Population Population

APHG – Spring 2013APHG – Spring 2013 http://www.poodwaddle.com/clocks/worldclock

If we shrank the Earth's population to a village of 100 If we shrank the Earth's population to a village of 100 people,people, with all of the existing human ratios with all of the existing human ratios

remaining the same,remaining the same, there would be:there would be:

57 Asians                          57 Asians                                              52 females                   52 females 21 Europeans                                   21 Europeans                                           48 males       48 males   8 Africans  8 Africans 14 people from the Western Hemisphere14 people from the Western Hemisphere                (north and south)               (north and south) 30 Christians                                            6 U.S. citizens holding30 Christians                                            6 U.S. citizens holding70 Non-Christians 70 Non-Christians 60% of the worlds wealth 60% of the worlds wealth 70 unable to read                                     1 with a college education70 unable to read                                     1 with a college education        

80 living in substandard housing80 living in substandard housing 1 with their own computer1 with their own computer 50 suffering from malnutrition50 suffering from malnutrition 1 near death                                                   1 near death                                                   1 near birth                                                       1 near birth                                                           Source: Mercy Housing Midwest, Omaha, NE.Source: Mercy Housing Midwest, Omaha, NE.

Critical Issues in Population Critical Issues in Population GeographyGeography

• More people are alive today than at any More people are alive today than at any other time in human history.other time in human history.

• The world’s population increased at a The world’s population increased at a faster rate during the second half of the faster rate during the second half of the 2020thth century than ever before. century than ever before.

• Virtually all population growth today Virtually all population growth today occurs in less developed countries occurs in less developed countries (LDCs)(LDCs)

Key Population IssuesKey Population IssuesKey Issues Key Issues

1.1. Where is the world's population distributed?Where is the world's population distributed?

2.2. Where has the world's population Where has the world's population increased? increased?

3.3. Why is population increasing at different Why is population increasing at different rates in different countries? rates in different countries?

4. Why might the world face an overpopulation 4. Why might the world face an overpopulation problem?problem?

Population DistributionPopulation Distribution

Key Issue 1: Key Issue 1: Where Is the World's Population Where Is the World's Population Distributed?Distributed? Population concentrationsPopulation concentrations Sparsely populated regionsSparsely populated regions Population densityPopulation density

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

Distribution of World PopulationDistribution of World PopulationPopulation concentrationsPopulation concentrations

The four largest population clusters (2/3 of world’s The four largest population clusters (2/3 of world’s population)population)1. East Asia – China, Japan, Korean Penn.1. East Asia – China, Japan, Korean Penn.2. South Asia – India, Bangladesh, Pakistan, Sri Lanka2. South Asia – India, Bangladesh, Pakistan, Sri Lanka3. Southeast Asia – Indonesia, Indochina Penn.3. Southeast Asia – Indonesia, Indochina Penn.4. Europe – Western Europe, Eastern Europe4. Europe – Western Europe, Eastern Europe

Other population clustersOther population clusters1. Northeastern United States1. Northeastern United States2. Southeastern Canada2. Southeastern Canada3. Western Africa – Half live in Nigeria3. Western Africa – Half live in Nigeria

Population DistributionPopulation Distribution

World Population DistributionWorld Population Distribution

World population is very unevenly distributed across the Earth’s surfaceWorld population is very unevenly distributed across the Earth’s surface and it can be compared to climate distribution.and it can be compared to climate distribution.

World Population CartogramWorld Population Cartogram

This cartogram displays countries by the size of their populationThis cartogram displays countries by the size of their population rather than their land area. rather than their land area.

(Only countries with 50 million or more people are named.)(Only countries with 50 million or more people are named.)

Population DistributionPopulation Distribution

Sparsely populated regionsSparsely populated regions

-The ecumene-The ecumene

-People generally avoid:-People generally avoid:Dry landsDry landsCold landsCold landsWet landsWet lands High landsHigh lands

Expansion of the EcumeneExpansion of the Ecumene 5000 B.C.–A.D. 1900 5000 B.C.–A.D. 1900

The ecumene, or the portion of the Earth with permanent human settlement, hasThe ecumene, or the portion of the Earth with permanent human settlement, has expanded to cover most of the world’s land area.expanded to cover most of the world’s land area.

World Population Distribution by Region World Population Distribution by Region 1800–20501800–2050

Population DensityPopulation Density

Arithmetic Density – the total number of people Arithmetic Density – the total number of people divided by the total land area ( This measure is also divided by the total land area ( This measure is also called population density.) Arithmetic density enables called population density.) Arithmetic density enables geographers to make approximate comparisons of geographers to make approximate comparisons of the number of people trying to live on a given piece of the number of people trying to live on a given piece of land in different regions of the world. land in different regions of the world.

There is There is nono relationship between arithmetic density relationship between arithmetic density and standard of living. and standard of living.

Arithmetic Population DensityArithmetic Population Density

Arithmetic population density is the number of people per total land area.Arithmetic population density is the number of people per total land area.The highest densities are found in parts of Asia and Europe.The highest densities are found in parts of Asia and Europe.

Effect of Migration on Effect of Migration on Population GrowthPopulation Growth

Q&A. How densely populated is the planet?Q&A. How densely populated is the planet?

11stst Western Europe, 433 people per sq. mile Western Europe, 433 people per sq. mile 22ndnd Caribbean, 417 people per sq. mile Caribbean, 417 people per sq. mile Least densely settled region is Oceania: 10 people Least densely settled region is Oceania: 10 people

per sq. mileper sq. mile United States is 78 people per sq. mileUnited States is 78 people per sq. mile

Q. Does high density in urbanized areas equal Q. Does high density in urbanized areas equal environmental degradation????environmental degradation????

Population Densities, 2003Population Densities, 2003

RegionRegion Pop./Sq. MilePop./Sq. MileWorldWorld 122122 CaribbeanCaribbean 417417More Developed CountriesMore Developed Countries 6161 South AmericaSouth America 5252Less Developed CountriesLess Developed Countries 160160 AsiaAsia 312312AfricaAfrica 7474 Western AsiaWestern Asia 112112Sub-Saharan AfricaSub-Saharan Africa 7676 South Central AsiaSouth Central Asia 376376Northern AfricaNorthern Africa 5757 Southeast AsiaSoutheast Asia 313313Western AfricaWestern Africa 108108 East AsiaEast Asia 334334Eastern AfricaEastern Africa 107107 EuropeEurope 8282Middle AfricaMiddle Africa 4141 Northern EuropeNorthern Europe 141141Southern AfricaSouthern Africa 4949 Western EuropeWestern Europe 433433North AmericaNorth America 4242 Eastern EuropeEastern Europe 4141Latin AmericaLatin America 6868 Southern EuropeSouthern Europe 288288Central AmericaCentral America 150150 OceaniaOceania 1010

Source: Population Reference Bureau, 2003 World Population DataSource: Population Reference Bureau, 2003 World Population Data

Physiological DensityPhysiological Density

A more meaningful population measure is by looking A more meaningful population measure is by looking at the number of people per area of a certain type of at the number of people per area of a certain type of land in a region. land in a region.

The number of people supported by a unit of arable The number of people supported by a unit of arable land is called the land is called the physiologicalphysiological density. density.

Comparing physiological and arithmetic densities Comparing physiological and arithmetic densities helps geographers to understand the capacity if the helps geographers to understand the capacity if the land to yield enough food for the needs of people. land to yield enough food for the needs of people.

Physiological DensityPhysiological Density

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

Agriculture DensityAgriculture Density

Two countries can have similar physiological Two countries can have similar physiological densities, but they may produce different amounts of densities, but they may produce different amounts of food because of different economic conditions. food because of different economic conditions. Agriculture density Agriculture density is the ratio of the number of is the ratio of the number of farmers to the amount of arable land. farmers to the amount of arable land.

The Netherlands has a much higher physiological The Netherlands has a much higher physiological density than does India but a lower agriculture density than does India but a lower agriculture density.density.

Agriculture density is directly related to standard of Agriculture density is directly related to standard of livingliving

Measures of DensityMeasures of Density

Distribution of World Population Distribution of World Population GrowthGrowth

Key Issue 2: Key Issue 2: Where has the World’s Where has the World’s Population Increased?Population Increased?

Natural Increase – the percentage by which Natural Increase – the percentage by which a population grows in a yeara population grows in a year

Crude birth rate (CBR) – the number of Crude birth rate (CBR) – the number of births per 1,000 populationbirths per 1,000 population

Crude death rate (CDR) – the number of Crude death rate (CDR) – the number of deaths per 1,000 populationdeaths per 1,000 population

Doubling time – the number of years needed Doubling time – the number of years needed to double a populationto double a population

World Population GrowthWorld Population Growth1950–20101950–2010

Total world population increased from 2.5 to 6 billion in this half century. The naturalTotal 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 ofincrease rate peaked in the early 1960s and has declined since, but the number of

people added each year did not peak until 1990.people added each year did not peak until 1990.

World Population Growth, 1750–2150World Population Growth, 1750–2150

Source: United Nations, World Population Prospects, The 1998 Revision; and estimates by the Population Reference Bureau.

http://www.youtube.com/watch?v=9_9SutNmfFk&feature=BF&list=ULadYPZ59_AUc&index=1

Natural IncreaseNatural Increase Q&A: When could world population stop Q&A: When could world population stop

growing?growing?First one – half million years: the population First one – half million years: the population

growth rate was about zerogrowth rate was about zero1700s modern era of population growth 1700s modern era of population growth

beganbeganBetween 1850 and 1900, the annual growth Between 1850 and 1900, the annual growth

rate reached 0.5 percentrate reached 0.5 percentBy the mid-1960’s rate surged to 2.0 percentBy the mid-1960’s rate surged to 2.0 percentDropped to 1.7 percent by the mid-1980s, Dropped to 1.7 percent by the mid-1980s,

and declined to about 1.4 percent by 2000.and declined to about 1.4 percent by 2000.

Natural Increase RatesNatural Increase Rates

The natural increase rate (NIR) is the percentage growth or decline in the 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 population of a country per year (not including net migration). Countries in

Africa and Southwest Asia have the highest current rates, while Russia Africa and Southwest Asia have the highest current rates, while Russia and some European countries have negative rates.and some European countries have negative rates.

Crude Birth RatesCrude Birth Rates

The crude birth rate (CBR) is the total number of births in a country per 1,000The 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 inpopulation per year. The lowest rates are in Europe, and the highest rates are in

Africa and several Asian countries.Africa and several Asian countries.

Crude Death RatesCrude Death Rates

The crude death rate (CDR) is the total number of deaths in a country 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 lateper 1,000 population per year. Because wealthy countries are in a late

stage of the demographic transition, they often have a higher CDR thanstage of the demographic transition, they often have a higher CDR than poorer countriespoorer countries..

Population Growth through Natural Increase, Population Growth through Natural Increase, 1775–20001775–2000

Total Fertility RatesTotal Fertility Rates

The Total fertility rate (TFR) is the number of children an average woman inThe 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 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.Europe, and the highest are in Africa and parts of the Middle East.

Infant Mortality RatesInfant Mortality Rates

The infant mortality rate is the number of infant deaths per 1,000 live birthsThe 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 poorestper year. The highest infant mortality rates are found in some of the poorest

countries of Africa and Asia.countries of Africa and Asia.

World Infant Mortality Rates World Infant Mortality Rates in Selected Countries, 2000in Selected Countries, 2000

Source: Carl Haub and Diana Cornelius, 2000 World Population Data Sheet (Washington, DC: Population Reference Bureau, 2000).

Life Expectancy at birthLife Expectancy at birth

Life expectancy at birth is the average number of years a newborn infant canLife 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 expect to live. The highest life expectancies are generally in the wealthiest

countries, and the lowest in the poorest countries. countries, and the lowest in the poorest countries.

Doubling TimeDoubling 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 population’s annual growth rate to determine the years needed to double the size of the population.

Human Population Doubling TimeHuman Population Doubling Time

Why has the worlds population Why has the worlds population grown at such different rates grown at such different rates

throughout history?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.

Population increases at Population increases at different ratesdifferent rates

Key Issue 3: Why is population increasing at different rates in different countries?The demographic transition modelPopulation pyramidsCountries in different stages of

demographic transitionDemographic transition and world

population growth

Demographic Transition Model: Demographic Transition Model: Development & Population Intersect…Development & Population Intersect…

Demographic TransitionDemographic TransitionStage 1: Stage 1: Early Stationary Stage Early Stationary Stage

Population growth: slow increasePopulation growth: slow increase Birth rates: highBirth rates: high Death rates: highDeath rates: high

Most of humanity’s several-hundred year occupancy of Earth was Most of humanity’s several-hundred year occupancy of Earth was characterized by stage 1. Birth and death rates varied considerably characterized by stage 1. Birth and death rates varied considerably from one year to the next and from one region to another, but over 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.the long term they were roughly comparable, at very high levels.

Between 8000 B.C. and A.D. 1750, Earth’s human population Between 8000 B.C. and A.D. 1750, Earth’s human population increased from 5 million to 800 million. The burst of population increased from 5 million to 800 million. The burst of population growth around 8000 B.C. was caused by the growth around 8000 B.C. was caused by the agriculture revolution.agriculture revolution. Despite the agriculture revolution, the human population remained Despite the agriculture revolution, the human population remained in stage1 of the demographic transition because food supplies were in stage1 of the demographic transition because food supplies were unpredictable.unpredictable.

Demographic TransitionDemographic TransitionStage II: Stage II: Early Expanding StageEarly Expanding Stage

Birth rates: highBirth rates: high Death rates: decreasingDeath rates: decreasing Population growth: rapid and increasingPopulation growth: rapid and increasing

After around A.D1750 the world’s population suddenly began to After around A.D1750 the world’s population suddenly began to grow10 times faster than in the past. In stage II, the crude death 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 rate plummets, while the crude birth rate remains the same as in stage I. Most African countries are still in a stage II.stage I. Most African countries are still in a stage II.

With the advent of the With the advent of the Industrial Revolution Industrial Revolution and the and the improvements in technology, population growth rate changed. improvements in technology, population growth rate changed. Countries in Europe and North America entered stage II of the Countries in Europe and North America entered stage II of the demographic transition about 1800, but stage II did not diffuse demographic transition about 1800, but stage II did not diffuse to most countries in Africa, Asia, and Latin America until the to most countries in Africa, Asia, and Latin America until the 1950’s. 1950’s. The late 20The late 20thth century push of countries into stage II was century push of countries into stage II was caused by the medical revolutioncaused by the medical revolution. .

Percent of Population under 15Percent of Population under 15

About one-third of world population is under 15, but the percentage byAbout 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, tocountry varies from over 40% in most of Africa and some Asian countries, to

under 20% in much of Europe.under 20% in much of Europe.

Rapid Growth in Cape VerdeRapid Growth in Cape Verde

Cape Verde, which entered stage 2 of the demographic transition inCape Verde, which entered stage 2 of the demographic transition in about 1950, is experiencing rapid population growth. Its populationabout 1950, is experiencing rapid population growth. Its population

history reflects the impacts of famines and out-migration.history reflects the impacts of famines and out-migration.

Demographic TransitionDemographic TransitionStage III: Stage III: Late Expanding StageLate Expanding Stage

Birth rates: decreasingBirth rates: decreasing Death rates: leveling offDeath rates: leveling off Population growth: rapid but slowingPopulation growth: rapid but slowing

A country moves from a stage II to a stage III when the A country moves from a stage II to a stage III when the birth rate birth rate begins to drop sharplybegins to drop sharply. European and North American countries . European and North American countries moved from stage II to a stage III during the first half of the 20moved from stage II to a stage III during the first half of the 20 thth century. Most countries in Asia and Latin America have moved century. Most countries in Asia and Latin America have moved to a stage III in recent years. to a stage III in recent years.

A society enters a stage III when people decide to have fewer A society enters a stage III when people decide to have fewer children. children. Medical practicesMedical practices introduced in stage II improve the introduced in stage II improve the probability of infant survival, but many years pass before probability of infant survival, but many years pass before families react by conceiving fewer babies. families react by conceiving fewer babies.

Demographic TransitionDemographic TransitionStage III continued……Stage III continued……

Economic changes Economic changes in stage III also induce families to have in stage III also induce families to have fewer offspring. Farmers often consider a large family to be an fewer offspring. Farmers often consider a large family to be an asset. In contrast, children living in cities are generally not asset. In contrast, children living in cities are generally not economic assets. economic assets.

About 75% of the world’s population is stranded in stages II and About 75% of the world’s population is stranded in stages II and III. III.

Q&A: Q&A: What does improve technology increase?What does improve technology increase?resource availabilityresource availabilitystandard of livingstandard of livinghealth carehealth care????

Moderate Growth in ChileModerate Growth in Chile

Chile entered stage 2 of the demographic transition in the 1930s, and itChile entered stage 2 of the demographic transition in the 1930s, and itentered stage 3 in the 1960s.entered stage 3 in the 1960s.

Demographic TransitionDemographic TransitionStage IV: Stage IV: Late Stationary StageLate Stationary Stage

Birth rates: lowBirth rates: low Death rates: lowDeath rates: low Population growth: lowPopulation growth: low

A country reaches stage IV when the A country reaches stage IV when the birth rate declines to the point birth rate declines to the point where it equals the death ratewhere it equals the death rate. The condition is called . The condition is called ZPGZPG. Most . Most European countries have reached stage IV. The United States has European countries have reached stage IV. The United States has moved slightly below ZPG since 2000. When families lived on farms, moved slightly below ZPG since 2000. When families lived on farms, employment and child rearing were conducted at the same place, but in employment and child rearing were conducted at the same place, but in urban societies parents leave the home to work.urban societies parents leave the home to work.

Changes in lifestyles also encourage smaller families. Several Eastern Changes in lifestyles also encourage smaller families. Several Eastern European countries, most notably Russia, have negative natural European countries, most notably Russia, have negative natural increase rates, a legacy of Communist rule. increase rates, a legacy of Communist rule.