Module 1

Module 1: Perspectives on the Environment

Overview

This module will introduce you to the concept of how the four systems of the environment—the biosphere, atmosphere, hydrosphere, and lithosphere—interact. You will learn about the history of the environmental movement and how it evolved to its present status. We also will discuss the impact that humans have had on the environment.

Report broken links or any other problems on this page.

Copyright © by University of Maryland University College.

Module 1: Perspectives on the Environment

Objectives

After completing this module, you should be able to:

define biosphere, atmosphere, hydrosphere, and lithosphere, and give an example of how they interact
explain how the human population increase can affect the environment
develop a general understanding of how human impact has affected the current state of the environment
discuss how the environmental movement evolved by naming, describing, and explaining the four major stages of the environmental movement
define environmental terms

Report broken links or any other problems on this page.

Copyright © by University of Maryland University College.

Module 1: Perspectives on the Environment

Commentary

Introduction

The Earth's Spheres
Chaos Theory

Human Population Issues

Growth Rate
Carrying Capacity
Thomas Malthus
Resource Use

Current State of the Environment

Air and Water Pollution
Loss of Wetlands
Overpopulation
Urban Sprawl
Waste Generation
Conspicuous Consumption
Technological Advances/Obsolescence
Tragedy of the Commons

Development of the Environmental Movement

The Conservation Movement
The Preservation Movement
The Environmental Protection Movement
The Sustainability Movement

Introduction

Environmental science is a branch of science that applies biology, chemistry, geology, physics, meteorology, and other disciplines toward solving environmental problems. By studying the interaction of these disciplines, we can better understand how the earth's environment functions.

Just as the human body has systems that perform vital functions, the earth also has systems that work together to ensure a viable planet. The earth's systems are described as spheres: the atmosphere, biosphere, hydrosphere, and the lithosphere. The atmosphere is the layer of gases that surround the earth and the biosphere is the layer of living organisms that are on the earth. The hydrosphere is the liquid layer and includes the oceans, rivers, lakes, and other bodies of water. The lithosphere is the rock layer that forms the surface of the earth and is composed of the crust(Popup 1 linked here) and the upper portion of the mantle.

These spheres interact with one another and help the earth system function as a whole. Matter and energy flow from one sphere to another and form biogeochemical cycles(Popup 2 linked here) that transport elements such as carbon, hydrogen, oxygen, and nitrogen through the spheres. These cycles occur when matter changes form and enters another phase.

These systems, or spheres, can transport elements, compounds, and pollutants between living and nonliving components of the earth.

Pollution occurring in one sphere can be transported to another sphere. For example, the by-products of fossil fuel combustion can combine with water vapor in one sphere (the atmosphere) to form acid rain. This acidified rain can fall to the ground, affecting the biosphere and the hydrosphere, causing trees to lose their leaves, lakes to become acidic, and aquatic organisms to die.

In 1960, a meteorologist by the name of Edward Lorenz developed the Chaos Theory, which described how small changes in one part of a system could bring about large changes in another part of a system. Specifically, Lorenz was interested in explaining how the atmosphere is affected by small changes in other spheres. The Chaos Theory was also called the "Butterfly Effect." If the Chaos Theory were correct, could a butterfly flapping its wings in one part of the world create a tornado in another part of the world?

There is much to be learned about how the earth's spheres interact and about the feedback mechanisms, both positive and negative, that are at work. However, scientists are aware that human activities are providing input into the system and changing the balance of the natural cycles at an unprecedented rate.

Return to top of page

Human Population Issues

The growth rate of the human population is an important issue in the study of environment science. The expanding and growing human population is rapidly placing great demands on the earth's limited resources. The exploitation of these resources is creating environmental problems on a global scale. Approximately 5.8 billion people inhabit the earth and 10,000 people are added every hour (McKinney and Schoch 1996, 114). Water, mineral, and soil resources are not equally distributed on earth and therefore, not every part of the terrain on earth is suitable for human habitation.

Approximately 1 million years ago, the earth's total human population was about 125,000 (ibid.). About 10,000 years ago, humans developed agrarian societies that learned to grow their own food instead of hunting and gathering. This settled lifestyle allowed women to bear and raise more children that were necessary for the planting and harvesting of crops. By the year 1750, the human population had grown to 800 million, then to 1.2 billion in the 1850s, and then to over 2.5 billion in the 1950s (ibid., 117–118). The current world population is estimated to be over 6 billion and growing. Would you like to see how fast the world's population is growing?(Popup 3 linked here).

What is the earth's carrying capacity(Popup 4 linked here)? Some scientists argue that the earth's carrying capacity has already been exceeded because humans are conducting activities in the environment that are not sustainable.

Thomas Malthus(Popup 5 linked here), in his 1798 essay, "An Essay on the Principle of Population, as it Affects the Future Improvement of our Society," explained that an increasing population would soon outstrip the resources that it was dependent on. He added that if the population did not find a means of stabilizing itself, its rate of growth would be corrected through disease, famine, or possibly warfare (ibid., 120).

Unfortunately, as population size increases, the environment becomes degraded, but various populations affect the environment differently. People in the more developed countries (MDCs) create a greater demand on the earth's resources than do people living in less developed countries (LDCs). The United States alone makes up only 5 percent of the world’s population, but uses 25 percent of the world's energy resources (ibid., 126).

Although the world's population is increasing, the diversity of cultures is decreasing. Tribal people and indigenous cultures have been threatened and some have already become extinct. For example, in Brazil, almost 100 tribes have become extinct during this century (ibid., 134). Indigenous people preserve and maintain their diverse ecological environment by having a low ecological impact through their limited use of resources.

The human species will need to learn how to reduce its impact on the earth's limited resources by developing sustainable lifestyles.

Return to top of page

Current State of the Environment

The earth's environment is regulated by a series of complex organic and inorganic processes, which are being altered by the activities of humankind. This has led to concern about such issues as global warming and ozone depletion. Some scientists believe that the build-up of carbon dioxide, methane, CFCs(Popup 6 linked here), and nitrous oxide are contributing to global warming; other scientists question whether there is a link. Do we wait and see or do we implement regulations that will limit emissions and require the installation of expensive technological solutions? Whatever the outcome of this debate, we cannot ignore the very real environmental degradation that has been caused by human activities.

In 1985, scientists reported that the ozone layer over Antarctica was thinning and was 50 percent lower than normal (Nebel and Wright 1998, 422). CFCs were discovered to be the culprit behind this ozone depletion(Popup 7 linked here) and their production is gradually being phased out by the industrial nations of the world. The destruction of the world's rainforests is a very real problem; every year, approximately 50,000 square miles of tropical rainforest are lost to logging and field clearing (Buchholz 1998, 5). With this deforestation comes a loss in diversity. Rainforests cover less than 5 percent of the world's surface, but are home to perhaps 50 percent of the earth's species (ibid., 4). Biologists believe that species extinction is occurring at a more rapid rate than at any time since the extinction of the dinosaurs.

Acid rain and acid deposition(Popup 8 linked here) are devastating forests(Popup 9 linked here) worldwide; air pollution problems have caused approximately 60 cities in the United States to exceed one or more of the Clean Air Standards(Popup 10 linked here). Coastal towns along the U.S. Atlantic Ocean and the Gulf of Mexico have had to close their beaches. Groundwater is being contaminated through the application of fertilizers, pesticides, and mismanaged waste disposal. In the United States, wetlands are being destroyed at a rate of between 350,000 and 500,000 acres per year (ibid.). Americans generate 158 million tons of municipal solid waste every year and 70 percent of their municipal landfills are expected to reach capacity by the year 2013 (ibid.).

Worldwide problems also are emerging. A quarter of Russia's drinking water is unsafe and all its major rivers are polluted (ibid., 6). In East Germany, a third of the rivers and 9,000 lakes are biologically dead, and in Romania, 80 percent of the river water is not potable(Popup 11 linked here) (ibid.). Similar situations exist throughout the world.

Contributors to the Problem: Ninety million people are added to the planet every year (Nebel and Wright 1998, 13). Population growth means more people, which means more goods and services to meet their growing needs. Urban sprawl(Popup 12 linked here) has contributed more cars, more roads, and more air pollution. Rising affluence allows people to buy more, consume more, and discard more. Technological advances have created new products (with more packaging) and rapid innovation has increased the rate of obsolescence. Synthetic products are replacing natural products, making disposal and degradation of these new products difficult. The environmental cost of making a product is not taken into consideration when evaluating the cost of its production. This had led to the Tragedy of the Commons. A commons is a resource that is available for all members of society to use without cost. When there is no incentive for society to limit its use, the commons soon becomes severely polluted and its carrying capacity(Popup 4 linked here) exceeded. This realization has led to the development of regulations at a national level and international treaties at a global level that are designed to protect the interests of society.

Return to top of page

Development of the Environmental Movement

The human race started out as a hunter/gatherer society that had a low impact on the environment. Eventually, the human race evolved into an agrarian culture and this change brought a new perspective on the environment. The environment was viewed as a resource that could be used without consequence. It was at this point that the earth's resources began to diminish and the Conservation Movement emerged.

The Conservation Movement

The Conservation Movement's main focus was resource management through the wise and efficient use of resources. In the latter half of the nineteenth century, national parks and preserves were set aside to provide areas for future enjoyment. In 1872, Congress passed legislation making Yellowstone(Popup 13 linked here) a National Park and in 1890, Congress passed legislation establishing Yosemite National Park(Popup 14 linked here), along with Sequoia National Park(Popup 15 linked here), and General Grant National Park in California. During this time, individuals such as John Muir(Popup 16 linked here) and Henry David Thoreau(Popup 17 linked here) wrote about the inherent value of the environment. This period in history led to the Conservation Movement, which curbed the exploitation of our environmental resources.

The Preservation Movement

Over time, environmentalists realized that conservation was not enough because it still allowed the development and exploitation of natural resources. The Wilderness Act of 1964(Popup 18 linked here) introduced a new way of thinking, which recognized nature as having inherent value not necessarily based on its usefulness for human purposes. The Endangered Species Act(Popup 19 linked here) also reinforced this approach by preserving resources in their natural state, for their own sake. Areas of the country were designated as wilderness areas and closed to resource development.

The ability for a small portion of the population to grow food for a larger portion allowed individuals to move away from the farms and into cities where manufacturing, trade, and other specialty activities occurred. As human society became more industrialized, the environment became a recipient of the waste products and pollution became a concern; this led to the Environmental Movement.

The Environmental Protection Movement

The 1960s brought about a concern for the quality of life and the protection of human health. Rachel Carson(Popup 20 linked here)'s book, Silent Spring, pointed out the problems associated with society's increased use of pesticides and their bioaccumulation(Popup 21 linked here) in the fatty tissues of animals. The Environmental Protection Movement brought with it the view that the world is a commons and needs environmental protection from a global perspective. It was during this time that the U.S. Environmental Protection Agency(Popup 22 linked here) was established and new laws and regulations created at the federal, state, and local levels to deal with environmental concerns. By the year 2000, the United States is expected to spend about $170 billion dollars per year to clean up pollution (McKninney and Schoch 1996, 9).

The human population was starting to realize that the earth has limited resources which were being depleted, resulting in a degraded environment. This realization led to the Sustainability Movement.

Sustainability Movement

The Sustainability Movement recognizes that resources are limited and that to meet the needs of the present generation without compromising the needs of future generations, growth and development need to be sustainable. The Global 2000 Report(Popup 23 linked here) and the Club of Rome study(Popup 24 linked here) made it clear how vulnerable the human population is regarding our limited resources. The concern shifted from protection of human health and the environment to a concern for the ecosystem as a whole. The shift was from a human-centered approach to more of an ecological approach. It is now recognized that the human race is part of a global ecosystem and that as the quality of the ecosystem declines, so does the quality of human life.

The human species is at a crossroads. It must decide whether it will and can achieve sustainability or whether it will continue its current practice of unsustainable growth.

References

Buchholz, Rogene A. Principles of Environmental Management: The Greening of Business, 2d ed. Upper Saddle River, NJ: Prentice Hall, 1998, ISBN 0-13-684895-8.

Mackenzie, Fred T. Our Changing Planet: An Introduction to Earth Science and Global Environmental Change, 2d ed. Upper Saddle River, NJ: Prentice Hall, 1998, ISBN 0-13-271321-7.

McKinney, Michael L., and Robert M. Schoch. Environmental Science: Systems and Solutions. St. Paul: West Publishing Company, 1996, ISBN 0-314-06401-X.

Nebel, Bernard J., and Richard T. Wright. Environmental Science, 6th ed. Upper Saddle River, NJ: Prentice Hall, 1998, ISBN 0-13-835331-X.

What is Acid Rain?(Popup 9 linked here)

Yellowstone Park(Popup 13 linked here)

The Wilderness Act of 1964(Popup 25 linked here)

Yosemite National Park(Popup 14 linked here)

Sequoia National Park(Popup 15 linked here)

Our Changing World Population(Popup 26 linked here)

John Muir(Popup 27 linked here)

The Writings of John Muir(Popup 28 linked here)

Henry David Thoreau(Popup 17 linked here)

Deep Ecology(Popup 29 linked here)

Conservationism(Popup 30 linked here)

EPA's Global Warming Site(Popup 31 linked here)

The Butterfly Effect(Popup 32 linked here)

The Concept of the Ecosystem(Popup 33 linked here)

Return to top of page

Report broken links or any other problems on this page.

Copyright © by University of Maryland University College.

These are the popups for this section, in order of their appearance.

Popup 1:

Crust is the outermost layer of the lithosphere that contains light, low melting materials. The continental crust consists mostly of granite and granodiorite, whereas the ocean crust consists mostly of basalt.

Popup 2:

Biogeochemical cycles are the cycles of compounds and elements that travel through the biosphere, atmosphere, hydrosphere, and lithosphere.

Popup 3:

http://www.ibiblio.org/lunarbin/worldpop

Popup 4:

Carrying capacity is the maximum population that a habitat can support without being degraded over time.

Popup 5:

http://www.blupete.com/Literature/Biographies/Philosophy/Malthus.htm

Popup 6:

Chlorofluorocarbon (CFC) is a compound consisting of chlorine, fluorine, and carbon. CFCs are very stable in the troposphere, but are broken down by strong ultraviolet light in the stratosphere. They react with the oxygen in the atmosphere and release chlorine atoms that deplete the ozone layer. CFCs are commonly used as refrigerants, solvents, and foam blowing agents.

Popup 7:

http://www.epa.gov/ozone/ods.html

Popup 8:

Acid deposition (acid rain) is the process by which acids are delivered to the Earth's surface from the atmosphere. The deposition may take place in either wet (i.e., precipitation) or in dry form (i.e., fog or mist). The acid is produced when water vapor combines with sulfur dioxide and nitrogen oxide gases, which are emitted into the atmosphere from the smokestacks of electricity generating stations, smelters, and automobile exhaust pipes. Acid rain damages buildings, kills aquatic plants and animals, weakens and kills trees, and also aggravates human health problems. Any form of acid precipitation, such as acid rain, fog, snow, or any other form of precipitation, that is more acidic than normal (i.e., a pH of less than 5.6).

Popup 9:

http://www.epa.gov/airmarkets/acidrain/index.html

Popup 10:

http://www.epa.gov/oar/primer/

Popup 11:

Potable means water that is suitable for drinking

Popup 21:

Bioaccumulation is the ability of a material to accumulate and reach toxic levels in an organism's body. When bioaccumulation is compounded through the food chain, it is referred to as biomagnification.