objectives define 5 ways scientists predict future population sizes. explain different stages of...
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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