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1

ENVIRONMENTAL

PROBLEMS, THEIR CAUSES,

AND SUSTAINABILITY

KEY QUESTIONS

1 What are some principles of sustainability? 1 How are our ecological footprints affecting the earth?

Copyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).

1 Why do we have environmental problems?

1 What is an environmentally sustainable society?

No civilization has survived

the ongoing destruction of

its natural support system.

Nor will ours.

l e s t e r r. b r o w n

Forests such as this one in California’s Sequoia National Park help to sustain all life and economies. Robert Harding World Imagery/Alamy

Concept 1 5

####### 1 WHAT ARE SOME PRINCIPLES

####### OF SUSTAINABILITY?

CONC E P T 1. 1 A Life on the earth has been sustained for billions of years by solar energy, biodiversity, and chemical cycling.

CONC E P T 1. 1 B Our lives and economies depend on en- ergy from the sun and on natural resources and ecosystem services (natural capital) provided by the earth.

CONC E P T 1. 1 C We could shift toward living more sustain- ably by applying full-cost pricing, searching for win-win so- lutions, and committing to preserving the earth’s life-support system for future generations.

Environmental Science Is a Study of Our

Interactions with the World

The environment is everything around us. It includes the living and the nonliving things (air, water, and energy) with which we interact in a complex web of relationships that connect us to one another and to the world we live in. Despite our many scientific and technological ad- vances, we are utterly dependent on the earth for clean air and water, food, shelter, energy, fertile soil, and all other components of the planet’s life-support system. This textbook is an introduction to environmental science, an interdisciplinary study of how humans interact with the living and nonliving parts of their environment. It integrates information and ideas from the natural sciences such as biology, chemistry, and geology; the social sciences such as geography, economics, and political science; and the humanities such as ethics. The three goals of environ- mental science are (1) to learn how life on the earth has survived and thrived, (2) to understand how we interact with the environment, and (3) to find ways to deal with environmental problems and live more sustainably. A key component of environmental science is ecol- ogy, the biological science that studies how living things interact with one another and with their environment. These living things are called organisms. Each organism belongs to a species, a group of organisms that has a unique set of characteristics that distinguish it from other groups of organisms. A major focus of ecology is the study of ecosystems. An ecosystem is a set of organisms within a defined area of land or volume of water that interact with one another and with their environment of nonliving matter and en- ergy. For example, a forest ecosystem consists of plants (especially trees; see chapter-opening photo), animals, and various other organisms that decompose organic materi- als, all interacting with one another, with solar energy, and with the chemicals in the forest’s air, water, and soil. We should not confuse environmental science and ecology with environmentalism, a social movement

dedicated to trying to sustain the earth’s life-support sys- tems for all forms of life. Environmentalism is practiced more in the political and ethical arenas than in the realm of science. Environmentalism and environmental science are both being practiced vigorously on many college and university campuses (Core Case Study).

Three Scientific Principles of Sustainability How has the incredible variety of life on the earth been sustained for at least 3 billion years in the face of cata- strophic changes in environmental conditions? Such changes included gigantic meteorites impacting the earth, ice ages lasting for hundreds of millions of years, and long warming periods during which melting ice raised sea levels by hundreds of feet. The latest version of our species has been around for only about 200,000 years—less than the blink of an eye, relative to the 3 billion years that life has existed on the planet (see the Geologic and Biological Time Scale in Supplement 6, p. S49). Yet, there is mounting scientific evidence that, as we have expanded into and dominated almost all of the earth’s ecosystems during that short time, and especially since 1900, we have seriously degraded these natural systems that support all species, including our own, and our economies. Our science-based research leads us to believe that three major natural factors have played the key roles in the long-term sustainability of life on this planet, as summa- rized below and in Figure 1 (Concept 1). We use these three scientific principles of sustainability, or lessons from nature, throughout the book to suggest how we might move toward a more sustainable future.

Dependence on solar energy: The sun’s input of energy, called solar energy, warms the planet and provides energy that plants use to produce nutrients, the chemicals necessary for their own life processes and for those of most other animals, including humans. The sun also powers indirect forms of solar energy such as wind and flowing water, which we use to produce electricity.
Biodiversity: The variety of genes, organisms, species, and ecosystems in which organisms exist and interact are referred to as biodiversity (short for biological diversity). The interactions among species, especially the feeding relationships, provide vital ecosystem services and keep any population from growing too large. Biodiversity also provides countless ways for life to adapt to changing environmental conditions, even catastrophic changes that wipe out large numbers of species.
Chemical cycling: The circulation of chemicals necessary for life from the environment (mostly from soil and water) through organisms and back to the environment is called chemical cycling, or nutrient

6 ChAPTEr 1 ENVIrONMENTAL PrOBLEMS, ThEIr CAUSES, AND SUSTAINABILITY

cycling. The earth receives a continuous supply of energy from the sun, but it receives no new supplies of life-supporting chemicals. Thus through their complex interactions with their living and nonliving environment, organisms must continually recycle the chemicals they need in order to survive. This means that there is little waste in nature, other than in the human world, because the wastes and decayed bodies of any organism become nutrients or raw materials for other organisms. In nature, waste = useful resources Ecology and environmental science reveal that interde- pendence, not independence, is what sustains life and allows it to adapt to a continually changing set of environmental conditions. Many environmental scientists argue that un- derstanding this interdependence is the key to learning how to live more sustainably.

Sustainability Has Certain Key Components Sustainability, the central integrating theme of this book, has several critical components that we use as subthemes. One such component is natural capital—the natural resources and ecosystem services that keep us and other species alive and support human economies (Figure 1). Natural resources are materials and energy in na- ture that are essential or useful to humans. They are often classified as inexhaustible resources (such as energy from the sun and wind), renewable resources (such as air, water, topsoil, plants, and animals) or nonrenewable or depletable resources (such as copper, oil, and coal). Ecosystem ser- vices are processes provided by healthy ecosystems that support life and human economies at no monetary cost to us. Examples include purification of air and water, re- newal of topsoil, nutrient cycling, pollination, and pest control.

Solar Energy

Chemical Cycling Biodiversity

FIGURE 1 Three scientific principles of sustainability based on how nature has sustained a huge variety of life on the earth for 3 billion years, despite drastic changes in environmental conditions (Concept 1).

8 ChAPTEr 1 ENVIrONMENTAL PrOBLEMS, ThEIr CAUSES, AND SUSTAINABILITY

a scientific solution to the problems of depletion of forests is to stop burning or cutting down biologically diverse, mature forests (Figure 1). A scientific solution to the problem of pollution of rivers is to prevent the excessive dumping of harmful chemicals and wastes into streams and to allow them to recover naturally. However, to im- plement such solutions, governments often have to enact and enforce environmental laws and regulations. The search for solutions often involves conflicts. For example, when a scientist argues for protecting a long- undisturbed forest to help preserve its important biodiver- sity, the timber company that had planned to harvest the trees in that forest might protest. Dealing with such con- flicts often involves making trade-offs, or compromises—

another component of sustainability. For example, the timber company might be persuaded to plant and harvest trees in an area that it had already cleared or degraded, instead of clearing the undis- turbed forest. In return, the government might give the company a subsidy, or financial support, to meet some of the costs for planting the trees. In making a shift toward sustainability, the daily actions of each and every individual are im- portant. In other words, individuals matter—an- other subtheme of this book. History shows that almost all of the significant changes in human systems that have improved environmental quality have come from the bottom up, through the col- lective actions of individuals and from individuals inventing more sustainable ways of doing things.

Other Principles of Sustainability Come from the Social Sciences Our study of environmental problems, proposed solutions, and trade-offs has led us to propose three social science principles of sustainability (Figure 1), derived from studies of eco- nomics, political science, and ethics:

Full-cost pricing (from economics): Many economists urge us to find ways to include the harmful environmental and health costs of producing and using goods and services in their market prices—a practice called full-cost pricing. This would give consumers better information about the environmental impacts of their lifestyles, and it would allow them to make more informed choices about the goods and services they use.
Win-win solutions (from political science): We can learn to work together in dealing with environmental problems by recognizing our interdependent connections with others and with our life-support system. This means shifting from a win-lose approach based on competition and dominance of other humans and of ecosystems to win-win solutions that are based on compromise in light of our interdependence and that benefit both people and the environment.
A responsibility to future generations (from ethics): We should leave the planet’s life-support systems in at least as good a condition as that which we now enjoy, if not better, for future generations.

Other researchers have proposed additional sustain- ability principles, but we believe that our six prin ciples of sustainability (Figure 1, Figure 1, and Supplement 7, pp. S50–S51) can serve as key guidelines for helping us live more sustainably.

The clearing of vast areas of forest is an example

of natural capital degradation.

John Lee/Aurora Photos

FIGURE 1 Small remaining area of once diverse Amazon rain forest surrounded by vast soybean fields in the Brazilian state of Mato Grosso.

Concept 1 9

Resources Are Inexhaustible, Renewable, or Nonrenewable A resource is anything that we can obtain from the envi- ronment to meet our needs and wants. Some resources, such as surface water, trees, and edible wild plants, are directly available for use. Other resources, such as petro- leum, minerals, wind, and underground water, become useful to us only with some effort and technological ingenuity. Resources can be classified as inexhaustible, renewable, or nonrenewable (exhaustible) (Figure 1). Solar energy is called an inex- haustible resource because its continuous supply is expected to last for at least 6 bil- lion years until the sun dies. It also pro- vides us with inexhaustible wind and flowing water that we use to produce electricity. A renewable resource is one that can be replenished by nat- ural processes within hours to centuries, as long as we do not use it up faster than natural processes can renew it. Exam- ples include forests, grasslands, fishes, fertile topsoil, clean air, and freshwater. The highest rate at which we can use a renewable resource indefinitely without re- ducing its available supply is called its sustainable yield.

Inexhaustible Solar energy Wind energy Geothermal energy

Renewable Trees Topsoil Freshwater

Nonrenewable (Exhaustible) Fossil fuels (oil, natural gas, coal) Iron and copper

FIGURE 1 We depend on a combination of inexhaustible, renewable, and exhaustible (nonrenewable) natural resources.

ECONOMICS Full-cost pricing

Win-win results POLITICS

ETHICS

Responsibility to future generations

FIGURE 1 Three social science principles of sustainability can help us make a transition to a more environmentally and economically sustainable future.

Left: Minerva Studio/Shutterstock. Center: mikeledray/Shutterstock. Right: Kali Nine LLC/istockphoto.

Left: Carole Castelli/Shutterstock. Center: Alexander Kalina/Shutterstock. Right: Karl Naundorf/Shutterstock.

Concept 1 11

According to this study, human activities have degraded or overused about 60% of the earth’s ecosystem services (Figure 1, orange boxes), mostly since 1950. The report’s summary statement warned that “human activity is put- ting such a strain on the natural functions of Earth that the ability of the planet’s ecosystems to sustain future genera- tions can no longer be taken for granted.” The report also concluded that we have scientific, economic, and political solutions to these problems that we could implement within a few decades, as you will learn in reading this book.

Pollution Comes from a Number of Sources

One major environmental problem is pollution, which is contamination of the environment by any chemical or other agent such as noise or heat to a level that is harmful to the health, survival, or activities of humans or other organisms. Polluting substances, or pollutants, can enter the environment naturally, such as from volcanic erup- tions, or through human activities, such as the burning of coal and gasoline, and the dumping of chemicals into riv- ers, lakes, and oceans. At a high enough concentration in the air, in water, or in our bodies, almost any chemical can cause harm and be classified as a pollutant. The pollutants we produce come from two types of sources. Point sources are single, identifiable sources. Examples are the smokestack of a coal-burning power or industrial plant (Figure 1), the drainpipe of a factory, and the exhaust pipe of an automobile. Nonpoint sources are

dispersed and often difficult to identify. Examples are pes- ticides and particles of topsoil blown from the land into the air and the runoff of fertilizers, pesticides, and trash from the land into streams and lakes (Figure 1). It is much easier and less costly to identify and control or prevent pollution from point sources than from widely dispersed nonpoint sources. We have tried to deal with pollution in two very differ- ent ways. One approach is pollution cleanup, which involves cleaning up or diluting pollutants after we have produced them. For example, we can use tall smokestacks (Figure 1) to dilute and reduce the local effects of air pollutants. However, while tall smokestacks can reduce local air pollution they can increase air pollution in down- wind areas. The other approach is pollution prevention, efforts focused on greatly reducing or eliminating the production of pollutants. For example, we can enact pollution control laws that ban, or set low levels for, the emission of various pollutants into the atmosphere or into bodies of water.

We Are Degrading Commonly Shared Renewable Resources: The Tragedy of the Commons Some renewable resources, known as open-access renewable resources, are not owned by anyone and can be used by almost anyone. Examples are the atmosphere, the open ocean and its fishes, and the earth’s life-support system. Other examples of less open, but often shared resources, are

GOOD NEWS

FIGURE 1 Point-source air pollution from smokestacks in a coal- burning industrial plant.

FIGURE 1 The trash in this river came from a large area of land and is an example of nonpoint-source water pollution.

Dudarev Mikhail/Shutterstock Jandric/Shutterstock

12 ChAPTEr 1 ENVIrONMENTAL PrOBLEMS, ThEIr CAUSES, AND SUSTAINABILITY

grasslands, forests, and streams. Many of these renewable resources have been environmentally degraded. In 1968, biologist Garrett Hardin (1915–2003) called such degrada- tion the tragedy of the commons. Degradation of such shared or open-access renewable resources occurs because each user reasons, “The little bit that I use or pollute is not enough to matter, and anyway, it’s a renewable resource.” When the number of users is small, this logic works. Eventually, however, the cumula- tive effect of large numbers of people trying to exploit a widely available or shared resource can degrade it and eventually exhaust or ruin it. Then no one can benefit from it. That is the tragedy.

Our Ecological Footprints Are Growing When people use renewable resources, it can result in natural capital degradation (Figure 1), pollution, and wastes. We can think of this harmful environmental impact as an ecological footprint—the amount of land and wa- ter needed to supply a population or an area with renew- able resources and to absorb and recycle the wastes and pollution produced by such resource use. The per capita

ecological footprint is the average ecological footprint of an individual in a given country or area. Figure 1 shows the human ecological impact in different parts of the world. (See Figure 6 in Supplement 4, p. S21, for the human eco- logical footprint in North America.) If the total ecological footprint for a city, a country, or the world is larger than its biological capacity to replenish its renewable resources and absorb the resulting wastes and pollution, it is said to have an ecological deficit. In other words, its people are living unsustainably by depleting natural capital instead of living off the renewable supply of resources and ecosystem services provided by such capital. Globally we are running up a huge ecological deficit, as shown by the map in Figure 4, p. S19, in Supplement 4. According to the 2013 Living Planet Report from the World Wide Fund for Nature (WWF), we would need 1 planet Earths to indefinitely sustain the world’s 2012 rate of total resource use. A relatively new school of thought, led by architect William McDonough and scientist Michael Braungart, takes a slightly different approach to the notion of human environmental impacts and how to reduce them. Called upcycling, this approach acknowledges our growing eco-

FIGURE 1 Natural capital use and degradation: The human ecological footprint has an impact on about 83% of the earth’s total land surface.

National Geographic Earth Pulse; Data from Mark Levy at Columbia University’s Center for International Earth Science Information, 2002and WWF,

Living Planet Report 2012.

14 ChAPTEr 1 ENVIrONMENTAL PrOBLEMS, ThEIr CAUSES, AND SUSTAINABILITY

Experts Have Identified Several Causes of Environmental Problems According to a number of environmental and social scien- tists, the major causes of the environmental problems we face are (1) population growth, (2) wasteful and unsus- tainable resource use, (3) poverty, (4) failure to include the harmful environmental and health costs of goods and services in their market prices, and (5) increasing isolation from nature (Concept 1) (Figure 1). We discuss each of these causes in detail in later chapters of this book. Let us begin with a brief overview of them.

The Human Population Is Growing at a Rapid Rate Exponential growth occurs when a quantity such as the human population increases at a fixed percentage per unit of time, such as 0% or 2% per year. Exponential growth starts off slowly. But after only a few doublings, it grows to enormous numbers because each doubling is twice the total of all earlier growth. For an example of the awesome power of exponential growth, consider a simple form of bacterial reproduction in which one bacterium splits into two every 20 minutes. Starting with one bacterium, after 20 minutes, there would be two; after an hour, there would be eight; ten hours later, there would be more than 1,000, and after just 36 hours (assuming that nothing interfered with their repro- duction), there would be enough bacteria to form a layer 0 meters (1 foot) deep over the entire earth’s surface. The human population has grown exponentially (Fig- ure 1), and in 2013, the rate of growth was 1%. As a result, there are now about 7 billion people with about 85 million more people added each year. There could be 9 billion of us by 2050. This projected addition of 2 bil- lion more people within your lifetime is more than eight

times the current U. population and almost twice that of China, the world’s most populous nation.

CONSIDER THIS ... CONNECTIONS Exponential Growth and Doubling Time: The Rule of 70 The doubling time of the human population or of any growing quantity can be calculated by using the rule of 70: doubling time (years) = 70/annual growth rate (%). The world’s population is growing at about 1% per year. At this rate how long will it take to double its size?

No one knows how many people the earth can support indefinitely, or at what level of average resource consump- tion per person, without seriously degrading the planet’s life-support system. However, our large and expanding ecological footprints (Figure 1 and Figure 6, p. S21, in Supplement 4) and the resulting widespread natural capi- tal degradation are disturbing warning signs. Some scien- tists argue that we could control such severe degradation by slowing population growth with the goal of having it level off at around 8 billion by 2050. We examine the pos- sible ways to do this in Chapter 6.

Affluence Has Harmful and Beneficial Environmental Effects The lifestyles of the world’s expanding population of con- sumers are built on growing affluence as more people achieve higher incomes. This results in higher levels of total and per capita resource consumption along with more environmental degradation, waste, and pollution. These results can be dramatic. The WWF has estimated that the United States is responsible for almost half of the global ecological footprint. The average American con- sumes about 30 times the amount of resources that the average Indian consumes and 100 times the amount con-

FIGURE 1 Environmental and social scientists have identified five basic causes of the environmental problems we face (Concept 1). Question: For each of these causes, what are two environmental problems that result? Left: Jeremy Richards/Shutterstock. Left center: steve estvanik/Shutterstock. Center: Lucian Coman/Shutterstock. Right center: El Greco/ Shutterstock. Right: CREATISTA/Shutterstock.

Population growth Unsustainable resource use

Poverty Excluding environmental costs from market prices

Increasing isolation from nature

Causes of Environmental Problems

Concept 1 15

sumed by the average person in the world’s poorest coun- tries. As a result, the WWF projected that we would need 5 planet Earths to indefinitely sustain the rate of resource use of the average American. The problem is that providing such resources contrib- utes to air pollution and water pollution from factories and motor vehicles and land degradation from the mining of raw materials used to make the products we consume. Another downside to wealth is that it allows affluent con- sumers to obtain their resources from almost anywhere in the world without seeing the harmful effects of their high- consumption lifestyles. On the other hand, affluence can allow for more wide- spread and better education, which can lead people to become more concerned about environmental quality. Af- fluence can also make more money available for develop- ing technologies to reduce pollution, environmental degradation, and resource waste along with other ways to increase our beneficial environmental impact. As a result, in the United States and most other afflu- ent countries, the air is clearer, drinking water is purer, and most rivers and lakes are cleaner than they were in the 1970s. In addition, the food supply is more abundant and safer, the incidence of life-threatening infectious diseases has been greatly reduced, life spans are longer, and some endangered species are being rescued

GOOD NEWS

from extinction hastened by human activities. These im- provements were largely financed by affluence.

Poverty Can Have Harmful Environmental and Health Effects Poverty is a condition in which people are unable to fulfill their basic needs for adequate food, water, shelter, health care, and education. According to the World Bank, about 900 million people—almost three times the U. popula- tion—live in extreme poverty, struggling to live on the equiva- lent of less than $1 a day, which is less than what many people spend for a bottle of water or a cup of coffee. About one of every three, or 2 billion, of the world’s people struggles to live on less than $2 a day. Could you do this? Poverty can cause a number of harmful environmental and health effects. The daily lives of the world’s poorest people are focused on getting enough food, water, and cooking and heating fuel to survive. Desperate for short- term survival, these individuals do not have the luxury of worrying about long-term environmental quality or sus- tainability. Thus, collectively, they can degrade forests, topsoil, and grasslands, and deplete fisheries and wildlife populations in order to stay alive. However, poverty does not necessarily lead to environ- mental degradation. Some of the world’s poor people have

GLOBAL POPULATION GROWTH

2–5 million years

8000 6000 4000 2000 AD

2000

1800 (1 billion)

2100 Time

Billions of people

BC Hunting and gathering

Agricultural revolution Industrial revolution

1960 (3 billion) 1930 (2 billion)

1974 (4 billion)

1987 (5 billion)

1999 (6 billion)

2011 (7 billion)

FIGURE 1 Exponential growth: The J-shaped curve represents past exponential world population growth, with projections to 2100 showing possible population stabilization as the J-shaped curve of growth changes to an S-shaped curve. (This figure is not to scale.)

Compiled by the authors using data from the World Bank, United Nations, and Population Reference Bureau. Photo: NASA.

Concept 1 17

gue that this has led to a phenomenon known as nature deficit disorder (see About the Cover on page ii.) Thus, it is not surprising that many people do not know the full story of where their food, water, and other goods come from. Similarly, many people are unaware of the amounts of wastes and pollutants they produce, where these wastes and pollutants go, and how they affect the en- vironment. Some analysts ask: How will we live more sus- tainably by shrinking our ecological footprints and expanding our beneficial environmental impact, if we do not appreciate the beauty and importance of nature and understand that we are utterly dependent on the earth’s natural systems and the natural capital they provide? Some environmental lead- ers are focusing on this problem (Individuals Matter 1).

People Have Different Views about Environmental Problems and Their Solutions People differ over the nature and seriousness of the world’s environmental problems and over what we should do to help solve them, and these disagreements arise mostly be- cause of differing environmental worldviews. Your environ-

mental worldview is your set of assumptions and values reflecting how you think the world works and what you think your role in the world should be. Environmental ethics, the study of varying beliefs about what is right and wrong with how we treat the environment, provides useful tools for examining worldviews. For example, here are some important ethical questions relating to the environment:

Why should we care about the environment?
Are we the most important species on the planet or are we just another one of the earth’s millions of different forms of life?
Do we have an obligation to see that our activities do not cause the extinction of other species? If so, should we try to protect all species or only some? How do we decide which to protect?
Do we have an ethical obligation to pass the natural world on to future generations in a condition that is as good as or better than what we inherited?
Should every person be entitled to equal protection from environmental hazards regardless of race, gender, age, national origin, income, social class, or any other factor? (This is the central ethical and political issue for

Juan Martinez—Working to Reconnect People with Nature

National Geographic Emerging Explorer Juan Martinez learned first-hand about the value of connecting with nature, and now he spends his time working to pass along his experience and knowledge of that value to others, particularly to disadvantaged youths. Martinez grew up in a poor area of Los Angeles, California, where as a boy he was in dan- ger of becoming absorbed by a gang culture. One of his teachers recognized Martinez’s po- tential and gave him a chance to pass a class that he was failing by joining the school’s Eco Club. Martinez took that opportunity and when the club planned a field trip to see the Grand Teton Mountains of Wyoming, he jumped at the chance. As a result, he says, “I still can’t find words to describe the first moment I saw those mountains rising up from the valley. Watching bison, seeing a sky full of stars, and hiking through that scenery was overwhelming.” The experience transformed Martinez’s life. Today, he spearheads the Natural Leaders Network of the Children & Nature Network, an organization creating links between envi- ronmental organizations, corporations, government, education, and individuals to reconnect children with nature. His work as an environmental leader has inspired many others to do similar work. Martinez has received a great deal of recognition for his efforts, including invitations to White House forums on environmental education. His greatest reward, however, is in seeing how his efforts help others. He notes: “Some kids on my trips have been in foster care their whole lives, feeling very disconnected from other people and nature. Suddenly they’re out in the backcountry rely- ing on each other. Nature can be a real facilitator for skills that are so crucial in life—communicating, working together, and real- izing you can do things you never thought you could.” Background photo: djgis/Shutterstock

REBECCA HALE/National Geographic Creative

individuals matter 1.

18 ChAPTEr 1 ENVIrONMENTAL PrOBLEMS, ThEIr CAUSES, AND SUSTAINABILITY

what is known as the environmental justice movement; see Chapter 17 and the online Guest Essay by Robert D. Bullard for more on this topic.)

Should we seek to live more sustainably, and if so, how?

CONSIDER THIS... THINKING ABOUT Our Responsibilities How would you answer each of the questions above? Compare your answers with those of your classmates. Record your answers and, at the end of this course, return to these questions to see if your answers have changed.

People with widely differing environmental worldviews can take the same data, be logically consistent with it, and arrive at quite different answers to such questions because they start with different assumptions and moral, ethical, or religious beliefs. Environmental worldviews are discussed in detail in Chapter 17, but here is a brief introduction. There are three major categories of environmental worldviews: human-centered, life-centered, and earth- centered. A human-centered environmental world- view sees the natural world primarily as a support system for human life. One such worldview, the planetary manage- ment worldview, holds that humans are separate from and in charge of nature and that we can manage the earth mostly for our benefit, into the distant future. Another is the stewardship worldview, which holds that we can and should manage the earth for our benefit, but that we have an ethical responsibility to be caring and responsible man- agers, or stewards, of the earth. According to the life-centered environmental worldview, all species have value as participating mem- bers of the biosphere, regardless of their potential or actual use to humans. Most people with a life-centered world- view believe we have an ethical responsibility to avoid hastening the extinction of species through our activities. The earth-centered environmental worldview holds that we are part of, and dependent on, nature and that the earth’s life-support system exists for all species, not just for us. According to this view, our economic suc- cess and the long-term survival of our cultures and our species depend on learning how life on the earth has sus- tained itself for billions of years and integrating such les- sons from nature into the ways we think and act.

The Rise of Environmental Conservation and Protection in the United States European colonists arriving in the early 1600s viewed North America as a continent with seemingly inexhaust- ible resources and as a wilderness to be conquered and managed for human use. As the colonists spread across the continent, they cleared forests for cropland and settle- ments, plowed up grasslands to plant crops, and mined gold, lead, and other minerals.

In 1864, George Perkins Marsh, a scientist and member of Congress from Vermont, questioned the idea that the country’s resources were inexhaustible. He also used scien- tific studies and case studies to show how the rise and fall of past civilizations were linked to the use and misuse of their soils, water supplies, and other resources. Thus he was one of the founders of the U. conservation movement. Early in the 20th century, this movement split into two factions with differing views over how public lands should be used. The preservationist school, led by naturalist John Muir (Figure 1), wanted wilderness areas on some pub- lic lands to be left untouched. The conservationist school, led by Teddy Roosevelt (Figure 1) and Gifford Pinchot, the first chief of the U. Forest Service, believed all public lands should be managed wisely and scientifically, primar- ily to provide resources for people. U. conservation efforts continued to straddle these two schools of thought, and Aldo Leopold (Figure 1), wildlife manager, professor, writer, and conservationist, personified this dual approach. Trained in the conservation school, he eventually shifted toward the preservation school. He became a pioneer in forestry, soil conservation, wildlife ecology, and wilderness preservation. In 1935, he helped to found the U. Wilderness Society. Largely through his writings, especially his 1949 book A Sand County Almanac, he laid the groundwork for the field of environ- mental ethics. He contended that the role of the human species should be to protect nature, not to conquer it. Later in the 20th century, it became necessary to broaden the concept of resource conservation to include

FIGURE 1 As leader of the preservationist movement, John Muir (1838–1914) called for setting aside some of the country’s public lands as protected wilderness, an idea that was not enacted into law until 1964. Muir also proposed creating a national park system on public lands and was largely responsible for establishing Yosemite Na- tional Park in 1890. In 1892 he founded the Sierra Club, which is to this day a political force working on behalf of the environment.

20 ChAPTEr 1 ENVIrONMENTAL PrOBLEMS, ThEIr CAUSES, AND SUSTAINABILITY

Since 1970, many grassroots environmental organiza- tions have sprung up to help deal with environmental threats. Interest in environmental issues grew on many college and university campuses, resulting in the expan- sion of environmental studies courses and programs (Core Case Study). In addition, there came a growing awareness of critical, complex, and largely invisible environmental issues, including losses in biodiversity, aquifer depletion, ocean pollution and acidification, and atmospheric warm- ing and the threat of climate disruption. In the 1970s, the United States led the world in envi- ronmental awareness, wildlife conservation, and environ- mental protection. Some analysts point to this fact and call for new U. leadership in dealing with these larger and less visible long-term threats and in finding paths toward more environmentally sustainable societies and economies.

####### 1 WHAT IS AN

####### ENVIRONMENTALLY

####### SUSTAINABLE SOCIETY?

CONCEP T 1. 4 Living sustainably means living off the earth’s natural income without depleting or degrading the natural capital that supplies it.

Environmentally Sustainable Societies Protect Natural Capital and Live Off Its Income According to most environmental scientists, our ultimate goal should be to achieve an environmentally sustainable society—one that meets the current and future basic re- source needs of its people in a just and equitable manner without compromising the ability of future generations to meet their basic resource needs. This is in keeping with the future generations principle of sustainability. Imagine that you win $1 million in a lottery. Suppose you invest this money (your capital) and earn 10% inter- est per year. If you live on just the interest, or the income made by your capital, you will have a sustainable annual income of $100,000 that you can spend each year indefi- nitely without depleting your capital. However, if you consistently spend more than your income, you will de- plete your capital. Even if you spend just $110,000 per year while still allowing the interest to accumulate, your money will be gone within 18 years. The lesson here is an old one: Protect your capital and live on the income it provides. Deplete or waste your capital and you will move from a sustainable to an unsustainable lifestyle. The same lesson applies to our use of the earth’s natural capital (Figure 1)—the global trust fund of free natural resources and ecosystem services that nature has provided for us, for future generations, and for the earth’s other spe-

cies. Living sustainably means living on natural income, the renewable resources such as plants, animals, soil, clean air, and clean water, provided by the earth’s natural capital. By working to preserve and replenish the earth’s natural capital, which supplies this income, we can find the best ways to reduce our ecological footprints while expanding our beneficial environmental impact (Concept 1).

A More Sustainable Future Is Possible Making a shift toward a more sustainable future will in- volve some tough challenges. Ecologists note that, given enough time, nature can recover from many of our envi- ronmentally harmful impacts. However, natural recovery can take hundreds to thousands of years, while harmful human impacts are expanding exponentially within a time period of 10 to 100 years. Thus, in learning to live more sustainably, time is our most scarce resource. Here are two pieces of good news: First, research by social scientists suggests that it takes only 5–10% of the population of a community, a country, or the world to bring about major social and environmental change. Second, such research also shows that such change can occur in a much shorter time than most people think. Anthropologist Margaret Mead summarized our potential for social change: “Never doubt that a small group of thoughtful, committed citizens can change the world. In- deed, it is the only thing that ever has.” This is now being demonstrated on many college campuses around the world (Core Case Study). One of our goals in writing this book has been to pro- vide a realistic vision of how we can change the world, for the benefit of us all, as well as for the environment. We base this vision not on immobilizing fear, gloom, and doom, but on energizing and realistic hopes.

GOOD NEWS

A more sustainable future will require that we rely more on energy from the sun and other renewable energy sources, protect biodiversity through the preservation of natural capital, and avoid disrupting the earth’s vitally important chemical cycles.
A major goal for becoming more sustainable is full-cost pricing—the inclusion of harmful environmental and health costs in the market prices of goods and services.
We will benefit ourselves and future generations if we commit ourselves to finding win-win solutions to our problems and to leaving the planet’s life-support system in a condition as good as or better than what we now enjoy.

B

IG

IDEAS

Chapter review 21

####### Chapter Review

Core Case Study

Define sustainability, and summarize the story of how many college campuses are working to become more environmentally sustainable.

Section 1.

What are the three key concepts for this section? Define environment. Distinguish among environ- mental science, ecology, and environmentalism. Distinguish between an organism and a species. What is an ecosystem? What are three scientific princi- ples of sustainability derived from how the natural world works? What is solar energy and why is it im- portant to life on the earth? What is biodiversity and why is it important to life on the earth? Define nutri- ents. Define chemical cycling (or nutrient cycling) and explain why it is important to life on the earth.
Define natural capital. Define natural resources and ecosystem services, and give two examples of each. Give three examples of how we are degrading natural capital. Explain how finding solutions to en- vironmental problems involves making trade-offs. Explain why individuals matter in dealing with the environmental problems we face. What are three

social science principles of sustainability? What is full-cost pricing and why is it important? 4. What is a resource? Distinguish between an inex- haustible resource and a renewable resource and give an example of each. What is the sustainable yield of a renewable resource? Define and give two examples of a nonrenewable or exhaustible re- source. Distinguish between more-developed countries and less-developed countries and give one example each of a high-income, middle-income, and low-income country.

Section 1. 5. What is the key concept for this section? Define and give three examples of environmental degrada- tion (natural capital degradation). About what percentage of the earth’s natural or ecosystem ser- vices have been degraded by human activities? De- fine pollution. Distinguish between point sources and nonpoint sources of pollution and give an ex- ample of each. Distinguish between pollution cleanup and pollution prevention and give an ex- ample of each. What is the tragedy of the commons? 6. What is an ecological footprint? What is a per capita ecological footprint? Use the ecological footprint concept to explain how we are living unsus- tainably. What is meant by upcycling? What is the IPAT model for estimating our environmental impact?

We opened this chapter with a Core

Case Study about college students around the United States who are working to address many of the serious environmen- tal problems we face and to improve environmental quality on their campuses. Thousands of students on campuses all over the world are doing the same. Many of these students are learning that a key to most solutions is to apply the three scientific principles of sustainability (Figure 1) and the three social science principles of sustainability (Figure 1) to the design of our economic and social systems, and to our individual lifestyles. We can use such strategies to try to slow the rapidly expanding losses of biodiversity, to sharply reduce our production of wastes and pollution, to switch to more sustainable

sources of energy, and to promote more sustainable forms of agriculture and other uses of land and water. We can also use these principles to sharply reduce poverty and slow human population growth. You and all of your fellow students have the good fortune to be members of the 21st century’s transition generation that will play a major role in deciding whether humanity cre- ates a more sustainable future or continues on a path toward further environmental deg- radation and disruption. This means confront- ing the urgent challenges presented by the major environmental problems discussed in this book. It is an incredibly exciting and chal- lenging time to be alive as we struggle to de- velop a more sustainable relationship with this planet that is our only home.

####### TyING IT All TOGEThER

The Greening of American Campuses and Sustainability

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