1. Counting the Worlds Population
Population Geography
Counting the Worlds Population

2. A Lesson In Exponential Growth!
Bacteria Bottles
A Lesson In Exponential Growth!
This puzzle illustrates the concept of exponential growth using bacteria. Bacteria multiply by division. One bacterium becomes two. Then two divide into four; the four divide into eight, and so on. For a certain strain of bacteria, the time for this division process is one minute. If you put one bacterium in a bottle at 11:00 p.m., by midnight the entire bottle will be full.
John Madden /10

3. Bacteria Bottles
1) When will the bottle be half-full? How do you know?
2) Suppose you could be a bacterium in this bottle. At what time would you first realize that you were running out of space? Why?
John Madden /10

4. Bacteria Bottles
Suppose that at 11:58 some bacteria realize that they are running out of space in the bottle. So they launch a search for new bottles. They look far and wide (working at the speed of light). Finally, offshore in the Arctic Ocean, they find three new bottles! Great sighs of relief come from all the bacteria. This is three times the number of bottles they’ve ever known. Surely, they think, their space problems are over. 3) Is that so? Explain why the bacteria are still in trouble. Since their space resources have quadrupled, how long can their growth continue? (Remember it takes an hour to fill up the first bottle)
John Madden /10

5. Bacteria Bottles Ready For The Answers???
1) The bottle will be half-full at 11:59 p.m. because the doubling time is one minute and the bottle will be full at midnight.
2) At 11:55 p.m., when the bottle was only 3% full and 97% empty, would it be easy to perceive that there was a space problem?
John Madden /10

6. Bacteria Bottles
3) With space resources quadrupled, the bacteria have two more doubling times, or two minutes before they will run out of space.
11:58 p.m. : Bottle 1 is one-quarter full.
11:59 p.m. : Bottle 1 is half-full.
12:00 a.m. : Bottle 1 is full.
12:01 a.m. : Bottles 1 and 2 are full.
12:02 a.m. : Bottles 1, 2, 3, and 4 are full
John Madden /10

7. Bacteria Bottles
So, what does this suggest about Human Population Growth??
John Madden /10

8. Bacteria Bottles
John Madden /10

9. Bacteria Bottles
John Madden /10

10. Bacteria Bottles
Human Population Growth!
Year
John Madden /10

11. Why study population?
Over the last 12,000 years of history, population is increasing faster than ever before!
In the last 2000 years, the Earth’s population has increased 10 times
In the last 50 years, Earth’s population has doubled
Will this population growth increase to a level that will cause a global crises?

13. Population Basics Demography: the study of human populations
Currently 7 billion people on the Earth
This study is very important because the number of people in a country can influence the infrastructure and support systems of a country
Population Equation
Scale of inquiry: size of a geographic investigation (world, regional or local) important to understand
On global scale, demographers focus on where earth’s populations are increasing fastest and where they are expanding more slowly-least stable areas experiencing the fast growth

14. Population Facts
About 81% of earth’s population lives in poorer, less developed countries
The only two countries to have more than 1 billion people are India and China
1 in 3 of earth’s people live in China or India
Nearly 3 of every 5 people live in Asia and Europe
Largest population concentration is East Asia-nearly 25% of earth’s total population: most people subsistent farmers
Third largest population cluster is Europe: most people are urban dwellers

15. Population Distribution and Density

16. Population Distribution
Defined: pattern of people across the earth’s surface-where they live
Over history, people have been unevenly distributed-Why?
Few people live in desert/tundra
About 75% of global population lives on 5% of worlds surface
Area people can live is called the ecumene
50% of earth’s people live in cities

17. Worlds Population Density

18. World Areas of Population Density
East Asia: China, South and North Korea and Japan
1.5 billion people with 1.3 billion in China
South Asia: India, Pakistan and Bangladesh
Within 50 years, India will pass China as most populace country on planet
Southeast Asia: Vietnam, Indonesia and Thailand
Western and Central Europe: mostly urban
Northeastern United States and Canada: includes megalopolis from Boston to Washington D.C.

21. Population Density Defined: number of people in a particular land area
Arithmetic density
Total number of people divided by total land area
Example: Egypt has arithmetic density of 177 people per square mile but only 98% of population lives on 3% of land
Physiological density
Number of people per unit of arable land
Helps in analyzing amount of farmland available to population
U.S. physiological density is 340 people per square mile; Japan is 7,000 people per square mile; Egypt's is 3,000 people per square mile
Agricultural density
Number of farmers per unit of arable land
High density meant many farmers are on each piece of farmland; low density suggests the presence of larger farms

25. Population Math

26. Adding up population numbers
Equations exist to allow demographers to determine actual populations
Demographic accounting equations
Global population accounting equation
P1=P0+B-D
P1 is size of population at end of interval of measurement
P0 is size of population at start of interval of measurement
B is number of births during interval of measurement
D is number of deaths during interval of measurement
Subglobal population accounting equation
P1=P0+B-D+I-E
P1, P0, B and D same as above
I is number of immigrants moving into region during interval of measurement
E is number of emigrants moving out of region during interval of measurement
Immigration: people moving into a region/country
Emigration: people leaving a region/country

27. Math Example
Country A has 1 million people in Over the next 10 years 75,000 babies are born; 50,000 people die; 10,000 people move into the country; and 5,000 people exit. What would the population be in 2000?
P1=1,000,000+75,000-50,000+10,000-5,000= 1,030,000 people

28. Population Pyramids
Also known as age-sex structures used to evaluate the distribution of ages and genders in a given population
Shows sex ratio (number of males compared to females in a population) at ANY GIVEN TIME!
Cohorts (people of the same age) are split between men and women on the pyramid
Used to analyze population and/or predict future population
Cannot determine country size from pyramids but can determine placement in DTM

29. Population Pyramid
Algeria’s pyramid has a wide base and a flattened top. What does that mean?
Italy’s pyramid is wider in the middle than at the base. What does that mean?
What expectations do you have for a population pyramid from 2025?

31. Expanding Populations
Contracting
Population
Stable Population

32. 2025 Predictions Did Algeria’s growth rate decrease? How can you tell?
What happened to Italy’s population?
Graying population: when a population has more middle-aged and older people than young people. Why is this a problem?

33. South Africa and the United States

35. Fertility and Mortality
Fertility: reproductive behavior of a population
Impacted by
Fecundity of population
Diet and nutritional intake
Economic and industrialization levels
Sociocultural factors like age of marriage
Mortality: death related behavior of a population

36. Population Key Terms
Crude Birth Rate (CBR): number of live births per 1,000 people in a year
Crude Death Rate (CDR): number of deaths per 1,000 people in a year
LDC’s average CDR of 20 while MDC’s average CDR of 10
Infant mortality rate (IMR): number of infant (children who die before their first birthday) deaths per 1,000 live births
Life expectancy: average number of years to be lived by a person
Fecundity: ability of a woman to conceive (usually 15 to 45)
General fertility rate (GFR): number of births per 1,000 women in the fecund years
Total fertility rate (TFR): predicted number of births a woman will have as she passes through fecund years
TFR has declined on every continent but Africa over the last 50 years
Example : in 1975 Mexico’s TFR was 7 but in 2009 had dropped to 2.37 – in China in 1970 TFR was 6 but 1.6 in 2009
2006 TFR rate was greater than 3.0 across the globe
2006 TFR rate in U.S., Europe and China was 2.1 or less

37. Fertility Rates Country Growth Rate % Per Year Birth Rate per 1,000
Death Rate per 1,000
United States
0.883
14.6
8.25
Japan
0.139
7.87
9.26
China
0.629
13.71
7.03
Russia
-0.474
11.03
16.06
Australia
0.801
11.90
7.62
Mexico
1.142
20.04
4.78
South Africa
-0.501
17.71
22.70
India
1.578
22.22
6.40
United Kingdom
0.276
10.65
10.05

38. Replacement-Level Fertility
A TFR of 2.1 is considered replacement-level fertility meaning parents will produce the number of children needed to replace themselves
TFR of 2.1 causes zero population growth (ZPG)
Rate of Natural Increase (RNI) is growth rate of a population using the formula
CBR-CDR/10
Does NOT include immigration and emigration
RNI that equals zero means population won’t grow or decline
Global RNI in 2006 was 1.2%
More developed countries had an RNI of 0.1%
Less developed countries had an RNI of 1.5%
Africa’s RNI in 2006 was 2.3%
RNI does NOT include migration

39. Population Graph Options: S-curves and J curves

40. Rule of 70 Defined: time that it takes for a population to double
Equation: Divide 70 by current growth rate of population
70/ current growth rate = doubling time
Examples
70/5% = 14 years
70/2% = 35 years

41. Population Consequences
The good AND the bad!

42. A Graying Population
What would be the positives and negatives of a graying population?
Dependency ratio: show relationship between dependents and nondependent's
Dependents: people who depend on workers for survival
Nondependent's: people who can support themselves through work
High ratio means more people are dependent than working
Fewer people to pay taxes
Social security dependency
2000 was first time in history that people under 14 years of age were outnumbered by people over 60

44. Carrying Capacity and Overpopulation
Carrying capacity: number of people an area can sustain or support
Japan: imports food
Saudi Arabia: desalinizes water to increase carrying capacity
Overpopulation: when a region’s population outgrows its carrying capacity
Resource availability very important but resources can be indigenous or imported
Some areas have resources to produce more than they harvest-lack of infrastructure, political/economic stability, etc.

45. Other population growth consequences
In China, boys now outnumber girls 119 for every 100 girls born – natural average 105 to 100

46. Population growth theories
Thomas Malthus
Wrote An Essay on the Principle of Population, 1798
Argued that global population was growing exponentially while food supplies were growing arithmetically
Advocated birth control and celibacy (positive checks) and warned of war, starvation and disease (negative checks)
Said population growth caused poverty, crime and misery
Karl Marx
Said population wasn’t problem-the problem was unequal distribution of resources and wages
Said population growth was caused by poverty and unequal distribution so if things were distributed evenly, population wouldn’t grow
Ester Boserup
Believed overpopulation problem could be solved by increasing number of subsistence farmers because when humans are faced with starvation, they WILL develop new technology
Neo-Malthusians
Argue that sustainable development hinges on Malthusian idea that human population must reach a “sustainable” level within carrying capacity

49. Is population growth a problem
Is population growth a problem? Two very different, but supportable ideas
Yes
Most of our increased food availability is tied to non-sustainable resources like oil
Humans bring about environmental destruction
I=PAT
Environmental Impacts= Population size times affluence times technology
Most humans live a lifestyle that is not sustainable No
Food supplies have increased - in 1970 average caloric intake was 2,435 but in 2000 average was 2,087
Countries like China have industrialized quickly BECAUSE of increased population that create workers and a market
Humans are the ultimate resource and will continue to advance to support ourselves

50. Historical Growth
The DTM

51. Population Explosion
Over last three centuries, earth has experienced a population explosion
Currently population is growing at exponential rate
Exponential growth: the more people that are added, the faster the population is growing
Linear (a.k.a. arithmetic) growth: constant fixed rate of growth
In 1750 world population was 700 million
In 200 years (1950) population grew to 6 billion

52. Historical population growth
10,000-12,000: first agricultural revolution
Humans domesticated crops
Led to development of cities and stationary settlements
City development leads to population growth
1700’s Industrial Revolution and second agricultural revolution
Industrial revolution was new technologies and industries-started in England
Move people into cities
Second industrial revolution improved fertilization and food storage increasing food supply
Allowed more people in cities because extra food is grown can be sold in cities

54. What causes population growth?
Medical Advances
Inoculations, better health care, new medications
Quantity and quality of food
Agricultural technology has increased availability and health benefit of food
Ethnic and religious issues
Many cultures forbid birth control or abortion
Some cultures have beliefs that spread disease
Economic issues
Agricultural base economy=higher birth rate
Industrial or service base=low or no population growth

55. Population Projections for the Future
Different growth scenarios exist
Medium growth (most accepted)
2050=9 billion; 2100=9.5 billion
Low-growth
Population will begin declining: 2050=7.5 billion; 2100=5.1 billion
High-growth scenario
2050=11 billion; 2100=16 billion

57. Demographic Transition Model
Defined: DTM predicts changes in birth, death and natural increase rates in countries as they transition or mature
Based on assumption that economics drive demographic change and that all countries will pass through five stages of demographic transition or change
The three measurements in the model are CBR, CDR and RNI

58. Stage 1: Low Growth (high stationary stage)
Hunter and Gatherer Societies
High CBR and CDR leading to low RNI
Fluctuation in CBR and CDR because of disease, famine and war
Usually characterizes a subsistence farming country without industrialized economy

59. Stage 2: High Growth (Expanding Stage)
Agricultural Societies
High CBR: children are still needed on the farms to help
Declining CDR: CDR starts to drop as new health care systems arrive-industrialization has begun but CBR has not fallen because children still seen as economic necessity
RNI increases because same high number of births is occurring with fewer deaths to match the high birth numbers
Population expansion is high

60. Stage 3: Moderate Growth (expanding stage)
Industrial Societies
Declining CBR
CBR drops because families’ decisions to lower number of children they are having
RNI is decreasing but still greater than zero so population is still expanding

61. Stage 4: Low Growth (low stationary stage)
Tertiary Societies
CBR and CDR meet at equal levels (equilibrium) but this time they are at low levels
RNI is low
Seen as modern society stage with zero population growth

62. Criticisms of DTM
Based on England's transition from subsistent economy to industrialized society
All countries may not pass through this system
Some African countries received medicines and food from more developed countries
England took 100 years to go from stage 2 to 3 and countries today are being pushed at a much faster rate
We don’t know exactly where the 5th stage is headed. It includes a decline in the CBR as seen in modern countries like France and Germany-something that shows the graying population but what else will happen?

63. Demographic Momentum Also known as hidden momentum
Occurs in many developed countries when population continues to grow even after replacement-fertility is reached
Happens when people live longer-even though TFR is 2.1 to 2.5 population is still growing because people are dying at slower rates
Makes zero population growth difficult to attain

64. Global DTM All countries on globe are out of stage 1
Most Latin American and Asian countries are in stage 3
Most African countries remain at high growth in stage 2
Many Europeans at end of stage 4
Japan, Germany and France are facing a fifth stage or the graying population problem

65. Checks on Population
Public and Private

66. Negative Checks on Population
Three basic categories: natural disasters, war or political turmoil and economic issues
Black Plague: killed 40% of European population and 13 million Chinese in 1300s
Irish potato famine: killed almost 50 percent and caused massive emigration
HIV/AIDS: since 1980s has risen to pandemic (disease affecting very large amounts of people in large area) levels
In 2005, 39 million people living with HIV, nearly 3 million died from AIDS
In Sub-Saharan Africa, 19% of all adults are infected
China expected to see nearly 11 million infections by 2010
More than ½ of 5 million new cases every year are people ages 15-24
In 2010 were 25 million AIDS orphans

67. Global HIV/AIDS Rates

68. Population Policies
Pro-natalist policies promote reproduction and bigger families-sometimes called expansive policies
Examples include tax breaks for children or antiabortion laws
Found in Europe, 1950s China and modern United States
Also found historically and in susbistent type economies
Anti-natalist policies discourage high fertility rates-sometimes calls restrictive policies
Examples include easily accessible abortions and contraceptives, or government policies limiting children
Examples include India and China

70. Global population control
1984 UN population conference held in Mexico influenced by new technologies to increase global food production and China’s recent enactment of one-child policy
1994 conference in Egypt proposed the Cairo Strategy-Teaching contraceptive uses in schools in poorer countries
Cairo Strategy has been very controversial with certain conservative groups
2004 conference declared the key to limiting population growth is to empower women through education and economic parity (equality)

71. Population Movement
a.k.a. Migration

72. Population Movement
In the modern world, friction of distance (difficulty of distance) has been reduced
Process of coming together even though distances are not decreasing is called space-time compression
Spatial interaction is the interconnectedness of two places
Migration: permanently moving from home region and crossing an administrative boundary

74. Why do people migrate?
Migration stream is pathway from a place of origin to a destination
Many develop because of information exchange between people
Usually found with migration counter stream
Push factors: reasons people leave a place
Examples: high taxes, high crime rates and abusive governments
Pull factors: reasons people go to a new place
Place desirability: possession of positive features making people want to move there
Examples: affordable real estate, being near family member, good schools

75. Voluntary vs. Forced Migration
Voluntary Migration
Occurs when migrants have an option of whether or not to move
Usually not associated with violence or abusive governments
Example: a new job, moving to be near family
Forced Migration
Emigrants pushed from land
Refugees: migrants fleeing some form of persecution or abuse
International refugees: fell country to move to another country
Intranational refugees: abandon homes but remain in their country to escape persecution
Sometimes called internally displaced peoples

76. Brief history of migration
About 3% of worlds people have migrated from their countries of origin
North America, Oceania and Europe have net immigration
Asia, Africa and Latin America have net emigration
50% of Southwest Asia’s population are immigrants
U.S. had three major waves of immigration
Colonial era ( ) primarily from Europe and Africa and was both voluntary and involuntary
19th century primarily from Europe
Before 1840 England, ’s German and Irish
20th century
1907 northern and western Europe and Russia; ’s Asia leading source of immigrants, 1980’s Latin America primary source
Immigration altered by Quota Act of 1921 which allowed highest number of immigrants from European countries and discriminated against Asians and other regions

77. 8 Great Migrations (KNOW THESE!)

78. Internal Migration Defined: movement within a country
Interregional migration
Moving from region in the country to another region
Intraregional migration
Moving within a region, such as from a city to a suburb
Urban migration
Migration from farms to cities

79. Migration Selectivity
Often, migration fits into a pattern based on age, income and other socioeconomic factors
Defined: evaluation of how likely someone is to migrate based on personal, social and economic factors
Most influential factor is age
Most people move 12 times in their lifetimes, ½ before age 25
Brain Drain: net out-migration from one place of most educated workers who leave for more attractive places
Guest Workers: people let into a country to work jobs native people don’t necessarily want to do like heavy, dangerous or disagreeable work

80. Ravenstein’s Migration “Laws”
Late 1800s, British geographer Ernst Ravenstien identified 11 generalizations about migration-some still apply today
The majority of migrants travel short distances
Step migration: person has a long distance goal in mind and achieves it in a series of small steps
Intervening opportunity: when an opportunity is found along destination that journey is stopped
Intervening obstacles: barriers in migration journey like financial problems, roadblocks, immigration requirements and wars

81. Ravenstein’s “Laws”, cont.
Migrants who are traveling a long way tend to move to larger cities than smaller cities
Large city has more opportunities creating an almost magnetic pull
Keep in mind, Ravenstein was writing during height of industrial revolution
Rural residents are more likely to migrate than are urban residents
True in Ravenstein’s time because of industrial revolution
Seen in many developing countries like China and Brazil

82. Last two “Laws”
Families are less likely to migrate across national borders than are young adults
It is easier for single people to migrate than whole families
Singe people less encumbered with responsibilities
Every migration stream creates a counter stream
Net migration is the number of people in the original flow minus the number of people in opposite flow (counter stream)
Caused by many factors
Example: Jews leaving Germany before WWII who were captured at borders and forced to return or young boy from rural setting who moves to city and then returns to rural area after trying city life

83. Chain Migration
Occurs when people migrate to be with other people who migrated before them and with whom they feel some tie
Tie can be religious, familial, cultural, ethnic or any type of connection
Most common type of migration to the U.S.