ENVIRONMENTAL SCIENCE CHAPTER 6: The Human Population and Urbanization

Global Population http://www.youtube.com/watch?v=sc4HxPxNrZ0

Core Case Study: Are There Too Many of Us? (1) 6.8 billion people 83 million more each year 2050: 9.5 billion people at current growth rates Most growth in low-income and middle-income countries Enough resources for growing population?

A important question Can we provide an adequate standard of living for a projected 2.7 billion more people by 2050 without causing widespread environmental damage? Overpopulation vs overconsumption

Core Case Study: Are There Too Many of Us? (2) Negative viewpoint 20% currently lack basic necessities Declining conditions increase death rate Increased resource use Increased environmental degradation Positive viewpoint Technological solutions will increase carrying capacity Growing population a valuable resource

Together China and India are home to 1 of every 3 people on Earth Crowded street in China: largest population of all countries with 1.3 Billion people Together China and India are home to 1 of every 3 people on Earth Crowded street in China: largest population of all countries 1.3 Billion people. Together China and India are home to 1 of every 3 people on earth an the resource use per person in these 2 countries is projected to grow rapidly as they become more industrialized. Fig. 6-1, p. 94

6-1 How Many People Can the Earth Support? Concept 6-1 We do not know how long we can continue increasing the earth’s carrying capacity for humans without seriously degrading the life-support system that keeps us and many other species alive.

Human Population Explosion Exponential growth (J-curve) in past 200 years Three major reasons Ability to expand into diverse habitats Emergence of agriculture Sanitation systems and control of infectious diseases decreased death rates

How Long Can the Human Population Grow? Rate slowing, but still exponential Uneven global growth No population can grow indefinitely 2050: 9.5 billion people at current growth rates Most growth in developing countries, least likely to cope

Industrial revolution Black Death—the Plague Agricultural revolution 13 12 11 10 9 8 7 6 5 4 3 2 1 Exponential Growth: the J-shaped curve of past world population growth ? Industrial revolution Figure 1-10: Exponential growth: the J-shaped curve of past exponential world population growth, with projections to 2100 showing possible population stabilization with the J-shaped curve of growth changing to an S-shaped curve. (This figure is not to scale.) (Data from the World Bank and United Nations, 2008; photo L. Yong/UNEP/Peter Arnold, Inc) Black Death—the Plague 2-5 million years 8000 6000 4000 2000 2000 2100 B.C. A.D. Hunting and gathering Agricultural revolution Industrial revolution Fig. 1-1, p. 1 Fig. 1-10, p. 16

UN world population projections 12 11 High 10.8 10 Medium 9.5 9 8 Population (billions) 7 Low 7.8 6 5 Figure 6.2: Global connections: U.N. world population projections, assuming that by 2050, women will have an average of 2.5 children (high estimate), 2.0 children (medium), or 1.5 children (low). The most likely projection is the medium one—9.5 billion by 2050. (Data from United Nations). 4 3 2 1950 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 Year Fig. 6-2, p. 96

Natural Capital Degradation Altering Nature to Meet Our Needs Reduction of biodiversity Increasing use of the earth's net primary productivity Increasing genetic resistance of pest species and disease-causing bacteria Elimination of many natural predators Introduction of potentially harmful species into communities Active Figure 6.3: Major ways in which humans have altered natural systems to meet our growing population’s resource needs and wants (Concept 6-1). See an animation based on this figure at CengageNOWTM. Questions: Which three of these impacts do you believe have been the most harmful? Explain. How does your lifestyle contribute directly or indirectly to each of these harmful impacts? Using some renewable resources faster than they can be replenished Interfering with the earth's chemical cycling and energy flow processes Relying mostly on polluting and climate-changing fossil fuels Fig. 6-3, p. 97

6-2 What Factors Influence the Size of the Human Population? Concept 6-2A Population size increases through births and immigration and decreases through deaths and emigration. Concept 6-2B The average number of children born to women in a population (total fertility rate) is the key factor that determines the population size.

Population Change Population change = (births + immigration) - (deaths + emigration) Demographers look at birth rates and death rates 2009: China, 1.3 billion people India, 1.1 billion people USA, 306 million people

Number of Children Fertility rates affect population size and growth rate Total fertility rate (TFR) 1950-2009: Global TFR fell to: 1.6 from 2.5 in developed countries 2.8 from 6.5 in developing countries

Case Study: The U.S. Population Is Growing Rapidly Quadrupled in 100 years, despite oscillations in TFR Baby boom: High TFR Current births outnumbering deaths and legal immigration Growing faster than other developed countries 2050 estimate: 439 million

TFR for US 4.0 3.5 3.0 2.5 2.1 Births per woman 2.0 1.5 Baby boom (1946–64) Replacement level 1.0 0.5 Figure 6.4: Total fertility rates for the United States between 1917 and 2009. Question: The U.S. fertility rate has declined and remained at or below replacement levels since 1972, so why is the population of the United States still increasing? (Data from Population Reference Bureau and U.S. Census Bureau) 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 Year Fig. 6-4, p. 98

Factors Affecting Birth Rates (1) Importance of children as part of labor force Cost of raising and educating children Availability of retirement systems Urbanization Educational and employment opportunities for women

Factors Affecting Birth Rates (2) Average marriage age Availability of legal abortion and reliable birth control methods Religious beliefs, traditions, cultural norms

Factors Affecting Death Rates Population growth is also response to decline in crude death rate Life expectancy and infant mortality rate important indicators of overall health Average life expectancy increased Infant mortality – barometer of a society’s quality of life

Supplement 3, Fig. 8, p. S10

*6-3 How Does a Population’s Age Structure Affect Its Growth or Decline? Concept 6-3 The numbers of males and females in young, middle, and older age groups determine how fast populations grow or decline.

*Age Structure Distribution of population Prereproductive Reproductive Postreproductive Country with many young people grows rapidly Country with many older people will decline Developing countries: >30% under 15 years old

Think, Pair, Share Activity Fig. 6-6, p. 102

Fig. 6-6, p. 102

Age Structure Predicts the Future 36% of U.S. population baby boomers Graying of America Over time: increasing percentage of older baby boomers Changes the economy

Tracking the baby-boom generation in the United States Tracking the baby-boom generation in the United States. US population by age and sex for years indicated. 1955 1985 2015 2035 Figure 6.8: Tracking the baby-boom generation in the United States. U.S. population by age and sex, 1955, 1985, 2015 (projected), and 2035 (projected). See an animation based on this figure at CengageNOW. (Data from U.S. Census Bureau) Stepped Art Fig. 6-8, p. 103

Declines Occur in Aging Populations “Baby bust” or “birth dearth” – TFR below 1.5 children per couple Labor shortages Strain on governments for public services Fewer taxpayers

*6-4 How Can We Slow Human Population Growth? Concept 6-4 We can slow population growth by -reducing poverty -encouraging family planning -and elevating the status of women.

*Stages of Demographic Transition Preindustrial Transitional – demographic trap Industrial Postindustrial Some analysts believe that most of the world’s developing countries will make a demographic transition over the next few decades, mostly because modern technology can raise per capita incomes by bringing economic development and family planning to such countries. Other analysts fear rapid pop growth, extreme poverty, and increasing environmental degradation in some low-income countries could leave them stuck in stage 2.

Birth rate and death rate Population grows very slowly because of a high birth rate (to compensate for high infant mortality) and a high death rate Stage 1 Preindustrial Growth rate over time 80 70 60 50 40 30 20 10 (number per 1,000 per year) Birth rate and death rate Low Death rate Total population Birth rate Population grows rapidly because birth rates are high and death rates drop because of improved food production and health Decreasing Stage 2 Transitional Increasing Very high Population growth slows as both birth and death rates drop because of improved food production, health, and education Stage 3 Industrial Low Population growth levels off and then declines as birth rates equal and then fall below death rates Stage 4 Postindustrial Negative Zero Figure 6.10: The demographic transition that the population of a country can experience as it becomes industrialized can take place in four stages. See an animation based on this figure at CengageNOW. Question: At what stage is the country where you live? Stepped Art Fig. 6-10, p. 105

Think about it Stage 1: birth rate, death rate, population

Family Planning (1) Birth spacing, birth control, health care Increased availability of contraception 55% drop in TFR of developing countries Developing countries Almost half pregnancies unplanned Often lack access to family planning

Family Planning (2) Invest in family planning Reduce poverty Elevate the social and economic status of women

Empowering Women Can Slow Population Growth (1) Women tend to have fewer children if they: are educated control their own fertility have a paying job outside the home do not have their rights suppressed

*Empowering Women Can Slow Population Growth (2) Women do almost all domestic housework and childcare Women do 60-80% of agriculture, wood gathering, water hauling Globally, women do 2/3 of all work for 10% of income

Empowering Women Can Slow Population Growth (3) Illiterate woman 64% of world’s population, 70% of the poor When daughters considered less valuable, not sent to school Poor conditions for women leads to environmental degradation

Case Study: Slowing Population Growth in China (1) One-child families Halved birth rate and drastically reduce TFR Improved quality of life Strict family planning Sons still preferred – gender imbalance

Case Study: Slowing Population Growth in China (2) Population rapidly aging Rapidly growing economy Larger middle class increases resource consumption and waste Sustainable economic plan needed to avoid environmental degradation

Case Study: Slowing Population Growth in India Tried to slow population growth for five decades Most populous country in 2015 Problems increase with growing population Poverty Malnutrition Environmental degradation Growing middle class – resource consumption

Assignment Read Handout: “What do you think? Cultural Choices and the Rate of Population Growth” that discusses the approach to population control taken by two Indian states, Kerala and Andra Pradesh Answer the question Which method of population control (that used by Kerala or Andra Pradesh) offers better insights and models for other countries? What are the benefits and limitations of each approach? What do you think of the approach taken in Thailand? Why might this approach not work everywhere?

6-5 What Are the Major Urban Resource Environmental Problems? Concept 6-5 Most cities are unsustainable because of high levels of resource use, waste, pollution, and poverty.

Urban Living Half the world lives in urban areas 79% of Americans live in cities 50% of world population lives in cities Urban areas continue to grow Natural increase Immigration

Major Trends in Urban Growth Proportion of urban global population growing Number and sizes of urban areas mushrooming Rapid increase in urban populations in developing countries Urban growth slower in developed nations Poverty increasing

Shows populations of 18 megacities (each with 10 million or more people) in 2009 and their projected populations in 2015. All but 3 are located in developing countries. Karachi 10.4 million 16.2 million Dhaka 13.2 million 22.8 million Beijing 10.8 million 11.7 million Tokyo 26.5 million 27.2 million New York 16.8 million 17.9 million Los Angeles 13.3 million 19.0 million Cairo 10.5 million 11.5 million Mumbai (Bombay) 16.5 million 22.6 million Osaka 11.0 million Calcutta 13.3 million 16.7 million Mexico City 18.3 million 20.4 million Sao Paulo 18.3 million 21.2 million Manila 10.1 million 11.5 million Lagos 12.2 million 24.4 million Delhi 13.0 million 20.9 million Jakarta 11.4 million 17.3 million Key Figure 7.12: Four stages of the demographic transition, which the population of a country can experience when it becomes industrialized. There is uncertainty over whether this model will apply to some of today’s developing countries. Question: At what stage is the country where you live? See an animation based on this figure at ThomsonNOW. Shanghai 12.8 million 13.6 million 2004 (estimated) 2015 (projected) Buenos Aires 12.1 million 13.2 million Fig. 6-11, p. 108

Case Study: Urbanization in the United States (1) 1800–2009: urban population increased from 5% to 79% Migration patterns Rural areas to large cities Large cities to suburbs and smaller cities Cities and suburbs to rural areas North and East to South and West

Almost 8 of every 10 Americans live in urban areas. Areas with names in white Are fastest growing metropolitan areas. 48% of all Americans live in cities of 1 million or more Fig. 6-12, p. 109

Urban Sprawl is a product of Prosperity Ample and affordable land Automobiles Cheap gasoline Poor urban planning Urban sprawl=growth of low density development on the edges of cities and towns

Urban Sprawl Problems Increased automobile use Decreased energy efficiency Destruction of cropland, forests, wetlands Economic deaths of some cities

Natural Capital Degradation Urban Sprawl Land and Biodiversity Water Energy, Air, and Climate Economic Effects Loss of cropland Increased use of surface water and groundwater Increased energy use and waste Decline of downtown business districts Loss of forests and grasslands Figure 6.14: Some undesirable impacts of urban sprawl, a form of urban development that is dependent on cars. Question: Which five of these effects do you think are the most harmful? Increased runoff and flooding Increased air pollution Increased unemployment in central city Loss of wetlands Increased greenhouse gas emissions Increased surface water and groundwater pollution Loss and fragmentation of wildlife habitats Can enhance climate change Loss of tax base in central city Decreased natural sewage treatment Fig. 6-14, p. 110

Advantages of Urbanization (1) Economic development Innovation Education and jobs Technological advances Longer life spans

Advantages of Urbanization (2) Better social and medical services Recycling more feasible Biodiversity increased Increased energy efficiency

Disadvantages of Urbanization (1) Unsustainable systems Lack of vegetation Water problems Pollution and health problems

Disadvantages of Urbanization (2) Noise pollution Climate and artificial light Urban heat islands Light pollution

Natural capital degradation: urban areas rarely are sustainable systems. Typical city Depends on large non-urban areas for huge inputs of matter and energy resources and for large outputs of waste matter and heat. Inputs Outputs Energy Solid wastes Waste heat Food Air pollutants Water Water pollutants Raw materials Greenhouse gases Manufactured goods Manufactured goods Noise Money Figure 6.15: Natural capital degradation: urban areas rarely are sustainable systems. The typical city depends on large nonurban areas for huge inputs of matter and energy resources and for large outputs of waste matter and heat. According to an analysis by Mathis Wackernagel and William Rees, an area 58 times as large as that of London, England, is needed to supply its residents with resources. They estimate that if all the world’s people used resources at the same rate as Londoners do, it would take at least three more planet Earths to meet their needs. Question: How would you apply the three principles of sustainability (see back cover) to lessen some of these impacts? Wealth Information Ideas Fig. 6-15, p. 111

Urban Poor in Developing Countries Slums Shantytowns and squatter settlements Lack of basic services

Slums Mexico City

Case Study: Mexico City (1) Large population Severe noise, water, and air pollution 50% unemployment 100,000 premature deaths per year

Case Study: Mexico City (2) 3 million without sewer Fecal snow Geography contributes to air pollution Progress – tree planting and lower air pollution

6-6 How Does Transportation Affect Urban Environmental Impacts? Concept 6-6 In some countries, most people live in dispersed urban areas and depend mostly on motor vehicles for their transportation.

Cities Can Grow Outward or Upward Compact cities Transportation by walking, biking, or mass transit Hong Kong, Tokyo Dispersed cities Transportation by automobile Most American cities

Automobiles Gas guzzlers 40,000 people per year die from auto accidents in the United States World’s largest source of air pollution Lead to urban sprawl and congestion

Reduce Automobile Use User-pays system Full-cost pricing Tax revenues to finance mass transit, bike paths, sidewalks High gasoline tax unlikely Need to discourage automobile use

Alternatives to Cars Bicycles Mass transit systems in urban areas Bus systems Rapid rail

Trade-Offs Bicycles Advantages Disadvantages Are quiet and non-polluting Provide little protection in an accident Take few resources to make Provide no protection from bad weather Figure 6.18: Advantages and disadvantages of bicycles. The key to increased bicycle use is the creation of bicycle-friendly systems, including bike lanes. Bicycling and walking account for about a third of all urban trips in the Netherlands and in Copenhagen, Denmark, compared to only 1% in the United States. Paris, France, has almost 21,000 bikes available for rental at 1,450 rental stations throughout the city at a cost of just over $1 a day. Question: Which single advantage and which single disadvantage do you think are the most important? Burn no fossil fuels Are impractical for long trips Require little parking space Secure bike parking not yet widespread Fig. 6-18, p. 115

Trade-Offs Mass Transit Rail Advantages Disadvantages Uses less energy and produces less air pollution than cars do Is expensive to build and maintain Is cost-effective only in densely populated areas Reduced need for more roads and parking areas Figure 6.19: Advantages and disadvantages of mass transit rail systems in urban areas. Question: Which single advantage and which single disadvantage do you think are the most important? Commits riders to transportation schedules Causes fewer injuries and deaths than cars do Reduces car congestion in cities Can cause noise and vibration for nearby residents Fig. 6-19, p. 116

Trade-Offs Buses Advantages Disadvantages Can greatly reduce car use and air pollution Can lose money because they require affordable fares Can be rerouted as needed Can get caught in traffic and add to noise and pollution Figure 6.20: Advantages and disadvantages of bus rapid transit (where several buses running in express lanes can be hooked together) and conventional bus systems in urban areas. Question: Which single advantage and which single disadvantage do you think are the most important? Cost less to develop and maintain than heavy-rail system Commit riders to transportation schedules Fig. 6-20, p. 116

Trade-Offs Rapid Rail Advantages Disadvantages Is much more energy efficient per rider than cars and planes are Is costly to run and maintain Causes noise and vibration for nearby residents Produces less pollution than do cars and planes Figure 6.21: Advantages and disadvantages of rapid-rail systems between urban areas. Western Europe and Japan have high-speed bullet trains that travel between cities at up to 306 kilometers (190 miles) per hour. Question: Which single advantage and which single disadvantage do you think are the most important? Can reduce need for more air travel, cars, roads, and parking areas Has some risk of collision at car crossings Fig. 6-21, p. 116

*6-7 How Can Cities Become More Sustainable and Livable? Concept 6-7 An ecocity allows people to choose walking, biking, or mass transit for most transportation needs; recycle or reuse most of their wastes; grow much of their food; and protect biodiversity by preserving surrounding land. What is an Ecocity? What is an example of an ecocity?

Environmentally Sustainable Cities Smart growth Ecocities Use renewable energy as much as possible Build and design people-oriented cities Use energy and matter efficiently Prevent pollution and reduce waste Recycle, reuse, and compost Protect and encourage biodiversity Promote urban gardens and farmers markets Zone for environmentally stable population levels

Homework Assignment Go on an ecocity scavenger hunt! Find at least 3 things in Athens or on campus that could be found in an ecocity. Take pictures and email them with a description of why you think you would find it in an ecocity  You may work in pairs or groups of 3 if you wish

Solutions Smart Growth Tools Limits and Regulations Protection Limit building permits Preserve existing open space Urban growth boundaries Buy new open space Buy development rights that prohibit certain types of development on land parcels Greenbelts around cities Public review of new development Taxes Zoning Tax land, not buildings Encourage mixed use of housing and small businesses Tax land on value of actual use (such as forest and agriculture) instead of on highest value as developed land Concentrate development along mass transportation routes Promote high-density cluster housing developments Tax Breaks Figure 6.22: Smart growth or new urbanism tools that are used to control urban growth and sprawl. Questions: Which five of these tools do you think are the most important ways to prevent or control urban sprawl? Which, if any, of these tools are used in your community? For owners agreeing not to allow certain types of development (conservation easements) Planning Ecological land-use planning For cleaning up and developing abandoned urban sites (brownfields) Environmental impact analysis Integrated regional planning Revitalization and New Growth Revitalize existing towns and cities State and national planning Build well-planned new towns and villages within cities Fig. 6-22, p. 117

*Case Study: Curitiba, Ecocity in Brazil (1) Curitiba – “ecological capital” of Brazil Inexpensive, efficient mass transit High-rise apartments near bus routes, mixed-use structures Bike and pedestrian paths

Case Study: Curitiba, Ecocity in Brazil (2) 1.5 million trees planted Recycling Many services for the poor Emphasis on ecological awareness, health, literacy

Curitiba Video http://www.youtube.com/watch?v=hRD3l3rlMpo&feature=fvw

passengers can pay before getting on the bus. Bus rapid transit system in Curitiba, Brazil. Boarding is speeded up by the use of Extra-wide doors and boarding platforms sheltered by large glass tubes where passengers can pay before getting on the bus. Fig. 6-23, p. 118

Each of the 5 major spokes has 2 express lanes used only by buses. City center Figure 6.23: Solutions: bus rapid transit (BRT) system in Curitiba, Brazil. This system moves large numbers of passengers around rapidly because each of the five major spokes has two express lanes used only by buses. Double- and triple-length bus sections are hooked together as needed to carry up to 300 passengers. Boarding is speeded up by the use of extra-wide doors and boarding platforms sheltered by large glass tubes where passengers can pay before getting on the bus (top right). Route Express Interdistrict Direct Feeder Workers Fig. 6-23, p. 118

Three Big Ideas from This Chapter - #1 The human population is increasing rapidly and may soon bump up against environmental limits.

Three Big Ideas from This Chapter - #2 We can slow human population growth by reducing poverty, encouraging family planning, and elevating the status of women.

Three Big Ideas from This Chapter - #3 Most urban areas, home to half of the world’s people, are unsustainable, but they can be made more sustainable and livable within your lifetime.

Review Growth Curves Exponential Growth Logistic Growth Carrying capacity= capacity of a given habitat to support a given species, stated in terms of the maximum population of the species that the habitat can support over a given period

*What will happen to the population size in the future in each of the age structure diagrams?

*What will happen here? Fig. 6-6, p. 102