Chapter%206:%20The%20Human%20Population%20and%20Its%20Impact

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Chapter 6 The Human Population and Its Impact

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Human Population Growth Continues but Is Unevenly
Distributed

• 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

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Core Case StudySlowing Population Growth In
China A Success Story

• China is the worlds 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
  Chinas women from 5.7 to 1.5

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Core Case StudySlowing Population Growth In
China A Success Story

• China has undergone rapid industrialization- 100
  million new people have created a middle class
• We should care about Chinas population because
• We all depend on Earths life support systems to
  meet our basic needs for air, water, food,
  land, shelter, and energy.
• Our current world population is not meeting the
  basic needs of 1.4 billion people.

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Slowing Population Growth in China A Success
Story

• China is the worlds 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
  worlds most extensive, intrusive, and strict
  family planning and birth control program.
• Their goal in this has been to sharply reduce
  population growth.

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6-1 How Many People Can The Earth
Support?Human Population Growth Continues but
is Unevenly Distributed

• Due to advances in technology, medicine, and
  modern agriculture, population has increased
  exponentially.
• Rate of population growth has slowed but the
  worlds population is still increasing
  exponentially at a rate of 1.21 a year.
• 83 million new people added in 2010 1 added to
  MDCs.
• Projected to be 7.8-10.8 by 2050.

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6-1 How Many People Can The Earth Support?
Human Population Growth Continues but is Unevenly
Distributed

• 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.

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6-2 What Factors Influence the Size of the Human
Population? The Human Population Can Grow
,Decline, or Remain Fairly 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)

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6-2 What Factors Influence the Size of the
Human Population? Women Are Having Fewer Babies
but Not Few Enough to Stabilize the Worlds
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.

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

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6-2 What Factors Influence the Size of the Human
Population? Several Factors Affect Death Rates

• 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.

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6-2 What Factors Influence the Size of the Human
Population? Several 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 worlds highest teenage pregnancy
  rate.
• Child mortality varies greatly from region to
  region.
• According to the United Nations, the worlds
  child mortality rate dropped 20 between 1960s
  and 2008.

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6-2 What Factors Influence the Size of the Human
Population? Migration Affects an Areas
Population Size

• 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.

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Migration Affects an Areas Population

• Migration 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.

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6-3 How Does a Populations Age Structure Affect
Its Growth or Decline?A Populations Age
Structure Helps Us to Make Projections

• 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 populations
  percentages of males and females in each of three
  age categories pre-reproductive (0-14),
  reproductive(15-44), and post-reproductive(45).

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6-3 How Does a Populations Age Structure Affect
Its Growth or Decline?A Populations Age
Structure Helps Us to Make Projections

• 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.

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6-3 How Does a Populations Age Structure Affect
Its Growth or Decline? Populations Made Up of
Mostly Older People Can Decline Rapidly

• 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.
• Chinas One Child Policy means less children by
  2020- 31 of population 60 years old.

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6-3 How Does a Populations Age Structure Affect
Its Growth or Decline? Populations Made Up of
Mostly Older People Can Decline Rapidly

• 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.

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6-3 How Does a Populations Age Structure Affect
Its Growth or Decline? Populations Can Decline
Due to a Rising Death Rate The AIDS Tragedy

• 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.

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6-4 How Can We Slow Human Population Growth?The
First Step Is to Promote Economic Development

• 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

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

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6-4 How Can We Slow Human Population
Growth?Empowering Women Helps to Slow
Population Growth

• 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 worlds
  population, in most societies they have fewer
  rights, education, and economic opportunities
  than men.

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6-4 How Can We Slow Human Population Growth?The
First Step Is to Promote Economic Development

• Globally, women account for 2/3 of all work done
  but receive only 10 of the worlds income.
• Women own less than 2 of the worlds land
• Women make up more than 70 of the worlds poor
  and 64 of its 800 million illiterate adults

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6-4 How Can We Slow Human Population
Growth?Promote Family Planning

• 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.

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

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Case Study The U.S Population is Growing Rapidly

• 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 .

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Case Study The United States A Nation of
Immigrants

• Currently, legal and illegal immigration
  accounts for about 36 of the countrys 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.

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Case Study The United States A Nation of
Immigrants

• Some argue that it would diminish the United
  states historical role of the land of opportunity
  to limit immigration, taking away from the
  worlds 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.

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Case 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, 111 Americans were 65. This number
  will grow sharply through 2030. This is called
  the graying of America.

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Case Study Slowing Population Growth in India

• In 1952, India added 5 million people to its
  population. In 2010, it added 18 million.
• 32 of Indias population is under the age of 15.
  
• India has the worlds largest economy and is
  thriving, but it faces serious poverty and
  malnutrition.

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Case Study Slowing Population Growth in 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 worlds land resources
  and 2 of its forests
• More than 2/3 of its water is seriously polluted
  and they also have serious air pollution.

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Science Focus Projecting Population Change

• 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

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Science Focus How Long Can the Human Population
Keep Growing?

• Human activities have directly affected 83 of
  the earths 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.

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Science Focus How Long Can the Human Population
Keep Growing?

• Overconsumption and overpopulation are considered
  the key problems
• At todays 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

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Science Focus How Long Can the Human Population
Keep Growing?

• 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

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