Introduction to Environmental Science Chapter 6: Human Population and Urbanization

CASE STUDY Are there too many of us?

6-1 How many people can the Earth support? The human population has grown rapidly due to technology, improved medical techniques, emphasis on hygiene, and expansion of agriculture and industry. Population growth has slowed but is troubling because we do not know how long we can continue without overshooting earth's carrying capacity for humans. No population, including humans, can continue to grow indefinitely. "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. "

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 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

6-2 What Factors Influence the Size of the Human Population? 3 Factors of Human Population Birth: Fertility Death: Mortality Migration: Emigration and Immigration Population increases through births and immigration and decreases through deaths and emigration. [Population change = (Births + Immigration) - (Deaths + Emigration)] 1. The crude birth rate is the number of live births per 1,000 people in a population in a specific year. 2. The crude death rate is the number of deaths per 1,000 people in a population in a specific year.

UN WORLD POPULATION PROJECTION BY 2050

FERTILITY Fertility is the number of births that occur to an individual woman or in a population. 1. The changing nature of fertility rates affect population growth. a. Replacement-level fertility is the number of children needed to replace their parents. b. Total fertility rate (TFR) is the average number of children that a woman has during her fertile years.

Factors Influence Birth and Fertility Rate 1. More children work in developing countries; they are important to the labor force. 2. The economic cost of raising and educating children determines their numbers. 3. If there are available private/public pension systems, adults have fewer children because they don't need children to take care of them in old age. 4. People in urban areas usually have better access to family planning, so have fewer children. 5. If women have educational and economic choices, they tend to have fewer children. 6. When the infant mortality rate is low, people have fewer children. 7. The older the age at which women marry, the fewer children they bear. 8. If abortions are available and legal, women have fewer children. 9. The availability of reliable birth control allows women to space children and determines the number of children they bear.

Factors that have caused a decline in death rates are the following: 1. Better food supplies and nutrition, and safer water supplies contribute to people living longer. 2. Advances in medicine and public health, and improved sanitation and personal hygiene also contribute to people living longer.

Measures of overall health 1. Life expectancy is the average number of years a newborn can expect to live. 2. Infant mortality rate is the number of babies out of every 1,000 born who die before their first birthday. a. This rate reflects a country's level of nutrition and health care. b. It is the single best measure of a society's quality of life. 3. U.S. infant mortality rate is higher than 40 other countries because: a. Inadequate health care for poor women and for their babies. b. Drug addiction among pregnant women. c. High birth rate among teenagers.

Migration Historically, the United States has admitted more immigrants than all other countries combined. Some 60% of the U.S. population supports limiting legal immigration. A recent study suggests that to maintain a viable workforce as baby boomers retire, the U.S. would have to absorb many more immigrants per year than it currently does. However, a reduction in immigration may help mediate the enormous environmental footprint the United States currently has.

THE U.S. POPULATION IS GROWING RAPIDLY CASE STUDY THE U.S. POPULATION IS GROWING RAPIDLY

BIRTH RATE IN U.S. (1910-2008)

THE UNITED STATES: A NATION OF IMMIGRANTS CASE STUDY THE UNITED STATES: A NATION OF IMMIGRANTS

• Immigration – legal and illegal – 39% population growth • 1820–1960: Most immigrants European • Since 1960 – Latin America – 53% – Asia – 25% – Europe – 14%

• Opponents of immigration – Stabilize population sooner – Reduce growing environmental impact – 60% of population favor reducing immigration • Proponents of immigration – Important historical role – Do menial jobs and pay taxes – Add cultural vitality – Replace retiring baby boomers

6-3 HOW DOES POPULATION'S AGE STRUCTURE AFFECT ITS GROWTH AND DECLINE? GENERALIZED POPULATION AGE STRUCTURE DIAGRAMS

POPULATION AGE STRUTURE BY AGE AND SEX IN DEVELOPED AND DEVELOPING COUNTRIES

TRACKING THE BABY-BOOM GENERATION IN THE UNITED STATES

Some Problems with Rapid Population Decline Can threaten economic growth Labor shortages Less government revenues with fewer workers Less entrepreneurship and new business formation Less likelihood for new technology development Increasing public deficits to fund higher pension and health-care costs Pensions may be cut and retirement age increased

RISING DEATH RATE: THE AIDS TRAGEDY 25 million killed by 2008 Many young adults die: loss of most productive workers Sharp drop in life expectancy International community called upon to Reduce the spread of HIV through education and health care Financial assistance and volunteers

6-4 HOW CAN WE SLOW HUMAN POPULATION Demographic transition stages Preindustrial Transitional May lead to a demographic trap Industrial Postindustrial

FAMILY PLANNING Information is given on birth spacing, birth control, and health care. Family planning has been responsible for at least 55% of the drop in TFRs in developing countries. Family planning has also reduced both legal and illegal abortions per year. Services come through educational and clinical services. Almost one-half of pregnancies in developing countries are unplanned and 26% end in abortion. Women want to limit their pregnancies but have no access to contraceptives. Empowering women by providing education, paying jobs, and support for their human rights can slow population growth. Women work two-thirds of all the hours worked, but receive 10% of the world’s income.

SLOWING POPULATION GROWTH IN CHINA CASE STUDY SLOWING POPULATION GROWTH IN CHINA

POPULATION GROWTH IN CHINA One-child families Halved birth rate and drastically reduce TFR Improved quality of life Strict family planning Sons still preferred – gender imbalance Population growth in China has been controlled by a strongly enforced government program. Between 1972 and 2004, China’s birthrate was cut in half. Couples with one child are rewarded with extra food, larger pensions, better housing, bonuses, free school tuition, and preferential employment treatment for the child. China currently faces challenges relating to a large elderly population and a larger male population of more males than females. As the economy continues to grow, China’s ecological footprint is bound to expand.

POPULATION GROWTH IN CHINA Population rapidly aging Rapidly growing economy Larger middle class increases resource consumption and waste Sustainable economic plan needed to avoid environmental degradation

SLOWING POPULATION GROWTH IN INDIA CASE STUDY SLOWING POPULATION GROWTH IN INDIA

POPULATION GROWTH IN INDIA Tried to slow population growth for five decades Most populous country in 2015 Population Control: Gender bias Problems increase with growing population Poverty Malnutrition Environmental degradation Growing middle class – resource consumption India has tried to control its population growth for years. Poverty, malnutrition, and environmental problems abound in India. Efforts to limit population have not been especially successful because poor couples believe they need several children for work and care ,and there is a strong preference for male children so many do not use birth control. India is currently undergoing tremendous economic growth that will likely continue. This may increase the ecological footprint of the nation, but may also serve to hasten the demographic transition.

6-5 WHAT ARE THE MAJOR URBAN RESOURCE AND ENVIRONMENTAL PROBLEM 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

AS OF 2005

URBANIZATION IN UNITED STATES CASE STUDY URBANIZATION IN UNITED STATES

URBANIZATION IN UNITED STATES 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 Better working and housing conditions compared to the past Improved environmental conditions Problems in urban areas Aging infrastructure Budget problems

URBAN SPRAWL CAUSES Prosperity Ample and affordable land Automobiles Cheap gasoline Poor urban planning

URBAN SPRAWL PROBLEMS Increased automobile use Decreased energy efficiency Destruction of cropland, forests, wetlands Economic deaths of some cities

1973 2003 Urban sprawl in and around the U.S. city of Las Vegas, Nevada, between 1973 and 2003.

Natural Capital Degradation Urban Sprawl Economic Effects Land and Biodiversity Water Energy, Air, and Climate Loss of cropland Loss of forests and grasslands Loss of wetlands Loss and fragmentation of wildlife habitats Increased use of surface water and groundwater Increased runoff and flooding Increased surface water and groundwater pollution Decreased natural sewage treatment Increased energy use and waste Increased air pollution Increased greenhouse gas emissions Can enhance climate change Decline of downtown business districts Increased unemployment in central city Loss of tax base in

ADVANTAGES OF URBANIZATION Economic development Innovation Education and jobs Technological advances Longer life spans Better social and medical services Recycling more feasible Biodiversity increased Increased energy efficiency

DISADVANTAGES OF URBANIZATION Unsustainable systems Lack of vegetation Water problems Pollution and health problems Noise pollution Climate and artificial light Urban heat islands Light pollution

Inputs Outputs Solid wastes Energy Waste heat Food Air pollutants Water pollutants Greenhouse gases Manufactured goods Noise Wealth Ideas Information Energy Food Water Raw materials Manufactured goods Money

CASE STUDY MEXICO CITY

MEXICO CITY Large population Severe noise, water, and air pollution 50% unemployment 100,000 premature deaths per year 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 IMPACT 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

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 : 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. Burn no fossil fuels Are impractical for long trips Require little parking space Secure bike parking not yet widespread

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 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

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 Can reduce need for more air travel, cars, roads, and parking areas Has some risk of collision at car crossings

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 Cost less to develop and maintain than heavy-rail system Commit riders to transportation schedules

Environmentally Sustainable Cities Smart growth Eco cities 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

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 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

THE ECOCITY CONCEPT IN CURITIBA, BRAZIL CASE STUDY THE ECOCITY CONCEPT IN CURITIBA, BRAZIL

CURITIBA, BRAZIL CURITIBA -“ecological capital” of Brazil Inexpensive, efficient mass transit High-rise apartments near bus routes, mixed-use structures Bike and pedestrian paths 1.5 million trees planted Recycling Many services for the poor Emphasis on ecological awareness, health, literacy

END OF CHAPTER 6