Objectives

Define 5 ways scientists predict future population sizes.Explain different stages of demographic transition.

Key Terms

DemographySurvivorshipFertility RateLife ExpectancyDemographic Transition

Study of human populationsAnalyze trends to predict future populations

economics social structure

Demography

Demography

Countries with similar population trends are grouped into:

developed countriesdeveloping countries

Demography

Developed countries have:high average incomeslow population growthindustrial economiessocial support systems

DemographyDeveloping countries have:

low average incomesrapid population growthagriculture-based economieslittle social support

1800s brought exponential growthIncreases due to:

food production hygienemedicine

World Population

World Population

Earth cannot sustain this continued growth

Age-Structure

•Population grouped by age/gender•High growth rate - more young than old•Slow or no growth - even distribution of ages

Survivorship

Percentage of newborns expected to survive to a given age.Demographers study people born in same time period and record when each member dies.

Survivorship

Type I survivorship - Developed countriesType II – Emerging countries.Type III - Developing countries

Survivorship

What do the different lines show about the relationship between survival and age?

Type IType IIType III

Fertility Rate

No. of live births per 1,000 womenDemographers also use total fertility rates - average number of births per womanReplacement level - average no. of offspring necessary for each parent to “replace” their number in population

2.1

USA Total Fertility Rates

MigrationMovement of individuals from one location to anotherPopulation increases in developed countries – due to immigration

Life Expectancy

Average length of time an individual is expected to liveAffected by infant mortality

death rate of infants < 1 year olddetermined by parents’ access to education, food, and clean water

Life Expectancy

Talk to your partnerExplain the 5 ways demographers study

populations to predict future trends.Be prepared to answer!

Demographic Transition

Change from high birth/death rates to low birth/death ratesTheory: industrial development affects population growth rates

Stages of the Transition

First stage: pre-industrial society:

birth rate and death rate are similar

Second stage: population explosion:

Death rates decline; birth rates stay high

Stages of the Transition

Third stage: birth rate decreasesPopulation size stabilizesPopulation is much larger than before

Fourth stage: birth rate drops below replacement level

Population decreases

Takes 1-3 generations for demographic transition to occur

Women and Fertility

Decline in birth rates - due to increase in women’s:

education economic independence

Lower death rate in second stage - due to increased education

Women and Fertility

Objectives

Describe 3 problems caused by rapid human population growth.

Key Terms

Arable landUrbanization

Changing Population Trends

Global environmental issues caused by countries with large populations

Strain community resourcesFirewoodClean waterLand

Shortage of Fuelwood

Main fuel source in many countriesDeadwood is used when populations are stable

Shortage of Fuelwood

With growing populations, living trees are used

reduces amount of wood available the next year.

WaterUsed by developing countries for drinking, washing, sewage disposalSupply becomes tainted

parasites, disease

Treatment systems cannot be developed quickly enough to match explosive growth

Land

Growing populations have a shortage of arable land.Natural ecosystems destroyed for land

housing, agriculture

Urban Sprawl

Urbanization - increase in density of people living in urban areas.Leads to gridlock, development, loss of natural habitats.

Urban Sprawl

Housing within cities becomes more dense, supply decreases

Demand increases; what happens to cost?

International community is focusing on least developed countries

Lowest incomes and resources

Most eligible for foreign aid and development programs

to help reduce population and related environmental problems

Demographic Diversity

Some countries may never become developed, due to population growth rates.China, Thailand, and India have incentives to reduce fertility rates.

Development and Population Growth

1994 - United Nations held International Conference on Population and Development (ICPD) in Cairo, Egypt

Discussed relationships between population, development, and environment

Many countries want to stabilize population growth by

developing infrastructureimprovement women’s status

Development and Population Growth

ICPD Goals for 2015Provide access to family-planning methodsReduce infant mortality below 35 deaths per 1000 birthsIncrease life expectancy to 75 yearsProvide access to primary education to allProvide access to secondary+ education to females

ICPD goals are impacting worldwide fertility rates

Development and Population

Slowing Growth

Demographers prediction:trend will continue worldwide population growth will be slower this century than last century.

If trends continue, world population growth will stabilize by 2050

World population will be 9 billion