ENVIRONMENTAL SCIENCE CHAPTER 6: The Human Population and Urbanization

Core Case Study: Are There Too Many of Us? 6.8 billion people 82 million more each year 2050: 9.5 billion people at current growth rates Most growth in low-income and middle-income countries Are there enough resources for this growing population?

Core Case Study: Are There Too Many of Us? Negative viewpoint At present, 20% currently lack basic necessities Declining conditions have increase death rate There is an increased in our resource use Increased environmental degradation Positive viewpoint Technological solutions will allow us to increase our carrying capacity Growing population in of itself is a valuable resource

Sect. 6-1: How Many People Can the Earth Support? Concept To Learn in Sect. 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.

How Many People Can the Earth Support? Read “Human population growth continues but it is unevenly distributed”, pages 95-96.

Human Population Explosion Exponential growth (J-curve) in past 200 years Three major reasons Humans have ability to expand into diverse habitats Development of modern agriculture, which has created more available food Sanitation systems and control of infectious diseases has decreased death rates

How Long Can the Human Population Grow Rate slowing, but its still exponential at 1.22% per year Uneven global growth (more in low income/developing countries) Can we grow indefinitely? Science: No population can grow indefinitely! 2050: 9.5 billion people at current growth rates Most of growth in developing countries, least likely to cope (What is different there compared to developed countries?)

Cultural Carrying Capacity Read:“CULTURAL CARRYING CAPACITY: A biological approach to human problems” by Garrett Hardin (URL on my web page) Assignment: What inferences about carrying capacity can be made by studying carrying capacity in a non-human setting? How does carrying capacity relate to quality of life? What is the conflict that exists between economists & ecologists? How does Hardin suggest that we make corrections to overpopulation?

Sect. 6-2: What Factors Influence the Size of the Human Population? Concepts to learn in Sect. 6-2A: Population size increases through births and immigration and decreases through deaths and emigration. Concept to learn in Sect. 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: Growth, Decline, or Stability (births + immigration) - (deaths + emigration) 1. within a specific area, during 1 year 2. which ever category is greater will dictate an increase or decrease in population Demographers look at birth rates and death rates (the rate of births or deaths per 1000 people) In 2009: China: 1.3 billion people India: 1.1 billion people USA: 306 million people (we’re third!)

Number of Children born Fertility rates: The key factor in determining population size. 1. Affects population size and growth rate Total fertility rate (TFR): the average # of children born to women in a population during their reproductive years From1950 to 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: had a high TFR Current births are still outnumbering deaths and immigration out of the US Our growth is faster than other developed countries 2050 estimate: 439 million in the US alone

Baby Boomers: In-class assignment Answer the following: What was the total population change that took place during the baby-boomer era? What % of the current population do the baby-boomers represent? What was the peak year & what was the total increase? Have there been any other similar spikes in population? What year?

Case Study: The U.S. Population Is Growing Rapidly Why is the US growth rate faster/greater than any other developed country? 1. Birth rate vs. death rate 2. Immigration vs. emmigration How has the US ecological footprint changed since the early 1900’s? 1. Disease? 2. Resource use? 3. Environmental impact per person?

Factors Affecting Birth & Fertility Rates Importance of children as part of labor force 1. Have children, for the purpose of working and contributing their income to the family budget. Cost of raising and educating children 1. Very high in developed countries a. Approx. $300,000 till age 18 (middle class) 2. Lower in developing countries a. Need their children to go to work to survive.

Factors Affecting Birth & Fertility Rates Availability of retirement systems (pensions) 1. reduce the need to have children Urbanization 1. Better access to family planning. Educational and employment opportunities for women 1. the greater the opportunities, the lower will be the birth rates & TFR

Factors Affecting Birth & Fertility Rates Average marriage age 1. Rates are lower if average age is 25+ Availability of legal abortion and reliable birth control methods Religious beliefs, traditions, cultural norms 1. Will favor large families 2. Strongly oppose abortion laws.

Factors Affecting Death Rates Population growth is also response to decline in crude death rate What factors have lowered death rates? Both Life expectancy and infant mortality rate important indicators of overall health Average life expectancy increased (77 years) Infant mortality – barometer of a society’s quality of life 1. # of babies/1000 that die before their 1st birthday

Infant Mortality Rates: an indicator of overall health Which country in the world has the lowest Infant Mortality Rate? What is the rate for the US? Where do we rank in the world for Infant Mortality Rate? 1. Why do you think we are not ranked top in the world?

Migration: a factor in population change. Migration is mostly driven by economic desires 1. movement of people into/out of specific geographical locations Other reasons for migration: 1. Religious persecution 2. Political oppression Ethnic conflicts 4. Environmental degradation

Case Study: The United States - A Nation of Immigrants Immigration – (legal and illegal) account 42% of population growth 1820–1960: Most immigrants came from Europe Since 1960: Latin America – 53% Asia – 25% Europe – 14%

Case Study: The United States - A Nation of Immigrants Opponents of immigration: 1. Concerns of attracting the worlds poor 2. Stabilize population sooner 3. Reduce growing environmental impact 4. 60% of population favor reducing immigration Proponents of immigration: 1. US holds important historical role 2. Immigrants will do menial jobs, and pay taxes 3 Add cultural vitality 4. Replace retiring baby boomers

Sect 6.3: How Does a Population’s Age Structure Affect Its Growth or Decline? Concept to learn in sect. 6-3: The numbers of males and females in young, middle, and older age groups determine how fast populations grow or decline.

Age Structure description: Distribution of population Prereproductive (0-14) Reproductive (15-44) Postreproductive (45+) Countries with many young people grows rapidly Countries with many older people will decline Developing countries: >30% under 15 years old (greater than1 in every 4 persons)

Age Structure Predicts the Future for a Country’s Population 36% of U.S. population are baby boomers By 2029, we will experience the “Graying of America” 1. Between now and 2029, we will have an increasing percentage of older baby boomers 2. What changes would you expect as this takes place?

Declines That will Occur in an Aging Population: A sudden & rapid decline in birth rate can lead to “Baby bust” or “birth dearth” 1. a prolonged TFR below 1.5 children per couple 2. Can lead to: a. Labor shortages b. Strain on governments for public services (like social security & medicare) c. Fewer working taxpayers Japan has world’s highest % of elderly

Declines from disease: “Rising Death Rate: The AIDS Tragedy” Large #s of deaths from AIDS will disrupt social and economic structure 1. It removes productive young adults from its age structure a. Lose trained workers, children orphaned 1981-2008: 27 million deaths have occurred from AIDS Eight African countries: 16–39% infected adults 1. Their life expectancy: 30–40 years

Sect. 6-4: How Can We Slow Human Population Growth? Concept to learn in sect. 6-4: We can slow population growth by reducing poverty, encouraging family planning, and elevating the status of women.

How Can We Slow Human Population Growth? 1. Promote economic development 2. Promote family planning 3. Empower women

Stages of Demographic Transition Demographic Transition: a hypothesis of population change that states that as a country becomes industrialized, their population growth will slow down. Countries are categorized as: 1. Preindustrial 2. Transitional 3. Industrial 4. Postindustrial

Family Planning: a way of controlling population growth Provides education about birth spacing, birth control, & available health care Increased availability of contraception Is responsible for a 55% drop in TFR of developing countries 1. Developing countries: a. Almost half pregnancies unplanned b. Often lack access to family planning

Family Planning Countries are “investing” in family planning ($1 spent $10-16 in savings on education, health, etc costs) Japan & China have shown that population growth can be reduced thru: 1. Reducing poverty 2. Elevating the social and economic status of women 3. Encouraging family planning

Empowering Women Can Slow Population Growth Women tend to have fewer children if they: 1. Are educated 2. Control their own fertility 3. Have a paying job outside the home 4. Do not have their rights suppressed Most women are “trapped”, and purposely limited from being empowered.

Empowering Women Can Slow Population Growth Women do almost all the worlds domestic housework and childcare Women do 60-80% of all agriculture (food growth), wood gathering, & water hauling Globally, women do 2/3 of all the work for only 10% of earned income.

Empowering Women Can Slow Population Growth Illiterate women account for 64% of world’s population, and 70% of the poor Women own only 2% of land When daughters considered less valuable, they are often not sent to school Poor conditions for women leads to environmental degradation

Case Study: Slowing Population Growth in China 1960’s: China’s population was growing so rapidly, it caused a serious threat of mass starvation, which lead to governmental laws: 1. One-child families 2. Halved birth rate and drastically reduce TFR (from 5.7 to 1.6) 3. Improved quality of life 4. Strict family planning 5. Sons are still preferred – leading to a gender imbalance (and a “bride” shortage)

Case Study: Slowing Population Growth in China Population rapidly aging 1. will probably lead to less restrictions in the one child/family laws Rapidly growing economy (3rd in world) Have a growing middle class (increases resource consumption and waste) A sustainable economic plan is needed to avoid environmental degradation

Case Study: Slowing Population Growth in India Tried to slow population growth for five decades! Is projected to be the most populous country in 2015 Problems increase with growing population: 1. Poverty 2. Malnutrition 3. Environmental degradation 4. Growing middle class leads to an increased resource consumption

Controlling population size thru controlling migration & family planning Controversial. 1. Faith often plays a part. 2. Beliefs in our countries founding principles may play a part. 3. What is your opinion? Should there be more control? Less control? Take a moment to think about this.

Sect. 6-5: What Are the Major Urban Resource Environmental Problems? Concept to learn in sect. 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: 1. By natural increase (births over deaths) By immigration from other areas. a. For jobs, freedoms, etc. 3. Urban area = 1 million + people.

4 Major Trends in Urban Growth: 1. Proportion of urban global population is growing Number and sizes of large urban areas is mushrooming a. Megacity = 10 million + people b. Hypercity = 20 million + people c. There is a rapid increase in urban populations in developing countries 3. Urban growth slower in developed nations Poverty is increasing in urban areas of developing countries.

Case Study: Urbanization in the United States 1800–2009: urban population increased from 5% to 79% 4 phases of migration patterns in US: 1. From rural areas to large cities 2. From large cities to suburbs and smaller cities 3. From cities and suburbs to rural areas 4. From the North and East to South and West (like Florida, Nevada, Arizona)

Case Study: Urbanization in the United States There are better working and housing conditions compared to the past 1. lead to lower death rates Improved environmental conditions 1. our biodiversity is better protected Problems in urban areas Aging infrastructure (bridges, sewers, etc) Budget problems (due to declining tax base)

Urban Sprawl Urban Sprawl: the growth/development on the edges of cities & towns. 1. Causes: a. Prosperity b. Ample and affordable land c. Automobiles d. Availability of cheap gasoline e. Poor urban planning

Urban Sprawl Effects on the Environment: Increased automobile use 1. Effect? Decreased energy efficiency, requiring greater use of resources. Destruction of cropland, forests, wetlands Economic deaths of some cities 1. Businesses will move from city into urban sprawl areas.

Urban Sprawl Benefits: Larger lot sizes for single family homes Newer schools Lower crime rates than in the city Less congestion and traffic Can take advantage of city opportunities without disadvantages of city living. Do the advantages of Urban Sprawl outweigh it’s disadvantages/

Advantages of Urbanization Greater economic development & job opportunities More innovation Better education opportunities More technological advances Longer life spans than in rural areas. (more so for the rich than the poor) Save energy by using mass transportation

Advantages of Urbanization Better social and medical services Recycling more feasible Biodiversity increased

Disadvantages of Urbanization Most of worlds cities are unsustainable systems. Why? Lack of vegetation 1.What does vegetation do for the environment? Water problems: 1. Need more! It has to come from somewhere! Pollution (more in smaller area)

Disadvantages of Urbanization Noise pollution Climate and artificial light (interfere with some plant & animal species) 1. climates are worse in urban areas. Why? Urban heat islands Light pollution Flooding, due to lack of impervious surfaces. Health problems: quick spread of infectious diseases.

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

Case Study: Mexico City Large population Severe noise, water, and air pollution 50% unemployment 100,000 premature deaths per year Most live in slums called “barrios” Lack basic necessities, like running water & electricity

Case Study: Mexico City 3 million without sewer Fecal snow Geography contributes to air pollution Progress: 1. tree planting has lowered air pollution 2. restricted car use

6-6 How Does Transportation Affect Urban Environmental Impacts? Concept to learn in sect. 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: 1. Transportation is mostly by walking, biking, or mass transit 2. Examples: Hong Kong, Tokyo Dispersed cities: 1. Transportation is mostly by automobile 2. Most American cities

Automobiles: The Disadvantages 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 (Like in Europe) 1. they pay $10-$15 per gallon, which is mostly tax. “Full-cost pricing” means that we would pay for all the costs incurred due to auto pollution by placing a tax on gas Tax revenues to finance mass transit, bike paths, sidewalks High gasoline tax unlikely in US (Why?)

Alternatives to Cars Need to discourage automobile use 1. Bicycles 2. Mass transit systems in urban areas 3. Bus systems 4. Rapid rail

6-7 How Can Cities Become More Sustainable and Livable? Concept to learn in Sect. 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.

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

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

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.