Chapter 9

The environment is everything around you. It includes all the living things (such as plants and animals) and the nonliving things (such as air, water, and sunlight) with which you interact. You are part of nature and live in the environment. Despite humankind’s many scientific and technological advances, our lives depend on sunlight and on the earth for clean air and water, food, shelter, energy, fertile soil, a livable climate, and other components of the planet’s life-support system.

Environmental science is a study of connections in nature.

 it strives to answer several questions: What environmental problems do we face? How serious are they? How do they interact? What are their causes? How has nature solved such problems? How can we use our understanding of nature to solve such problems? To answer such questions, environmental science integrates information and ideas from fields such as biology, chemistry, geology, engineering, geography, economics, political science, and ethics. A key component of environmental science is ecology, the branch of biology that focuses on how living organisms interact with the living and nonliving parts of their environment. Each of the earth’s organisms belongs to a species, or a group of organisms having a unique set of characteristics that set it apart from other groups. 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 energy. For example, a forest ecosystem consists of plants (especially trees; see chapter-opening photo), animals, and other organisms that decompose organic materials. These organisms interact with one another, with solar energy, and with the chemicals in the forest’s air, water, and soil. These ecological interactions take place in the biosphere—the parts of the earth’s air, water, and soil where life is found. Environmental science and ecology should not be confused with environmentalism or environmental activism, which is a social movement dedicated to protecting the earth’s life and its resources. Environmentalism is practiced more in the realms of politics and ethics than in science. However, the findings of environmental scientists can sometimes provide evidence to back the claims and activities of environmentalists. The earth is the best example that we have of a sustainable system. Life on the earth has existed for around 3.8 billion years. During this time, the planet has experienced several catastrophic environmental changes. They include gigantic meteorite impacts, ice ages lasting millions of years, long warming periods that melted land-based ice and raised sea levels by hundreds of feet, and five mass extinctions—each wiping out more 60% to 95% of the world’s species. Despite these dramatic environmental changes, an astonishing variety of life has survived. Our study of the history of life on the earth indicates that three scientific factors play key roles in the long-term sustainability of the earth’s life, as summarized below. Understanding these three scientific principles of sustainability, or major lessons from nature, can help us move toward a more sustainable future.

• Dependence on solar energy: The sun’s energy warms the planet and provides energy that plants use to produce nutrients, the chemicals that plants and animals need to survive.

• Biodiversity: The variety of genes, species, ecosystems, and ecosystem processes are referred to as biodiversity (short for biological diversity). Interactions among species provide vital ecosystem services and keep any population from growing too large. Biodiversity also provides ways for species to adapt to changing environmental conditions and replace species wiped out by catastrophic environmental changes with new species.

• Chemical cycling: The circulation of chemicals or nutrients needed to sustain life from the environment (mostly from soil and water) through various organisms and back to the environment is called chemical cycling, or nutrient cycling. The earth receives a continuous supply of energy from the sun, but it receives no new supplies of life-supporting chemicals. Through billions of years of interactions with their living and nonliving environment, organisms have developed ways to continually recycle the chemicals they need to survive. This means that the wastes and decayed bodies of organisms become nutrients or raw materials for other organisms. In nature, waste = useful resource. Sustainability, the integrating theme of this book, has several key components that we use as subthemes. One is natural capital—the natural resources and ecosystem services that keep humans and other species alive and that support human economies. Natural resources are materials and energy provided by nature that are essential or useful to humans. They fall into three categories: inexhaustible resources, renewable resources, and nonrenewable (exhaustible) resources. Solar energy is viewed as an inexhaustible or perpetual resource because it is expected to last for at least 5 billion years until the death of the star we call the sun. A renewable resource is any resource that can be replenished by natural processes within hours to decades, as long as people do not use the resource faster than natural processes can replace it. Examples include forests, grasslands, fertile topsoil, fishes, clean air, and fresh water. The highest rate at which people can use a renewable resource indefinitely without reducing its available supply is called its sustainable yield. Nonrenewable or exhaustible resources exist in a fixed amount, or stock, in the earth’s crust. They take millions to billions of years to form through geological processes. On the much shorter human time scale, we can use these resources faster than nature can replace them. Examples of nonrenewable resources include fossil fuel energy resources (such as oil, coal, and natural gas), metallic mineral resources (such as copper and aluminum), and nonmetallic mineral resources (such as salt and sand). As we deplete nonrenewable resources, sometimes we can find substitutes.

• Ecosystem services are natural services provided by healthy ecosystems that support life and human economies at no monetary cost to us. For example, forests help purify air and water, reduce soil erosion, regulate climate, and recycle nutrients. Thus, our lives and economies are sustained by energy from the sun and by natural resources and ecosystem services (natural capital) provided by the earth.

• A vital ecosystem service is nutrient cycling, which is a scientific principle of sustainability. For example, without nutrient cycling in topsoil there would be no land plants, and no humans or other land animals. This would also disrupt the ecosystem services that purify air and water.

• A second component of sustainability—and another subtheme of this text—is that human activities can degrade natural capital. We do this by using renewable resources faster than nature can restore them, for example, by depleting fisheries faster than the fish can reproduce or by overloading the earth’s normally renewable air, water, and soil with pollution and wastes. These are both examples of the tragedy of the commons. People in many parts of the world are replacing forests with crop plantations that require large inputs of energy, water, fertilizer, and pesticides. We also add pollutants to the air and dump chemicals and wastes into rivers, lakes, and oceans faster than they can be cleansed through natural processes. Many of the plastics and other synthetic materials people use poison wildlife and disrupt nutrient cycles because they cannot be broken down and used as nutrients by other organisms.

This leads us to a third component of sustainability: creating solutions to the environmental problems we face. For example, a solution to the loss of forests (see chapter-opening photo) is to stop burning or cutting down mature forests. This cannot be done unless governments and citizens are aware of the ecosystem services forests provide and citizens pressure governments to pass laws to protect mature forests. Overfishing might be reduced by instituting fishing quotas or by issuing permits limiting the number of fish that can be taken by commercial fishing fleets so that fisheries have a chance to recover.

Conflicts can arise when environmental protection has a negative economic effect on groups of people or certain industries. Dealing with such conflicts often involves both sides making compromises or trade-offs. For example, a timber company might be persuaded to plant and harvest trees in an area that it had already cleared or degraded instead of clearing an undisturbed mature forest area. In return, the government may subsidize (pay part of the cost) of planting the new trees.

Each of us can play an important role in learning how to live more sustainably. Thus, individuals matter—another sustainability subtheme of this book.

Economics, politics, and ethics can provide us with three additional principles of sustainability.

• Full-cost pricing (from economics): Some 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. This practice, called full-cost pricing, would give consumers information about the harmful environmental impacts of products.

• Win-win solutions (from political science): Political scientists often look for win-win solutions to environmental problems based on cooperation and compromise that will benefit the largest number of people as well as the environment.

• Responsibility to future generations (from ethics): Ethics is a branch of philosophy devoted to studying ideas about what is right or wrong. According to environmental ethicists, we should leave the planet’s life-support systems in a condition that is as good as or better than it is now as our responsibility to future generations.

The United Nations (UN) classifies the world’s countries as economically more developed or less developed, based primarily on their average income per person. More-developed countries—industrialized nations with high average incomes per person—include the United States, Japan, Canada, Australia, Germany, and most other European countries. These countries, with 17% of the world’s population use about 70% of the earth’s natural resources. The United States, with only 4.3% of the world’s population, uses about 30% of the world’s resources.

All other nations are classified as less-developed countries, most of them in Africa, Asia, and Latin America. Some are middle-income, moderately developed countries such as China, India, Brazil, Thailand, and Mexico. Others are low-income, least-developed countries including Nigeria, Bangladesh, Congo, and Haiti. The less-developed countries, with 83% of the world’s population, use about 30% of the world’s natural resources. As the world’s dominant animal, we have an awesome power to degrade or sustain the life-support system for our own and other species. We decide whether forests are preserved or cut down and engineer the flows of rivers. Our activities affect the temperature of the atmosphere and the temperature and the acidity of the ocean. We also contribute to the extinction of species. At the same time, our creativity, economic growth, scientific research, grassroots political pressure by citizens, and regulatory laws have improved the quality of life for many of the earth’s people, especially in the United States and in most other more-developed countries.

We have developed an astounding array of useful materials and products. We have learned how to use wood, fossil fuels, the sun, wind, flowing water, the nuclei of certain atoms, and the earth’s heat (geothermal energy) to supply us with enormous amounts of energy. We have created artificial environments in the form of buildings and cities. We have invented computers to extend our brains, robots to do work for us, and electronic networks to enable instantaneous global communication.

Globally, lifespans are increasing, infant mortality is decreasing, education is on the rise, some diseases are being conquered, and the population growth rate has slowed. While one out of seven people live in extreme poverty, we have witnessed the greatest reduction in poverty in human history. The food supply is generally more abundant and safer, air and water are getting cleaner in many parts of the world, and exposure to toxic chemicals is more avoidable. We have protected some endangered species and ecosystems and restored some grasslands and wetlands, and forests are growing back in some areas that we cleared.

Scientific research and technological advances financed by affluence helped achieve these improvements in life and environmental quality. Education also spurred many citizens who insist that businesses and governments work toward improving environmental quality. We are a globally connected species with growing access to information and technologies that could help us to shift to a more sustainable path. According to a large body of scientific evidence, we are living unsustainably. We waste, deplete, and degrade much of the earth’s life-sustaining natural capital—a process known as environmental degradation, or natural capital degradation. Research reveals that human activities directly affect about 83% of the earth’s land surface (excluding Antarctica). This land is used for things such as growing crops, grazing livestock, harvesting timber, mining, burying wastes, towns and cities (urban land), and recreation such as hiking and skiing. In parts of the world, we are destroying forests and grasslands, withdrawing water from some rivers and underground aquifers faster than nature replenishes them, and harvesting many fish species faster than they can be renewed. We also litter the land and oceans with wastes faster than they can be recycled by the earth’s natural chemical cycles. In addition, we add pollutants to the air (including some that are altering the earth’s climate), soil, underground aquifers, rivers, lakes, and oceans.

In many parts of the world, renewable forests are shrinking, deserts are expanding, and topsoil is eroding. The lower atmosphere is warming, floating ice and many glaciers are melting at unexpected rates, sea levels are rising, and ocean acidity is increasing. There are more intense floods, droughts, severe weather, and forest fires in many areas. In a number of regions, rivers are running dry, harvests of many species of fish are dropping sharply, and 20% of the world’s species-rich coral reefs are gone and others are threatened. Species are becoming extinct at least 100 times faster than in prehuman times. In addition, extinction rates are projected to increase at least another 100-fold during this century, creating a sixth mass extinction caused by human activities.

Humans use, and in some cases, degrade about 83% of the earth’s land. Much of this land use benefits humans. However, land use by humans can also have harmful environmental effects. Examples are forest loss, overgrazing of grassland, soil erosion, runoff of fertilizers and pesticides from cropland, oil spills from oil wells, large pits created by mining, removal of mountaintops to extract coal, and loss of wildlife habitat. Indeed, the biggest threat to the earth’s biodiversity of species is loss and fragmentation of land habitats.

Lands are often classified according to their use as private and public. Private lands are owned by individuals or business. Owners use them for purposes such growing crops, grazing livestock, harvesting timber, mining, housing, and other buildings.

Public lands are typically owned jointly by the citizens of a country but are managed by the government. In the United States, the federal government owns and manages about 28% of the country’s land. This includes 47% of the land in the western United States and 61% of the land in Alaska.

Federal public lands in the United States include the:

• National Park System managed by the National Park Service (NPS]

• Nation Forest System managed by the US Forest Service (USFS)

• Land managed by the Bureau of Land Management (BLM)

• National Wildlife Refuges managed by the US Fish and Wildlife Service

• National Wilderness Preservation System consisting of designated areas in the above systems and managed by the government agencies in charge of those systems. These protected lands are open only for recreational activities such hiking, fishing, camping, sport fishing, and nonmotorized boating.

The use and harmful environmental effects of private and public land is discussed in 14 of the 20 chapters in this book. In other words, land use is a major theme that runs throughout most of this book. Using renewable resources benefits us but can result in natural capital degradation, pollution, and wastes. This harmful environmental impact is called an ecological footprint—the amount of biologically productive land and water needed to supply a population in an area with renewable resources and to absorb and recycle the wastes and pollution such resource use produces.

This measure of sustainability evaluates the ability or biocapacity of the earth’s productive ecosystems to regenerate the renewable resources used by a population, city, region, country, or the world in a given year. The per capita ecological footprint is the average ecological footprint of an individual in a given country or area.

The World Wide Fund for Nature (WWF) and the Global Footprint Network estimate that we would need 1.5 planet earths to sustain the world’s 2012 rate of renewable resource use far into the future. In other words, the world’s total ecological footprint in 2012 was 50% higher than the planet’s estimated long-term biocapacity and has increased since 2012. This overdraft of the earth’s natural resources and ecosystem services is being passed on to future generations.

In the early 1970s, scientists Paul Ehrlich and John Holdren developed a simple environmental impact model. This IPAT model shows that the environmental impact (I) of human activities is the product three factors: population size (P), affluence (A) or resource consumption per person, and the beneficial and harmful environmental effects of technologies (T). The following equation summarizes this IPAT model: I=(p)(a)(t)

While the ecological footprint model emphasizes the use of renewable resources, the IPAT model includes the environmental impact of using both renewable and nonrenewable resources.

The T factor can be harmful or beneficial. Some forms of technology such as polluting factories, gas-guzzling motor vehicles, and coal-burning power plants increase our harmful environmental impact by raising the T factor. For example, new fishing technology for harvesting large quantities of fish led to the collapse of the Atlantic cod fishery.

Other technologies reduce our harmful environmental impact by decreasing the T factor. Examples are pollution control and prevention technologies, fuel-efficient cars, and wind turbines and solar cells that generate electricity with a low environmental impact.

In a less-developed country such as India, population size is a more important factor than resource use per person in determining the country’s environmental impact. In a highly developed country such as the United States with a much smaller population, resource use per person and the ability to develop environmentally beneficial technologies play key roles in the country’s environmental impact.

Until about 10,000 to 12,000 years ago, we were mostly hunter–gatherers who obtained food by hunting wild animals or scavenging their remains, and gathering wild plants. Our hunter–gatherer ancestors lived in small groups, consumed few resources, had few possessions, and moved as needed to find enough food to survive.

Since then, three major cultural changes have occurred. First was the agricultural revolution, which began around 10,000 years ago when humans learned how to grow and breed plants and animals for food, clothing, and other purposes and began living in villages instead of frequently moving to find food. They had a more reliable source of food, lived longer, and produced more children who survived to adulthood.

Second was the industrial–medical revolution, beginning about 300 years ago when people invented machines for the large-scale production of goods in factories. Many people moved from rural villages to cities to work in the factories. This shift involved learning how to get energy from fossil fuels (such as coal and oil) and how to grow large quantities of food in an efficient manner. It also included medical advances that allowed a growing number of people to have longer and healthier lives. Third, about 50 years ago the information–globalization revolution began when we developed new technologies for gaining rapid access to all kinds of information and resources on a global scale.

Each of these three cultural changes gave us more energy and new technologies with which to alter and control more of the planet’s resources to meet our basic needs and increasing wants. They also allowed expansion of the human population, mostly because of larger food supplies and longer lifespans. In addition, these cultural changes resulted in greater resource use, pollution, and environmental degradation and allowed us to dominate the planet and expand our ecological footprints.

On the other hand, some technological leaps have enabled us to shrink our ecological footprints by reducing our use of energy and matter resources and our production of wastes and pollution.

Many environmental scientists and other analysts see such developments as evidence of an emerging fourth major cultural change: a sustainability revolution, in which we could learn to live more sustainably during this century. This involves not degrading or depleting the natural capital that supports all life and our economies and restoring natural capital that we have degraded. Making this shift involves learning how nature has sustained life for over 3.8 billion years and using these lessons from nature to shrink our ecological footprints and grow our beneficial environmental impacts. Exponential growth occurs when a quantity increases at a fixed percentage per unit of time, such as 0.5% or 2% per year. Exponential growth starts slowly but after a few doublings it grows to enormous numbers because each doubling is twice the total of all earlier growth. When we plot the data for an exponentially growing quantity, we get a curve that looks like the letter J.

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 reproduction), there would be enough bacteria to form a layer 0.3 meters (1 foot) deep over the entire earth’s surface.

The human population has grown exponentially to the current population of 7.5 billion people. In 2016, the rate of growth was 1.20%. Although this rate of growth seems small, it added 89.8 million people to the world’s huge base of 7.5 billion people. By 2050, the world’s population could reach 9.9 billion—an addition of 2.4 billion people. The human population is still growing rapidly but its annual rate of growth has generally dropped since the 1960s. No one knows how many people the earth can support indefinitely. However, our large and expanding ecological footprints and the resulting widespread natural capital degradation are disturbing warning signs.

Some analysts call for us to reduce environmental degradation by slowing population growth and level it off at around 8 billion by 2050 instead of 9.9 billion.  The lifestyles of the world’s expanding population of consumers are built on growing affluence, or resource consumption per person, as more people earn higher incomes. As total resource consumption and average resource consumption per person increase, so does environmental degradation, wastes, and pollution from the increase in environmental footprints.

The effects can be dramatic. The WWF and the Global Footprint Network estimate that the United States, with only 4.3% of the world’s population, is responsible for about 23% of the global environmental footprint. The average American consumes about 30 times the amount of resources that the average Indian consumes and 100 times the amount consumed by the average person in the world’s poorest countries. The WWF has projected that we would need five planet earths if everyone used renewable resources at the same rate as the average American did in 2012. The earlier number of earths involved the world’s average per capita use of renewable resources. This one assumes that everyone if the world has the same use of renewable resources as the average American had in 2012’’ On the other hand, affluence can allow for widespread and better education that can lead people to become more concerned about environmental quality. Affluence also makes more money available for developing technologies to reduce pollution, environmental degradation, and resource waste along with ways to increase our beneficial environmental impacts. Poverty is a condition in which people lack enough money to fulfill their basic needs for food, water, shelter, health care, and education. Bad News: According to the World Bank, about one of every three people, or 2.6 billion people, struggled to live on less than $3.10 a day in 2015. In addition, 1 billion people living in in extreme poverty struggled to live on the equivalent of less than $1.90 a day—less than what many people spend for a bottle of water or a cup of coffee. Could you do this?

The daily lives of the world’s poorest people center on getting enough food, water, and cooking and heating fuel to survive. Typically, these individuals are too desperate for short-term survival to worry about long-term environmental quality or sustainability. Thus, they may be forced to degrade forests, topsoil, and grasslands, and deplete fisheries and wildlife populations to stay alive.

Poverty does not always lead to environmental degradation. Some of the poor increase their beneficial environmental impact by planting and nurturing trees and conserving the soil that they depend on as a part of their long-term survival strategy.

Environmental degradation can have severe health effects on the poor. One problem is life-threatening malnutrition, a lack of protein and other nutrients needed for good health. Another effect is illness caused by limited access to adequate sanitation facilities and clean drinking water. As a result, about one of every nine of the world’s people get water for drinking, washing, and cooking from sources polluted by human and animal feces. The World Health Organization (WHO) estimates that these factors—mostly related to poverty—cause premature death for about 7 million children under age of 5 each year. Some hopeful news is that this number of annual deaths is down from about 10 million in 1990. Even so, every day an average of at least 19,000 young children die prematurely from these causes. This is equivalent to 95 fully loaded 200-passenger airliners crashing every day with no survivors. The news media rarely cover this ongoing human tragedy.

Ways to reduce to reduce poverty include:

• Reducing malnutrition and infectious diseases that kill millions of people

• Making small, low-interest loans (microloans) to poor people who want to increase their income 

Another basic cause of environmental problems has to do with how the marketplace prices goods and services. Companies providing goods for consumers generally are not required to pay for most of the harmful environmental and health costs of supplying such goods. For example, timber companies pay the cost of clear-cutting forests but do not pay for the resulting environmental degradation and loss of wildlife habitat.

The primary goal of a company is to maximize profits for its owners or stockholders, so it is not inclined to add these costs to its prices voluntarily. Because the prices of goods and services do not include most of their harmful environmental and health costs, consumers have no effective way to know the harm caused by what they buy. This lack of information is a major reason for why we are degrading key components of our life-support system.

For example, producing and using gasoline results in air pollution and other problems that damage the environment and people’s health. Scientists and economists have estimated that the price of gasoline to US consumers would rise by $3.18 per liter ($12 per gallon) if the estimated short- and long-term harmful environmental and health costs were included in its pump price. Thus, when gas costs $2 per gallon, US consumers are really paying about $14 per gallon. Consumers pay these hidden environmental and health costs, but not at the gas pump.

Today, more than half of the world’s people and three out of four people in more-developed countries live in urban areas. This shift from rural to urban living is continuing at a rapid pace. Urban environments and the increasing use of cell phones, computers, and other electronic devices are isolating people, especially children, from the natural world. Some argue that this has led to a phenomenon known as nature deficit disorder.

Children and adults can gain many benefits from outdoor activities. Research indicates that experiencing nature (see the chapter opening photo) can lead to better health, reduced stress, improved mental abilities, and increased imagination and creativity. It also can provide a sense of wonder and connection to the earth’s life-support system that keeps us alive and supports our economies.

One of the reasons why environmental problems persist is that people differ over the nature and seriousness of the world’s environmental problems as well as how to solve them. These conflicts arise mostly because of differing environmental worldviews.

Your environmental worldview is the assumptions and beliefs that you have about how the natural world works and how you think you should interact with the environment. Your environmental worldview is determined partly by your environmental ethics—what you believe about what is right and what is wrong in your behavior toward the environment. The collapse of the Atlantic cod fishing industry in Newfoundland, Canada illustrates one of the causes of environmental problems. A growing population increases the consumption of fish, which puts pressure on the fishing industry to harvest increasingly larger fish catches. Rising affluence leads to increased resource use per person, which also promotes larger fish harvests. The resulting increase in industrialized commercial fishing can deplete populations of cod and other fish that some of the poor catch and eat in order to survive. The market prices of Atlantic cod and other fish do not include the harmful environmental and health effects of the industrialized fishing industry that uses large amounts of energy to catch and process fish, which adds pollutants to the air and water. Driving the Atlantic cod to commercial extinction also disrupts the aquatic ecosystem where it is found and affects other species that feed on the cod.

Because people are increasingly isolated from nature, they do not understand how the earth’s life-support systems works and how it keeps them alive and supports the economies that provide them with goods and services, including Atlantic cod and other fish. Thus, there is little political pressure to regulate fishing industry catches to prevent the overfishing of commercially valuable fish species.

The predominant planetary management environmental worldview is that we are in charge of nature and that nature exists primarily to meet our needs and wants. With this view, there is little pressure to develop regulations that could prevent the collapse of the Atlantic cod and other commercial fisheries by establishing sustainable harvest levels for each species.

One way to deal with the difficult problem of the tragedy of the commons is to use a shared or open-access renewable resource at a rate well below its estimated sustainable yield. Many coastal fishing communities have developed allotment and enforcement systems for controlling fish catches in which each fisher gets a share of the total allowable catch. This cooperative approach has sustained fisheries and fishing jobs in many communities for thousands of years. However, the rise of international industrialized fishing fleets has reduced the effectiveness of this approach. Today, some coastal fishing communities and the government work together to manage fisheries to prevent overfishing.

Another approach is to convert open-access renewable resources to private ownership. The reasoning is that if you own something, you are more likely to protect your investment. However, history shows that this does not necessarily happen. In addition, this approach is not possible for open-access resources such as the atmosphere, ocean fisheries, and our global life-support system, which cannot be divided up and sold as private property. Economics is the social science that deals with the production, distribution, and consumption of goods and services to satisfy people’s needs and wants. Most economic systems use three types of capital, or resources, to produce goods and services. Natural capital includes resources and ecosystem services produced by the earth’s natural processes that support all life and all economies. Human capital includes the physical and mental talents of the people who provide labor, organizational and management skills, and innovation. Economic growth includes the machinery, materials, and factories that people create using natural resources.

Economic growth is an increase in the capacity of a nation, state, city, or company to provide goods and services to people. Today, a typical industrialized country depends on a linear high-throughput economy, which attempts to boost economic growth by increasing the flow of matter and energy resources through the economic system to produce more goods and service. Such an economy produces valuable goods and services. However, it also converts large quantities of high-quality matter and energy resources into waste, pollution, and low-quality heat, which tend to flow into planetary sinks (air, water, soil, and organisms). Ecological economists have a biosphere-based model for an economy. They view human economic systems as subsystems of the biosphere that depend heavily on the earth’s irreplaceable natural resources and ecosystem services. According to environmental economists and environmental scientists, the best long-term and more sustainable solution to our environmental and resource problems is to shift away from a linear, high-throughput (high-waste) economy based on ever-increasing matter and energy flow. The goal would be to shift to a more sustainable circular, low-throughput (low-waste) economy over the next several decades. A low-throughput economy works with nature by

• (1)

• reusing and recycling most nonrenewable matter resources;

• (4)

• reducing environmentally harmful forms of consumption; and

• (5)

• promoting pollution prevention and waste reduction.

According to environmental economists, we could live more sustainably and increase our beneficial environmental impact by including the harmful environmental and health costs of the goods and services into market prices and placing a monetary value on the natural capital that supports all economies. This practice is called full-cost pricing, and is one of the six principles of sustainability. 

Another problem can arise when governments (taxpayers) give companies subsidies such as tax breaks and payments to assist them with using resources to run their businesses. This helps to create jobs and stimulate economies.

However, some subsidies can encourage the depletion and degradation of natural capital. Examples include depletion subsidies and tax breaks for extracting minerals and fossil fuels, cutting timber on public lands, and irrigating with low-cost water. Environmental scientists and economists call for phasing out environmentally harmful subsidies and tax breaks and phasing in environmentally beneficial subsidies and tax breaks. More subsidies and tax breaks would go to businesses involved in pollution prevention, waste prevention, sustainable forestry and agriculture, conservation of water supplies, energy efficiency improvements, renewable energy use, and measures to slow projected climate change.

A number of economists call for taxing pollution and wastes that people want less of instead of taxing wages and profits that people want more of. A more environmentally sustainable economic and political system would lower taxes on labor, income, and wealth, and raise taxes on environmental activities that produce pollution, wastes, and environmental degradation. Economic growth is usually measured by the percentage of change per year in a country’s gross domestic product (GDP): the annual market value of all goods and services produced by all firms and organizations, foreign and domestic, operating within a country. A country’s economic growth per person is measured by changes in the per capita GDP: the GDP divided by the country’s total population at midyear.

GDP and per capita GDP indicators provide a standardized, useful method for measuring and comparing the economic outputs of nations. However, the GDP was deliberately designed to measure such outputs without taking into account their beneficial or harmful environmental and health impacts. Environmental and ecological economists and environmental scientists call for the development and widespread use of new indicators—called environmental indicators—to help monitor environmental quality and human well-being.

Governments play a key role in dealing with environmental problems. They do this by developing environmental policy. It consists of environmental laws, regulations, and programs that are designed, implemented, and enforced by one or more government agencies. 

During the 1950s and 1960s, the United States experienced severe pollution and environmental degradation as its economy grew rapidly without pollution control laws and regulations. This changed in the late 1960s and 1970s when massive protests by millions of US citizens led Congress to pass a number of major environmental laws and establish government regulatory agencies to develop environmental regulations and implement them. These agencies include the Environmental Protection Agency (EPA), the Department of Energy (DOE), the US Fish and Wildlife Service (USFWS), National Marine Fisheries Service (NMFS), and the Occupational Safety and Health Administration) (OSHA). Implementing these laws has provided millions of jobs and profits from many new technologies for reducing pollution and environmental degradation. Since 1980, a well-organized and well-funded movement has mounted a strong campaign to weaken the country’s environmental laws (often by reducing EPA funding for implementing them) laws), repeal existing US environmental laws and regulations, and do away with the EPA. Since 2000, these efforts have intensified. Despite such intensive and prolonged efforts US environmental laws, have been effective, especially in controlling some forms of pollution and in protecting wild species from extinction. Implementing these laws has also provided millions of jobs and profits from many new technologies for reducing pollution and environmental degradation. Governments are legitimately concerned with military security and economic security. However, ecologists and many economists point out that all economies are supported by the earth’s natural capital. They call for governments to increase their efforts for providing environmental security and recognizing that environmental, economic, and national security are interrelated.

According to environmental scientist Norman Myers: “If a nation’s environmental foundations are degraded or depleted, its economy may well decline, its social fabric deteriorate, and its political structure become destabilized as growing numbers of people seek to sustain themselves from declining resource stocks. Thus, national security is no longer about fighting forces and weaponry alone. It relates increasingly to watersheds, croplands, forests, genetic resources, climate, and other factors that, taken together, are as crucial to a nation’s security as are military factors.”

A number of international environmental organizations help shape global environmental policy and improve environmental security and sustainability. Perhaps the most influential is the United Nations, which houses a large family of organizations including the UN Environment Programme (UNEP), the World Health Organization (WHO), the UN Development Programme (UNDP), the World Bank, and the UN Food and Agriculture Organization (FAO). An environmentally sustainable society protects natural capital and lives on its income. Such a society would meet the current and future basic resource needs of its people. This would be done 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 ethical principle of sustainability.

Imagine that you win $1 million in a lottery. Suppose you invest this money (your capital) and earn 10% interest per year. If you live on just the interest income made by your capital, you will have a sustainable annual income of $100,000. You can spend $100,000 each year indefinitely and not deplete your capital. However, if you consistently spend more than your income, you will deplete your capital. Even if you spend just $10,000 more 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 . This natural capital is a global trust fund of natural resources and ecosystem services available to people now and in the future and to the earth’s other species. Living sustainably means living on natural income, which is the renewable resources such as plants, animals, soil, clean air, and clean water, provided by the earth’s natural capital. By preserving and replenishing the earth’s natural capital that supplies this income, we can reduce our environmental footprints and expand our beneficial environmental impact.

Living more sustainability means learning to live within limits imposed on all life by the earth and the unbreakable scientific laws that govern our use of matter and energy. Doing this requires:

• Learning from nature 

• Protecting natural capital

• Not wasting resources (there is no waste in nature)

• Recycling and reusing nonrenewable resources

Environmental problems are so complex and widespread that it may seem hopeless, but that is not true. There is plenty of reason to hope and to act. For instance, consider these two pieces of good news from the social sciences. First, research suggests that it takes only 5% to 10% of the population of a community, a country, or the world to bring about major social and environmental change. Second, this research also shows that such change can occur much faster than most people believe.

Anthropologist Margaret Mead summarized the potential for social change: “Never doubt that a small group of thoughtful, committed citizens can change the world. Indeed, it is the only thing that ever has.” Engaged citizens in communities and schools around the world are proving Mead right.

One of our goals in writing this book has been to provide a realistic vision of how we can live more sustainably. We base this vision not on immobilizing fear, gloom, and doom, but on education about how the earth sustains life and on energizing and realistic hope.