62 Unit 6 POPULATION GROWTH AND CONTROL LEARNING OBJECTIVES 1. Learn the size of the population of the world and where the major distributions of people occur. 2. Learn the general trend in population growth for the world over the last 2000 years. 3. Learn how to determine growth rate. 4. Learn how to determine doubling times for populations. 5. Learn how age structure affects future population growth. 6. Learn the differences in life expectancy in various countries of the world and some of the factors that influence these differences. INTRODUCTION The world’s population passed six billion in 1999. It is still growing at an alarming rate. Along with increased population comes increased energy use, increased use of raw materials, and increased production of wastes. Are there too many people on earth or are many of them just living in the wrong places? Should we be trying to reduce or stop population increase or are more people a desirable thing? Is there a correlation between population density and standard of living? In this unit we will examine distribution of populations and rates of increase. We shall look at factors that have and continue to lead to population increase, and methods being used to bring about zero population growth in some countries. HUMAN POPULATION GROWTH Demographics refers to the statistical data of a population particularly its growth, age, income, education, etc. The normal growth curve is an S-shaped curve (fig. 6-1).
Transcript
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Unit 6
POPULATION GROWTH AND CONTROL LEARNING OBJECTIVES 1. Learn the size of the population of the world and where the major distributions of
people occur. 2. Learn the general trend in population growth for the world over the last 2000 years. 3. Learn how to determine growth rate. 4. Learn how to determine doubling times for populations. 5. Learn how age structure affects future population growth. 6. Learn the differences in life expectancy in various countries of the world and some
of the factors that influence these differences. INTRODUCTION The world’s population passed six billion in 1999. It is still growing at an alarming rate. Along with increased population comes increased energy use, increased use of raw materials, and increased production of wastes. Are there too many people on earth or are many of them just living in the wrong places? Should we be trying to reduce or stop population increase or are more people a desirable thing? Is there a correlation between population density and standard of living? In this unit we will examine distribution of populations and rates of increase. We shall look at factors that have and continue to lead to population increase, and methods being used to bring about zero population growth in some countries. HUMAN POPULATION GROWTH Demographics refers to the statistical data of a population particularly its growth, age, income, education, etc. The normal growth curve is an S-shaped curve (fig. 6-1).
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Figure 6-1. Normal growth curve.
Figure 6-2. Human population growth curve. A human population growth curve is shown in figure 6-2. Projection of population size in the future is based upon growth rate today. Figures 6-3, 6-4, and 6-5 from Vital Signs 2002, page 89 graphically illustrate similar information shown in table 6-1, from U.S. Census Bureau and represent several ways of showing population increase. Table 6-1 also gives predictions to 2050. As of August 10, 2006, the world population was 6,533,215,610. It is estimated that the world population in 2100, if the present growth rate declines at a moderate pace to zero, will be a little over ten billion. This ten billion will not be evenly distributed over the face of the earth. Table 6-2 lists the world’s 50 most
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populous countries for 2005 from U.S. Census Bureau. China had 1,313,973,713, India had 1,095,351,995 and the United States had 298,444,215. China, India, and the other developing nations have about 72% of the world’s population. Table 6-3 lists the 20 most populous cities of the world for the year 2005. Definitions for each city and approximate surface area are also indicated. The populations listed are, in most cases, for the city proper and not for the entire metropolitan area, taken from Wilipedia, the free encyclopedia. Table 6-1. Total midyear population for the world for 1950-2050, and the average annual growth rate (%) and average annual population change.
Source: U.S. Census Bureau, International Data Base. Note: Data updated 08-24-2006 (Release notes). Growth rates are calculated using the formula: r(t) = ln [ P(t+1) / P(t) ] where: t = year r(t) = growth rate from midyear t to midyear t+1 P(t) = population at midyear t ln = natural log
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Table 6-2. World’s 50 Most Populous Countries for 2006
Rank Country Population 1. China 1,313,973,7132. India 1,095,351,9953. United States 298,444,2154. Indonesia 245,452,7395. Brazil 188,078,2276. Pakistan 165,803,5607. Bangladesh 147,365,3528. Russia 142,893,5409. Nigeria 131,859,73110. Japan 127,463,61111. Mexico 107,449,52512. Philippines 89,468,67713. Vietnam 84,402,96614. Germany 82,422,29915. Egypt 78,887,00716. Ethiopia 74,777,98117. Turkey 70,413,95818. Iran 68,688,43319. Thailand 64,631,59520. Congo, Dem. Rep. 62,660,55121. France 60,876,13622. United Kingdom 60,609,15323. Italy 58,133,50924. Korea, South 48,846,82325. Myanmar (Burma) 47,382,63326. Ukraine 46,710,81627. South Africa 44,187,63728. Colombia 43,593,03529. Sudan 41,236,37830. Spain 40,397,84231. Argentina 39,921,83332. Poland 38,536,86933. Tanzania 37,445,39234. Kenya 34,707,81735. Morocco 33,241,25936. Canada 33,098,93237. Algeria 32,930,09138. Afghanistan 31,056,99739. Peru 28,302,60340. Nepal 28,287,147
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41. Uganda 28,195,75442. Uzbekistan 27,307,13443. Saudi Arabia 27,019,73144. Iraq 26,783,38345. Venezuela 25,730,43546. Malaysia 24,385,85847. Korea, North 23,113,01948. Taiwan 23,036,08749. Ghana 22,409,57250. Romania 22,303,552
Source: U.S. Census Bureau, International Database.
Figure 6-3. World population 1950-2001
Figure 6-4. Annual addition to world population, 1950-2001
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Figure 6-5. Annual growth rate of world population, 1950-2001. Table 6-3. Worlds 20 most populous cities for 2005. Rank City Population Area Population (km2) Density (/km2) 1 Mumbai 12,778,721 440 29,042 (Bombay) 2 Kaarachi 11,507,254 3,530 3,458 3 Delhi 11,055,365 1,400 7,896 4 Shanghai 10,840,516 1,600 6,775 5 Moscow 10,375,688 1,080 9,607 6 Seoul 10,297,004 605.52 17,005 7 Sao Paulo 10,136,978 1,520 6,669 8 Istanbul 10,124,000 1,970 5,137 9 Mexico City 8,548,639 1,550 5,515 10 Jakarta 8,407,479 660 12,738 11 New York City 8,158,957 780 10,460 12 Tokyo 8,124,310 620 13,103 13 Lima 7,866,160 2,672 2,944 14 Beijing 7,741,274 1,370 5,650 15 Cairo 7,438,376 210 34,420 16 Tehran 7,404,515 660 11,218 17 London 7,287,555 1,580 4,612 18 Bogota 7,220,971 1,590 4,612 19 Logos 7,181,111 330 21,760 20 Hong Kong 6,752,001 1,092 6,183 Source: List of cities by population-Wikipedia, the free encyclopedia
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Table 6-4 indicates the time it has taken to increase the world’s population by billions. Figure 6-6 from U.S. Census Bureau, 2002 shows a graph of the time to successive billions in world populations,1800-2050. It is important to remember that the larger the population the larger the increase for each generation even with the rate of growth remaining the same. Population increase was 77 million in 2000 over 1999. 95% of the increase occurred in developing countries; Asia accounted for 57% of the growth, Africa 23%, Latin America 9%, and the Near East 5%. Six countries account for half the annual growth: India, China, Pakistan, Nigeria, Bangladesh, and Indonesia. Nearly 60% of the projected population growth is expected to occur in Asia, which is projected to grow to 5.4 billion by 2050. With the major proportion of population increase occurring in developing, non industrialized, nations; this must mean that many nations had little or no increase. Table 6-4. World population increase.
People (billions)
Time required (years) Year it occurred
First 2-5 million 1800 Second 130 1930 Third 30 1960 Fourth 15 1975 Fifth 12 1987 Sixth 12 1999
Figure 6-6. Time to successive billions in world population: 1800-2050.
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Table 6-5 lists 16 countries with populations over 10 million that had zero or near zero population growth in 2006. Botswana with a population of 1,765,000 and South Africa with a population of 47,432,000 have growth rates of -0.035 and -0.369 respectively. Botswana’s death rate is 29.50 and birth rate is 23.00, and South Africa’s death rate is 22.00 and its birth rate 18.30. What has caused the difference between death rate and birth rate in these two countries. Table 6-5. Sixteen countries with zero population growth, 2006
Country Annual Rate of Natural Increase
(percent)
Midyear Population (million)
Belarus -0.055 10.3 Belgium 0.134 10.4 Czech Republic -0.060 10.2 France 0.351 60.9 Germany -0.019 82.4 Greece 0.178 10.7 Hungary -0.253 10.0 Italy 0.039 58.1 Japan 0.021 127.5 Netherlands 0.494 16.5 Poland 0.51 38.5 Romania -0.120 22.3 Russia -0.368 142.9 Spain 0.133 40.4 Ukraine -0.600 46.7 United Kingdom 0.276 60.6 Source: U.S. Bureau of the Census, International Data Base, electronic database, Suitland, MD, 10 October 2006.
GROWTH RATE Growth rate is expressed as a percent of the difference in birth rate/1000 and the death rate/1000. i.e. birth = 15 and death = 10; therefore, 15-10 1000 = 0.005 x 100 = 0.5% Using Canada as an example, it has a birth rate of 13/1000 and a death rate of 6/1000. What is its growth rate? __________. The annual growth rate in the world has been slowly dropping from its record high of 2.2% in 1963 to 1.4% in 1998. The 2.2% growth rate in 1963 yielded 69 million more people; whereas, the 1.4% growth rate in1998 produced an additional 78 million. What does this suggest about the future population increase if the growth rates decrease in developed nations but remain relatively high in the developing nations? Population is continuing to increase, but is growing more slowly than expected (table 6-1 from U.S. Census Bureau) and table 6.6 from U.S. Census Bureau). Table 6-6 shows the births and deaths per 1,000 and the growth rate and predicted growth rate for
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the world from 1996 to 2050. Note the consistent decrease in both rate of natural increase and growth rate. Worldwide, the average number of children born to a woman in her lifetime dropped by more than one child per woman between 1985 and 1996. During this same period of time the total fertility rate fell 26% in India, 30% in Brazil, and 35% in Bangladesh. China has adopted a one child per family policy and enforces it by severe economic penalties. Recently this policy has been eased to allow a second child under specified conditions. Worldwide, two out of five people live in nations where fertility has dropped to replacement level. But in dozens of African nations, the average woman bears more than 6 children leading to growth rates of 3%. The decline in population growth in Africa is not all good news, because part of the decline is due to the spread of AIDS. Some 3 million people died of AIDS in 2000. In 35 AIDS-afflicted African countries, the projection is that they will have populations 10% lower than they would have had if not because of AIDS. Table 6-6 shows the births and deaths per 1,000 population and the growth rate and predicated growth rate for the world from 1996 to 2050. Table 6-7 indicates the percentage of the world’s population in various regions at selected times. Figure 6-7 shows the known and predicated global fertility levels (TFR) relative to replacement level from 2002 to 2050. It is predicted that, if current trends persist, the gap between the actual level of fertility and the replacement level will decrease gradually, with the actual level dipping below replacement in 2043. Figure 6-8 shows the 2001 and predicted 2050 populations for the world’s most populous countries. Table 6.6 Births and deaths per 1,000 population and rate of natural increase and growth rate for the world , 1996-2050.
Table 6.7. Showing the percentages of the world’s population in various regions of the world for selected times in the past and predictions for 2000 and 2100.
Region 1800 1900 1975 2000 2100 Africa 11.1 9.0 9.2 13.9 23.4 Asia 64.7 56.8 55.3 59.7 56.9 Europe 21.0 26.9 21.5 13.1 8.3 Latin America 2.5 4.0 7.4 8.6 8.5 North America 0.7 5.2 6.6 4.7 2.9
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Figure 6-7. Global fertility levels relative to replacement level: 2002-2050.
Figure 6-8. Shows the 2001 and predicted 2050 populations for the world’s most populous countries. (fig. 3-1, p. 41 from 2003 State of the World)
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Doubling time Doubling time refers to the time in years that it takes for a population to double in number. This can be determined by the equation d = 70/gr, where d = doubling time, gr = growth rate, and 70 = demographic constant. Using the growth rate for Canada based upon the birth rate and death rate provide earlier in this unit, what is the doubling time for Canada? __________. Figure 6-9 compares the birth rates, death rates, and growth rates for selected countries.
Figure 6-9. Showing the birth rate, death rate and growth rate for selected counties. AGE STRUCTURE An age structure diagram provides one with information about the percent of individuals in various age categories in the population. Figure 6-10 shows a generalized diagram for the developing and develop countries. The percentage of people in the reproductive range is of extreme importance because they will be largely responsible for the growth rate. Others factors such as better medical care resulting in fewer babies dying at birth, extending the life of elderly, and environmental factors also play a role in the growth rate. Notice the large number of individuals in the developing countries in the reproductive ranges and in the children who will move into the reproductive ranges. This is indicative of a rapid increase in population if the growth rate continues at the same level. Growth rate for more developed countries has stabilized at about 0.5%. How long will it take these countries to double their populations? ______________. The developing countries had a growth rate of about 2.0% in 1998; it peaked at 2.4% between
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1960-1965. It was estimated that it would reach 1.8% in 2000. At that rate, how long will it take for the population to double? _________
Figure 6-10. Age-structure diagram for more developed nations (A) and developing nations (B). AGE EXPECTANCY In addition to the number of children born per female of reproductive age, life expectancy also will influence growth rate. Table 6-9 lists worldwide life expectancy for selected times. Table 6-10 lists life expectancy through 2006. Notice the significant decrease in life expectancy from 2003 to 2006. Figure 6-11 shows life expectancy for 2002 and projected figures through 2050. World life expectancy is expected to increase gradually through 2050, but these expectancies have not taken into consideration the devastating effects of AIDS. Figure 6-11 from Vital Signs 1999, page 101 list life expectancy from 1950 through 1998. It shows that a person born today will live about 20 years longer than a person born in 1950. Figure 6-12 shows life expectancy at birth for 2002 and 2005 and predicted ages through 1950. Figure 6-13 from Vital Signs 1999, page 101 shows life expectancy in developed (industrial) nations has increased nine years over that period of time, but it has increased 24 years in the developing nations. Life expectancy is about 75 years in the developed nations compared to 64 for the developing nations. Figure 6-14 from Vital Signs 1999. page 101 indicates what has happened to life expectancy in two African nations in the last 20 years. In many African nations, individuals can be expected to live only 45 years due to hunger, disease, and social turmoil. Table 6-11 lists the countries with the lowest life expectancy for 2005. In general life expectancy correlates with income level. Individuals in Japan have the longest life expectancy of any of the top populated countries. Table 6-12 compares life expectancy of people in the United States as related to sex and race.
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Table 6-9. Average worldwide life expectancy during the last 2000 years.
Source: United Nations, World Population Prospects: The 1998 Revision (New York: December 1998)
Table 6-11. List of countries with lowest life expectancy for 2005.
Country Life Expectancy (yrs) Afghanistan 43.3 Angola 38.6 Botswana 33.7 Burkina Faso 48.9 Central African Republic 43.5 Chad 47.5 Cote d’Ivoire 48.8 Djibouti 43.2 Equatorial Guinea 49.5 Ethiopia 49.0 Guinea 49.5 Guinea-Bissau 46.9 Kenya 48.9 Lesotho 34.4 Liberia 39.7 Malawi 41.7 Mali 49.0 Mozambique 39.8 Namibia 43.4 Niger 43.4 Nigeria 47.1 Rwanda 47.3 Sierra Leone 40.2 Somalia 48.5 South Africa 42.7 Swaziland 32.6 Tanzania 45.6 Zambia 40.0 Zimbabwe 39.3
Populations are 2005 estimates based on data from the United Nations and other official government sources
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Figure 6-11. World Average Life expectancy 1950-1998
Figure 6-12. World Life Expectancy at Birth: 2002-2050.
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Figure 6-13. Life Expectancy in Industrial and Developing Countries, 1950-1998
Figure 6-14. Life Expectancy in Zimbabwe and Botswana, 1950-1998. Table 6-10. Shows years of life expected at birth from 1900 to 2002 for different races and sexes in the United States.
OBJECTIVE QUESTIONS OVER POPULATION GROWTH AND CONTROL
1. The largest numbers of people live in (A) North America (B) South America
(C) Asia (D) Europe (E) Africa. 2. The life expectancy is lowest in (A) North America (B) South America (C)
Asia (D) Europe (E) Africa. 3. The current world population is about (A) 3.5 (B) 4.5 (C) 5.5 (D) 6.6 (E)
7.5 billion. 4. Mexico has a birth rate of 27 and a death rate of 10. Its growth rate is (A) 1.7
(B) 2.7 (C) 27 %. 5. The growth rate of the United States is .65%. The doubling time would be about
(A) 25 (B) 50 (C) 75 (D) 100 (E) 200 years. 6. Average life expectancy for the world is about (A) 46 (B) 56 (C) 66 (D) 77
years. 7. It took about (A) 2 (B) 12 (C) 30 (D) 130 years for the world’s population
to increase from 5 to 6 billion. 8. The largest number of countries with zero population growth are in (A) Asia (B)
Europe (C) South America (D) Africa. 9. (A) United States (B) Russia (C) Brazil (D) China (E) India has the
largest population. 10. The greatest increase in life expectancy in the world’s population occurred in the
decade (A) 1960-1970 (B) 1970-1980 (C) 1980-1990. 11. (A) China (B) India (C) Japan (D) Mexico (E) United States has the
highest growth rate. 12. The region of the earth predicted to show the greatest percent increase of the total
world population from 1900 to 2100 is (A) Africa (B) Asia (C) Europe (D) Latin America (E) North America.
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13. A pyramid shaped age structure diagram indicates future grow rates will (A) increase (B) decrease (C) stay about the same.
DISCUSSION QUESTIONS OVER POPULATION GROWTH AND CONTROL
1. In 1994, the birth rate in the world was 25 and the death rate 9. What was the
growth rate? 2. What affect does rapid population growth have on developing countries’ ability to
address urgent social, economic, and environmental problems? 3. India’s total fertility rate dropped from 4.3 in 1985 to 3.2 in 1996. Will this result in a
leveling off of its population size in the near future? Explain. 4. What could be some of the reasons that fertility rates are still relatively high in many
of the developing nations?
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5. No matter what one’s estimate of the carrying capacity of the earth, the present rate of increase is going to exceed it in a relatively short period of time. What is carrying capacity?
6. What are some reasons that the growth rate of most of the European nations is near
zero? 7. What are some of the reasons for the increase of 5.5 years in life expectancy from
1850 to 1950? 8. What are some of the reasons for the increase of 11.5 years in life expectancy from
1950 to 1970? 9. Using table 6-7 on life expectancy of U.S. population with respect to sex and race,
what are some of the reasons for the differences in life expectancy for the different sexes and races?
10. Using the same data, what does this tell you about the possibility of getting a
significant increase in life expectancy in the different groups within the next few years?
