Chapter 1
Lecture
Outline
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Learning Outcomes
After studying this chapter, you should be able to answer the following
questions:
• Describe several of the most important environmental problems
facing the world. Are there signs of hope for solving these
problems?
• What do we mean by sustainability and sustainable
development?
• Why does science support—but rarely prove—particular
theories?
• How can scientists know if their research is reliable and
important?
• How can critical thinking help us understand environmental
issues?
• Explain how we can use graphs and statistics to answer
questions in environmental science.
• What are some arguments for conservation or preservation of
nature?
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Today we are faced with a challenge that
calls for a shift in our thinking,
so that humanity stops threatening its
life-support system.
–Wangari Maathai, winner of 2004 Nobel
Peace Prize
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1.1 Understanding Our
Environment
• The conditions on
Earth are unique.
• Perfect for the
existence of life as
we know it.
The life sustaining ecosystems on which we all depend are unique in the
universe, as far as we know.
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What is environmental science?
• Environmental
science is the
systematic study of
our environment
and our place in it.
• Because
environmental
problems are
complex,
environmental
science draws on
many fields of
knowledge (fig 1.4).
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1.2 Environmental Problems
and Opportunities
• Polluted water contributes
to the death of more than
15 million people every
year, most of them
children under age 5.
• Food supplies: currently
more than 850 million
people are chronically
undernourished.
• Energy resources: Fossil
fuel supplies are
diminishing. There are
many problems
associated with them.
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Environmental Problems
• Climate change:
Burning fossil fuels,
making cement,
cultivating rice
paddies, clearing
forests, and other
human activities
release carbon
dioxide and other
so-called
greenhouse gases,
which trap heat in
the atmosphere.
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Environmental Problems
• Air quality: Air quality has worsened
dramatically in many areas
• Biodiversity loss: Biologists report that
habitat destruction, overexploitation,
pollution, and introduction of exotic
organisms are eliminating species at a
rate comparable to the great extinction
that marked the end of the age of
dinosaurs.
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Environmental Problems
continued….
• Marine
resources: The
ocean is an
irreplaceable
food resource for
many people.
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Environmental Opportunities
• Marine resources: Around the world,
people who depend on seafood for their
livelihood and sustenance are finding that
setting aside marine reserves can restore
fish populations as well as promote
human development.
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Environmental Opportunities
• Population has stabilized in most
industrialized countries and even in some
very poor countries where social security
and democracy have been established.
– Over the past 25 years, the average
number of children born per woman
worldwide has decreased from 6.1 to 2.6
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Environmental Opportunities
continued…
• Health: The incidence of life-threatening
infectious diseases has been reduced
sharply in most countries during the past
century,
– Life expectancies have nearly doubled, on
average.
• Conservation of forests and nature
preserves: Deforestation has slowed in
Asia, from more than 8 percent during the
1980s to less than 1 percent in the 1990s.
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Environmental Opportunities
• Renewable energy: Encouraging progress
is being made in a transition to renewable
energy sources.
– The European Union has announced a goal of
obtaining 22 percent of its electricity and 12 percent
of all energy from renewable sources by 2010.
• Information: The increased speed at
which information and technology now
flow around the world holds promise that
we can continue to find solutions to our
environmental dilemmas.
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1.3 Human Dimensions of
Environmental Science
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Sustainability is a
central theme
• Sustainability is a search for ecological
stability and human progress that can
last over the long term.
• Sustainable development is “meeting
the needs of the present without
compromising the ability of future
generations to meet their own needs.”
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Where do the rich and poor live?
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Indigenous peoples are guardians
of much of the world’s biodiversity
• Often, the 500 million
indigenous people
who remain in
traditional homelands
still possess valuable
ecological wisdom
and remain the
guardians of littledisturbed habitats
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1.4 Science Helps Us Understand
Our Environment
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Deductive and inductive reasoning
are both useful
• Logical reasoning
from general to
specific is known as
deductive
reasoning.
• Reasoning from many
observations to
produce a general
rule is inductive
reasoning.
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The scientific method is an orderly
way to examine problems
• 1. Observe that your flashlight
doesn’t light; also, there are
three main components of the
lighting system (batteries, bulb,
and switch).
• 2. Propose a hypothesis, a
testable explanation: “The fl
ashlight doesn’t work because
the batteries are dead.”
• 3. Develop a test of the
hypothesis and predict the
result that would indicate your
hypothesis was correct: “I will
replace the batteries; the light
should then turn on.”
• 4. Gather data from your test:
After you replaced the
batteries,
did the light turn on?
• 5. Interpret your results: If the
light works now, then your
hypothesis was right; if not,
then you should formulate a
new hypothesis, perhaps that
the bulb is faulty, and develop
a new test for that hypothesis.
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Understanding probability
helps reduce uncertainty
• Probability is
a measure of
how likely
something is to
occur.
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Experimental Design
• A natural experiment, is
one that involves
observation of events that
have already happened.
• Manipulative experiments
have conditions deliberately
altered, and all other
variables are held constant.
• Blind experiments are
often used, in which the
researcher doesn’t know
which group is treated until
after the data have been
analyzed.
• In health studies, such as
tests of new drugs, doubleblind experiments are
used, in which neither the
subject (who receives a
drug or a placebo) nor the
researcher knows who is in
the treatment group and
who is in the control group.1-32
What is sound science?
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1.5 Critical Thinking
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1.6 A Brief History of Conservation
and Environmental Thought
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Our Conservation and Environmentalism
History has four Distinct Stages:
– Pragmatic Resource Conservation
– Moral and Aesthetic Nature Preservation
– Modern Environmentalism
– Global Environmental Citizenship
36
Pragmatic Resource
Conservation
President Theodore Roosevelt and his chief
conservation advisor, Gifford Pinchot,
believed in utilitarian conservation.
– Forests should be saved so they can be
used to provide homes and jobs.
– Should be used for “the greatest good for
the greatest number, for the longest time.”
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Moral and Aesthetic Nature
Preservation
John Muir, first president of the Sierra Club,
opposed Pinchot’s utilitarian policies.
– Biocentric Preservation
– emphasizes the fundamental right of all
organisms to pursue their own interests
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Modern Environmentalism
Rachel Carson’s Silent Spring (1962) started
the modern environmental movement.
– awakened the public to threats of pollution
and toxic chemicals to humans as well as
other species
– modern environmentalism extends
concerns to include both natural resources
and environmental pollution.
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Global Concerns
Increased travel and communication enables
people to know about daily events in places
unknown in previous generations.
Global environmentalism is the recognition
that we share one environment that is common to
all humans.
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Part 5: Current
Environmental Conditions
• Half the world's wetlands were lost in the last 100
years.
• Land conversion and logging have shrunk the world's
forests by as much as 50%.
• Nearly three-quarters of the world's major marine fish
stocks are over-fished or are being harvested beyond
a sustainable rate.
• Soil degradation has affected two-thirds of the world's
agricultural lands in the last 50 years.
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Rising pollution levels led to the
modern environmental movement
• The tremendous expansion of chemical
industries during and after World War II added a
new set of concerns to the environmental
agenda.
• Silent Spring, written by Rachel Carson (fig.
1.24a) and published in 1962, awakened the
public to the threats of pollution and toxic
chemicals to humans as well as other species.
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Practice Quiz
1. Describe how fishing has changed at Apo Island, and the direct and indirect effects
on people’s lives.
2. What are some basic assumptions of science?
3. Distinguish between a hypothesis and a theory.
4. Describe the steps in the scientific method.
5. What is probability? Give an example.
6. What does significance mean in statistics?
7. What’s the first step in critical thinking according to table 1.4?
8. Distinguish between utilitarian conservation and biocentric preservation. Name two
environmental leaders associated with each of these philosophies.
9. Why do some experts regard water as the most critical natural
resource for the twenty-first century?
10. Where in figure 1.7 do the largest areas of persistence of greening occur? What is
persistence of greening?
11. Describe some signs of hope in overcoming global environmental problems.
12. What is the link between poverty and environmental quality?
13. Define sustainability and sustainable development.
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