Population

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Population
APHG Spring 2013
http//www.poodwaddle.com/clocks/worldclock
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If we shrank the Earth's population to a village
of 100 people, with all of the existing human
ratios remaining the same, there would be
57 Asians                                         
     52 females 21 Europeans                     
                      48 males   8 Africans 14
people from the Western Hemisphere
               (north and south) 30
Christians                                        
    6 U.S. citizens holding 70 Non-Christians
60 of the worlds wealth 70 unable to
read                                     1 with a
college education     80 living in substandard
housing 1 with their own computer 50
suffering from malnutrition 1 near
death                                           
       1 near birth                              
                           Source Mercy
Housing Midwest, Omaha, NE.
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Critical Issues in Population Geography

• More people are alive today than at any other
  time in human history.
• The worlds population increased at a faster rate
  during the second half of the 20th century than
  ever before.
• Virtually all population growth today occurs in
  less developed countries (LDCs)

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Key Population Issues

• Key Issues
• Where is the world's population distributed?
• Where has the world's population increased?
• Why is population increasing at different rates
  in different countries?
• 4. Why might the world face an overpopulation
  problem?

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Population Distribution

• Key Issue 1 Where Is the World's Population
  Distributed?
• Population concentrations
• Sparsely populated regions
• Population density

The scientific study of population
characteristics is demography. At a global
scale,. .. the world's so-called overpopulation
problem is not simply a matter of the total
number of people . . . but the relationship
between number of people and available resources.
At a local scale, geographers find that
overpopulation is a threat in some regions of the
world but not in others. Regions with the most
people are not necessarily the same as the
regions with an unfavorable balance between
population and resources.
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Distribution of World Population

• Population concentrations
• The four largest population clusters (2/3 of
  worlds population)
• 1. East Asia China, Japan, Korean Penn.
• 2. South Asia India, Bangladesh, Pakistan, Sri
  Lanka
• 3. Southeast Asia Indonesia, Indochina Penn.
• 4. Europe Western Europe, Eastern Europe
• Other population clusters
• 1. Northeastern United States
• 2. Southeastern Canada
• 3. Western Africa Half live in Nigeria

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Population Distribution
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World Population Distribution
World population is very unevenly distributed
across the Earths surface and it can be
compared to climate distribution.
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World Population Cartogram
This cartogram displays countries by the size of
their population rather than their land area.
(Only countries with 50 million or more people
are named.)
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Population Distribution

• Sparsely populated regions
• -The ecumene
• -People generally avoid
• Dry lands
• Cold lands
• Wet lands
• High lands

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Expansion of the Ecumene 5000 B.C.A.D. 1900
The ecumene, or the portion of the Earth with
permanent human settlement, has expanded to
cover most of the worlds land area.
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World Population Distribution by Region
18002050
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Population Density

• Arithmetic Density the total number of people
  divided by the total land area ( This measure is
  also called population density.) Arithmetic
  density enables geographers to make approximate
  comparisons of the number of people trying to
  live on a given piece of land in different
  regions of the world.
• There is no relationship between arithmetic
  density and standard of living.

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Arithmetic Population Density
Arithmetic population density is the number of
people per total land area. The highest densities
are found in parts of Asia and Europe.
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Effect of Migration on Population Growth

• QA. How densely populated is the planet?
• 1st Western Europe, 433 people per sq. mile
• 2nd Caribbean, 417 people per sq. mile
• Least densely settled region is Oceania 10
  people per sq. mile
• United States is 78 people per sq. mile
• Q. Does high density in urbanized areas equal
  environmental degradation????

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Population Densities, 2003

• Region Pop./Sq. Mile
• World 122 Caribbean 417
• More Developed Countries 61 South America 52
• Less Developed Countries 160 Asia 312
• Africa 74 Western Asia 112
• Sub-Saharan Africa 76 South Central Asia 376
• Northern Africa 57 Southeast Asia 313
• Western Africa 108 East Asia 334
• Eastern Africa 107 Europe 82
• Middle Africa 41 Northern Europe 141
• Southern Africa 49 Western Europe 433
• North America 42 Eastern Europe 41
• Latin America 68 Southern Europe 288
• Central America 150 Oceania 10
• Source Population Reference Bureau, 2003 World
  Population Data

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Physiological Density

• A more meaningful population measure is by
  looking at the number of people per area of a
  certain type of land in a region.
• The number of people supported by a unit of
  arable land is called the physiological density.
• Comparing physiological and arithmetic densities
  helps geographers to understand the capacity if
  the land to yield enough food for the needs of
  people.

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Physiological Density
Physiological density is the number of people
per arable land area. This is good measure of
the relation between population and agricultural
resources in a society.
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Agriculture Density

• Two countries can have similar physiological
  densities, but they may produce different amounts
  of food because of different economic conditions.
  Agriculture density is the ratio of the number of
  farmers to the amount of arable land.
• The Netherlands has a much higher physiological
  density than does India but a lower agriculture
  density.
• Agriculture density is directly related to
  standard of living

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Measures of Density
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Distribution of World Population Growth

• Key Issue 2 Where has the Worlds Population
  Increased?
• Natural Increase the percentage by which a
  population grows in a year
• Crude birth rate (CBR) the number of births per
  1,000 population
• Crude death rate (CDR) the number of deaths per
  1,000 population
• Doubling time the number of years needed to
  double a population

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World Population Growth19502010
Total world population increased from 2.5 to 6
billion in this half century. The natural
increase rate peaked in the early 1960s and has
declined since, but the number of people added
each year did not peak until 1990.
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World Population Growth, 17502150
Source United Nations, World Population
Prospects, The 1998 Revision and estimates by
the Population Reference Bureau.
http//www.youtube.com/watch?v9_9SutNmfFkfeature
BFlistULadYPZ59_AUcindex1
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Natural Increase

• QA When could world population stop growing?
• First one half million years the population
  growth rate was about zero
• 1700s modern era of population growth began
• Between 1850 and 1900, the annual growth rate
  reached 0.5 percent
• By the mid-1960s rate surged to 2.0 percent
• Dropped to 1.7 percent by the mid-1980s, and
  declined to about 1.4 percent by 2000.

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Natural Increase Rates
The natural increase rate (NIR) is the
percentage growth or decline in the population of
a country per year (not including net migration).
Countries in Africa and Southwest Asia have the
highest current rates, while Russia and some
European countries have negative rates.
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Crude Birth Rates
The crude birth rate (CBR) is the total number
of births in a country per 1,000 population per
year. The lowest rates are in Europe, and the
highest rates are in Africa and several Asian
countries.
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Crude Death Rates
The crude death rate (CDR) is the total number of
deaths in a country per 1,000 population per
year. Because wealthy countries are in a late
stage of the demographic transition, they often
have a higher CDR than poorer countries.
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Population Growth through Natural Increase,
17752000
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Total Fertility Rates
The Total fertility rate (TFR) is the number of
children an average woman in a society will have
through her childbearing years. The lowest rates
are in Europe, and the highest are in Africa and
parts of the Middle East.
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Infant Mortality Rates
The infant mortality rate is the number of infant
deaths per 1,000 live births per year. The
highest infant mortality rates are found in some
of the poorest countries of Africa and Asia.
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World Infant Mortality Rates in Selected
Countries, 2000
Source Carl Haub and Diana Cornelius, 2000 World
Population Data Sheet (Washington, DC Population
Reference Bureau, 2000).
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Life Expectancy at birth
Life expectancy at birth is the average number of
years a newborn infant can expect to live. The
highest life expectancies are generally in the
wealthiest countries, and the lowest in the
poorest countries.
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Doubling Time

• Doubling Time of a population (years)
• 70 / Population Growth Rate ()
• ( 70 / 2.0 35 years )
• Rule of 70 determine how long it would take for
  a population to double at its present growth
  rate.
• divide 70 by the populations annual growth rate
  to determine the years needed to double the size
  of the population.

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Human Population Doubling Time
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Why has the worlds population grown at such
different rates throughout history?

• 3 variables births, deaths, and migration
• Balancing Equation
• A. The difference between births and deaths in a
  population produces the natural increase(or
  decrease) of a population.
• B. Net migration is the difference between the
  number of persons entering a geographic area
  (immigrants) and those leaving (emigrants)
• C. Natural increase usually accounts for the
  greatest amount of growth in a population,
  especially within a short period of time.

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Population increases at different rates

• Key Issue 3 Why is population increasing at
  different rates in different countries?
• The demographic transition model
• Population pyramids
• Countries in different stages of demographic
  transition
• Demographic transition and world population growth

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Demographic Transition Model Development
Population Intersect
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Demographic Transition

• Stage 1 Early Stationary Stage
• Population growth slow increase
• Birth rates high
• Death rates high
• Most of humanitys several-hundred year
  occupancy of Earth was characterized by stage 1.
  Birth and death rates varied considerably from
  one year to the next and from one region to
  another, but over the long term they were roughly
  comparable, at very high levels.
• Between 8000 B.C. and A.D. 1750, Earths human
  population increased from 5 million to 800
  million. The burst of population growth around
  8000 B.C. was caused by the agriculture
  revolution. Despite the agriculture revolution,
  the human population remained in stage1 of the
  demographic transition because food supplies were
  unpredictable.

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Demographic Transition

• Stage II Early Expanding Stage
• Birth rates high
• Death rates decreasing
• Population growth rapid and increasing
• After around A.D1750 the worlds population
  suddenly began to grow10 times faster than in the
  past. In stage II, the crude death rate plummets,
  while the crude birth rate remains the same as in
  stage I. Most African countries are still in a
  stage II.
• With the advent of the Industrial Revolution and
  the improvements in technology, population growth
  rate changed. Countries in Europe and North
  America entered stage II of the demographic
  transition about 1800, but stage II did not
  diffuse to most countries in Africa, Asia, and
  Latin America until the 1950s. The late 20th
  century push of countries into stage II was
  caused by the medical revolution.

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Percent of Population under 15
About one-third of world population is under 15,
but the percentage by country varies from over
40 in most of Africa and some Asian countries,
to under 20 in much of Europe.
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Rapid Growth in Cape Verde
Cape Verde, which entered stage 2 of the
demographic transition in about 1950, is
experiencing rapid population growth. Its
population history reflects the impacts of
famines and out-migration.
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Demographic Transition

• Stage III Late Expanding Stage
• Birth rates decreasing
• Death rates leveling off
• Population growth rapid but slowing
• A country moves from a stage II to a stage III
  when the birth rate begins to drop sharply.
  European and North American countries moved from
  stage II to a stage III during the first half of
  the 20th century. Most countries in Asia and
  Latin America have moved to a stage III in recent
  years.
• A society enters a stage III when people decide
  to have fewer children. Medical practices
  introduced in stage II improve the probability of
  infant survival, but many years pass before
  families react by conceiving fewer babies.

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Demographic Transition

• Stage III continued
• Economic changes in stage III also induce
  families to have fewer offspring. Farmers often
  consider a large family to be an asset. In
  contrast, children living in cities are generally
  not economic assets.
• About 75 of the worlds population is stranded
  in stages II and III.
• QA What does improve technology increase?
• resource availability
• standard of living
• health care
• ?
• ?

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Moderate Growth in Chile
Chile entered stage 2 of the demographic
transition in the 1930s, and it entered stage 3
in the 1960s.
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Demographic Transition

• Stage IV Late Stationary Stage
• Birth rates low
• Death rates low
• Population growth low
• A country reaches stage IV when the birth rate
  declines to the point where it equals the death
  rate. The condition is called ZPG. Most European
  countries have reached stage IV. The United
  States has moved slightly below ZPG since 2000.
  When families lived on farms, employment and
  child rearing were conducted at the same place,
  but in urban societies parents leave the home to
  work.
• Changes in lifestyles also encourage smaller
  families. Several Eastern European countries,
  most notably Russia, have negative natural
  increase rates, a legacy of Communist rule.