by fifteen or twenty years, reaching a level of forty-five to fifty years. By 1960 another twenty years of life had been gained. Life expectation in Western Europe and North America reached a level of about seventy years.

Although some changes in birth rates were also involved, it is clear that the major factor in the great acceleration of population growth, first evident in Europe and areas of European settlement, was the decline in the death rate. Three factors contributed to this decline. The first was the general increase in level of living resulting from technological advances and increased productivity and the achievement of relatively long periods of peace and tranquillity by reason of the emergence of relatively powerful and stable central government. The second major factor accounting for the decrease in mortality was the achievement of environmental sanitation and improved personal hygiene. During the nineteenth century great strides were made in purifying food and water and improving personal cleanliness, which contributed materially to the elimination of parasitic and infectious diseases. The third major factor is of course to be found in the great and growing contribution of modern medicine, enhanced by the recent progress in chemotherapy and the insecticides.

These developments during the Modern Era upset the equilibrium between the birth rate and the death rate that had characterized most of the millennia of human existence. In eighteenth-century France, for example, of 1000 infants born, 233 had died before they reached age one, 498 had died before they reached age twenty, and 786 had died before they reached age sixty. In contrast, in present-day France, of 1000 infants born only 40 had died before age one, only 60 had died before age twenty, and only 246 had died before age sixty. In eighteenth-century France, of the original 1000 infants only 214 survived to age sixty. In contemporary France, 754 of the original 1000 infants were still alive at age sixty. As a result of such a decrease in death rates, the 100 million Europeans in 1650 three centuries later had about 940 million descendants.

The acceleration in rate of total population growth was the result of sharp declines in mortality while fertility remained at relatively high levels. This pattern, an example of which is given for England and Wales, characterized the demographic transition in Europe and in areas colonized by European stock. At mid-eighteenth century the birth rate in England was at a level of about 37–that is, 37 births per 1000 persons per year. The death rate stood at a level of about 33–33 deaths per 1000 persons per year. Natural increase, the excess of births over deaths, approximated 4 persons per 1000 per year, or a .4 of 1 per cent per year rate of population growth. A century later, by 1850, the death rate had declined to a level of 21, while the birth rate remained at the relatively high level of approximately 34. Natural increase with this fertility and mortality was therefore 13, producing a population growth of 1.3 per cent per year, more than three times the rate of increase a century earlier. As in the case of England and Wales, mortality in Western Europe began its relatively rapid descent toward the end of the eighteenth and early part of the nineteenth century, while fertility still remained at relatively high levels. It is only with considerable lag that the birth rate began to decline and, therefore, to dampen rates of population increase. This is the manner in which the “demographic transition” occurred.

Prior to World War II, the spectacular decrease in the death rate of the economically advanced nations had not been shared by most of the population of the world. Of the peoples of non-European stock, only Japan had managed appreciably to increase longevity. The two thirds of the world’s people who live in the economically underdeveloped regions–Asia, Latin America, and Africa–before World War II had achieved some decrease in mortality, largely through contact with advanced nations. But most of the world’s people prior to World War II were characterized by an expectation of life at birth no greater than that which Western Europeans had during the Middle Ages.

This situation has dramatically changed since the end of World War II. A combination of factors, including the advent of the United Nations and the specialized agencies with programs emphasizing economic development and improved health conditions, “the revolution of rising expectations,” the development and dissemination of chemotherapy and insecticides, have opened up to the mass of the world’s people the achievement of the twentieth-century death rates. Since the end of World War II, declines in mortality among the economically underdeveloped areas of the world have been more dramatic than those in the industrialized areas.

Longevity is increasing much more rapidly in the less developed areas than it did among Europeans and European stock, because of the much more efficient means now available for eliminating causes of mortality. For example, the death rate of the Moslem population in Algeria in 1946–47 was higher than that of Sweden in 1771–80, more than a century and a half earlier. By 1955, however, in eight years the decrease in the death rate in Algeria was greater than that Sweden experienced during the century from 1775 to 1875. Between 1940 and 1960 Mexico, Costa Rica, Venezuela, Ceylon, Malaya, and Singapore were among the nations which decreased their death rates by more than 50 per cent. Ceylon’s death rate was decreased by more than 50 per cent in less than a decade.

Without question the most important population development in the twentieth century is the spectacular decline which is taking place in the death rates of the people in the less developed areas. As a result of the decline in mortality rates, population growth among the two thirds of the world’s people in the less developed areas is now greater than that previously experienced by European stock. Whereas annual rates of population growth among the industrialized nations rarely exceeded 1 per cent per year through natural increase during most of the Modern Era, populations in the present less developed areas of Asia, Latin America, and Africa are increasing at rates from 2 to 3 per cent per year. The reason for the more rapid rate of population growth in the less developed areas today than was experienced by the economically advanced nations during their period of rapid population growth is to be found of course in relation between the death rate and the birth rate. In the experience of economically advanced countries a decline in mortality was spread out over the entire three centuries of the Modern Era, during the latter part of which, over periods ranging from half a century to perhaps a century and a half, the birth rate also began to decline.

Precise statistics are not available for birth and death rates of the less developed regions of the world. Reasonably good estimates are available through the United Nations which, from the time it was first organized, has devoted considerable attention to population trends. Birth rates in the less developed regions of the world tend to average 40 or more (births per 1000 persons per year), a level little lower, if any, than it was centuries ago. In contrast the birth rates in the economically advanced regions in Europe, North America and Oceania range from below 15 to 25 (births per 1000 persons per year).

The great acceleration in the rate of population growth in the less developed regions is brought about by the retention of their high birth rates while they are experiencing precipitous decline in death rates. The death rates in the less developed continents, although higher than those which obtain in the more developed regions, have now fallen to levels (deaths per 1000 persons per year) from below 10 to about 20 (per 1000 persons per year). This difference between the death rate and the birth rate gives a natural increase of about 20 to 30–a population growth rate of 2 to 3 per cent per year.

At the present time a number of the industrialized countries of the world, largely European nations and Japan, are growing relatively slowly at rates which would double their populations in from fifty to 100 years. Some of the industrialized countries, including the United States, the Soviet Union, Australia, New Zealand, Canada and Argentina are growing somewhat more rapidly, at rates which would double their populations in about thirty to forty years, about the average for the world.

The less developed areas of the world, containing two thirds of the total population, are now the most rapidly growing regions of the world. They are increasing at rates which would double their population in from twenty to forty years.

The less developed areas are now experiencing the demographic transition already experienced by the industrialized nations, but at a much more rapid pace. The implications of the present patterns of fertility and mortality for future population have great significance, particularly in view of the national aspirations of the less developed areas for improving levels of living. To achieve higher levels of living, income per capita must, of course, be increased. Planners must, therefore, be aware of what the prospects are for future population so as to be in a position to set desired economic goals and lay plans for their achievement....

Índice

• Cover Page
• Population Growth
• copy
• Contents
• Introduction
• 1. The Population of The World: Recent Trends and Prospects
• 2. The Demographic Transition: From High to Low Birth Rates and Death Rates
• 3. How A Population ages or Grows Younger
• 4. Population and Economic Growth
• 5. World Urbanization: Trends and Prospects
• 6. Taking an Inventory of 180 Million People: The U. S. Census
• 7. Longevity and Mortality in the American Population
• 8. The Fertility of the American Population
• 9. Internal Migration and Population Redistribution in the United States
• 10. The Growth of The American Population
• 11. Population Trends in Newly Developing Countries
• 12 Population and Family-Planning Programs in Newly Developing Countries
• 13 The Population of Latin America
• 14 The Population of India
• 15 The Population of Africa
• 16 The Population of Japan
• 17 The Population of Communist China
• 18 The Population of the Soviet Union
• 19 The Population of Europe
• About the Authors