1. Ch 09 Human Population, Factors affecting growth
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2. A. HUMAN POPULATION GROWTH: A BRIEF HISTORY
The human population has grown rapidly because of the expansion of agriculture and industrial production and lower death rates from improvements in hygiene and medicine.
In 2006, the population of developed countries grew exponentially at 0.1% per year.
Developing countries grew (15 times faster at 1.5% per year.
No population, including humans, can continue to grow indefinitely

3. We do not know how long we can continue increasing the earth’s carrying capacity for humans.
There are likely to be between billion people on earth by 2050.
97% of growth in developing countries living in acute poverty.
What is the optimum sustainable population of the earth based on the cultural carrying capacity?

4. Black Death—the Plague?
Billions of people
Figure 1.1
Exponential growth: the J-shaped curve of past exponential world population growth, with projections to Exponential growth starts off slowly, but as time passes the curve becomes increasingly steep. Unless death rates rise, the current world population of 6.6 billion people is projected to reach 8–10 billion people sometime this century. (This figure is not to scale.) (Data from the World Bank and United Nations; photo courtesy of NASA)
Black Death—the Plague
Time
Industrial
Revolution
Hunting and
Gathering
Agricultural revolution
Fig. 1-1, p. 6

5. Where Are We Headed?
U.N. world population projection based on women having an average of 2.5 (high), 2.0 (medium), or 1.5 (low) children.
Go to us cencus database
Figure 9-2

6. B. FACTORS AFFECTING HUMAN POPULATION SIZE
Population increases because of births and immigration and decreases through deaths and emigration.
Instead of using raw numbers, crude birth rates and crude death rates are used (based on total number of births or deaths per 1,000 people in a population).

7. Average crude birth rate Average crude death rate21
World 9
All developed
countries 11 10
All developing
countries 23
Figure 9.3
Global connections: average crude birth and death rates for various groupings of countries in (Data from Population Reference Bureau) 8
Developing
countries
(w/o China) 27 9
Fig. 9-3, p. 174

8. Africa Latin and Central America Asia Oceania United States North38 15
Latin and
Central America 21 6
Asia 20 7
Oceania 17 7
United
States 14
Figure 9.3
Global connections: average crude birth and death rates for various groupings of countries in (Data from Population Reference Bureau) 8
North
America 14 8
Europe 10 11
Fig. 9-3, p. 174

9. There are currently more births than deaths throughout the world
The crude birth rate is the number of live births per 1,000 people in a population in a specific year
The crude death rate is the number of deaths per 1,000 people in a population in a specific year.
There are currently more births than deaths throughout the world
The annual rate of natural population change (%) = birth rate- death rate divided by 1,000 persons multiplied by 100
Cruden birth/ death because This measure ignores the age and sex structure of the population.

10. The rate of the world’s population growth has decreased.
The annual population growth dropped by almost half between 1963 and 2004, from 2.2% to 1.2%.
During this same period, the population base doubled from 3.2 to 6.4 billion.
The six fastest growing countries in terms of population are India, China, Pakistan, Nigeria, Bangladesh, and Indonesia
The populations of China and India comprise 37% of the world’s population.
The next most populated country is the United Stated with 4.5%

11. China 1.3 billion 1.5 billion India 1.1 billion 1.4 billion USA
300 million
349 million
Indonesia
225 million
264 million
Brazil
187 million
229 million
Pakistan
166 million
229 million
Bangladesh
147 million
190 million
Figure 9.4
Global connections: the world’s 10 most populous countries in 2006, with projections of their population size in In 2006, more people lived in China than in all of Europe, Russia, North America, Japan, and Australia combined. By 2050, India is expected to have a larger population than China. (Data from World Bank and Population Reference Bureau)
Russia
142 million
130 million
Nigeria
135 million
199 million
Japan
128 million
121 million
2006
2025
Fig. 9-4, p. 174

12. Declining Fertility Rates: Fewer Babies per Women
The average number of children that a woman bears has dropped sharply.
This decline is not low enough to stabilize the world’s population in the near future.
Replacement-level fertility: the number of children a couple must bear to replace themselves.
Total fertility rate (TFR): the average number of children a woman has during her reproductive years.

13. The replacement level to sustain a population is 2.0 children.
In 2006, the average global Total Fertility Rate was 2.7 children per woman.
1.6 in developed countries (down from 2.5 in 1950).
3.0 in developing countries (down from 6.5 in 1950).

14. Fertility and Birth Rates in the United States
Nearly 2.9 million people were added to the U.S. in 2006:
59% occurred because of births outnumbering deaths.
41% came from illegal and legal immigration.

15. Video: People Explosion
PLAY
VIDEO
From ABC News, Human Biology in the Headlines, 2006 DVD.

16. From 1946-1964 the United States had a sharp rise in birth rate, called the baby-boom period
At its peak the TFR reached 3.7 children per woman

17. In 2006, the total fertility rate in the United States was slightly > 2.0
The population growth of the United States is still greater than any other developed country and is not close to leveling off
Other major developed countries have slower population growth and most are expected to have declining populations after 2010
The baby bust that followed the baby boom was largely due to delayed marriage, contraception, and abortion.
ROE V WADE was decide in january 22, 1973 that overturned opposition of the

18. Hourly manufacturing job wage (adjusted for inflation) $3 2000 $15
47 years
Life expectancy
77 years 8%
Married women working
outside the home
81%
15%
High school
graduates
83%
10%
Homes with
flush toilets
98%
Homes with
electricity 2%
99%
Living in
suburbs
10%
Figure 9.7
Some major changes that took place in the United States between 1900 and QUESTION: Which two of these changes do you think were the most important? (Data from U.S. Census Bureau and Department of Commerce)
52%
1900
Hourly manufacturing job wage (adjusted for inflation) $3
2000
$15
Homicides per
100,000 people
1.2
5.8
Fig. 9-7, p. 176

19. 12. Factors Affecting Birth Rates and Fertility Rates
The number of children women have is affected by:
More children work in developing countries; they are important to the labor force
The cost of raising and educating them.
If there are available private/public pension systems, adults have fewer children because they don’t need children to take care of them in old age
People in urban areas usually have better access to family planning
If women have educational and economic choices, they tend to have fewer children.
Infant deaths, Marriage age, Availability of contraception and abortion.
Show the video from sci Friday regarding population control.

20. 13. Factors Affecting Death Rates
Death rates have declined because of:
Increased food supplies, better nutrition.
Advances in medicine.
Improved sanitation and personal hygiene.
Safer water supplies.
Measures of overall health are life expectancy and infant mortality rates
Life expectancy is the average number of years a newborn can expect to live
Infant mortality rate is the number of babies out of every 1,000 born who die before their first birthday
Life expectancy and infant mortality is the single best measure of a society’s quality of life.

21. Arguments to limit immigration into the U.S. are:
U.S. infant mortality is higher than it could be (ranked 46th world-wide) this is due to:
Inadequate pre- and post-natal care for poor.
Drug addiction.
High teenage birth rate.
Arguments to limit immigration into the U.S. are:
Limitations would aid in stabilizing the population sooner
Limitations would help reduce the US’s enormous environmental impact
Arguments for generous immigration policies in the U.S. are
Since 1820, the U.S. has admitted almost twice as many immigrants and refugees as all other countries combined
Show the link for the world infant mortality to show overall health of the planet.

22. Number of legal immigrants (thousands)
1907
1914
New laws
restrict
Immigration
Number of legal immigrants (thousands)
Great
Depression
Figure 9.8
Legal immigration to the United States, 1820–2003. The large increase in immigration since 1989 resulted mostly from the Immigration Reform and Control Act of 1986, which granted legal status to illegal immigrants who could show they had been living in the country for several years. (Data from U.S. Immigration and Naturalization Service and the Pew Hispanic Center)
Year
Fig. 9-8, p. 178

23. C. POPULATION AGE STRUCTURE
Age structure diagrams are visual aids, which show the distribution of males and females in each age group.
The percentages of male and females in the total population are divided into the following age categories:
Pre-reproductive ages (0-14)
reproductive ages (15-44)
Post-reproductive ages (45-up)
The number of people in young, middle, and older age groups determines how fast populations grow or decline.

24. The number of people younger than age 15 is the major factor determining a country’s population growth.
In 2004, 30% of the planet’s population was under 15
Changes in the distribution of a country’s age groups have long-lasting economic and social impacts.

25. POPULATION AGE STRUCTURE
The difference being that as the base increases the potential for growth increases dramatically
Populations with a large proportion of its people in the pre-productive ages 1-14 have a large potential for rapid population growth.
Figure 9-9

26. POPULATION AGE STRUCTURE
32% of the people in developing countries were under 15 years old in 2006 versus only 17% in developed countries.
Figure 9-10

27. Population (millions)
Developed Countries
Male
Female
Age
Figure 9.10
Global connections: population structure by age and sex in developing countries and developed countries, (Data from United Nations Population Division and Population Reference Bureau)
Population (millions)
Fig. 9-10a, p. 179

28. Developing Countries Male Female Age Population (millions)
Figure 9.10
Global connections: population structure by age and sex in developing countries and developed countries, (Data from United Nations Population Division and Population Reference Bureau)
Population (millions)
Fig. 9-10b, p. 179

29. The ‘baby bust’ generation compared to that of the ‘baby boom’
Changes in the distribution of a country’s age groups, like the ‘baby boom’ generation, long-lasting economic and social impacts.
Such a group can dominate the population’s demands for goods and services
They influence elections and legislation and economic demand
The ‘baby bust’ generation compared to that of the ‘baby boom’
There will be fewer people to compete for education, jobs, and services
It may be more difficult to get job promotions because a larger baby-boom group will occupy most upper-level positions.

30. There can be a sharp rise in the proportion of older people.
Reduced fertility and population decline can have long-term consequences, especially if the decline is rapid.
A gradual population decline, its harmful effects can usually be managed.
There can be a sharp rise in the proportion of older people.
Producing a sharp rise in public services’ cost for health, etc.
It may have many fewer working taxpayers & labor shortages.
It may be necessary to raise retirement age, raise taxes, cut retirement benefits and increase legal immigration, which are generally unpopular moves.

31. Age structure predictions based on a medium fertility projection.
The cost of an aging population will strain the global economy.
Figure 9-12

32. If population declines because of deaths, consequences are serious.
Deaths from disease such as AIDS disrupt a country’s social and economic structure.
Large number of people in a particular age are removed from the country’s future:
Life expectancy drops.
In the case of AIDS, the deaths are mostly young adults, those who usually help run the country and everyday life for millions.

33. Rapidly Declining Population Problems
• Can threaten economic growth
• Less government revenues with fewer workers
• Less entrepreneurship and new business formation
• Less likelihood for new technology development
• Increasing public deficits to fund higher pension and healthcare costs
Fig. 9-13, p. 182