The Human Population and Urbanization Chapter 6
Key Concepts Factors affecting population size Human population problems Managing population problems Urban growth Resource and environmental problems in urban areas Transportation in urban areas Achieving sustainable cities
Is the World Overpopulated? 7.2 - 10.6 billion people by 2050 Limited resources Environmental impacts (I=PAT) Some say no- Longer lifespans Economic growth- stimulated by pop. increase Religion and population growth Freedom and population growth Poverty- 20% people without basic necessities Ecological footprint Fig. 6-1, p. 94
Is the World Overpopulated? Click for Current US and World Population http://www.census.gov/main/www/popclock.html Fig. 6-1, p. 94
Factors Affecting Human Population Size Population change equation Population change = (Births +Immigration) – (Deaths + Emigration) Crude birth rate = # live births per 1,000 people per year Crude death rate = # deaths per 1,000 people per year Global population growth = 1.2% = 214,000 people per day (97% in developing countries) Rule of 70: 70/ percentage growth rate = doubling time in years Doubling time: 70/1.2 = 58 years
Average Crude Birth and Death Rates Average crude birth rate Average crude death rate World 21 World’s birth rate = 2.1% 9 World’s death rate = 0.9% World’s pop. Growth rate = 1.2% All developed countries 11 10 All developing countries 24 8 Developing countries (w/o China) 27 9 Crude Growth Rate ÷ 10 = % Growth Rate
Average Crude Birth and Death Rates Average crude birth rate Average crude death rate Africa 38 14 Latin America 22 6 Asia 20 7 18 Oceania 7 United States 14 8 North America 14 8 10 Europe 12
Current and projected population sizes by region. Animation Current and projected population sizes by region.
How Did the Human Population Increase So Rapidly? Human intelligence and adaptation- enabled expansion to diverse habitats & new climate zones Agriculture - feeds more people per unit area Medical technologies and sanitation- controls infectious disease
Describing Population Changes Replacement-level fertility= # children a couple must bear to replace themselves (approx 2.1 - 2.4) Total fertility rate (TFR)= average # children woman has in her reproductive years (2005 TFR = 2.7) (TFR in MDCs = 1.6 : LDCs = 3.0) Projecting global populations: 2050 projected pop. = 7.2-10.6 billion Most growth (97%) expected in developing countries US fertility rates- see figure 6-4, p. 98
World Population Projections Fig. 6-2, p. 96
US Fertility Rates (1917-2005) Fig. 6-4, p. 98
Major Changes in US Society (1900-2000) 47 years Life expectancy 77 years 8% Married women working outside the home 81% 15% High school graduates 83% 10% Homes with flush toilets 98% 2% Homes with electricity 99% 10% Living in suburbs 52% 1900 $3 Hourly manufacturing job wage (adjusted for inflation) 2000 $15 1.2 Homocides per 100,000 people 5.8 Fig. 6-5, p. 99
Factors Affecting Birth Rates and Fertility Rates *** Child labor- very important in developing countries Cost of raising and educating children - more expensive in developed countries Availability of pension systems - pensions reduce need for children to support in old age Urbanization- better access to family planning services in cities Education and employment of women - TFR drops with increasing education & employment opportunities Infant mortality rate - Directly proportional to TFR Average age of marriage- Fewer children when marriage age ≥ 25 years Abortion- 46 million abortions yearly (20 million illegal) Availability of birth control Culture, religious values, and traditions
Very Effective Birth Control Methods Extremely Effective Total abstinence 100% Sterilization 99.6% Vaginal ring 98-99% Highly Effective IUD with slow-release hormones 98% IUD plus spermicide 98% Vaginal pouch (“female condom”) 97% IUD 95% Condom (good brand) plus spermicide 95% Oral contraceptive 93%
Mostly Effective Birth Control Methods Cervical cap 89% Condom (good brand) 86% Diaphragm plus spermicide 84% Rhythm method (Billings, Sympto-Thermal) 84% Vaginal sponge impreg- nated with spermicide 83% Spermicide (foam) 82%
Least Effective Birth Control Methods Moderately Effective Spermicide (creams, jellies, suppositories) 75% Withdrawal 74% Rhythm method (daily temperature readings) 74% Condom (cheap brand) 70% Unreliable Douche 40% Chance (no method) 10%
Factors Affecting Death Rates Life expectancy: global average years = 69 Infant mortality rate = # of babies out of every 1,000 who die before 1st birthday ** Best single measure of a society’s quality of life (reflects nutrition, health care) 46 countries have lower infant mortality rates than USA Improvements: Food, medicine, nutrition, medicine, sanitation, hygiene, water supply
Immigration into the US 41% of annual population growth Source of immigrants into the US Pre 1960: Mostly Europe Post 1960: Latin America (53%), Asia (25%), Europe (14%) Arguments to reduce immigration: 58% support • Allow population to stabilize • Reduce environmental impact Arguments for immigration • “Give me your hungry, your tired your poor…’ • Tax revenues $$$ • immigrants occupy menial, low-paying jobs • After 2020 workers will be needed as Boomers retire
Population Age Structures 0.3 - 1.4% 0 - 0.2% 1.5 - 3% Negative growth Male Female Male Female Male Female Male Female Expanding Rapidly Guatemala Nigeria Saudi Arabia Expanding Slowly United States Australia Canada Stable Spain Austria Greece Declining Germany Bulgaria Italy Prereproductive ages 0-14 Reproductive ages 15-44 Postreproductive ages 45-85+ In 2005, 29% of people on planet were younger than 15 years old Fig. 6-6, p. 102
Examples of age structure interaction Animation Examples of age structure interaction
Tracking the US Baby Boom Generation Fig. 6-8, p. 103
U.S. age structure interaction. Animation U.S. age structure interaction.
Effects of Population Decline 40 nations have stable or declining populations UN predicts that pop of most develop countries will stabilize by 2050 (not USA) Rapid declines can create severe social and economic problems Labor and social security problems Social and economic impacts of AIDS
Solutions: Influencing Population Size ***Demographic transition Family planning Improve health care Empowering women- worldwide, women account for 66% of hours worked, but receive 10% of world’s income. See stats of p.138 Developing national population policies Improve education, especially for women Increase involvement of men in parenting Reduce poverty Reduce unsustainable consumption
Demographic Transition Stage 1 Preindustrial Stage 2 Transitional Stage 3 Industrial Stage 4 Postindustrial High 80 70 60 Birth rate 50 Birth rate and death rate (number per 1,000 per year) Relative population size 40 30 Death rate 20 10 Total population Low Low Increasing Very high Decreasing Low Zero Negative Growth rate over time Fig. 6-10, p. 105
Animation- Demographic transition model
Case Study: Hindrances to Family Planning Programs in India Poor planning of family planning programs Bureaucratic inefficiency Low status of women Extreme poverty Lack of administrative and financial support
Case Study: Family Planning in China Economic incentives- extra food, larger pensions, better housing, $$ Free medical care for participants Preferential treatment for participants- free school tuition Very coercive and intrusive- free sterilization, contraception, Human rights violations- gender imbalance, abortions, infanticide China’s Pop could peak in 2040, then decline
Demographic Data on India and China Percentage of world population 17% 20% Population 1.1 billion 1.3 billion Population (2025) (estimated) 1.4 billion 1.63 billion Illiteracy (%of adults) 47% 17% Population under age 15(%) 36% 22% Population growth rate (%) 1.6% 0.6% 3.0 children per woman (down from 5.3 in 1970) Total fertility rate 1.7 children per woman (down from 5.7 in 1972) Infant mortality rate 64 27 62 years Life expectancy 71 years Percent living below $2 per day 81 47 GDP PPP per capita $2,880 $4,980
Urbanization and Urban Growth Urban and rural populations Rural migration to urban areas Megacities and megalopolises Poverty and shantytowns Patterns of urbanization
Major Urban Areas of the World Karachi 10.4 million 16.2 million Dhaka 13.2 million 22.8 million Beijing 10.8 million 11.7 million Los Angeles 13.3 million 14.5 million Cairo 10.5 million 11.5 million Tokyo 26.5 million 27.2 million New York 16.8 million 17.9 million Mumbai (Bombay) 16.5 million 22.6 million Calcutta 13.3 million 16.7 million Mexico City 18.3 million 20.4 million Osaka 11.0 million Lagos 12.2 million 24.4 million Sao Paulo 18.3 million 21.2 million Delhi 13.0 million 20.9 million Manila 10.1 million 11.5 million Jakarta 11.4 million 17.3 million Shanghai 12.8 million 13.6 million Buenos Aires 12.1 million 13.2 million Fig. 6-11, p. 108
Megalopolises of Bowash and Chipitts
US Urbanization Initial migration to large central cities Later migration from large cities to suburbs Migration from north and east to south and west Recent migration back to rural areas Advantages and disadvantages of US urban areas
Major Urban Areas of the US Fig. 6-12, p. 109
Some Undesirable Effects of Urban Sprawl See Fig. 6-14, p. 110
Some Undesirable Effects of Urban Sprawl Human Health and Aesthetics Contaminated drinking water and air Noise pollution Sky illumination at night Traffic congestion Weight gain
Some Undesirable Effects of Urban Sprawl Water Increased runoff Increased surface water and groundwater pollution Increased use of surface water and groundwater Decreased storage of surface water and groundwater Increased flooding Decreased natural sewage treatment
Animation SF Bay region growth animation
Advantages of Urbanization (especially in Developed Countries) Jobs Education Better access to health care Some environmental advantages Biodiversity may be preserved in some rural areas
Disadvantages of Urbanization Resource use and waste Reduction in vegetation Water supply problems and flooding Don’t grow food Air, noise and water pollution Disease, poverty, crime and accidents Microclimates: Urban heat islands
Urban Areas as Open Systems © 2006 Brooks/Cole - Thomson Inputs Outputs Energy Solid wastes Waste heat Food Air pollutants Water Water pollutants Raw materials Greenhouse gases Manufactured goods Manufactured goods Noise Money Wealth Information Ideas Fig. 6-15, p. 111
Urban Areas as Open Systems © 2006 Brooks/Cole - Thomson Permanent damage begins after 8-hour exposure Noise Levels (in dbA) 85 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 Normal breathing Quiet rural area Rainfall Vacuum cleaner Lawn mower Rock music Earphones at loud level Boom cars Whisper Quiet room Normal conversation Average factory Chain saw Thunderclap (nearby) Air raid siren Military rifle Fig. 6-16, p. 112
Extreme Poverty in Urban Areas Fig. 6-17, p. 113
Transportation and Urban Development Compact and dispersed cities Personal automobiles Motor vehicles in the US Advantages and disadvantages of motor vehicles Reduction of motor vehicle use Alternatives to motor vehicles
Tradeoffs of Bicycles See Fig. 6-18, p. 115 Trade-Offs Bicycles Advantages Disadvantages Affordable Produce no pollution Quiet Require little parking space Easy to maneuver in traffic Take few resources to make Very energy efficient Provide exercise Little protection in an accident Do not protect riders from bad weather Not practical for trips longer than 8 kilometers (5 miles) Can be tiring (except for electric bicycles) Lack of secure bike parking See Fig. 6-18, p. 115
Tradeoffs of Mass Transit Rail Advantages Disadvantages More energy efficient than cars Produce less air pollution than cars Require less land than roads and parking areas for cars Cause fewer injuries and deaths than cars Reduce car congestion in cities Expensive to build and maintain Cost effective only along a densely populated narrow corridor Commit riders to Transportation schedules Can cause noise and vibration for nearby residents Fig. 6-19, p. 116
Tradeoffs of Buses Trade-Offs Buses Advantages Disadvantages More flexible than rail system Can be rerouted as needed Cost less to develop and maintain than heavy-rail system Can greatly reduce car use and pollution Can lose money because they need low fares to attract riders Often get caught in traffic unless operating in express lanes Commit riders to transportation schedules Noisy Fig. 6-20, p. 116
Tradeoffs of Rapid Rail Advantages Disadvantages Can reduce travel by car or plane Ideal for trips of 200–1,000 kilometers (120–620 miles) Much more energy efficient per rider over the same distance than a car or plane Expensive to run and maintain Must operate along heavily used routes to be profitable Cause noise and vibration for nearby residents Fig. 6-21, p. 116
Making Urban Areas More Livable and Sustainable Land-use planning (Smart Growth) Walkability Environmental sustainability Smart transportation Ecocities Reduce pollution and waste Protect biodiversity Curitiba, Brazil
Smart Growth Fig. 6-17, p. 117 Solutions Limits and Regulations Smart Growth Tools Limits and Regulations Protection Limit building permits Urban growth boundaries Green belts around cities Public review of new dvlmt Preserve existing open space Buy new open space Buy development rights that prohibit certain types of development on land parcels Taxes Tax land, not buildings Tax land on value of actual use (such as forest and agriculture) instead of highest value as developed land Zoning Encourage mixed use Concentrate development along mass transportation routes Promote high-density cluster housing developments Tax Breaks For owners agreeing legally to not allow certain types of development (conservation easements) For cleaning up and developing abandoned urban sites (brownfields) Planning Ecological land-use planning Environmental impact analysis Integrated regional planning State and national planning Revitalization and New Growth Revitalize existing towns and cities Build well-planned new towns and villages within cities Fig. 6-17, p. 117
Bus System of Curitiba, Brazil City center City center Express Interdistrict Direct Feeder Workers Fig. 6-23, p. 118