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10e Practice Quiz Answers
Introduction: Learning to Learn
1. Depends on the individual student.
2. Be honest about your habits. Make a study schedule and stick to it. Allow enough time for
sleep, meals, exercise and recreation so you are rested, healthy, and efficient. Plan some study
times when you’re fresh. Divide your work into reasonable sized segments. Give yourself
adequate time. Use a calendar to keep track of assignments. (p 4)
3. Visual learner, Verbal learner, Logical learner, Active learner. Which fits best depends on the
individual (p 4).
4. SQ3R means Survey, Question, Read, Recite, and Review. (p 5)
5. Ten steps in critical thinking are:
What is the purpose of my thinking?
What precise question am I trying to answer?
Within what point of view am I thinking?
What information am I using?
How am I interpreting that information?
What concepts or ideas are central to my thinking?
What conclusions am I aiming at?
What am I taking for granted; what assumptions am I making?
If I accept the conclusions, what are the implications?
What would the consequences be, if I put my thoughts into action? (Table I.4, p 8)
6. Attributes or dispositions in critical thinking:
Skepticism and independence: Question authority. Don’t believe everything.
Open-mindedness and flexibility: Consider different points of view; try arguing from a different
perspective than your own.
Accuracy and orderliness: Strive for as much precision as the subject warrants; deal
systematically with parts of an issue; be disciplined in your standards.
Persistence and relevance: Stick to the point; don’t allow diversions or biases to lead you astray.
Contextual sensitivity and empathy: Consider the total situation; imagine being in someone
else’s place.
Decisiveness and courage: Draw conclusions and take a stand when the evidence warrants.
Humility: Realize that you may be wrong. (p 8-9)
7. Words that introduce premises include: as, because, assume that, given that, since, whereas,
and we all know that. Words that indicate a conclusion include: and, so, thus, therefore, it
follows that, consequently, the evidence shows, and we can conclude that. (p 9)
8. An Ad hominem attack criticizes the opponent rather than the logic of an argument. An appeal
to ignorance argues that because some facts are in doubt, a conclusion is impossible. (p 10)
9. Some questions about information on the internet (among many):
What information do you have about this issue?
Why might this person or group be taking this stand?
What kind of language is used? Is it moderate or inflammatory?
Is it a well-reasoned analysis?
Is the purpose to inform or outrage you?
What other sources are quoted or what links are provided? (p 11)
Chapter 1
Our environment includes both the natural world and the “built” or technological, social, and
cultural world in which we live. Environmental science is the systematic study of our
environment and our proper place in it.
The four main stages of conservation history (and leaders in each) are: Pragmatic resource
conservation (Theodore Roosevelt, Gifford Pinchot); Ethical and moral preservation (John
Muir); Modern environmentalism (Rachael Carson, David Brower, Wangari Maathai); and
Global environmentalism (Yu Xiaogang, Dai Qing, and Muhammad Yunis).
Major environmental dilemmas include human population growth that threatens to overwhelm
our resource base, water shortages and lack of sanitation that affect one to three million people,
land degradation that threatens continued food production, overdependence on fossil fuels that
are releasing “greenhouse gases” and causing global climate change, air pollution that may kill 3
million people per year, and biodiversity losses that could disrupt life-supporting ecological
processes.
Poor countries, such as China, are turning to renewable energy sources; many cities are cleaner
and more livable than they were a century ago; population growth is slowing; diseases are being
vanquished while millions of people have improved water supplies and modern sanitation;
democracy and international cooperation are more prevalent now than ever before.
Extreme poverty is defined as living on less than $1U.S. per day. We should care because people
at this level usually suffer a low quality of life and because there is a strong link between
poverty, environmental degradation, and insecurity for us all.
The difference in per capita income, infant mortality, and CO2 production between the poorest
and richest countries is 100X, 20X and 65X respectively.
If all the 1.3 billion people in China were to try to live at the same level of affluence and comfort
using the same technology and energy supplies that we enjoy now in the richer countries of the
world, the environmental consequences would be disastrous.
Sustainable development means meeting the needs of the present without compromising the
ability of future generations to meet their own needs. Another way of saying this is that we can’t
deplete resources or create wastes faster than nature can recycle them.
It would it take roughly $135 billion per year (or only about 0.7 percent of our income) to
eliminate acute poverty and ensure basic human needs for everyone.
Indigenous people who remain in traditional homelands possess valuable ecological wisdom and
remain the guardians of little-disturbed habitats that are the refuge for rare and endangered
species and relatively undamaged ecosystems.
Chapter 2
Science is a process for producing knowledge methodically and logically based on precise
observations of natural phenomena.
In science, a theory is not a speculative explanation unsupported by facts but rather a consensus
by a majority of experts that an overwhelming body of evidence and experience requires a
particular explanation as the closest approximation of the truth available.
Probability is the likelihood that something is true or will happen. A dependent variable (or
response variable) is one that is affected by other factors. An independent variable (or
explanatory variable) affects the properties of other variables. A model is a simple representation
of something.
Deductive reasoning is logical reasoning from general principles to specific examples.
Inductive reasoning is logical reasoning from specific examples to general principles.
Your diagram should look very much like fig 2.1 o p 35.
A scientific consensus is a general agreement among informed scholars. It’s important because
this interactive process is how scientific theories are established.
A positive feedback loop is a series of reactions or relationships in which a flow or change in one
state creates conditions that further enhance that flow or change.
An anthropocentric viewpoint places humans at the center of importance. A biocentric viewpoint
accords living organisms as the center of importance. A utilitarian viewpoint seeks the greatest
good for the greatest number for the longest time. A preservationist viewpoint seeks to preserve
nature as much as possible.
Stewardship implies taking care of creation. It is often inspired by religious beliefs.
Environmental justice combines civil rights with environmental protection to demand a safe,
healthy, life-giving environment for everyone.
Chapter 3
1. Elements are substances that cannot be broken down into simpler forms by ordinary chemical
reactions. Atoms are the smallest particles that exhibit the characteristics of an element. (p 50)
2. Under ordinary circumstances matter is neither created nor destroyed, but recycled over and
over again. Some of the carbon atoms in our bodies have undoubtedly been part of prehistoric
organisms, possibly including dinosaurs.
3. Characteristics of water include: polar (making it a good solvent), liquid under normal
conditions, cohesive (capillary action), expands when it freezes, high heat of vaporization
(makes a good way to move heat), and high specific heat (keeps temperatures moderate).
4. Matter is always recycled or reused in ecosystems, while energy is always degraded and
dissipated so that living systems need a constant supply of external energy.
5. Energy that is diffuse, dispersed, and low in temperature is considered low-quality. Highquality energy is intensely concentrated, high temperature and useful to do work. The energy
stored in the oceans is immense but diffuse, low-temperature, and hard to capture, so it is
considered low-quality.
6. For most living organisms the ultimate source of energy is sunlight. As this energy is captured
by photosynthesis and used for metabolic processes, it is gradually degraded in each step in these
processes and lost as heat, which ultimately radiates off into space.
7. This question isn’t addressed specifically in this chapter, but there is a discussion of how high
and low temperatures are detrimental to organisms on p 59. Large organisms typically have less
surface area per unit volume than small organisms, and therefore, don’t dissipate heat as
effectively.
8. Photosynthesis captures solar energy and stores it in chemical bonds that hold organic
molecules together and create biological structures. Respiration breaks down those bonds. The
materials (minerals) contained in the organic molecules are released and made available for
further reactions. Some of the energy captured by photosynthesis is degraded each time it is used
for metabolism or chemical synthesis and lost as heat. Eventually, all the solar energy captured
by living systems will be irradiated back to space.
9. Carbon and nitrogen fixation refer to the transformation of gaseous forms of these elements
(CO2 and NOx) into less mobile, more useful forms that can be used by living organisms to build
organic molecules and complex structures.
10. Following the second law of thermodynamics, much less food energy is available in each
higher trophic level in an ecosystem than in the level on which it feeds. Every time energy is
transferred and transformed in living processes, some of that energy is degraded and lost as heat.
Furthermore, some of the food eaten by organisms is undigested and doesn’t provide useable
energy. Much of the energy that is absorbed is used in the daily processes of living and thus isn’t
stored as biomass that can be eaten. Finally, predators can’t eat all their prey, or there won’t be
any reproduction of the prey and there will be nothing to eat in the future.
11. A species refers to all the organisms of the same kind that are genetically similar enough to
breed in nature and produce live, fertile offspring. It is important to recognize and understand
species because they often carry out different ecological roles. Ecologists study the interactions
of species at different levels of ecological organization.
Chapter 4
1. Highly specialized species often have very narrow limits of tolerance for one or more
environmental factors. This can sharply limit their distribution, as it the case for saguaro cacti,
which cannot survive in areas in which temperatures drop below freezing for more than a few
hours at a time. A graph of tolerance of these cacti to a temperature gradient would have a very
sharp cutoff at about zero Celsius. In contrast, generalist species such as starlings and cowbirds
can survive in a wide range of environmental conditions. Their tolerance curve for any of these
factors would likely be very broad.
2. The answer to this question depends on the location of the individual student. It should,
however, show some familiarity with the ecological concepts of productivity, diversity,
complexity, resilience, and structure as well as some understanding of local ecological
conditions.
3. Selective pressure is the effect on fitness (or reproductive success) exerted on organisms by
environmental factors. An example in your neighborhood might be evolution of traits that allow
certain species to survive temperature extremes, water stress, or availability of unique feeding or
habitat conditions.
4. A keystone species plays a critical role in a biological community out of proportion to its
abundance.
5. Intraspecific competition is the struggle for resources (growing space, sunlight, water,
nutrients, food, or mates) between members of the same species. Competitive exclusion states
that two species won’t occupy the same niche for very long, but members of the same species do
continue to compete for the same resources as long as they remain a single species.
6. Predators generally feed on the least fit members of a prey species. Thus, those members of
the species best able to survive predation will be the most successful in reproduction and their
offspring (and genes) will gradually come to dominate the population. As prey develop defenses,
they exert selective pressure on their predators to overcome those defenses. Thus, both predators
and prey co-evolve or shape each other.
7. Organisms in competition for scarce resources (whether with members of their own species or
others) may fight for access to the resource. More often, however, they change the timing or the
way they use those resources. Feeding, nesting, resting, growing toward the sunlight or carrying
out other activities in ways that minimize conflict and competition can allow an individual to
survive and pass its genes along to offspring.
8. Secondary succession occurs when an existing community (such as a forest) is disrupted by
destructive forces (such as fire). Pioneer species, such as mosses and lichens, that can migrate
into the area and survive harsh conditions and lack of resources are usually the first to grow in
the disturbed area. As organic material accumulates and some of the harshest conditions are
ameliorated, other species such as grasses, bushes, and eventually trees—together with the
animals and microbes that live with each type of plant community—occupy and modify the
habitat. Eventually, given fairly stable environmental conditions, a “climax” community may
develop that resists further change.
9 Tropical forests (moist ones), Estuaries, and coral reefs are roughly equal in biomass
accumulation. Deserts and open oceans are the least productive. The unit of measurement is
1,000 kcal/m2/year.
10. When new species are introduced into an unfamiliar habitat or community, they can cause
severe ecological damage. Organisms that may be held in check by diseases, predators, or
environmental conditions in their native habitat can become super-aggressive invasive species
when freed from these restraints. They may prey on or out of native species and drive them into
extinction. Weedy species, generalists and others with a wide tolerance range for environmental
conditions are the most likely to become problematic exotics.
Chapter 5
1. Grasslands occur where there is enough rain to support abundant grass, but not enough for
forests. Fire, periodic drought and abrupt temperature changes are important factors in
preventing tree and shrub growth in grasslands. The deep roots of many grass species help them
survive these stresses and re-sprout quickly after disturbance.
2. Taiga is a Russian name for the extreme, ragged edge of the boreal conifer forest. It occurs
around the world at northern latitudes (particularly Siberia, Scandinavia, Canada, and Alaska)
where cold temperatures limit tree growth. Because plant growth is slow in this climate this
biome recovers slowly from disturbance such as logging.
3. Broad-leaved deciduous forests occur in areas with warm summers, cool to cold winters, and
plentiful rainfall. They generally have rich, deep soils and fewer insect pests and disease
problems than tropical rainforests. These conditions make this biome highly suitable for
agriculture and human habitation. The soils of tropical rainforest, in contrast, tend to be thin, low
in nutrients, and unfavorable for cultivating most crops.
4. Depends on where you live.
5. Swamps are wetlands with trees. Marshes are wetlands without trees. Bogs are areas of
saturated ground that are generally composed of deep layers of undecayed vegetation called peat.
Fens are similar to bogs except that while bogs are fed mostly by precipitation and tend to be
acidic, fens are fed by mineral-rich groundwater
6. Tropical rainforests occur in hot climates. Taiga occurs in cold climates. Temperate rainforests
occur in wet climates. Deserts occur in dry climates.
7. Vertical stratification is a key feature of aquatic ecosystems. Light and temperature decreases
rapidly with depth, while pressure increases dramatically. Organisms that survive at great depths
must be adapted to survive these conditions. Deep-ocean species often grow slowly, while those
living in the warm, sunny, near-surface communities such as coral reefs and estuaries are among
the world’s most biologically productive.
8. Coral reefs consist of colonies of minute, colonial animals that live symbiotically with
photosynthetic algae. The calcium-rich skeletons of the corals provide structure to the reef,
which provides habitat for a diverse community. Mangrove forests grow in shallow salt water
along calm, tropical coastlines. They are critical nurseries for many marine species. Estuaries are
bays where rivers empty into the sea, mixing fresh and salt water. Rivers provide nutrient-rich
sediment that supports prolific plant and animal life in the estuary. Barrier islands are low,
narrow, sandy islands that form parallel to a coastline. They protect brackish inshore lagoons and
salt marshes from storms.
Chapter 6
1. Overfishing
2. Exponential growth is a constant rate of increase per unit of time. This rate of increase can be
expressed as a constant fraction or exponent by which the existing population is multiplied.
Arithmetic growth increases by a constant amount per unit of time. When graphed, arithmetic
growth is represented by a straight line, while exponential growth is shown as a rapidly
increasing curve.
3. At three percent annual growth, any size population (whether 100,000 or 10 million) will
double in approximately 23 years.
4. Environmental resistance is the sum of the external factors that tend to reduce population
growth rates.
5. Fecundity is the physical ability to reproduce, while fertility is a measure of the actual number
of offspring produced.
6. Some organisms such as whales, bears, and elephants tend to live their full physiological life
span if they reach maturity and then die in old age. In some species, such as sea gulls,
survivorship is unrelated to age and individuals die randomly. Many songbirds, rabbits, deer, and
humans in developing countries have high death rates early in life and again when they reach old
age and are susceptible to external factors such as predation, disease, starvation or accidents.
Finally, those prey organisms at the bottom of food webs or those especially susceptible to
mortality early in life tend to die at an early age. They produce a very large number of offspring,
only a few of which survive to adulthood. Those lucky individuals, however, generally live most
of the maximum life span for the species.
7. Interspecific population factors include predation, mutualism, and commensalisms.
8. Island biogeography is the study of biodiversity in small, isolated patches, such as islands. It’s
important because as habitats become fragmented and isolated they act as islands, and the
processes of colonization and extinction seen on islands becomes more important.
9. In a large population, genetic variation tends to persist because factors such as mutation rates,
mating choices, and gene flow (or lack thereof) make little difference in a large gene pool. In
small populations, these factors become more important.
10. The figure should look something like fig 6.14, on p 128. Source populations provide excess
individuals, which emigrate to and colonize; or add fresh genes to sink populations where
population decreases would occur if it were not for this emigration.
Chapter 7
1. The human population reached 1 billion in 1804. Diseases, famines, wars, and social factors
restricted population growth before that time. In the past two centuries increased commerce and
communications, agricultural developments, better power sources, health care, and hygiene all
played a role in rapid human population growth.
2. More people can mean larger markets, more workers, better ideas and technologies along with
efficiencies of scale in mass production that could overcome natural resource limitations.
3. Some economists, such as Julian Simon, believe that humans are the “ultimate resource,” and
that there is no evidence that pollution, crime, unemployment, crowding, the loss of species, or
any other resource limitation will worsen with population growth (see answer to question 2).
4. As figure 7.5 shows, the vast majority of population growth in this century is expected to be in
the less-developed regions of the world. Unmet needs for education, health care, civil rights, and
family planning, together with cultural, religious, and economic factors are the driving forces
behind this population growth.
5. The crude birth rate is the number of births in a year, per thousand persons. The total fertility
rate is the number of children born to an average woman in a population during her entire
reproductive life. The crude death rate is the number of deaths in a year per thousand persons.
Zero population growth occurs when births plus immigration in a population just equal deaths
plus emigration. In most developed countries this rate is usually about 2.1 children per couple
because some people are infertile, have children who do not survive, or choose not to have
children.
6. Life span is the maximum age to which a species is known to survive. Life expectancy is the
average age that a newborn infant can expect to attain in any given society.
7. The dependency ratio is the number of nonworking people compared to the workers in a
population. Those individuals under age 15 or over age 65 are generally considered to be
dependent on others (to some degree) for support. The growing number of retired persons and
shrinking numbers of workers in the United States (and other developed countries) may increase
the dependency ratio.
8. Children can be a source of pleasure, pride, and comfort. They may support elderly parents,
provide status in society, express parental creativity, help support the family, and do important
chores.
9. A demographic transition is usually caused by development that brings better jobs, medical
care, sanitation, and a generally improved standard of living.
10. Among the choice for birth control are abstinence, mechanical barriers (condoms, etc),
surgical methods (sterilization, tubal ligation, vasectomies), chemicals that prevent release of
sperm or eggs (the pill, etc), physical barriers to embryo implantation (IUD), and abortion.
Chapter 8
1. Guinea worms are parasites acquired by drinking polluted water containing copepods infected
with worm larvae.
2 The WHO defines health as a state of complete physical, mental, and social well-being, not
merely the absence of disease or infirmity. Disease is an abnormal change in the body’s
condition that impairs important physical or psychological functions.
3. Pneumonia, diarrhea, TB, measles, and Malaria were among the worst infectious diseases of
the past. The world is now undergoing a dramatic epidemiological transition. Chronic conditions,
such cardiovascular disease and cancer, no longer afflict only wealthy people. Diseases such as
depression and heart attacks that once were thought to occur only in rich countries are rapidly
becoming the leading causes of disability and premature death everywhere and will probably be
the leading cause of disability by 2050.
4. Emergent diseases are those never known before or that have been absent for at least 20 years.
Examples include SARS, AIDS, West Nile Virus, and Ebola.
5. Microbes acquire antibiotic resistance when random mutations make a few cells resistant.
When challenged by low doses of antibiotics some of these cells survive and reproduce,
gradually coming to dominate the population. Sexual reproduction (conjugation) or plasmid
transfer moves these genes for resistance to other species. We should stop treating domestic
animals with sub-therapeutic doses. When people are taking antibiotics they should follow
doctor’s orders and take the complete sequence. Doctors shouldn’t prescribe antibiotics for viral
diseases, even when patients demand them.
6.Toxins are poisons that damage or kill living tissues. Even at low concentrations many toxins
are dangerous. Hazardous substances are dangerous because they’re flammable, explosive,
acidic, caustic, irritants, or sensitizers. Most hazardous materials can be diluted, neutralized, or
treated to make them less dangerous. All the substances listed in Table 8.2 are toxic.
Formaldehyde is a sensitizer. Although not mentioned specifically, gasoline, dynamite, sulfuric
acid and lye also are examples of hazardous materials.
7. Water soluble chemicals move rapidly and widely throughout the environment and have rapid
access to cells once they enter the body. Oil soluble chemicals generally need a carrier to move
through the environment and through the body, but can cross cell membranes easily. They also
are stored in fat deposits and can accumulate through food chains very effectively. Substances
that are very stable can persist in the environment for long times. They often accumulate in food
webs and can reach toxic concentrations in top predators.
8. Acute toxic effects are caused by a single exposure to the toxin and result in an immediate
health crisis. Chronic effects are long lasting, perhaps even permanent. They may be caused by a
single dose or by repeated sublethal exposures.
9. Carcinogens cause cancer. Mutagens cause mutations in genetic material (DNA). Teratogens
cause birth defects. Neurotoxins damage nerves.
10. Your chance of dying from smoking is 1 in 4, driving a car (from an automobile accident) is
1 in 100, and drinking water with the EPA maximum level of trichloroethylene is 1 in 10 million.
These are clearly unequal risks but because some people like to smoke or ride in a car they
regard these risks as acceptable, while drinking contaminated water may be unacceptable.
Chapter 9
1. Currently, the UN estimates that 850 million people don’t have enough to eat. At least 6
million children under 5 years old die every year from hunger and malnutrition. Altogether as
much as 60 percent of all premature deaths may be related to malnutrition.
2. Poverty is the greatest threat to food security, or the ability to obtain sufficient food on a dayto-day basis. The 1.5 billion people in the world who live on less than $1 per day all to often
can’t buy the food they need and don’t have access to resources to grow it for themselves.
3. Malnutrition is a nutritional imbalance caused by a lack of specific dietary components or an
inability to absorb or utilize essential nutrients. Obesity is generally considered to be a body
mass greater than 30 kg/m, or roughly 30 pounds above normal for an average person.
4. Where earlier USDA diet recommendations advised daily servings of meat, milk, grains and
fruit, current recommendations stress reduction in both red meat and refined sugars and starches,
including white rice, white bread, potatoes. Instead, the diet should emphasize unsaturated oils,
whole grains, vegetables, fruits, nuts, legumes, and fish.
5. The green revolution is cultivation of high-yield, genetically modified crops. The blue
revolution is aquaculture of fish and sea food.
6. Wild fish are threatened by overfishing and habitat destruction. Aquaculture could provide
needed animal protein with minimal environmental or social disruption if properly practiced.
7. Soil is a complex mixture of weathered mineral materials, partially decomposed organic
molecules, and a host of living organisms. Humus is a sticky, brown, insoluble residue from
plants and animals. Soil organisms help create the structure, fertility, and tilth of soil.
8. Four kinds of erosion are sheet, rill, gully, and streambank erosion. They are a problem
because they remove fertile soil and reduce crop production. They also introduce sediment and
pollution into water bodies, as well as dust and toxic chemicals into the air.
9. Genetic engineering involves removing genetic material from one organism and splicing it
into the chromosomes of another organism. (Biotechnology isn’t defined in this chapter,
although it is sometimes used interchangeably with genetic engineering). Genetic engineering
has the potential to greatly increase the quantity and quality of our food supply by building new
genes, even new organisms in the laboratory. There are worries, however, about irresponsible
use of this technology or unforeseen social or environmental consequences arising from it.
There’s no “right” answer to this question. It’s a matter of individual opinion. The answer
should, however, be supported by facts and logic rather than mere emotion.
10. Sustainable agriculture aims to produce food and fiber on a sustainable basis, and to repair
the environmental damage caused by destructive practices.
Chapter 10
1. A pest is an organism that reduces the availability, quality, or value of resources useful to
humans. A pesticide is a chemical that kills pests. A biocide kills all living things, an herbicide
kills plants, an insecticide kills insects, and a fungicide kills fungi.
2. DDT is dichloro-diphenyl-trichloroethane, a chlorinated hydrocarbon. It was considered a
magic bullet because it is cheap to make, long-lasting, and very effective in killing insects. Its
persistence leads to bioaccumulation in food webs and its hormone-altering properties make it an
ecologically disruptive pollutant.
3. The EPA estimates that 5.7 billion pounds (2.6 million metric tons) of conventional pesticides
are used worldwide each year. “Inert” ingredients are of concern because some of them are
highly toxic or hazardous.
4. Fumigants are small, volatile compounds like carbon tetrachloride that penetrate easily into
soil. Botanicals are natural organic pesticides extracted from plants. Pyrethrum, a complex
extracted from chrysanthemum, is an example. Chlorinated hydrocarbons are hydrocarbons to
which chlorine atoms have been attached. DDT is an example. Organophosphates are organic
compounds, such as parathion or malathion, with reactive phosphorus molecules that have been
added. They tend to be short-lived but highly toxic. Carbamates, or urethanes, such as carbaryl
are less toxic than organophosphates and less persistent than chlorinated hydrocarbons.
Microbial pesticides are living organisms such as Bacillus thuringinensis, or toxins derived from
them to control insects.
5. Endocrine disrupters are environmental chemicals that block or interfere with the functions of
vital endocrine hormones that regulate many important bodily functions, including reproductive
and immune systems. Several pesticides, PCBs, dioxins, chlorinated solvents, and metals are
known to have such effects.
6. Pesticides almost never kill all of a target species. The most resistant members of a population
survive pesticide treatment and produce more offspring like themselves with genes that enable
them to withstand further chemical treatment. Each subsequent treatment makes the population
more resistant while also removing predators and competitors that might have helped keep pests
in check. It takes increasing amounts of pesticides to control this resurgence, a problem known
as a pesticide treadmill.
7. Alternatives to synthetic pesticides include: Behavioral Changes, such as rotating crops or
mechanical cultivation. Biological Controls, such as predators or pathogens can eliminate pests
specifically without harming other organisms. Genetic engineering and crop breeding can create
crops that resist pests. IPM (see question 8) doesn’t eliminate pesticides completely, but reduces
amounts used.
8. Integrated pest management (IPM) is a flexible, ecologically based pest-control strategy that
uses a combination of techniques applied at specific times, aimed at specific crops and pests.
9. Children are more vulnerable to environmental toxins because, pound for pound, they drink
more water, eat more food, and breathe more air than adults. In addition, children play in the dirt
and put fingers and other objects into their mouths more than most adults. In addition, children
go through critical stages of growth and development in which they are especially sensitive to
toxins.
10. You can reduce pesticides in your food by: washing fresh fruits and vegetables thoroughly,
peel fruits and vegetables when possible, store food carefully, cook or bake foods that may have
pesticides.
Chapter 11
1. Taxonomists estimate that there are between 3 and 50 million species. The range is so great
because most species haven’t been identified and methods for estimating the remaining number
vary widely.
2. Invertebrates (animals without backbones, such as insects, sponges, clams, worms, etc)
probably make up 95% of all species.
3. Extinction is the elimination of a species. The natural rate of extinction is thought to be about
one species per decade.
4. The rosy periwinkle provides valuable anticancer drugs.
5. The chapter doesn’t mention many wild plants used as food. It does say that 80,000 edible
wild plants could be utilized by humans. Indonesia has 250 edible fruits, only 43 of which have
been cultivated widely. Mangosteens are an example.
6. HIPPO is an acronym devised by E. O. Wilson to summarize human threats to biodiversity. It
stands for Habitat destruction, Invasive species, Pollution, Population (human), and
Overharvesting.
7. We think that hundreds or even thousands of species and varieties are being lost every year. If
true, this would probably be many thousands of times the natural rate.
8. The U.S. Endangered Species Act lists endangered and threatened species and regulates a
wide range of activities that may harm those species. Violation of this act can result in
substantial fines, forfeiture of property, and imprisonment. The act designates critical habitat for
endangered species, and requires specific recovery plans. CITES is an international program that
regulates trade in living species but is difficult to enforce in developing countries.
9. Endangered species are in imminent danger of extinction. Some examples are California
condors and all tiger species. Threatened species are those likely to become endangered—at least
locally—in the foreseeable future. Some examples are gray wolves, brown (or grizzly) bears, and
many native orchids.
10. Gap analysis is an analysis of landscapes for unprotected areas rich in species. It often uses
geographical information systems (GIS) to store, manage, retrieve, and analyze data and create
maps showing gaps in biodiversity protection.
Chapter 12
1. In a closed canopy forest, tree crowns cover most or all of the ground. An old-growth forest
covers a large enough area and has been undisturbed b human activities long enough that trees
can live out a natural life cycle and ecological processes can occur in a relatively normal fashion.
2. More wood is consumed than steel and plastic combined. More than half the world’s
population depends on wood or charcoal for heating and cooking.
3. A debt-for-nature swap is one in which a nation’s debt is forgiven if it promises to protect
some natural area.
4. Fire suppression is controversial because it allows dead wood and underbrush to accumulate
and make it more likely that when a fire does start, it will be larger and more destructive. On the
other hand, property owners demand that they be protected from fire no matter how risky their
behavior.
5. No pastures aren’t always damaged by grazing. Careful stewardship can actually improve
pasture conditions. Overgrazing causes loss of beneficial species, introduction of invasives,
increasing runoff and sedimentation in waterways.
6. Rotational grazing involves confining animals so they graze a particular area thoroughly and
then moving them to a new area on a regular basis. It is much like the grazing patterns of bison
on the American plains or gnu on the African steppe.
7. Although this chapter no longer has a thorough discussion of park history, Yellowstone was
the established in 1972 as the first official National Park in the world. Yellowstone was
originally set aside to preserve natural oddities, such as geysers and hot springs. Now, it is
viewed as protecting biodiversity and wilderness and providing education as much as
entertainment.
8. For many species, survival can depend on preserve size, shape, and design. Protecting critical
habitat and linking areas with travel corridors is essential. Some species only prosper in core (or
deep interior) areas. Edges (boundaries between different habitats) are favored by some species
but avoided by others. Small, highly convoluted areas have a relatively large amount of edge.
Large, compact areas have more interior core.
9. Ecotourism is ecologically and socially sustainable tourism. It pays attention to environmental
and cultural impacts and tries to reduce them as much as possible.
10. A biosphere reserve includes local or indigenous people in its design. A central core region is
limited to scientific research, while a buffer zone allows ecotourism and research facilities, and a
multiuse peripheral zone can have permanent habitation and sustainable resource harvesting.
Most wilderness areas lack buffer or peripheral zones, while most wildlife refuges lack a true
core area.
Chapter 13
Levees now guide the river 50 km out into the Gulf, where sediment dumps off the coastal shelf,
rather than settling out along the coastal margin.
Coastal wetlands absorb storm surges from the gulf and reduce flooding in New Orleans
Ecological restoration attempts to repair damage we’ve caused to biotic communities using good
science and pragmatic approaches.
A strict definition of restoration would be to return a biological community as nearly as possible
to a pristine, predisturbance condition. Restoration in a broad sense has a more pragmatic goal to
simply to develop a self-sustaining, useful ecosystem with as many of its original elements as
possible.
Florida’s wading bird populations recovered when hunting was restricted, and New England’s
forests have regrown since farm fields were abandoned and logging has been regulated.
Historically savannas were created by periodic fires and grazing. It’s difficult to replace the
proper regime of these disturbances in human-occupied areas.
Fire not only kills many weedy species, but it also removes nutrients (especially nitrogen). This
gives native species, which are adapted to low nitrogen soils, an advantage.
The buffalo commons is a proposal that a large area of the Great Plains should be set aside as a
park or preserved populated by great herds of buffalo and other wildlife and home to native
people living a traditional lifestyle.
Water that once flowed into the Everglades has been diverted. More than 90 percent of the
wading birds have died. Now many cities that called for flood control are experiencing drought
during dry seasons.
Wetland mitigation is the process of replacing a damaged wetland with a substitute (and often
artificial wetland.
Chapter 14
1. The core, or interior, of the earth is composed of a dense, intensely hot mass of metal (mostly
iron) which is solid in the center but more fluid in the outer core. Surrounding the molten core is
a hot, pliable layer or rock called the mantle, which is less dense because it contains high
concentrations of lighter elements such as oxygen, silicon, and magnesium. The outermost layer
is the crust, a cool, lightweight, brittle layer of rock that floats on the mantle.
2. A mineral is a naturally occurring, inorganic, solid element or compound with a definite
chemical composition and a regular internal crystal structure. A rock is a solid, cohesive,
aggregate of one or more minerals.
3. Tectonic plates are huge blocks of the crust that break apart and float across the earth’s
surface. Their movement reshapes continents, raises mountains, results in volcanism and
earthquakes, changes climates, and may help explain mass extinctions of life.
4. The ring of fire around the Pacific Ocean is an area of subduction where movement of
adjacent tectonic plates causes earthquakes and newly melted crust erupts through volcanic
vents.
5. The rock cycle includes the formation of igneous rocks from molten magma, weathering of
existing rock and sedimentation to form sedimentary rock, and transformation of both igneous
and sedimentary rock by heat, pressure, and chemical modification to create metamorphic rock
types.
6. Aluminum, iron, copper, lead, nickel, zinc, mercury, and tin are among our most important
commercial metals. They come from a variety of places, but Russia, Canada, China, Australia,
and the United States are among the largest producers of crucial metals.
7. Nonmetal minerals include gemstones used in jewelry, sand and gravel used in construction,
silica sand used to make glass, limestone used to make cement, halite used for water softening
and melting ice, and gypsum used for plaster.
8. We recycle used beverage cans, automobiles, appliances, catalytic converters, plumbing pipe,
and many other consumer products to recover the valuable metals they contain.
9. Placer mining (washing metals out of deposits with water) chokes streams with sediment and
disrupts aquatic ecosystems. Underground mining is dangerous to miners and abandoned mines
can collapse, causing surface subsidence. Contaminated water leaks from mine shafts and
pollutes streams and lakes. Open-pit, or strip mines, overturns large areas of land, creating a
barren landscape of spoil material. Mountaintop removal involves scraping off entire
mountaintops to get to mineral strata. The waste is generally dumped into valleys where it buries
streams, houses, fields, and whole towns.
10. Major geologic hazards include earthquakes (which destroy houses, bridges and other
structures), volcanoes (which produce molten lava, hot ash, and poisonous gases), mass wasting
(which results in landslides), and floods.
Chapter 15
1. Weather is the daily temperature and moisture conditions in a particular place. Climate is
long-term weather patterns.
2. The troposphere is the layer of air immediately adjacent to the earth’s surface where air
pressure is greatest and weather occurs. The stratosphere extends from about 10 km to 50km and
has a similar composition to the troposphere, but has almost no water vapor and 1,000 times
more ozone. Temperatures are high at the top of the stratosphere but decrease in the mesosphere,
which extends to a height of about 80 km. Above the mesosphere is the thermosphere, a region
of highly ionized gases. This is where aurora occurs as highly charged particles from solar and
cosmic radiation bombard our atmosphere.
3. The greenhouse effect results from the relative transparency of the atmosphere to visible light
and its relative opacity to long-wave infrared radiation. Incoming solar radiation passes through
the air and is absorbed by the earth’s surface. Heat re-radiates back toward space as infrared
radiation, it is then absorbed or reflected by greenhouse gases in the air, keeping the surface of
the earth would be much colder than it is now.
4. ENSO stands for the El Nino/Southern Oscillation, a periodic movement of a large pool of
warm water every few years from the western Pacific eastward toward Tahiti. Trade winds,
which normally blow westward across the Pacific die, and a upwelling of cold, deep water off
the coast of South America is blocked during these El Nino events. Normal conditions are
termed La Nina. The Pacific Decadal Oscillation (PDO) involves a long term (decades)
movement of warmer and cooler water north to south in the Pacific.
5. Jet streams are hurricane-force winds at the top of the troposphere that push air masses around
and bring storms, droughts, and other weather conditions to areas in their path.
6. Tornadoes are generated by “supercell” frontal systems where cold dry air meets warm, moist
air. As the warm air is drawn aloft, moisture condenses and releases heat causing violent
updrafts. One theory of tornado formation is that rolling vortex tubes generated by air currents
are drawn into the updraft, starting the rotation. Cold down drafts pushing down behind the
funnel cloud tighten the spiral and intensify its speed.
7. The Coriolis effect occurs because winds moving across the earth’s surface appear to curve as
the earth moves under them. In the Northern Hemisphere winds spin clockwise out of a high
pressure center and counterclockwise into a low pressure cell. This phenomenon also affects
ocean currents, but does not affect water going down a drain.
8. Global climate change could have many adverse effects on human societies, agriculture, and
nature. Severe storms, droughts, floods, and other extreme weather events are likely to become
more common. Rainfall patterns are likely to be disrupted and water shortages could result.
Melting of ice and snow will likely raise sea levels and flood coastal cities, as well as destroy ice
sheets on which marine mammals and arctic hunters depend. Melting permafrost is disrupting
towns, destroying roads, destroying forests, and could release huge amounts of carbon dioxide
and methane. Changing climate is forcing organisms to migrate to new areas or die if they cannot
adapt.
9. We could reduce CO2 emissions by burning less fossil fuel, driving less, insulating buildings,
producing less waste, and practicing energy conservation. We could plant trees to absorb carbon
dioxide or inject carbon dioxide into deep wells or into the deep ocean. Controlling methane
emissions is also an important way to prevent climate change. Passing legislation to allow carbon
trading and to place limits on carbon emissions are important in controlling climate change.
10. The U.S. hasn’t ratified the Kyoto Protocol because powerful corporations and politicians
believe that their economic interests might be threatened by greenhouse gas emissions limits.
Those who favor the Kyoto Protocol argue that global warming is a greater threat, in the long
run, to the U.S. economy than curbs on greenhouse gases. Furthermore, they argue, U.S.
businesses will soon lose competitiveness and the ability to do business in most of the world if
we fail to join the world community in combating global warming.
Chapter 16
1. Primary air pollutants are those released directly from the source into the air in a harmful
form. Secondary air pollutants are modified to a hazardous form after they enter the air or are
formed by chemical reactions as components of the air mix and interact.
2. The seven original criteria pollutants are sulfur dioxide, carbon monoxide, particulates,
hydrocarbons, nitrogen oxides, photochemical oxidants, and lead. Since 1970, some 667 toxic
chemicals have been added to the toxic release inventory. These pollutants were chosen because
they are considered to represent the greatest threat to human health and welfare.
3. Smoking is undoubtedly the most important air pollutant in the United States in terms of
human health. Every year more than 400,000 people die in the U.S. because of tobacco smoking.
Worldwide, poorly ventilated heating and cooking fires adversely affect the health of at least 2.5
billion people.
4. Acid deposition is precipitation of dry acidic particles or wet acidic solutions from the air. The
main forms of acid precipitation are sulfuric and nitric acids formed by burning fossil fuels.
5. An atmospheric inversion (often called a temperature inversion) occurs when a stable layer of
warmer air overlays cooler air, reversing the normal temperature decline with increasing height
and preventing convection currents from dispersing trapped pollutants.
6. Ambient ozone is in the air surrounding us at ground level. Stratospheric ozone is in the
stratosphere 10 to 50 km above us. The former is a dangerous air pollutant; the later protects us
from solar UV radiation. The main destructive force for stratospheric ozone is chlorinated
hydrocarbons.
7. Long-range transport carries air pollutants on wind currents thousands of kilometers from
sources to distant areas. Some examples are the “Asian Brown Cloud” that covers all of South
Asia at times, dust storms from Asia and Africa that drift over the Americas, and industrial haze
that accumulates over the Arctic and contaminates food chains there.
8. The new source review was adopted in 1977, because industry argued that it would be
intolerably expensive to install new pollution control equipment on old power plants and
factories that were about to close down anyway. Congress agreed to “grandfather” or exempt
existing equipment from new pollution limits with the stipulation that when they were upgraded
or replaced, more stringent rules would apply. The result was that owners kept old facilities
operating precisely because they were exempt from pollution control. In fact, corporations
poured millions into aging power plants and factories, expanding their capacity rather than
building new ones. A quarter of a century later, most of those grandfathered plants are still going
strong and continue to be among the biggest contributors to smog and acid rain. President Bush
says that determining which facilities are new and which are not represents a cumbersome and
unreasonable imposition on industries and therefore ordered the EPA to abandon this program.
Environmentalists argue that this decision will allow millions of pollutants to be emitted into our
air and that owner’s of old facilities are being allowed to buy political influence rather than clean
up their effluents.
9. Between 1970 and 1998, atmospheric lead concentrations in the U.S. fell 98 percent. Nitrogen
oxides and particulate materials are the only “criteria” pollutants that have not decreased.
Nitrogen oxides increased slightly and particulates roughly doubled during that time.
10. There are many air pollution problems in developing countries including industrial
emissions, vehicle emissions, and children’s lead exposure.
Chapter 17
1. Withdrawal is the total amount of water taken from a water body for any use. Consumption is
the fraction of withdrawn water that is lost in transmission, evaporation, absorption, chemical
transformation, or otherwise made unavailable for other purposes as a result of human use.
Degradation is alteration in water quality by pollution or heating that makes it less suitable for
other uses.
2. Water enters an aquifer by through recharge zones; it leaves where the aquifer comes to the
surface (springs) or intersects a water body.
3. There has been a rapid increase in both water withdrawal and consumption for agriculture. 3.
Worldwide, agriculture is responsible for two-thirds of all water withdrawal and 85 % of all
consumption. Domestic use is increasing more rapidly than industrial use.
4. Dams and water diversion projects displace people and wildlife, eliminate fishing and
recreation on free-flowing rivers, dry up lakes and rivers by diverting water sources, cause
pollution when diverted water dissolves toxins from newly flooded lands, flood farmland and
cities under reservoirs, lose massive amounts of water through evaporation and leakage, and
block fish migration along with a host of other deleterious effects.
5. The hydrologic cycle describes the circulation of water as it evaporates from land, water
bodies, or organisms; moves through the atmosphere; condenses and falls to the earth’s surface
as rain, mist, or snow; and moves either underground by infiltration or overland by runoff into
rivers, lakes, and eventually to the ocean.
6. The five largest rivers in the world are: Amazon, Orinoco, Congo, Yangtze and Bramaputra.
7. Mountains act as cloud formers and rain catchers. As air sweeps up the windward side of a
mountain, air pressure decreases and air cools as it rises. When the humidity reaches the
saturation point, moisture condenses and falls as rain or snow. As dry air descends along the
downwind side of the mountain it warms and relative humidity decreases, producing a “rain
shadow” where precipitation is dramatically lower than the other side of the mountain. Does it
affect you? Depends on where you live.
8. Over pumping aquifers causes local wells to go dry, allows saltwater intrusion, and can result
in subsidence and sinkholes.
9. Only 2.4% of all water on earth is fresh, the rest is salty. Of the fresh water, 87% is frozen in
ice and snow. Of the liquid freshwater, 95% is in the ground and only 3% is in lakes, rivers, and
streams.
10. When an aquifer near a coast is drawn down below sea level, salt water can enter the aquifer.
Chapter 18
1. Water pollution is any physical, biological, or chemical change in water quality that adversely
affects living organisms or makes water unsuitable for desired uses.
2. Major categories of water pollution include infectious agents (bacteria, parasites), organic
chemicals (pesticides, gasoline), inorganic chemicals (acids, metals), radioactive materials
(uranium, cesium), sediment (soil, silt), plant nutrients (nitrates, phosphate), oxygen-demanding
wastes (manure, plant residues) and thermal changes (heat).
3. Oxygen demanding wastes are organic materials such as sewage, paper pulp, or foodprocessing wastes that stimulate oxygen consumption by aquatic decomposers.
4. Red tides (they can also be other colors) are blooms of deadly aquatic microorganisms. They
are probably caused by eutrophication of slow-moving rivers, brackish lagoons, estuaries, and
bays, as well as nearshore ocean waters where nutrients and wastes wash from shore.
5. Eutrophication is an increase in nutrient levels and biological productivity in a water body.
Cultural eutrophication is caused by fertilizer, sewage or manure runoff, thermal increases, and
other human activities. It can result in algal blooms and thick growth of aquatic plants that
reduce fish populations and prevent recreational use.
6. An oxygen sag is a characteristic decline and restoration of oxygen levels in a stream or lake
near a point source discharge of nutrients such as a sewage plant. Upstream from the pollution
source, high oxygen levels support normal populations of clean-water organisms such as
mayflies and game fish. Where oxygen is depleted by bacterial growth and decay, only the most
resistant microorganisms and invertebrates can survive. Eventually, further downstream, oxygen
diffusion and action of photosynthetic plants will restore water quality and allow rebuilding of
clean water populations.
7. Silt is fine sediment that results from erosion. Many human activities, including farming,
construction, forestry, and grazing cause erosion and add billions of sediment to water bodies
every year. This sediment fills lakes and reservoirs, obstructs shipping channels, clogs turbines,
makes purification of drinking water more costly, smother fish habitat, and makes water cloudy
so that plants don’t grow and swimming, boating, and fishing are unattractive.
8. Primary sewage treatment filters out debris and allows sand, gravel, and suspended organic
solids to settle out. Many pathogens remain in the water after this treatment. Secondary treatment
consists of biological degradation of remaining dissolved organic materials. While most
pathogens are removed by this step, the effluent can cause eutrophication. Tertiary treatment
removes plant nutrients, especially nitrogen and phosphorous from the wastewater effluent. This
is generally the highest quality water treatment used.
9. Storm sewers carry runoff from streets, yards, and parking lots that are often contaminated
with fertilizers, oil, rubber, tar, lead, and other pollutants. Combining storm sewers with sanitary
sewers allows this contaminated water to be treated and purified at a municipal sewage treatment
plant before being released into rivers or lakes. However, heavy rains can overload combined
sewer systems resulting in the dumping of raw sewage into surface waters. Separating the sewers
is disruptive and expensive and allows storm runoff to introduce pollutants into waterways again.
10. The Clean Water Act is an immense and complex law with more than 500 sections regulating
everything from urban runoff, industrial discharges, and municipal sewage treatment, to land-use
practices and wetland drainage. It regulates everything that diminishes the chemical, physical,
and biological integrity of the Nation’s waters, and aims to return all U.S. surface waters to
“fishable and swimmable” conditions. It requires discharge permits and best practicable control
technology for point sources of pollution, and sets a national goal of best available, economically
achievable technology for toxic substances and zero discharge for 126 priority toxic pollutants.
11. MTBE is methyl tertiary butyl ether, a gasoline additive used to reduce formation of carbon
monoxide and unburned hydrocarbons from engine exhaust. It has leaked from hundreds of
thousands of gasoline storage tanks and contaminated ground water very widely in the United
States. It will cost billions of dollars to remove this contaminant from drinking water supplies.
12. Remediation means finding remedies for problems. Water remediation techniques include
confinement with an impermeable cap, in situ treatment by aeration to oxidize pollutants, and
extraction of contaminated water so it can be treated; it also includes injection of materials to
precipitate, immobilize, chelate, or solidify deeply buried pollutants. Bioremediation means
treatment of contaminated water by plants that remove pollutants.
Chapter 19
1. Energy is the capacity to do work. Power is the rate of flow of energy or the rate at which
work is done.
2. Fossil fuels (coal, oil, gas) now supply 86% of the commercial energy in the world and 83% of
all commercial energy in the U.S. Data are reported for commercial energy because renewable
energy such as solar or biomass are often collected privately or traded on informal markets for
which data are not available.
3. The mix of energy sources and the amount used per capita in the U.S. is quite similar to that of
most other developed countries. Many developing countries, on the other hand, depend to a
much greater extent on biomass and muscle power (making up as much as 90% of the energy
supply in some countries) or other renewable sources. Developing countries often use far less
energy per person than we do. On average, each person in the U.S. uses more than 300 GJ per
year. In contrast, citizens of Ethiopia, Kampuchea, Nepal, and Bhutan consume less than one GJ
per year, on average.
4. Proven reserves of coal are about 200 years supply at current consumption rates, or roughly 1
trillion metric tons (i.e. about 10% of the total resource of 10 trillion tons). Proven reserves of
liquid oil are about 1 trillion barrels (or a 40 year supply at current consumption rates), but oil
from tar sands and oil shales could double that amount. The proven reserves of natural gas are
5,500 trillion ft3 or a 60-year supply at current consumption rates.
5. Coal bed methane is natural gas trapped in or around coal seams. It is held in place by pressure
from overlying aquifers. Pumping water out of these aquifers releases the gas, but creates
phenomenal quantities of effluent that often contaminates surface water and poisons the land.
The huge number of proposed coal bed wells along with the noise, roads, traffic, and pollution
they generate is opposed by both environmental groups and local residents.
6. Mining and extraction of fossil fuels have many adverse health and environmental effects
including mine accidents and black lung disease that kill workers, transportation accidents that
cause oil spills, destructive mining techniques such as strip mining or mountain-top removal that
destroy landscapes, mine drainage, waste water seepage that pollutes streams and contaminates
soil, global climate change triggered by CO2 and methane emissions, acid rain caused by SO2
and NOx emissions, release of arsenic and radioactive elements, and asthma and other respiratory
illnesses triggered by soot, carbon monoxide, and sulfate particles among other problems.
7. Most nuclear reactors in operation in the U.S. use the heat generated by a nuclear chain
reaction to heat water, to generate steam, and to drive a turbine that spins an electric generator.
Enriched uranium fuel containing U235 is shaped into small pellets that are packed in steel fuel
rods and bundled together in the reactor core through which cooling water is pumped while the
chain reaction is occurring. The hot water flowing from the reactor passes through a heat
exchanger which generates steam for the turbine. Control rods made of neutron-absorbing
material, such as boron, regulates the nuclear reactions.
8. The four most common reactor designs are boiling water (BWR), in which radioactive water
from the reactor core drives the turbine; pressurized water (PWR), in which the reactor core
water passes through a heat-exchange device where it heats a secondary cooling loop; heavy
water reactors (CANDU) use deuterium as both a cooling and moderating agent; and graphitemoderated, water-cooled reactors (RBMK) from Russia use graphite (which burns when exposed
to high heat and air) as the moderator.
9. Breeder reactors produce fuel rather than consume it. They use abundant, stable forms of
uranium and plutonium from nuclear waste to create more plutonium and thorium. This would
extend the life of our supply of nuclear fuels for thousands of years. They can melt down and
release catastrophic amounts of radioactivity in seconds if a malfunction occurs. In addition, they
increase the likelihood of bomb production and nuclear terror because they require nuclear waste
reprocessing and create extra amounts of plutonium.
10. For years, the U.S. and other countries dumped radioactive waste at sea. Currently, the U.S.
is storing high-level radioactive waste at power plants (in pools of water inside the plants and in
dry casks outside) while searching for a suitable place for underground burial. Yucca Mountain,
Nevada has been chosen as the first such repository, but doubts persist about its suitability.
Chapter 20
1. We can save energy by using compact fluorescent bulbs and light-emitting diodes (LEDS);
insulating and weather-stripping our homes; buying new, efficient appliances; driving less or
buying hybrid gas-electric vehicles; walking or riding bicycles; building super-insulated
buildings; and turning off appliances and lights when not in use.
2. Net energy yield isn’t defined specifically, but table 20.1, gives net energy efficiencies (which
are essentially the same thing) and the text defines energy efficiency as a measure of energy
produced compared to energy consumed in that production. Hydroelectricity, for example, yields
90% of the energy in falling water as electricity. An open fireplace, in contrast, yields 10% less
energy than it consumes.
3. Passive solar energy systems use no moving parts to collect and store solar energy. Active
systems use fans, moveable mirrors, or other mechanical devices to collect and store solar
energy.
4. Photovoltaic cells capture solar energy and convert it directly to electricity by separating
electrons from their parent atoms and accelerating them across a one-way electrostatic barrier
formed by the junction between two different types of semiconductor material.
5. A fuel cell uses electrochemical reactions to produce an electric current. They consist of
positive and negative electrodes separated by an electrolyte, a material that allows the passage of
charged atoms, called ions, but is impermeable to electrons. In the most common type hydrogen
passes over the anode, while oxygen passes over the cathode. Electrons are stripped from the
hydrogen and a positively charged ion (or proton) crosses the electrolyte to join with oxygen to
form water.
6. Wood burning in most stoves and fireplaces creates air pollution that can be a major problem
in enclosed spaces or mountain valleys. Burning wood releases CO2, but if new trees are planted
to replace those harvested for firewood, the carbon cycle is balanced. Where reforestation isn’t
practiced, cutting firewood can deplete forests and destroy vital habitat for wildlife. Wood
shortages in some countries force residents (mostly women and girls) to walk long distances in
search of fuel.
7. Methane is created from biomass in a digester or reactor by anaerobic (oxygen-free) digestion
by bacteria of any moist organic material such as animal manure, crop residues, kitchen scraps,
or municipal sewage.
8. Dams produce electricity without releasing CO2 or other air pollutants. Once the dam is built,
operating costs are low and the electricity they produce is very cheap. However, dams flood river
valleys displace those residents and activities from land flooded by reservoirs, and destroy
habitat for fish and other wildlife dependent on flowing rivers. In some tropical countries, snailborne diseases have been exacerbated by stagnant water in reservoirs.
9. Some examples of biomass fuel (other than wood) include dried manure, straw, reeds, leaves,
starchy roots, feathers, and other plant and animal materials.
10. A tidal station works like a hydropower dam, with its turbines spinning as the water flows
through it both on an incoming and outgoing tide. It requires damming of a bay or estuary into
and out of which the tide flows. Wave power is harnessed use oscillating water columns that
push or pull air through a turbine, as well as a variety of floating buoys, barges, or cylinders that
bob up and down as waves pass. These motions are coupled mechanically to generators that
produce electricity.
Chapter 21
1. Solid waste includes agricultural wastes such as crop residues and animal manure; industrial
wastes including mine tailings, strip mine overburden, and metal slag; and municipal waste,
which includes domestic and commercial refuse. Altogether, the U.S. produces some 11 billion
tons of solid waste per year. Hazardous waste is a special category regulated by the EPA. It
includes any discarded material, liquid or solid, that contains substances known to be fatal to
humans or laboratory animals in low doses; toxic, carcinogenic, mutagenic, or teratogenic to
humans or other life-forms; ignitable with a flash point less than 60oC; corrosive, explosive, or
highly reactive.
2. In an open dump, garbage is simply dumped in a pile on the ground. In a sanitary landfill,
garbage is compacted and covered every day with a layer of dirt to exclude vermin, fires, and
insects. In a modern, secure landfill, the pit is lined (top and bottom) with a thick cushion of clay
and an impermeable plastic liner. Leachate standpipes are installed for removal of any water that
leaks into the pit; methane pipes collect methane generated by decomposing garbage. Testing
wells around and below the landfill monitor groundwater for evidence of leakage.
3. Landfill sites are becoming limited around most big cities in the U.S. This is not because there
isn’t cheap, unused land available, but because citizens have become concerned about health
hazards and aesthetics (or lack thereof) of existing and historic dumps. Stricter financial and
environmental protection requirements and siting processes have closed many old dumps, and
probably discourage many potential operators from entering this field.
4. Incinerating garbage in a safe and environmentally sustainable manner is difficult and
expensive. Because most municipal waste contains a wide variety of materials, toxic metals, and
carcinogenic chemicals or endocrine system disrupters are often emitted from incinerators.
Because incinerators make most economic sense in the city center close to both generators of
trash and markets for waste heat and electricity, these facilities often are close to large population
centers and more people are potentially exposed to their effluents.
5. Recycling is beneficial in that it reduces the amount of waste needing disposal. It also reduces
the demand for new material that must be produced by logging, mining, smelting, etc. Recycling
generally consumes much less energy that it takes to produce materials in the first place.
Recycling also provides more jobs and uses less space than does simply dumping our trash. One
of the biggest problems in recycling is finding a use for materials that may not be pristine. Even
a small amount of contamination in plastic, for example, can make it unsuitable for most uses.
The spread of diseases through recycled materials is also a concern. It’s also possible that an
overemphasis on recycling may discourage people from using less stuff in the first place.
6. Composting is biological degradation or breakdown of organic matter under aerobic (oxygenrich) conditions. The organic matter resulting from this process makes a nutrient-rich soil
amendment that aids water retention, slows soil erosion, and improves crop yields. Composting
can be done on a small scale in your backyard or in mammoth municipal facilities.
7. We can reduce the waste we generate by buying stuff with less packaging and taking reusable
containers to meetings; choosing recyclable or reusable glass or metal packaging where
available; buying degradable plastic; separating cans, bottles, papers and plastics for recycling;
washing and reusing bottles, aluminum foil, plastic bags, etc; composting yard and garden waste;
and encouraging legislators to vote for container deposits, recycling, and safe incinerators and
landfills.
8. Ten toxic substances in your home and how you’d dispose of them: see table 21.1, for
suggestions.
9. Brownfields are properties that have been abandoned or are not being used up their potential
because of real or suspected pollution. Cities want to redevelop them to create jobs, increase the
tax base, and prevent needless destruction of open space.
10. People object to waste handling facilities in their neighborhoods because the health and
safety record of these facilities has not been good. In addition, there often is inequity in racial
and class exposure to these facilities and how their effluents are cleaned up.
Chapter 22
1. A village is a collection of rural households linked by culture, custom, family ties, and
association with the land. A city is a differentiated community with a population and resource
base large enough to allow residents to specialize in arts, crafts, services, or professions rather
than natural resource-based occupations. A rural area is one in which most residents depend on
natural resource harvesting for their livelihood. An urban area is one in which a majority of the
residents are not directly dependent on natural resource-based occupations.
2. In 2000, 59.4% of the world population was urban. That percentage is growing rapidly, and by
2030 it’s expected that 70.5% of all people will live in cities. That means that cities are home to
about 4 billion people now, and could have a combined population of at least 5 billion in 2030.
3. It’s predicted that the urbanization will continue and that by 2025 at least 400 cities will have
populations of 1 million or more, and that 93 supercities will each have 5 million or more
residents. It’s estimated that 90% of all population growth will occur in the developing world.
4. The five largest cities in the world currently are Tokyo, New York City, Mexico City, Seoul,
and Sao Paolo. Only New York and Tokyo were among the ten largest cities in 1900.
5. Megacities in developing nations often suffer from air pollution, traffic congestion, lack of
sewage treatment, clean water, and adequate housing. Despite these problems, people are
attracted to cities by opportunities for jobs, education, housing, and entertainment lacking in the
countryside.
6. Slums are generally legal but inadequate multifamily tenements or rooming houses, either
built to rent to poor people or converted from some other use. Shantytowns are settlements
created when people move onto undeveloped lands and build their own houses out of discarded
materials or whatever they can find. Residents of shantytowns rarely have title to the property on
which their shelters stand.
7. The central cities of many large, old American cities are decaying and falling into disrepair as
jobs are lost to other areas and as middle and upper classes move to the suburbs and Sunbelt
states. With less tax revenue and more social problems, the city can’t solve problems described
in question 6. As problems worsen even more people abandon the city. Hostility toward inner
cities on the part of rich and politically powerful suburbs blocks money and governmental
programs that could help relive problems.
8. Transportation often determined the location and shape of modern cities which were built
around ports, railroad centers, rivers, and other transportation corridors. Current transportation
policies, especially those that favor private automobiles over mass transit, encourage sprawl and
flight from the central city.
9. Six goals for smart growth are presented in table 22.4. Specific design principles of the new
urbanist movement, which aim to make cities more livable, are discussed in the chapter.
Examples of how these principles have been applied are presented in the case studies at the
beginning and end of the chapter.
10. Greenfield developments are those on farmland or other non-urban, previously undeveloped
spaces usually outside city boundaries. Brownfield developments are construction projects on
formerly contaminated industrial lands, usually within city boundaries. It’s generally much
cheaper, in the short run, to develop raw, uncontaminated land, but it requires huge public
expenses for new infrastructure and results in urban sprawl, traffic congestion, and greatly
increased energy use. Brownfield development revitalizes innercity spaces, saves energy,
provides housing and jobs where they can be served by mass transit, and use existing
infrastructure. Brownfield development is popular with city planners and those with social
concerns but not with real estate agents, builders, and property owners who hope to profit from
urban sprawl.
Chapter 23
1. Economics is the management of resources to meet our needs in the most efficient manner
possible. Classical economics was a branch of moral philosophy concerned with how individual
interests and values intersect with larger social goals. It focused on supply and demand for
resources and services, market equilibriums, and marginal costs and benefits. Neoclassical
economics adapted principles of modern science to economic analysis. It strives to be
mathematically rigorous, noncontextual, abstract, and predictive. Neoclassical economists claim
to be value free, leaving social concerns to other disciplines. Nature, if it is considered at all, is
regarded merely as a source of raw materials and a sink for wastes. Ecological economics brings
the insights of ecology to economics. It strives to be holistic, contextual, value-sensitive, and
ecocentric. Intergenerational equity is important in ecological economics, and humans are
regarded as inextricably embedded in nature.
2. A resource is anything with potential use in creating wealth or giving satisfaction. Some
examples are material goods, services, knowledge, tools, or social organization. Nonrenewable
resources are minerals, fossil fuels, and other materials present in fixed amounts in nature.
Renewable resources are things that can be replenished or replaced within a reasonable time.
They include sunlight, biological organisms, and biogeochemical cycles. Intangible resources are
nonmaterial conditions or benefits that can be shared indefinitely, and yet can be destroyed
easily. They include open space, beauty, serenity, wisdom, diversity, and satisfaction.
3. Nonrenewable resources are the earth’s geological endowment: minerals, fossil fuels, and
other materials present in fixed amounts in our environment. Renewable resources are things
that can be replaced or replenished. They include sunlight and the biological organisms and
biogeochemical cycles that provide essential ecological services. Intangible resources include
open space, beauty, serenity, wisdom, diversity, and satisfaction. They can be shared infinitely
and yet can be easily destroyed.
4. Demand is the amount of a product or service that consumers are wiling and able to buy at
various possible prices. Supply is the quantity of that product being offered for sale at various
prices, other things being equal. In general, there’s an inverse relationship between supply and
demand. As prices rise supply increases, but demand falls. As prices decline demand increases,
but supply falls.
5. Some important ecological services are listed in Tables 23.2 and 23.3. They include soil
formation, recreation, nutrient recycling, water supplies, climate regulation, habitat provision,
flood and storm protection, genetic resources, atmospheric gas balances, and pollination (among
other things).
6. Cost-benefit analysis attempts to assign values to resources, as well as to social and
environmental effects of carrying out or not carrying out a given project. For example, it tries to
find the optimal efficiency point at which the marginal cost of pollution control equals the
marginal benefits. CBA is one of the main conceptual frameworks of resource economics and is
used by decision makers to justify building of dams, roads, and airports, as well as in considering
what to do about biodiversity loss, air pollution, and global climate change.
7. Scarcity can serve as a catalyst for innovation and change as is shown in fig 23.14. As
materials become more expensive and difficult to obtain, it becomes cost-effective to look for
new supplies or to use available ones more efficiently. The net effect is as if a new supply of
resources had been created or discovered.
8. The gross national product (GNP) is calculated in two ways. One is the money flow from
households to businesses in the form of goods and services purchased. The other is to add up all
the costs of production in the form of wages, rent, interest, taxes, and profits. In either case, a
subtraction is made for capital depreciation, the wear and tear on machines, etc, but not on
natural resource depletion or environmental degradation. An alternate measure is the genuine
progress index (GPI), which takes into account real per capita income, quality of life,
distributional equity, natural resource depletion, environmental damage, and the value of unpaid
labor.
9. Microlending, as described in the opening case study for this chapter, involves making small
loans to poor people who don’t qualify for credit from conventional banks. Usually, microcredit
programs require people to join a small group, all the members of which co-sign for each other’s
loans and who have regular meetings to provide advice and support for their businesses.
10. Several different approaches to or goals for an eco-efficient economy are listed in tables 23.4,
23.5, and 23.6. They urge us to not pollute our environment, measure prosperity by how much
natural capital we can accrue and productivity by how many people are gainfully and
meaningfully employed, produce nothing that will require constant vigilance, celebrate the
abundance of biological and cultural diversity, and to live on renewable resources rather than
nonrenewable ones.
Chapter 24
1. The policy cycle is a process for identifying and acting on social problems. After identifying a
problem the next steps are: setting an agenda, developing proposals, building support, enacting a
rule or law, implementing the policy, evaluating results, and suggesting changes.
2. In the United States, statutory law is established by Congress. Bills are written and introduced
by legislators (often with the help of lobbyists). The bill is assigned to a subcommittee and
hearings are conducted to give the public a chance to comment. If sufficient support exists, the
bill is “marked up” or revised and modified, to improve its chances of passing. It is then
forwarded to a full committee for further hearings and deliberation. A bill that succeeds in
committee is reported to the full House or Senate for a floor debate. If a bill passes both houses
of Congress, different versions are brought into agreement in a conference committee and sent
back to Congress for confirmation. If the President signs the bill it becomes law. Amendments
and alterations can be made at any time in the legislative process. Riders are provisions attached
to appropriation bills—usually in conference committee—that may be totally unrelated to the
purpose or subject of the original legislative intent. Because conference committee reports must
be voted up or down without further amendment, these riders frequently become law by sneaking
in the backdoor.
3. Criminal law derives from those federal and state statutes that prohibit wrongs against the state
or society, such as arson, rape, murder, and robbery. Convictions in such cases can result in fines
or prison terms. Civil law regulates relations between individuals and corporations. Issues such
as property rights or personal dignity and freedom are protected by civil law. Judgments in civil
cases can result in monetary awards but not incarceration. Administrative law deals with the
rules and powers of federal agencies and state or local boards and commissions. Administrative
judges hear challenges to agency rules and regulations. They also hear enforcement cases in
cases where an individual or corporation is accused of violating an agency rule or regulation.
4. A list of major U.S. environmental laws is presented in Table 24.1. Among the most important
of these are the National Environmental Policy Act of 1969, the Clean Air Act of 1970, the
Clean Water Act of 1972, and the Endangered Species Act of 1973.
5. Unfortunately, many international environmental treaties and conventions constitute little
more than vague, good intentions with no mechanism for enforcement. For example, the U.N
convention on global climate change, at the insistence of U.S. negotiators, only urges—but does
not require—nations to stabilize their release of greenhouse gases. By contrast, the 1987
Montreal Protocol on chlorofluorocarbons allowed a vote by two-thirds of the participating
nations to amend the agreement. When it was shown that stratospheric ozone depletion was more
serious than previously thought, an outright ban on CFC production was passed in spite of the
objections of a few nations.
6. Globalization is the revolution in communications, transportation, finances, and commerce
that has brought about increasing inter-dependence of national economies. It can provide
information, resources, and international cooperation that is essential for conserving resources
and maintaining a healthy environment. It can also allow corporations to shop for the lowest
level of environmental protection and worker’s rights, dump waste on unsophisticated nations,
and avoid taxes. Transnational companies now exceed the power and wealth of individual
nations, making them hard to control.
7. Wicked problems are those with no simple right or wrong answers. They aren’t wicked in the
sense of being malicious, but rather are obstinate or intractable, being nested within other sets of
interlocking issues. The definition of both the problem and its solutions differ for various
stakeholders. There are no value-free, objective answers, only choices that are better or worse
depending on your viewpoint.
8. Resilience is the ability to recover from disturbance. It is important because ecological
systems are always exposed to disturbing factors. If they are resilient, systems can reorganize in
creative and constructive ways. This doesn’t mean they always return to exactly the previous
state, only that they can re-establish important functions and relationships.
9. Collaborative or community-based planning involves all stakeholders and interest groups to
find creative solutions to problems. It recognizes the value of holistic, adaptive, multiuse,
multivalue approaches to planning.
10. The Dutch green plan is uniquely broad and all-encompassing in its scope. With 223 policy
changes aimed at reducing pollution and establishing economic stability, it incorporates three
important mechanisms for achieving its goals: integrated life-cycle management, energy
conservation, and improved product quality. Few other nations have adopted such a bold and
wide-ranging approach that includes a promise that environmental quality will not decline, that
pollution will be reduced at its source rather than being cleaned up later, that polluters will pay
for the costs of their effluents, that unnecessary pollution will be prevented, that best practicable
means for pollution control will be used, that waste disposal will be controlled, and that the
public will be motivated to behave responsibly.
Chapter 25
1. The desired outcomes from environmental education are grouped by some educators into four
categories listed in Table 25.1. Environmental education aims to produced citizens who
understand the scientific concepts that underlie environmental issues, who understand how
humans are affecting our shared environment, who are aware of their own and others values with
respect to environmental quality, and who are prepared to become active in protecting,
improving, or restoring environmental quality for all.
2. Conspicuous consumption is buying stuff you don’t need to impress people you don’t like.
3. Lohas is an acronym for “lifestyles of health and sustainability.” It describes people who
worry about the environment, want products to be produced in a fair, sustainable way and use
purchasing power to express their values. Cultural creatives are people who are socially
conscious, involved in improving communities and willing to translate values into action. They
are strongly aware of environmental problems and want to do something to remedy them.
4. Greenwashing is an attempt to claim that a product or service is “environmentally friendly” or
sustainable when it really isn’t. “Nontoxic” suggests that a product has no harmful effects, but
since there is no legal definition of the term, it could be misleading. “Biodegradable” may be
technically correct, but will the item actually biodegrade if dumped in a landfill? “Natural” is
another vague and misused term. Many natural ingredients—lead and arsenic, for example, are
natural but highly toxic. “Organic” doesn’t necessarily mean safe. Cholera bacteria and
rattlesnake toxin are organic, but not good for you. “Environmentally friendly” has no legal
definition, anyone can claim it.
5. The What Can You Do? Box on p 572 suggests a number of ways to reduce your individual
environmental impact including purchasing less, reducing excess packaging, avoiding disposable
items, conserving energy, and saving water. There are many subcategories within each of these
topics.
6. Fig 25.6 illustrates the life cycle analysis. The major stages at which we can analyze material
and energy balances within this process are (1) raw materials acquisition; (2) manufacturing,
processing and formulation; (3) distribution and transportation; (4) Use/reuse and maintenance;
(5) recycling; and (6) waste management.
7. The ten largest and most influential environmental organizations in the U.S. are the National
Wildlife Federation, the World Wildlife Fund, the Audubon Society, he Sierra Club, the Izaak
Walton League, Friends of the Earth, Greenpeace, Ducks Unlimited, the Natural Resources
Defense Council, and the Wilderness Society. Many of these organizations are international as
well.
8. The most widely used definition of sustainable development is that from the World
Commission on Environment and Development, which described it as “meeting the needs of the
present without compromising the ability of future generations to meet their own needs.” The six
goals of sustainable development include (1) a stable population size, (2) high efficiency energy
use and a switch to renewable sources, (3) reliance on nature’s income without depleting capital,
(4) a broader sharing of wealth, (5) complementary interests between various world regions, (6)
ethics that unite rather than separate us from other people or nature.
9 and 10. The messages and goals from the Millennium Development Assessment that you
regard as most important depend on your perspective. You’ll find a list of both messages and
goals from the Millennium Development Assessment on p 581. Any two items from these lists
would be a valid answer to these questions.