Chapter Summaries of Living in the Environment (AP® Edition), 17th Edition

Chapter 1: Environmental Problems, Their Causes, and Sustainability

1. All life depends on energy from the sun, solar capital, and the resources and ecological services of the earth, natural capital, to survive. An environmentally sustainable society provides for the current needs of its people without undermining the ability of future generations to do the same. 2. The world's population is growing exponentially, adding about 80 million people per year. Economic growth increases a country's capacity to provide goods and services to its people. Economic development uses economic growth to improve standards of living. Globalization is a process of increasingly interconnecting people through social, economic, and environmental global changes. 3. The earth's main resources are perpetual resources like solar energy, renewable resources like forests and fresh water, and nonrenewable resources like oil and gas. The resources can be depleted or degraded by overuse, by waste, by pollution, and by man's increasing "ecological footprint." 4. The principle types of pollution are air, water, soil, and food pollutants. We can prevent pollution or clean up pollution. Prevention is far preferable because cleaning up pollution often causes additional pollutants in another part of the environment. 5. The basic causes of today's environmental problems are population growth, wasteful use of resources, the tragedy of the commons, poverty, poor environment accounting, and ecological ignorance. They are interconnected because of political and economic practices that are not equitable for various populations, in resource consumption and in technological applications. 6. The world's current course is not sustainable. Environmental sustainable development encourages environmentally beneficial forms of economic growth and discourages environmentally harmful growth.

Chapter 22: Cities and Sustainability

1. Almost half of the world's population lives in urban areas and half in rural areas. Government policies, poverty, lack of land to grow food, declining agricultural jobs, famine, and war that force people out of rural areas are all factors that determine how urban areas develop. 2. Urban areas are rarely self-sustaining, threaten biodiversity, destroy and damage ecosystems, lack trees, grow little of their own food, concentrate pollutants and noise, spread infectious disease, and are centers of poverty, crimes, and terrorism. 3. Urban areas relying on mass transportation spread vertically and urban areas relying on automobiles spread horizontally. Advantages of automobiles include convenience, personal benefits, and boosted economies, Disadvantages include air pollution, promotion of urban sprawl, increase in death rate, and time- and gas-wasting traffic jams. Advantages of bicycles and motor scooters include low cost, little to no air or noise pollution, require little space, and are energy efficient. Disadvantages include little accident protection, impractical for long distances, can be tiring, little parking, and gas scooter engines emit high air pollution. Mass transit rail systems are more energy efficient than cars, produce lower air pollution, require less land, cause fewer injuries and deaths, and reduce car congestion. Disadvantages include high cost to build and maintain, rigid schedules, noise pollution, and they are cost effective only in densely populated areas. Buses are more flexible than rail systems, can easily be rerouted, cost less to develop, and can reduce car use. Disadvantages include rigid schedules, noise pollution, and they are not always cost efficient. Rapid rail systems can reduce car and plane travel, are ideal for long trips, and are more efficient than cars and planes. Disadvantages include high operation and maintenance cost, noise pollution, and they are not always cost efficient. 4. Land-use planning, zoning, and smart growth can be used for planning and controlling urban growth. 5. Cities can be made more sustainable and more desirable places to live by creating parks, greenbelts, urban growth boundaries, cluster developments, mixed-use villages, greenways, and ecocities.

Chapter 13: Water Resources

1. Approximately 0.024% of the earth's water supply is available as liquid freshwater. Management of the world's water supply is a huge 21st century challenge. 2. Freshwater shortages are caused by dry climate, droughts, desiccation, and water stress. Solutions for this problem include building dams and reservoirs, transporting freshwater between locations, withdrawing groundwater, and desalination. 3. Advantages of dams and reservoirs include cheap electricity, reduction of downstream flooding, and year-round water for irrigation. Disadvantages include displacement of people and disruption of aquatic systems, and the hydrological cycle. 4. Transferring large amounts of water from one area to another can give stream runoff from water-rich areas to water-poor areas and aid in irrigation of farmland. It can also cause ecological, economical, and health disasters. 5. The advantages of withdrawing groundwater include water for drinking and irrigation; availability and locality; low cost, no evaporation losses; and it is renewable. Disadvantages include aquifer depletion from over pumping, subsidence, pollution, saltwater intrusion, and reduced water flow. Desalination increases the supply of fresh water but is expensive and produces large quantities of wastewater. 6. We can waste less water by lining canals, leveling fields, irrigating at night or using new irrigation techniques, polyculture or organic farming, seasonal farming, irrigating with treated waste water, and importing water-intensive crops and meat. 7. Flooding is caused by heavy rain or melting of snow within a short time. To reduce flood damage or the risk of flooding we can avoid building on floodplains, removing water-absorbing vegetation, or draining wetlands. 8. Methods for achieving more sustainable use of the earth's water include not depleting aquifers, preserving aquatic systems and water quality, integrated watershed management, agreements among regions and countries sharing surface water resources, outside party mediation of water dispute nations, marketing of water rights, raising water prices, wasting less water, decreasing government subsidies for reducing water waste, and slowing population growth.

Chapter 11: Sustaining Aquatic Biodiversity

1. Aquatic biodiversity refers to the composition of plants and animals in the fresh and salt waters of the planet. The economic importance of aquatic diversity lies in the conservative estimate of the value of their ecological services, which is $21 trillion a year. Additionally, at least 3.5 billion people depend on the seas for their primary source of food and this number could double to 7 billion in 2025. Many medicines have been developed from sea organisms: sponges, anemones, puffer fish, porcupine fish, seaweeds, etc. The waters are used for extensive recreational activities, not to mention commercial transportation. 2. Human activities are undermining aquatic biodiversity by destroying and degrading coastal wetlands, coral reefs, seagrass beds, kelp beds, mangroves, and the ocean bottom. 3. We can protect and sustain marine biodiversity by using laws, international treaties, and education. We must identify and protect species that are endangered and/or threatened. This entails cleaning up aquatic environments, as well as inventing fishing methods that do not destroy animals and birds inadvertently caught in fishing nets. Poaching and illegal harvesting of marine creatures must also be eliminated. Public aquariums can also educate the public about protecting marine animals and birds. Marine sanctuaries and coastal management can protect aquatic environments as well as their creatures. 4. The world's marine fisheries can be managed by setting catch limits below the maximum sustained yield limits, by reducing/eliminating fishing subsidies, and by charging fees for fishing in publicly owned offshore waters. Some areas can be protected from any kind of fishing; there should be more marine protected areas and more integration of coastal management practices. Develop net-escape devices for fishing boats. Restriction of coastal locations for fish farms, control of pollution, and decreasing the pollution of ship ballast water into the sea will all protect marine fisheries. Multispecies management of large marine systems offers hope for conserving marine resources and for renewing those resources. 5. Wetlands can be protected, sustained, and restored by government regulations that prevent wetland loss. Destroyed wetlands can also be restored and adequately monitored for their protection. Development can be kept away from wetland areas and control of nonnative species needs to be instituted to prevent invasion into wetlands. 6. Freshwater fisheries, lakes, and rivers can be protected, sustained, and even restored by building and protecting populations of desirable species, by prevention of overfishing, and by decreasing populations of less desirable species. Laws can be enacted, and enforcers of these laws must be funded to protect scenic rivers; they should be protected from development and dam construction projects.

Chapter 9: Sustaining Biodiversity: The Species Approach

1. Biologists estimate extinction rates in one of three levels. Local extinction occurs when a species in a specific area is lost but the species is still found in other places. Ecological extinction describes a species that is so small it cannot play out its ecological role where it is found. Biological extinction means that the species is gone from the earth. Scientists use measurement and models to estimate extinction rates: studying past records, identifying species-area relationships, examining lists of threatened species. Extinction rates are increasing because of human activities. Our growing population, degrading and eliminating biological environments and biological hot spots all contribute to growing extinction rates. 2. Biodiversity and species extinction are important because species provide enormous economic and ecological services we need to survive. In 100 years, mankind will destroy species that it would take five million years to rebuild. These species may provide genetic information, medicines, and information about natural processes we need to discover. These wild plants and animals are economic, recreational, and health resources. 3. Many human activities endanger wildlife, such as degradation/loss of habitat; capture of wild animals, which prevents their breeding; overfishing, oil spills, and exposure to pesticides; and extinction from nonnative species, which we introduce. 4. To prevent premature extinction of species, we must reduce threats from nonnative species; end illegal poaching and hunting; provide means for people to survive economically without killing native animals for food; maintain predator species, not destroy them; reduce greenhouse emissions and deforestation throughout the world; develop governmental policies to support biodiversity; and protect wild species in sanctuaries.

Chapter 6: The Human Population and Its Impact

1. Birth, death, fertility, and migration rates are the factors that determine population size. As birth rates have declined in developed countries, population has increased due to people's migrating into these countries. Women's fertility rates have dropped but are still above the replacement-level fertility around the world. 2. Population size is profoundly affected by age structure. If women are past their primary child-bearing ages, population increase will be limited. If, however, the population has a large percentage of young women entering their childbearing years, the potential for large population increases is present. In general, the closer a country's young women are to 15-40 years of age, the more potential for a rapidly increasing population. 3. We can influence population size by encouraging smaller families, by encouraging adoption of children already born and discouraging new births. Population size is, also, affected by health care or its lack; by epidemics (such as AIDS); by losses through war, etc. Lack of prenatal care for expectant mothers, failure to protect children from communicable diseases (like measles) or wide-spread diseases (like malaria), can contribute to a smaller population. In the past economic development, family planning, and economic opportunities for women have reduced birth rates. 4. India and China have both made efforts to control their population growth. China has been more successful because, as a dictatorship, it has imposed restrictions on family size with rewards and punishments for those who support or defy the government's direction. India, without a policy of coercion, has reduced its birth rate; but the wish for male children and several children for the care of old parents has helped to maintain a growing population. 5. Effective methods for slowing the growth of world population include investing in family planning, reducing poverty, and elevating the status of women.

Chapter 10: Sustaining Terrestrial Biodiversity - The Ecosystem Approach

1. Conservation biology attempts to slow down the rate at which we are destroying and degrading the earth's biodiversity through the use of rapid response strategies. Hot spots, the most endangered and species-rich ecosystems, receive emergency action to slow down/stop the loss of biodiversity in these systems. Bioinformatics manages, analyzes, and communicates basic biological and ecological information to help sustain biodiversity. 2. Forests provide important ecological and economic services, are storehouses of biodiversity, and affect weather and climate throughout the world. Forest resource management varies according to the type of forests. In diverse forests, the age and size of trees are preserved to foster natural regeneration. Government policies will primarily determine the future of forests, including old-growth forests. 3. Forests in the United States should be managed so as to retain as much of the forests as possible. Clear-cutting and seed-tree cutting methods of harvesting are scourges on the forest; selective cutting is the most reasonable way to harvest trees. 4. Deforestation is one of the most serious ecological problems of this century. The earth's forests have been reduced by 20-50% and the destruction continues to this day. Deforestation has many harmful environmental effects: reduces ecological services of forests, releases large amounts of carbon dioxide in the air, produces a drier and hotter climate; reduces the control of water movements, and increases soil erosion. 5. Tropical deforestation is one of the biggest threats to world economic health and climate. To help sustain tropical forests, nations of the world must unite to discourage deforestation and degradation. 6. Problems affecting parks run from little/no protection from their governments or being too small to sustain large animal species, to being too popular and, therefore, overused by people. Some methods for managing parks include: limiting the number of visitors, raising entry fees to provide funds for maintenance and management, managing parks in reference to nearby federal lands, discouraging development around already established parks, and providing more volunteers and better paid employees to maintain the parks. 7. Only about 7% of the world's terrestrial areas are protected from potentially harmful human activities; these areas need to be expanded throughout the world. In order to adequately conserve biodiversity, at least 20% of the earth's land area should be protected in a global network of reserves. 8. Wilderness is an amount of land legally set aside to prevent/minimize harm from human activities. This is land where human beings may visit but not remain. Wilderness areas are important for: (1) their natural beauty, (2) their natural biological diversity, (3) their enhancement of mental and physical health of visitors, and (4) their contributions to biodiversity and to evolutionary possibilities. 9. Ecological restoration is the process of repairing damage caused by humans to the biodiversity and dynamics of natural ecosystems. 10. Initiatives that would help to sustain the earth's biodiversity include: - Immediately preserving the world's biological hot spots - Protecting the remaining old-growth forests - Mapping the world's terrestrial and aquatic biodiversity - Identifying and taking action for the world's marine hot spots, just as for the terrestrial hot spots - Protecting and restoring the world's lakes and river systems - Developing a global conservation strategy that protects the earth's terrestrial and aquatic ecosystems - Making conservation profitable - Initiating ecological restoration projects worldwide

Chapter 3: Ecosystems: What are they and how do they work?

1. Ecology is the study of connections in nature. 2. Life on earth is sustained by the one-way flow of high-quality energy from the sun, by the cycling of matter, and by gravity. 3. Matter, energy, and life are the major components of an ecosystem. 4. Energy in an ecosystem decreases in amount to each succeeding organism in a food chair or web. 5. Soil is a complex mixture of eroded rock, mineral nutrients, water, air, decaying organic matter, and billions of living organisms. It covers most of the earth and provides nutrients for plant growth. Soils are formed by a breaking down of rock, decomposing surface litter and organic matter. Bacteria and other decomposer microorganisms break down some of soil's organic compounds into simpler inorganic compounds. 6. Matter is recycled through the earth's ecosystem of air, land, water, and living organisms. This vast global recycling system is composed of nutrient cycles. 7. Scientists study ecosystems through the use of aquarium tanks, greenhouses, and controlled indoor and outdoor chambers. Specific variables are carefully controlled, like temperature, light, carbon dioxide, and humidity. 8. Two principles of sustainability found from learning how nature works are the law of conservation of matter and the two laws of thermodynamics.

Chapter 23: Economics, Environment, and Sustainability

1. Economic systems are the social institutions through which goods and services are produced, distributed, and consumed to satisfy people's wants in the most efficient possible way. Natural capital, human capital, financial capital, and manufactured capital all comprise economic resources, which must be managed to sustain the world's environmental health. 2. Neoclassical economists see natural resources as a part of the economic system and assume that economic growth potential is essentially unlimited. Ecological economists see economic systems as a component of nature's economy and would have higher optimum levels of pollution control and lower optimum levels of resource use than would neoclassical economists. 3. Economic and environmental progress is monitored through the gross national income (GNI), gross domestic product (GDP), and per capita GNI and GDP indicators. 4. Full-cost pricing includes the internal and external costs in the market price of any good or service. 5. Some components of an environmental economics perspective include phasing out environmentally harmful subsidies, levying taxes on environmentally harmful goods and services, passing laws to regulate pollution and resource depletion, and using tradable permits for pollution or resource use. 6. Poverty can be reduced by forgiving dept to developing countries, through increase of nonmilitary government and private aid, and by stabilizing populations. 7. Shifting to more environmentally sustainable economies includes rewarding sustainable activities and penalizing non-sustainable resource use, use of full-cost pricing, and reduction of poverty.

Chapter 12: Food, Soil, and Pest Management

1. Even though food production has leveled off in the last 25 years, the world still produces enough food to meet the basic nutritional needs of people. However, the food cannot be evenly distributed throughout the world, leading to malnutrition and starvation. Many of these deaths come from malnutrition, which leads to a lack of resistance to diseases. Modern agricultural techniques create significant environmental harm, but the green revolution is also responsible for large increases in agricultural productivity. 2. Three systems produce foods for human consumption. Croplands produce mostly grains, about 77% of the world's food. Rangelands provide meat, about 16% of the world's food. Ocean fisheries supply about 7% of the world's food. 3. Soils are degraded and eroded by water, wind, and people. Soil erosion is primarily caused by flowing water and wind. Human activities, such as farming, logging, construction, off-road vehicles, etc., also disturb soil and hasten erosion. In much soil there is also salt buildup and waterlogging. Crops can be planted today with less soil disturbance through conservation-tillage, tillage, contour farming, and strip farming. Farmers may also use cover crops to help hold the soil in place. Several crops planted between trees and shrubs, alley cropping, help preserve soil and its productivity. And windbreaks are used to prevent soil from being blown away. Conservation and fertilization can be used to restore soil fertility, but fertilizing with commercial pesticides brings its own set of problems. 4. The green revolution uses particular methods to raise crops. Monocultures are developed and planted, bred selectively, or genetically engineered to produce high yields of particular crops. Large amounts of fertilizer, pesticides, and water are added to the crops. Yields of crops are increased through multiple cropping throughout the year. The second green revolution since 1967 involved using fast-growing dwarf varieties of wheat and rice in countries with tropical and subtropical climates. Traditional agriculture: uses interplanting, several crops grown together on the same area of land; uses agroforestry, which grows crops and trees together; and applies polyculture, where various plants are planted together but mature at different times. 5. Food production can be increased by using crossbreeding techniques on similar organisms and using genetic engineering on different organisms. Genetic engineering, including using advanced tissue culture techniques, is growing in use; but many people are concerned about the potential harm such crops may cause. Irrigating more land and cultivating more land are additional solutions but they may not prove sustainable. Rangelands can be managed more efficiently, with the land area better protected; but a meat-based diet requires substantially more resources than a plant-based diet. Overfishing and habitat degradation dominate the marine environment; better management of this food source and protection of the marine environment would ensure continued availability of fish worldwide. 6. More sustainable agricultural systems can be created by reducing resource throughput and working with nature. Technologies based on ecological knowledge are used to increase crop production, to control pests, and to build soil fertility. Such low-input organic farming is often more friendly to the environment by using less energy than conventional farming demands, and by improving soil fertility. Low-input organic farming is also more profitable for farmers.

Chapter 4: Biodiversity and Evolution

1. Evolution is the change in a population's genetic makeup over time. Evolution forces adaptations to changes in environmental conditions in a population. The diversity of life on earth reflects the wide variety of adaptations necessary and suggests that environmental conditions have varied widely over the life of the earth. 2. An ecological niche is a species' way of life or its functional role in a community. Everything that affects its survival and reproduction (temperature tolerance, water needs, space needs, interactions with other organisms, etc.) is a part of that niche. The ecological niche helps a population survive by the adaptive traits that its organisms have acquired. 3. Extinction of species and formation of new species constantly change the biodiversity of the earth. 4. In the future, evolution will continue to influence our environment. Man's use of artificial selection and genetic engineering to evolve species may have unintended consequences because evolution is a long, slow process and is unpredictable.

Chapter 24: Politics, Environment, and Sustainability

1. In this century, we have increased concern about human activities and the harmful effects on biodiversity, shifted from local to regional and global concerns, focused on climate change, become aware of pollution in developing countries, increased concern about trace amounts of some chemicals, and are starting to rely more on our international community to deal with environmental problems. 2. Democracies are governments in which people elect officials and representatives who pass laws, develop budgets, and formulate regulations. Democracies are designed to deal mostly with short-term, isolated problems and are not always efficient when dealing with environmental problems. 3. Environmental policy in the United States is made through: persuasion of lawmakers that an environmental problem exists, influence on how the laws are written, finding funds to implement and enforce each law, drawing up regulations for implementing each law by the appropriate government department, and the enforcement of these regulations. 4. Environmental groups range from small grassroots groups to major global organizations. Their roles include monitoring environmental activities, working to pass and strengthen environmental law, and working with corporations to find solutions to problems. Opponents of these groups include some corporate leaders, some corporations, and some citizens.

Chapter 7: Climate and Biodiversity

1. Key factors that determine the earth's weather are short-term atmospheric conditions such as temperature, pressure, moisture content, sunshine, cloud cover, precipitation, wind direction, and wind speed. 2. Climate is a region's long-term atmospheric conditions over decades. The two main factors in determining climate are average temperature and average precipitation. 3. The average climate—annual precipitation and temperature—determines terrestrial regions with characteristic types of natural ecological communities. According to these two factors, biomes form. 4. The major types of desert biomes are hot, temperate, and cold. Human activities have created large desert cities, destroyed soil through urban development and off-road vehicles, salinized the soil through irrigation, depleted underground water supplies, disturbed land and polluted, stored toxic and radioactive wastes, and located arrays of solar cells and solar collectors. 5. The three major types of grasslands are tropical or savannas, temperate grasslands, and polar grassland/tundra. The savannas have been destroyed by grazing cattle, which destroy vegetation and kills grass through fecal droppings. The temperate grasslands have been used to grow crops and graze animals. As a result, the grasslands have disappeared. The arctic tundra has been compromised by oil drilling, mines, and military bases. 6. The three main types of forest biomes are tropical, temperate, and polar/boreal. Human activities have destroyed much of the native trees; grazing has compromised the vegetation and eliminated food sources for native animals. And the deforestation has changed the tropical forest's ecosystem, leading to death of plants and animals. The temperate forest has a fewer number of broadleaf trees and rich forest soil; but fires, logging, and hunting have undermined this type of forest. The evergreen firs of the polar forest support a variety of wildlife. But oil drilling and oil spills have compromised the water, the wildlife, and the vegetation in the arctic. 7. Mountain and arctic biomes play important ecological roles; they help regulate climate and effect sea levels. Mountain biome degradation arises from timber and mining extraction, from hydroelectric dams and reservoirs, from air pollution, increased tourism, and radiation from ozone depletion.

Chapter 17: Environmental Hazards and Human Health

1. Major types of hazards faced by humans include cultural, physical, chemical, and biological hazards. 2. Toxicology is the scientific field that measures the degree of harm a hazardous agent can cause. Scientists measure toxicity based on dosage, solubility, persistence, bioaccumulation, biomagnification, and chemical interactions. 3. Chemical hazards include agents that are flammable or explosive, damage or irritate lungs or skin, interrupt oxygen uptake, and cause allergies. Chemical hazards are defined by their toxicity, the person's acute and chronic reactions to it, and its pervasiveness in the environment. 4. The types of disease threatening people in developing countries are primarily infectious diseases of childhood, while those threatening people in developed countries tend to be chronic diseases of adults, such as heart disease, stroke, cancer, and respiratory conditions. 5. Risks can be estimated, managed, and reduced by identifying hazards, evaluating related risks (risk assessment), ranking risks (comparative risk analysis), determining alternative solutions, making decisions about reducing risks (risk management), and informing decision-makers about risk (risk communication).

Chapter 15: Nonrenewable Energy

1. Nonrenewable energy sources are obtained from the earth's crust and primarily from carbon-containing fossil fuels. They are non-renewable because they have finite lifetimes, but the different forms of non-renewable fuels (e.g., oil, coal, uranium) have highly variable lifetimes. 2. The advantages of oil include low cost, high net energy yield, easy transportation, low land use, well-developed technology, and efficient system of distribution. Disadvantages include need for a substitute discovery; low price encourages waste, air pollution, and water pollution. Oil supplies are estimated to be approximately 80% depleted between 2050 and 2100. 3. The advantages of natural gas include plentiful supplies, high net energy yield, low cost, less air pollution than oil, moderate environment impact, and easy transport. Disadvantages include the fact that it is a nonrenewable resource, comparative high cost, release of carbon dioxide when burned (although lower than other fossil fuels such as coal), leaks, and requirement for pipeline infrastructure for transport. 4. The advantages of coal include plentiful supplies, high net energy yield, low cost, well-developed technology, and air pollution can be partially managed with appropriate technology. Disadvantages include very high environmental impact, land disturbance, air and water pollution, threat to human health, high carbon dioxide emissions, and release of radioactive particles and mercury. 5. The advantages of nuclear power include large fuel supply, low environmental impact, low carbon dioxide emissions (none from energy generation), moderate land disruption and use, and low risk of accidents. Disadvantages include high cost, low net energy yield, high environmental impact in case of accident, catastrophic accidents, long-term storage of radioactive waste, and potential for nuclear proliferation.

Chapter 2: Science, Matter, Energy, and Systems

1. Science is an attempt to discover the natural world's order and use that in describing what is likely to happen in nature. Scientists ask a question or identify a problem to investigate. Then, they collect scientific data through observation and measurement. Experiments may be used to study specific phenomena. 2. The major components of complex systems are environmental inputs, flows within the system, and outputs to the environment. 3. The basic forms of matter are elements and compounds. Matter is useful to us as a resource because it makes up every material substance. 4. The major forms of energy are kinetic energy and potential energy. Energy is useful to us as a resource because it moves matter. 5. The Law of Conservation of Matter states that matter is neither created nor destroyed when a physical or chemical change occurs. 6. Matter can undergo three types of nuclear changes: natural radioactive decay, nuclear fission, and nuclear fusion. 7. The First Law of Thermodynamics states that in all physical and chemical changes, energy may be converted from one form to another but it is neither created nor destroyed. The Second Law of Thermodynamics states that when energy is changed from one form to another, there is always less usable energy left. 8. These laws, then, show that energy goes from a more useful to a less useful form and that high-quality energy cannot be recycled. So, the quality as well as the quantity of our resources and our environment will be reduced.

Chapter 21: Solid and Hazardous Waste

1. Solid waste is any unwanted or discarded material that is not a liquid or a gas. Thirty-three percent of the world's solid wasted is produced by one country—the United States—which represents 4.6% of the world's population. 2. Waste management, waste reduction, reduced usage, and pollution prevention can all be used to reduce, reuse, or recycle solid waste. 3. The advantages of burning waste include reducing trash volume, minimizing the need for landfills, and lowering water pollution. The disadvantages include high cost, air pollution, producing toxic ash, and encouraging waste production. The advantages of burying wastes include safety, wastes can be retrieved, ease of application, and low cost. Disadvantages include leaks and spills, existing fractures or earthquakes can cause waste escape, and encouraging waste production. 4. Hazardous waste is any discarded solid or liquid material that is toxic, ignitable, corrosive, or reactive enough to explode or release toxic fumes. We can use a pollution prevention or waste reduction approach to reduce production and manage existing hazardous waste mostly by burning or burying it. 5. Physical methods such as filtering and distilling, chemical reactions, bioremediation, phytoremediation, and plasma torches can all be used to detoxify hazardous waste. 6. Advantages of burning hazardous waste include reducing waste volume, minimizing the need for storage space, and lowering water pollution. The disadvantages include air pollutants such as toxic dioxins and production of toxic ash that must be stored. Advantages of burying hazardous waste include safety, wastes can be retrieved, ease of application, and low cost. Disadvantages include leaks and spills, existing fractures or earthquakes can cause waste escape, and encouraging waste production. 7. The United States regulates hazardous waste through the 1976 Resource Conservation and Recovery Act, which was amended in 1984.

Chapter 14: Geology and Nonrenewable Mineral Sources

1. Tectonic plates have rearranged the earth's continents and ocean basins over millions of years like pieces of a gigantic jigsaw puzzle. The plates have three types of boundaries. Natural hazards such as earthquakes and volcanoes are likely to be found at plate boundaries. 2. Rocks are large, natural, continuous parts of the earth's crust. There are three major types of rocks: igneous, sedimentary, and metamorphic. Rocks are affected by changes of physical and chemical conditions that change them over time from one type to another through the rock cycle. 3. Mineral resources include all naturally occurring materials that are used for human purposes. These resources include metals and fossil fuels, and the distribution of these materials across the earth's surface is highly variable leading to concentrated deposits in certain areas (e.g., diamonds in Angola or oil in Saudi Arabia). This unequal distribution can lead to conflicts and has implications for national security and international relations. 4. Mineral resource extraction methods include surface and subsurface mining. Surface mining types are open-pit, strip, contour strip mining, and mountain removal. Resource extraction technologies are constantly changing but always create some environmental disturbance. In some cases, the environmental impacts of mineral extraction can be severe. 5. All mineral resources are finite but the lifetime of materials varies with the rate of use and the size of the resource. Recycling of mineral resources leads to a longer depletion time compared to those that cannot be reused or recycled. 6. Scientists are developing new types of materials as substitutes for many metals. Mineral conservation and more sustainable manufacturing processes are helping to decrease our use and waste of such resources. Recent, dramatic increases in the cost of minerals are driving aggressive recycling of many resources and particularly metals (e.g., copper).

Chapter 16: Energy Efficiency and Renewable Energy

1. The advantages of improving energy efficiency include benefits to the environment, people, and the economy through prolonged fossil fuel supplies, reduced oil imports, very high net energy yield, low cost reduction of pollution, and improved local economies. 2. The advantages of solar energy include reduction of air pollution, reduction of dependence on oil, and low land use. Disadvantages include production of photocells results in release of toxic chemicals, life of systems is short, need backup systems, and high cost. 3. The advantages of hydropower include high net energy yield, low cost electricity, long life span, no carbon dioxide emissions during operation, flood control below dam, water for irrigation, and reservoir development. Disadvantages include high construction cost, high environmental impact, high carbon dioxide emissions from biomass decay, flooding of natural areas, conversion of land habitats to lake habitats, danger of dam collapsing, people relocation, limits fish populations below dam, and decrease flow of silt. 4. The advantages of wind power include high net energy yield and efficiency, low cost and environmental impact, no carbon dioxide emissions, and quick construction. Disadvantages include need for winds and backup systems, high land use, visual and noise pollution, interfering with bird migrations. 5. The advantages of biomass include large potential supplies, moderate costs, no net carbon increase, and use of agricultural, timber, and urban wastes. Disadvantages include nonrenewable resource if not harvested sustainably, moderate to high environmental impact, low photosynthetic efficiency, soil erosion, water pollution, and loss of wildlife. 6. The advantages of geothermal energy include very high efficiency, low carbon dioxide emissions, low cost and land use, low land disturbance, and moderate environmental impact. Disadvantages include scarcity of suitable sites, potential depletion, moderate to high air pollution, noise and odor, and high cost. 7. The advantages of hydrogen gas include the fact that it can be produced from water, the low environmental impact, no carbon dioxide emission, competitive price, ease of storage, safety, and high efficiency. Disadvantages include energy needed to produce the fuel, negative energy yield, nonrenewable, high cost, and no fuel distribution system exists. 8. The advantages of using smaller, decentralized micropower sources include size, fast production and installation, high energy efficiency, low or no CO2 emissions, low air pollution, easy repair, reliable, increased national security, and easily financed. 9. We can improve energy efficiency by increasing fuel efficiency standards, large tax credits for purchasing energy efficient cars, houses, and appliances, encouraging independent energy production, and increasing research and development.

Chapter 8: Aquatic Biodiversity

1. The basic types of aquatic life zones are the surface, middle, and bottom layers. The life in aquatic life zones is influenced by temperature, access to sunlight for photosynthesis, dissolved oxygen content, and availability of nutrients. 2. The major types of saltwater life zones are the coastal zone and the open sea. Coastal ecosystems contain estuaries, wetlands, and mangrove swamps. Because of their close proximity to man's activities, they are under constant strain from water pollution, industrial run-off, construction and soil erosion, agricultural pesticides flowing into rivers and streams, and aquaculture farming. The open sea contains the euphotic zone, which is the lighted upper zone of the ocean. The bathyal zone is in the middle and is dimly lit. The lowest zone, the abyssal zone, is dark and very cold. But all are being affected by human activities: over-harvesting, oil spills, filling-in of wetland areas, agricultural and industrial development and pollution, rising sea levels, and careless fishing/trawling techniques. 3. The major types of freshwater life zones are lakes, wetlands, and rivers. Human activities, such as dams or canals; flood control levees and dikes; and industrial, urban, agricultural pollutants all affect the flow and health of freshwater zones. Much of U.S. wetlands have been drained and filled to farm and/or to construct homes and businesses. These actions increase flood potential and encourage droughts. People overfish the waters; pollute the streams, rivers, and lakes; and dump excessive nutrients from pesticides and waste lots into the fresh water sources. 4. We must protect aquatic life zones from the pollutants, water controls, and deterioration that we press upon them every day.

Chapter 19: Climate Disruption and Ozone Depletion

1. The earth's average surface temperature and climate has changed in the past. The changes include prolonged periods of global cooling and global warming. 2. There is a natural greenhouse effect in the earth's atmosphere caused by the presence of gases that trap long-wave radiation (water, CO2, and others). Human emissions of carbon dioxide, methane, and nitrogen oxide increase the concentrations of greenhouse gases and cause additional warming of the earth's surface. 3. Factor's influencing changes of earth's average surface temperature include changes in the solar output, the earth's reflectivity, the ability of oceans and land ecosystems to store carbon dioxide, the ocean currents, the average sea level, cloud cover, and air pollution. 4. Possible effects from a warmer earth include shifts in plant-growing areas, crop yields and pests, extinction of some species, loss of habitats, prolonged heat waves and droughts, increased flooding, changes in water supplies, decreased water quality, changes in forest composition, increased fires, rising sea levels, beach erosion, contamination of aquifers, spread of tropical diseases into temperate zones, increased respiratory diseases and allergies, increased deaths, and migration. 5. To prevent or slow global warming we can limit fossil fuel use, shift from coal to natural gas use, place energy efficient technologies in developed and developing countries, improve energy efficiency, shift to renewable resources, reduce deforestation, use sustainable agriculture, limit urban sprawl, reduce poverty, and slow population growth. 6. Human activities that cause ozone depletion include emissions of chlorofluorocarbons, methyl bromide, hydrogen chloride, carbon tetrachloride, methyl chloroform, and others. The stratosphere contains high concentrations of ozone that absorbs UV radiation as it enters the atmosphere. Ozone depletion can lead to sunburns, cataracts, skin cancers, immune suppression, and reduced crop yields, particularly in the Southern Hemisphere. Note that students often confuse tropospheric ozone (air pollution) and stratospheric ozone (UV absorption), and confuse ozone depletion with global warming.

Chapter 18: Air Pollution

1. The layers of the atmosphere are the troposphere, stratosphere, mesosphere, and thermosphere. 2. Major classes of air pollutants include carbon, sulfur, and nitrogen oxides, volatile organic compounds, suspended particulate matter, photochemical oxidants, radioactive substances, and hazardous chemicals that can cause health problems. Primary sources of these pollutants include cars, industry, and natural phenomena such as volcanic eruptions. 3. The two types of smog are the photochemical and the industrial, or gray-air, smog. 4. Acid deposition includes wet deposition of acidic rain, snow, fog, and cloud vapor with pH less than 5.6, and dry deposition of acidic particles. Major sources of acid deposition are nitrogen oxides produced during fossil fuel combustion and sulfur oxides produced primarily from coal-fired power plants. 5. Harmful effects of air pollution include various respiratory diseases, premature deaths, damage to plants, and materials such as buildings, cars, statues, etc. 6. We can reduce air pollution by reducing emission through the use of low-sulfur coal, shifting to less polluting fuels (e.g., coal to natural gas), removal of pollutants after combustion or lower emissions through the use of mass transit or alternative transportation, improving fuel efficiency, and tax incentives.

Chapter 25: Environmental Worldviews, Ethics, and Sustainability

1. The planetary management worldview is the human-centered environmental worldview that guides most industrial societies. This worldview has as a key component the idea that humans are the most important species and that the earth should be managed for our benefit. Variations include the no-problems school, the free-market school, the responsible planetary management school, the spaceship school, and the stewardship school. 2. Life-centered and earth-centered worldviews include environmental wisdom worldview, species centered, biosphere centered, and ecosystem centered. All of these worldviews have far less emphasis on management for human benefit alone and all are far less human-centered. 3. Education is an important component of living sustainably. Education includes understanding ecosystems, developing environmental literacy, and viewing the earth as a complex, interconnected system. 4. We can live sustainably through pollution prevention, waste prevention, species protection, and environmental restoration.

Chapter 5: Biodiversity, Species Interactions, and Population Control

1. Two major factors affect the number of species in a community: the latitude in terrestrial communities and salinity/nutrients in aquatic systems. 2. Species play different roles in a community. Native species sustain the ecosystem in which they are a part. Some nonnative species will crowd out native species. Indicator species alert us to harmful changes in the community. Keystone species play ecological roles in the specific community: they may assist in pollination help regulate populations. Foundation species affect the community's habitat to benefit other species. 3. Species interact with each other in these different ways: interspecific competition, predation, parasitism, mutualism, and commensalism. 4. As environmental conditions change, one species may be replaced by other groups of species. This gradual change in the composition of species in a given area is called ecological succession. 5. A community has three aspects of sustaining itself: its persistence, the ability to resist being altered, its constant population, and its resilience in repairing damage. High biodiversity may give a community some edge in surviving, but we do not know this for certain.

Chapter 20: Water Pollution

1. Water pollutants include infectious agents from human or animal wastes; oxygen-demanding wastes from sewage, paper mills, and food processing; inorganic chemicals from surface runoff, industrial effluents, and household cleaners; organic chemicals from oil, plastics, pesticides, and detergents; sediment from erosion; and thermal pollution from power plant cooling. 2. Water pollution problems in streams and lakes relate to chemical and biological pollutants, with the greater problems being cultural eutrophication. 3. Groundwater pollution is caused by leaks from waste ponds and underground storage tanks, chemical dumping or spilling, surface runoff, and fertilizers. It can be prevented by finding substitutes for toxic chemicals, installing monitoring wells near landfills and underground tanks, requiring leak detectors on underground tanks, banning hazardous waste disposal in landfills and injection wells, and storing harmful liquids in aboveground tanks. 4. Water pollution of oceans relates to nitrogen oxide from industry and cars, heavy metals from effluents, toxic sediment, sewage, runoff of pesticides, manure, fertilizers, and red tides from excess nitrogen. 5. Reduction or prevention of water pollution can be achieved through reduction of use of toxic pollutants, banning of ocean dumping of sludge, protection of sensitive areas from oil drilling and oil transport, regulation of coastal development, and regulation of sewage treatment. 6. The U.S. Safe Drinking Water Act of 1974 requires that drinking water contain less than the maximum contaminant levels for any pollutants that may have adverse effects on human health. Restructuring of water treatment systems, enforcing current regulations, banning the use of lead in new structures, and chemical tests and biological indicators can be used to make drinking water safer.