chapter 6: the human population and its impact. human population growth continues but is unevenly...

Chapter 6: The Human Population Chapter 6: The Human Population and Its Impactand Its Impact

Human Population Growth Human Population Growth Continues but Is Unevenly Continues but Is Unevenly DistributedDistributed In the past 200 years the

human population has been growing exponentially (J-curve).

Three major factors of population growth:

1)ability of humans to expand into all of earths climate zones and habitats

2)emergence of modern agriculture allows us to produce more food

3)improvements in sanitation & health care and the development of antibiotics & vaccines have resulted in a drop of death rates

Core Case StudyCore Case StudySlowing Population Growth In China: A Success Slowing Population Growth In China: A Success StoryStory China is the world’s most populated country with1.3

billion people Expected to reach1.5 billion by 2025 and decline to

1.4 billion by 2050. Goal has been to sharply reduce the population using

the One Child Policy – those who follow the policy receive benefits such as better housing , more food , and free health care

Between 1972 and 2010, birth rates declined, trimming average number of children born to China’s women from 5.7 to 1.5

Core Case StudyCore Case StudySlowing Population Growth In China: A Success Slowing Population Growth In China: A Success StoryStory

China has undergone rapid industrialization- 100

million new people have created a middle class

We should care about China’s population because:

1) We all depend on Earth’s life support systems to

meet our basic needs for air, water, food, land,

shelter, and energy.

2) Our current world population is not meeting the

basic needs of 1.4 billion people.

SlowingSlowing Population Growth in Population Growth in China: A Success StoryChina: A Success Story China is the world’s

most populous country, with 1.3 billion people.

In 1960, in order to avoid a serious threat of mass starvation due to a rapidly growing population, government officials established the world’s most extensive, intrusive, and strict family planning and birth control program.

Their goal in this has been to sharply reduce population growth.

6-1: How Many People Can The Earth 6-1: How Many People Can The Earth Support?Support?

Human Population Growth Continues but is Unevenly Human Population Growth Continues but is Unevenly DistributedDistributed

Due to advances in technology, medicine, and modern

agriculture, population has increased exponentially.

Rate of population growth has slowed but the world’s

population is still increasing exponentially at a rate of

1.21% a year.

83 million new people added in 2010 – 1% added to

MDC’s.

Projected to be 7.8-10.8 by 2050.

6-1: How Many People Can The Earth 6-1: How Many People Can The Earth Support?Support?

Human Population Growth Continues but is Unevenly Human Population Growth Continues but is Unevenly DistributedDistributed

Cultural Carrying Capacity is the maximum

number of people that can live in a reasonable

freedom and comfort indefinitely without decreasing

the ability of the earth to sustain future generations.

6-2 What Factors Influence the Size of the Human 6-2 What Factors Influence the Size of the Human Population? Population?

The Human Population Can Grow ,Decline, or Remain The Human Population Can Grow ,Decline, or Remain Fairly StableFairly Stable

• If there are more births than deaths during a given period of time, population increases. If reverse is true, then it decreases.

• Crude birth rate is the number of live births per1,000 people in a population in a given year.

• Crude death rate is the number of live deaths per1,000 people in a population in a given year.

• Population change = (Births +Immigration) - (Deaths+ Emigration)

6-2 What Factors Influence the Size of the 6-2 What Factors Influence the Size of the Human PopulationHuman Population? ?

Women Are Having Fewer Babies but Not Few Enough to Women Are Having Fewer Babies but Not Few Enough to Stabilize the World’s PopulationStabilize the World’s Population

Fertility rate is the number of children born to a woman

during her lifetime.

Replacement level fertility rate is the average number

of children that couples in a population must bear to

replace themselves (2.1 in more developed countries and

2.5 in less developed countries).

Total fertility rate is the average number of children born

to women in a population during their reproductive years.

6-26-2 What Factors Influence the Size of the What Factors Influence the Size of the Human Population? Human Population?

Several Factors Affect Birth Rates and Fertility RatesSeveral Factors Affect Birth Rates and Fertility Rates

Factors affecting birth rates and fertility rates

include: Importance of children as part of the labor force Cost of raising and educating children. Availability of , or lack of, private and public

pension systems Urbanization Educational and employment opportunities

available for women Average age of marriage Availability of legal abortions/ birth control.

• Rapid growth of the worlds population over the

past 100 years is not primarily due to higher

birth rates but instead lower death rates.

• Life expectancy is the average number of years

a newborn infant can be expected to live.

• Infant Mortality Rate is the number of infants

out of every 1000 born who die before their first

birthday.

• Infant mortality rates have declined dramatically

since 1965.


Several Factors Affect Death RatesSeveral Factors Affect Death Rates

Child mortality rates are the annual number of

deaths among children under 5 per 1000 live births.

The USA has the world’s highest teenage pregnancy

rate.

Child mortality varies greatly from region to region.

According to the United Nations, the world’s child

mortality rate dropped 20% between 1960’s and

2008.


Several Factors Affect Death RatesSeveral Factors Affect Death Rates

Migration is the movement of people into

(immigration) and out of (emigration) specific

geographic areas.

Most people migrating from one area or country to

another seek jobs and economic improvement .

Religious persecution, ethnic conflicts, political

oppression, wars, environmental degradation are also

reasons people migrate.


Migration Affects an Area’s Population SizeMigration Affects an Area’s Population Size

Migration Affects an Area’s Migration Affects an Area’s PopulationPopulationMigration: the

movement of people into and out of specific geographic areas.

Most people migrate seeking jobs and economic improvement.

Religious persecution, ethnic conflicts, political oppression, wars, and certain types of environmental degradation also drive people to migrate.

• Age Structure is the number or

percentages of males and females in the

young middle, and older age groups in that

population.

• The population age structure diagram is

constructed by plotting a given population’s

percentages of males and females in each of

three age categories; pre-reproductive (0-

14), reproductive(15-44), and post-

reproductive(45+).

6-3 How Does a Population’s Age 6-3 How Does a Population’s Age Structure Affect Its Growth or Decline?Structure Affect Its Growth or Decline?

A Population’s Age Structure Helps Us to Make A Population’s Age Structure Helps Us to Make ProjectionsProjections

• A country with a large percentage of its people

younger than 15 will experience a rapid population

growth.

• Demographic momentum is the number of births

that will rise for several decades even if women have

an average of just 1-2 children, due to a large number

of girls entering their prime reproductive years.

6-3 How Does a Population’s Age 6-3 How Does a Population’s Age Structure Affect Its Growth or Decline?Structure Affect Its Growth or Decline?

A Population’s Age Structure Helps Us to Make A Population’s Age Structure Helps Us to Make ProjectionsProjections

Japan has the highest percentage of elderly people.

With a population of 127 million in 2010, it is

projected to shrink to 95 million by 2050.

China’s One Child Policy means less children by 2020-

31% of population 60+ years old.

6-3 How Does a Population’s Age Structure Affect Its 6-3 How Does a Population’s Age Structure Affect Its Growth or Decline? Growth or Decline?

Populations Made Up of Mostly Older People Can Decline Populations Made Up of Mostly Older People Can Decline RapidlyRapidly

6-3 How Does a Population’s Age Structure Affect Its Growth or 6-3 How Does a Population’s Age Structure Affect Its Growth or Decline? Decline?

Populations Made Up of Mostly Older People Can Decline Populations Made Up of Mostly Older People Can Decline RapidlyRapidly

Having a graying population leads to a declining work

force, limited funds for supporting continued

economic development, and fewer children and

grandchildren to take care of the growing number of

elderly people.

Economic and social problems result from the rapid

population decline - this can threaten population

growth and create labor shortages.

• Between 1981 and 2009, AIDS killed more than 27 million people

and takes about 2 million more lives each year.

• AIDS kills many young adults ands leaves many children orphaned .

• Results in drop in average age expectancy, loss of productive young

adult workers and trained personnel, and drastic change to a

country's age structure.

• Experts call for the international community to create and fund a

massive program to help countries ravaged by AIDS. The program

would reduce the spread of HIV by providing financial assistance for

improving education and health care and providing social workers to

try to compensate for the missing young-adult generation.

6-3 How Does a Population’s Age 6-3 How Does a Population’s Age Structure Affect Its Growth or Decline? Structure Affect Its Growth or Decline?

Populations Can Decline Due to a Rising Death Rate: Populations Can Decline Due to a Rising Death Rate: The AIDS TragedyThe AIDS Tragedy

The Demographic Transition states that as countries

become industrialized and economically developed, first

their death rates decline and then their birth rates decline.

It takes place in 4 stages.

The three most important steps:

1) Reduce poverty primarily through economic

development and universal primary education

2) Elevate the status of women

3) Encourage family planning and reproductive health

care

6-4 How Can We Slow Human 6-4 How Can We Slow Human Population Growth?Population Growth?

The First Step Is to Promote Economic DevelopmentThe First Step Is to Promote Economic Development

Some analysts believe that most lesser developed countries will make a demographic transition over the next few decades

Other analysts fear that rapid population growth, extreme poverty, and increasing environmental degradation in some low income, lesser developed countries will leave them stuck in stage two.



Women tend to have fewer children if they are

educated, have the ability to control their own

fertility, earn an income of their own, and live in

societies that do not suppress their rights.

Although women make up roughly half the world’s

population, in most societies they have fewer rights,

education, and economic opportunities than men.


Empowering Women Helps to Slow Population GrowthEmpowering Women Helps to Slow Population Growth

Globally, women account for 2/3 of all work

done but receive only 10% of the world’s

income.

Women own less than 2% of the world’s land

Women make up more than 70% of the

world’s poor and 64% of its 800 million

illiterate adults



Family planning provides educational and clinical services that help couples choose how many children to have and when to have them

Family planning has been a major factor in reducing the number of births throughout most of the world, the number of abortions performed each year, and the number of mothers and fetuses dying during pregnancy.

Responsible for a drop of 55% in total fertility rates in lesser developed countries.


Promote Family PlanningPromote Family Planning

6-4 How Can We Slow Human Population 6-4 How Can We Slow Human Population Growth?Growth?

Promote Family PlanningPromote Family Planning

Family planning also has financial benefits; studies show that each dollar spent on family planning saves $10-16 in health, education, and social service costs.

The United Nations Population Fund reports that 42% of pregnancies in lesser developed countries are unplanned and 26% end with abortion

Case Study: The U.S Population is Growing Case Study: The U.S Population is Growing RapidlyRapidly

The period of high birth rates between 1946 and 1964

is known as the baby boom. During the baby boom 79

million people were added to the US population.

The drop of the total fertility rate has slowed the rate of

population growth in the US , but the population is still

growing faster than China's population.

The leading causes of deaths in the US in 1907 were

pneumonia, tuberculosis and diarrhea .

Case Study: The United States: A Nation of Case Study: The United States: A Nation of ImmigrantsImmigrants

• Currently, legal and illegal immigration accounts for

about 36% of the country’s annual population growth.

• Latin Americans make up 53% of our immigrants, Asians

makes up 25%, and Europeans makes up 14%

• There are many debates of whether to reduce legal

immigration in the US.

• 60% of the American public supports reducing legal

immigration.

Case Study: The United States: A Nation of Case Study: The United States: A Nation of ImmigrantsImmigrants

Some argue that it would diminish the United states

historical role of the land of opportunity to limit

immigration, taking away from the world’s cultural

diversity.

Immigrants open up businesses and they help the US

succeed in the global economy.

Many immigrants take menial and low paying jobs that

Americans shun.

Case Study: The American Baby BoomCase Study: The American Baby Boom

The baby boom added 79 million more people to the US

population.

Baby boomers created the youth market in their teens and

twenties.

Due to the downturn in the economy in 2007, many of these

baby boomers lost their jobs and much of their savings.

In 1960, 1:11 Americans were 65+. This number will grow

sharply through 2030. This is called the graying of America.

Case Study: Slowing Population Growth Case Study: Slowing Population Growth in Indiain India

In 1952, India added 5 million people to its

population. In 2010, it added 18 million.

32% of India’s population is under the age of 15.

India has the world’s largest economy and is thriving,

but it faces serious poverty and malnutrition.

Case Study: Slowing Population Growth Case Study: Slowing Population Growth in Indiain India

• Indian women have an average of 2.6 children.

• They believe that they need more children to work and care

for them in old age.

• Like China, India has many critical environmental problems.

• They only have 2.3% of the world’s land resources and 2% of

its forests

• More than 2/3 of its water is seriously polluted and they also

have serious air pollution.

Science Focus: Projecting Population Science Focus: Projecting Population ChangeChange

There are countless factors that demographers have to consider when making population projections

They have to determine the reliability of current population estimates, estimate trends in fertility, and consider that different organizations use different sets of data and differing methods to make projections.

All these factors make for a variation of projections

Science Focus: How Long Can the Science Focus: How Long Can the Human Population Keep Growing?Human Population Keep Growing?

Human activities have directly affected 83% of the earth’s land surface, excluding Antarctica.

Thomas Malthus hypothesized that the human population tends to increase exponentially while food supplies tend to increase more slowly at a linear rate. However, because of technological advances in food production, food has also increased exponentially.

Overconsumption and overpopulation are considered the key problems

At today’s level of consumption, scientists estimate that we would need the equivalent of 1.3 planet Earths to sustain our per capita use of renewable resources indefinitely.

By 2050, with the projected population increase, we will likely need almost 2 planet Earths to meet such resource needs and 5 Earths if everyone reaches the current U.S level of renewable resource consumption per person


Some analysts believe that because of our technological ingenuity, there are few, if any, limits to human population growth and resource use per person

Most agree that we have used technology to alter natural systems to meet our growing needs and wants


chapter 6: the human population and its impact. human population growth continues but is unevenly...

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