CHAPTER FIVE PROCESSES & CYCLES of POPULATION CHANGE
Some population statistics can be disputed, but its historic accelerated growth is undisputable. Even if the global rate of population growth stabilizes or declines somewhat in years to come, there still may be 10 billion humans on the planet by the end of the 21 st century, which would exasperate many current problems.
The current reality is that different countries have different population issues. Some countries have populations that are very young and fast-growing, while others have aging populations that are barely growing or actually shrinking.
In the U.S., the population stands at more than 300 million and growing. But unlike less developed countries, where population growth stems from fertility rates, U.S. population growth stems primarily through immigration.
What is the projected U.S. population by the end of the 21 st century? At that time, what will be our population ranking as compared to other countries?
WORLDWIDE POPULATION TRENDS There are signs that a slowdown in population growth has begun, but any reduction in growth rate has been offset by the ever larger total on which it is based. The world map reveals the wide range of growth rates in different regions. The current international growth rate average is 1.5% Identify the regions with the highest natural increase rates.
For Kenya, what single factor has affected its population statistics? Explain the impact on Kenya’s population distribution. Has the Kenyan govt. made moves to curb population growth?
Unlike population growth rates in developing countries, developed countries, such as Japan and many in Western Europe, are seeing dramatic decreases in population growth. For Japan, describe the root of the population crisis and the impending consequences.
As a stark contrast to China’s one-child policy, the Japanese govt. is encouraging and providing economic incentives for young adults to get married and have children.
Study the graphs: What percent of the world’s population is in less developed countries? During the past four decades, approx. what percent of the population growth occurred in the less developed countries? Why is population growth a continuous problem in regions where it can least accommodate it?
No geographic realm is more important in studying population than South Asia, with approx. 1.4 billion people. South Asia includes the country, India, that appears likely to surpass China as the world’s most populous country sometime during this century. Only one country in this realm has a rate of increase lower than the world average (Sri Lanka).
Cultural norms play a big part in India’s population crisis. Why is there an emphasis on women? How many babies does the average woman living in northern India have? What might happen to an Indian woman who does not bear a son?
With a fast-rising population, explain the problems confronting India. Conversely, identify India’s greatest asset that could be its savior.
DIMENSIONS of POPULATION GROWTH Geographers study 3 types of population growth and its impact: LINEAR GROWTH : Uniform increases in growth during a series of equal time periods. EXPONENTIAL GROWTH : Growth that compounds continuously during a series of equal time periods. DOUBLING TIME : Determining how many years will be required for a population to to double.
THE POPULATION EXPLOSION The history of humanity is one of growing numbers and ever-higher rates of increase. Study the graph: How long did it take for the world’s population to double from ½ billion to 1 billion people? How long did it take for the world’s population to double from 2 billion to 4 billion people? When does it appear that the world’s population growth began to taper? What is the projected trend in world population growth?
EARLY WARNINGS As long ago as 1798, Thomas Malthus published An Essay on the Principle of Population as It Affects the Future Improvement of Society.
In his work, he sounded the alarm: Explain his population “doomsday” theory (hint: world population growth v. food production). Was Malthus correct?
POPULATION STRUCTURE AGE-SEX PYRAMIDS Maps showing population distributions and density reveal statistics, but they can’t reveal two other aspects of population: the numbers of men and women and their ages. Why is population structure a vital dimension of population geography? Identify & explain some of the advantages and/or challenges pertaining to each structure type.
Even within countries, especially developed ones, such as the U.S., age distributions vary from region to region. Describe the population age distribution for Pittsburgh.
THE UNITED STATES Based on the age distribution, how would you describe the current age of the population? Describe some of the advantages associated with this type of distribution. Compare the gender distributions for the older age brackets. Why do females outnumber males?
Consider the age distribution below. What are some of the impacts baby boomers will have on American society when they retire and achieve senior citizen status. And, do females continue to outnumber males in the older brackets?
CHINA Why do Chinese men greatly outnumber women, particularly at the younger age brackets?
What do you think caused the large indentation in the 35-39 age bracket in China’s 1997 age distribution?
Why does China’s 2025 pyramid look so markedly different from the 1997 pyramid?
GERMANY Identify some of the similarities between Germany’s age distribution and the United State’s age distribution.
What do you think caused the large indentation in the 50-54 age bracket in Germany’s 1997 population pyramid?
Which age bracket is predicted to be the largest for Germany in 2050? What challenges are confronting the German government?
BANGLADESH How is its 2000 population distribution so different from the U.S. and Germany distributions? What would be the primary factor accounting for the difference?
How many people in Bangladesh were under age 5 in 1997? What types of challenges would this create for the government?
Is Bangladesh’s population expected to exceed 200 million in 2050?
DEMOGRAPHIC CYCLES A population goes through stages of growth each of which forms part of its demographic cycle. The rate of natural increase of a population is the difference between the number of births and the number of deaths during a specific period. CRUDE BIRTH RATE v. CRUDE DEATH RATE
Another measure of the reproductive status of a population is the total fertility rate (TFR). Define this statistic – where are the TFR’s higher versus where are they lower?
The crude death rate, also called the mortality rate, has declined more dramatically than birth and fertility rates – what impact would this have on population growth and age structure? In studying the map below, where are mortality rates higher versus where they are lower (any patterns)?
Related to crude death rate is infant mortality. Define this statistic and explain how it would impact mortality rates. Describe any patterns associated with infant mortality.
LIMITS on POPULATION GROWTH The world’s population increased slowly until the early 19 th century. What were the reasons for this phenomenon? Thus, birth rates were high in early human history, as were death rates. And there were times when there were more deaths than births.
THE SECOND AGRICULTURAL REVOLUTION and the INDUSTRIAL REVOLUTION The Second Agricultural Revolution marked an increase in the population growth rate during the 19 th century, when farming methods improved, crop yields increased, storage capacities were expanded, and distribution systems improved.
The Industrial Revolution of the 19 th century had a major impact on population growth. Sanitation facilities made towns & cities safer from epidemics, and modern medical practices became widespread. Disease prevention through vaccinations introduced a new era in public health.
Migration and colonization brought European new-found methods of sanitation and medical techniques, thus reversing the earlier pattern of decimating native populations.
DEMOGRAPHIC CHANGE THE DEMOGRAPHIC TRANSITION Using the United Kingdom as a model, population geographers identified four stages in a demographic cycle. Identify & describe each of the four stages in this cycle. What marks the demographic transition? And in what stage would you find the United States?
DEMOGRAPHIC CHANGE in DEVELOPING COUNTRIES In contrast to Europe, much of the developing world was not greatly affected by the Second Agricultural Revolution, or the Industrial Revolution. Therefore, it is unwise to assume that all countries’ demographic cycles will follow the sequence that occurred in industrializing Europe or to believe that the explosive growth now taking place in numerous developing countries will simply subside. And, despite a slowing of the growth rates in developing countries, the population “bomb” remains a very real issue in the 21 st century, especially when you look at the impact of a population versus its number.