1. HUMAN POPULATION DYNAMICS

2. Is the World Overpopulated?
Much of the world’s population growth occurs in developing countries like China and India.
The world’s population is projected to increase from 7 billion to 10.8 billion by 2050.
Some argue that the planet has too many people.
97% of growth in developing countries living in acute poverty.
Some feel that the world can support billions of more people due to technological advances.
Constant debate over the need to reduce population growth.
Must consider moral, religious, and personal freedom.
Do not know how long we can continue increasing the earth’s carrying capacity for humans.
Fig. 6-1, p. 125

3. Problems with a Growing Population
World Hunger Issues
Unequal distribution of available food
Loss of arable land
Increasing population growth rate
Increasing poverty in developing countries
Strategies for ensuring adequate nutrition for a growing population:
Increase the number of new food crops from a diversity of plant species
Distribute food more equitably
Increase land are that is dedicated to grain production rather than meat production
Assist developing countries in efficient crop irrigation systems.

4. Five Most Populous Countries, 2010 and 2050
Figure 6.4: This chart shows the populations of the world’s five most populous countries in 2010 and 2050 (projected). In 2010, more than one of every three persons on the earth lived in China (with 19% of the world’s population) or India (with 17%). (Data from United Nations Population Division)
Fig. 6-4, p. 127

5. Demography
Demography is the study of human populations, their characteristics and changes. Demographics will measure:
Statistics about people, such as births, deaths, and where they live as well as total population size.
GO TO census.gov and obtain the current world population and the current US population.

6. Human Population Growth
The world population, now over 7.4 billion, is growing at the rate of about 80 million per year.
Projections put the world population at between 8 and 12 billion in 2050, with nearly all of this growth expected in the developing world.
Developing countries include: Africa, Asia, Latin America, the Caribbean, and regions of Melanesia, Micronesia, and Polynesia.
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.
The debate over interactions among population growth, economic growth, politics, and moral beliefs is one of the most important and controversial issues in environmental science.
Developed countries grew at 0.1%
Developing countries grew at 1.5% (15 times faster)

7. Demographic Transitions
Process where countries become economically developed then their birth and death rates begin to decline. In the past this was referred to as “first” and “third” world countries or “developed” and “developing”.
Currently this process is described by the different stages according to population growth:
Preindustrial stage shows little population growth due to high birth rate with high death rate.
Transitional stage is where industrialization begins, death rates drops and birth rates remain high. Rapid population growth occurs.
Industrial stage is birth rate dropping and approaching death rate. Population growth slowly declines.
Postindustrial stage are birth rate and death rate become similar and population growth slows or declines.
Post-industrial: 37 countries have reached this stage. (mainly in W. Europe) To most population experts, the challenge is to help the remaining 88% of the world to get to this stage.

8. Demographic Transition
97% of growth in developing countries living in acute poverty usually occurs during the transitional stage.
What is the optimum sustainable population of the earth based on the cultural carrying capacity?
Generalized model of demographic transition shows that the total fertility of a society decreases as the society progresses through the demographic transition.
Some developing countries may have difficulty making the demographic transition.

9. Determining Population Growth
The rate at which a population grows or declines depends on its age structure.
Age structure diagrams show the distribution of different age groups. These groups are further broken into cohorts:
Prereproductive age (0-14) are persons who are not mature enough to reproduce
Reproductive age (15-44)are those persons that are capable of reproduction.
Postreproductive age (45+) are those persons too old to reproduce.

10. Human Age Structure
Human age structure varies from country to country.
Number of people younger than age 15 is the major factor determining a country’s population growth.
In developing countries age structure tends to be in favor of younger individuals with a large proportion being under 15 years.
In developed nations, age structure is relatively even throughout the age groups.
Age Structure in Human Populations
Changes in distribution of a country’s age groups have long-lasting economic and social impacts.

11. Age Structure Diagrams: Histograms
Populations with a large proportion of its people in the preproductive ages 1-14 have a large potential for rapid population growth. Those with a large proportion of people in reproductive age are experiencing rapid population growth.

12. Age Structure
Since age structure diagrams are broken down by age, demographers can obtain:
Birth rate
Maturity rate
Death rate of an entire population.
These diagrams are usually broken down by country and divided into genders.
29% of the people in developing countries were under 15 years old in 2012 versus only 16% in developed countries.
Changes in the distribution of a country’s age groups have long-lasting economic and social impacts.

13. Population Pyramids Slow/Stable Growth Rapid Growth(Expanding)
Pyramid shaped histograms have a birth rate that exceeds the death rate. Lower cohorts have more males and females.
Population growth is rapid in countries that have a pyramid shape.
Current modern examples include Africa, Asia, and Latin America
“Box”-like shaped histogram shows stable or slow growth.
Birth rate is almost equal to death rate. Sometimes called Zero growth.
Current examples of slow growth: USA, Australia, & Canada
Current examples of stable growth: Denmark, Austria, & Italy
A relatively large segment of the population of the country is currently in the prereproductive/reproductive years and will soon begin having children (giving the population momentum).

14. Negative Growth Diagrams
Some Problems with Rapid Population Decline
Can threaten economic growth
Labor shortages
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 health-care costs
Pensions may be cut and retirement age increased
If there is declining or negative growth, then the birth rate with be less than the death rate.
Pyramids with declining populations tend to show larger numbers of older persons in their population.
Current examples: Germany, Japan, & Russia
Birth rate exceeds the death rate. Population is getting larger. Pyramid shaped histogram.
A slow decline is manageable
A rapid decline causes severe economic and social problems.
How do we pay for services for elderly?

15. Age Structure: United States
Today, baby boomers make up nearly half of all adult Americans and dominate the populations demand for goods and services.
Because of baby boom, the US has a bulge(yellow) in the pyramid with people in their 50’s-60’s.
There are more women than men in the older group because of differences in longevity between sexes.

16. Demographics in the USA
The baby bust that followed the baby boom was largely due to delayed marriage, contraception, and abortion.
Now becoming senior citizens (Graying of America)
In 2012, the total fertility rate in the United States was slightly > 2.0

17. Demographics in the USA
Nearly 2.3 million people were added to the U.S. in 2012:
70% occurred because of births outnumbering deaths
30% came from illegal and legal immigration. Population increase in recent years has been because of immigration
TFR in U.S. dropped
Rate of population
growth has slowed.
Current US
Population:
324,367,731

18. 20th Century Lifestyle Changes in the U.S.
Figure 6.7: This chart lists 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)
Fig. 6-7, p. 132

19. Where Population Growth Occurred, 1950-2010
Figure 6.3: Most of the world’s population growth between 1950 and 2010 took place in the world’s less-developed countries. This gap is projected to increase between 2010 and (Data from United Nations Population Division, The 2008 Revision and Population Reference Bureau, 2010 World Population Data Sheet)
Fig. 6-3, p. 123

20. Developing vs. Developed
Developing (Transitional, Third World):
Higher infant mortality rate because of a shortage in prenatal and pediatric care. Thus, they have more children to ensure some survive.
Agricultural societies need children to help in the labor force.
Lower per capita income or poorer countries need children to provide an income and sometimes contraceptives are not affordable.
Women lack education and job opportunities.
Developed (Industrial, First World):
Usually don’t have population problems but can be linked to poverty.
Educated and working women tend to delay childbearing.
Pension systems support people as they age.
Family planning and the ability to control fertility.
Higher cost of raising children causes people to have smaller families.
Abortion is legal.
Infant mortality higher in a country due to, for example, - contaminated drinking water - poor nutrition - poor health care- few or no educational opportunities for women.

21. Mortality and Fertility
Infant mortality rate: The number of child and/or infant deaths.
If a mother lives in an area with a high infant mortality rate she will tend to have a lot of children to ensure some will make it to adulthood. This ensures care for aging parents and a labor force.
Infant mortality rate is higher in developing countries than in developed countries.
Along with life expectancy, the infant mortality rate is a good indicator of the quality of life of a country
Replacement-level fertility: the number of children a couple must bear to replace themselves.
Slightly higher than two children per couple. (2.1 in developed countries and 2.5 in some developing countries.)
Infant mortality higher in a country due to, for example, - contaminated drinking water - poor nutrition - poor health care- few or no educational opportunities for women.

22. Infant Mortality Rates, 1950-2010
U.S. infant mortality is higher than it could be (ranked 49th world-wide by CIA and 30th by Save the Children) due to:
Inadequate pre- and post-natal care for poor.
Drug addiction.
High teenage birth rate.
Figure 6.10: This graph tracks the infant mortality rates for the world’s more-developed countries and less-developed countries, 1950–2010, with projections to 2050 based on medium population projections. (Data from United Nations Population Division)
Fig. 6-10, p. 129

23. Total Fertility Rates
Fertility rate – number of children born to a woman during her lifetime.
Total fertility rate (TFR): the average number of children a woman has during reproductive years.
In 2012, the average global Total Fertility Rate was 2.4 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).
If fertility rate drops to replacement level fertility but the population continues to grow, this is called population momentum and can be seen in pyramid shaped age structure diagrams.
Birth rates and fertility rates have been slowed or decreased because:
Cultural/religious practices prohibited birth control.
Cultural/religious practices favored large families.
Education/Employment/Status of women is low
Reasons for decline from 1950 to present: increased/improved family planning shows fewer pregnancies, control of fertility, and choice in # of children.
Increased education of women/social status shows a delay in having children. Women enter the workforce and delay having children. Reduced need for children in the workforce because of industrialization and urbanization. Improved health care allows for more children to survive.

24. Factors Affecting Birth Rates and Fertility Rates
The number of children women have is affected by:
The cost of raising and educating them.
Availability of pensions.
Urbanization.
Education and employment opportunities.
Infant deaths.
Child care
Marriage age.
Religious beliefs, politics, and cultural norms
Availability of contraception and abortion.

25. Factors Affecting Death Rates
Death rates have declined because of:
Increased food supplies, better nutrition due to Green Revolution
Advances in medicine. (Antibiotics and vaccines)
Improvement in prenatal or neonatal care
Improved sanitation, safer water supplies and personal hygiene due to Industrial Revolution.
Populations Can Decline from a Rising Death Rate: The AIDS Tragedy
30 million killed:
Many young adults die: loss of most productive workers
Sharp drop in life expectancy
International community
Reduce the spread of HIV through education and health care
Financial assistance and volunteers
Fertilizers and pesticides increased crop yields

26. Developing Countries
China, the largest, has taken drastic population control methods.
By 2050, India is predicted to pass China. Pakistan is projected to become 3rd (the US is 3rd now.)
Russia is losing 600,000 people a year, after being the 4th largest country in 1950 due to pollution, crime, corruption, hyperinflation, disease, and despair.
Environmentalists are concerned about resource use because developing countries are increasing their standard of living.
Russia’s declining population is because of environmental pollution, hyperinflation, crime, corruption, disease and despair.

27. India’s Population Control – 1.31 billion
India has tried population control methods with modest success. Poor planning, bureaucratic inefficiency, low status of women and lack of support have led to low success. The family planning method calls for:
Education of women including basic literacy.
Encouraged education of contraception use among women & birth spacing.
Possible problems include:
Cultural/Social issues.
Cost of programs.

28. China’s Population Control – 1.37 billion
China has used a government-enforced program, “One- Child Policy”, to reduce the fertility rate. The One-Child Policy includes:
Paid leave to women for fertility operations.
Monthly Subsidy to one-child families.
Tuition and job priorities for only children.
Housing preferences.
Additional food rations.
Monetary compensation.
Problems include:
Preference toward gender
Increase in orphans
Consequences or punishment for multiple births: raising their taxes, charging other fees, eliminating income tax deductions for a couple’s third child, and loss of health- care benefits, food allotments and job options
Since 1970, China has used a government-enforced program to cut its birth rate in half and sharply reduce its fertility rate.
- paid leave to women for fertility operations - monthly subsidy to single-child families - job priorities for only children - housing preferences for single-child families - additional food rations for one-child families - monetary compensation for single-child families

29. Illiteracy (% of adults) 47% 17% 36% Population under age 15 (%) 20%
Percentage of world
population
17%
India
20%
China
1.1 billion
Population
1.3 billion
Population (2050)
(estimated)
1.4 billion
1.6 billion
Illiteracy (% of adults)
47%
17%
36%
Population under age 15 (%)
20%
1.6%
Population growth rate (%)
0.6%
2.9 children per women (down from 5.3 in 1970)
Total fertility rate
1.6 children per women (down from 5.7 in 1972) 58
Infant mortality rate 27
Figure 9.15
Global connection: basic demographic data for India and China in (Data from United Nations and Population Reference Bureau)
62 years
Life expectancy
70 years
Percentage living
below $2 per day 80 47
$3,120
GDP PPP per capita
$5,890

30. INFLUENCING POPULATION SIZE
The best way to slow population growth is:
Investing in family planning(has reduced number of births and abortions throughout world).
Reducing poverty.
Education
Elevating the status of women by not suppressing their human rights and having paying job outside of home.
Family planning in less-developed countries
Responsible for a 55% drop in TFRs
Financial benefits: money spent on family planning saves far more in health, education costs
Women
Do most of the domestic work and child care
Provide unpaid health care
2/3 of all work for 10% of world’s income
Discriminated against legally and culturally

31. Global Contraceptive Usage
Two problems
Many couples do not have access to family planning
42% pregnancies unplanned, 26% end with abortion

32. Environmental Impact
Deforestation destroys habitats and reduces biodiversity:
Farming and the creation of monocultures, housing or development projects that cause urbanization, fuel from wood, and fossil fuel recovery from mining.
Fossil fuel burning releases CO2:
Results in climate change, change in temperature and precipitation patterns changing habitats.
Intensive fishing and fish farming:
Spreads disease to native fish and causes unsustainable fish populations.
Diversion and damming of water:
For agricultural, municipal, and industrial use reduces water supplies.
Building landfills:
To accommodate increased amounts of trash.