Download Environmental science

Scott Brennan • Jay Withgott
1
An introduction to
environmental science
PowerPoint® Lecture prepared by Jay Withgott
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
This lecture will help you understand:
• The nature of
environmental science
• The scientific method
and the scientific
process
• Natural resources and
their importance
• Culture and
worldviews
• Environmental ethics
• Sustainability
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
The “environment”
Consists of both:
Biotic factors (living things)
&
Abiotic factors (nonliving things)
that surround us and with which
we interact.
“Even Obi-wan Kenobi knew that much...”
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
Humans and the environment
• We humans exist within the environment and are a part
of the natural world.
• Like all other species, we depend for our survival on a
properly functioning planet.
• Thus, our interactions with our environment matter a
great deal.
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
Natural resources
• Renewable resources like sunlight cannot be depleted.
• Nonrenewable resources like oil CAN be depleted.
• Resources like timber and clean water are renewable only
if we do not overuse them.
Figure 1.1
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Global human population growth
• Our population has
skyrocketed to over
6 billion.
• The agricultural and
industrial revolutions
drove population
growth.
Figure 1.2
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Thomas Malthus (1766-1834)
Population growth will lead
to starvation, war, disease.
Death rates check
population unless birth rates
are lowered.
In our day, Paul Ehrlich
(The Population Bomb,
1968) is called
“neo-Malthusian.”
Figure 1.3
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“The tragedy of
the commons!”
Garrett Hardin, 1968:
In a “commons” open
to all, unregulated use
will deplete limited
resources.
Figure 1.4
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Environmental science
How does the natural world work?
How does our environment affect us?
How do we affect our environment?
Applied goal: Developing solutions to environmental
problems.
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What is an “environmental problem?”
Definitions differ.
The pesticide DDT:
was thought safe in
1945
is known to be toxic
today
but is used widely in
Africa to combat
malaria
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Figure 1.5
Environmental science
… can help us avoid mistakes made by past civilizations.
On Easter Island, people annihilated their culture by
destroying their environment.
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From The Science behind the Stories
Environmental science
… is an
interdisciplinary
field, drawing on
many diverse
disciplines.
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Figure 1.6
Environmental science
… is NOT the same as
environmentalism.
It is science, NOT
advocacy.
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Figure 1.7
Science
A systematic process for learning about the world and
testing our understanding of it
A dynamic process of observation, testing, and discovery
And the accumulated body of knowledge that results from
this process
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
Applications of science
Policy decisions and
management practices
are applications of science.
Prescribed burning, used to
restore forest ecosystems
altered by human
suppression of fire.
Figure 1.8a
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Applications of science
Technology is another
application of science.
Energy-efficient
methanol-powered
fuel cell car from
DaimlerChrysler
Figure 1.8b
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Scientific method: Assumptions
Fixed natural laws govern how the universe works
All events arise from causes, and cause other events
We can use our senses and reason to detect and describe
nature’s laws
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Scientific method
A step-by-step method
for testing ideas with
observations.
Figure 1.9
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
Scientific method
Scientists use educated guesses called hypotheses to
generate predictions
that are then tested experimentally.
Results may reject or fail to reject a hypothesis.
Results never confirm a hypothesis, but only lend support to
it by failing to reject it.
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Experiments
Manipulative experiments
are strongest.
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Natural or correlational
ones are often necessary.
Figure 1.10
Scientific process
Peer review,
publication,
and debate are
parts of the
larger
scientific
process.
Figure 1.11
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
Hypothesis, theory, and paradigm
Hypothesis = an educated guess, to be tested
Theory = a well-tested and widely accepted explanation,
validated by much previous research
Paradigm = a dominant view. May shift if new results
show old results or assumptions to be wrong
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
Ethics
Ethics is a discipline that
deals with how we value
and perceive our
environment.
Ethics influence our
decisions and actions.
Figure 2.1
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Worldview
Worldview = a person’s or group’s beliefs about the
meaning, purpose, operation, and essence of the world.
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Some questions in environmental ethics
Should the present
generation conserve
resources for future
generations?
Is is OK to destroy a
forest to create jobs
for people?
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Are humans justified
in driving other
species to extinction?
Is it OK for some
communities to be
exposed to more
pollution than others?
Three ethical worldviews
Figure 2.4
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Early environmental philosophers
The industrial revolution inspired reaction.
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The preservation ethic
John Muir (right, with President Roosevelt at Yosemite)
advocated preserving unspoiled nature, for its own sake and
for human fulfillment.
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Figure 2.5
The conservation ethic
Gifford Pinchot advocated using natural resources, but
exploiting them wisely, for the greatest good for the greatest
number for the longest time.
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Figure 2.6
The land ethic
Aldo Leopold urged people to view themselves as part of
nature, and to strive to maintain “the integrity, stability, and
beauty of the biotic community.”
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Figure 2.7
Environmental justice (EJ)
Poor people and minorities suffer more than their share of environmental
problems, EJ advocates say.
The EJ movement began with a protest against a toxic waste dump in an
African-American community in North Carolina.
Figure 2.8
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Sustainability
The key concept for our future:
Limiting human impact on the natural world so that our
civilization can continue to exist
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Sustainable development
UN: Development that “meets the needs of the present
without sacrificing the ability of future generations to meet
theirs”.
Figure 1.17
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Conclusions: Challenges
We live on a planetary island with limited resources.
Population and consumption are growing.
Many feel that we have not yet developed the ethical basis
for sustainability.
Environmental justice remains a challenge.
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
Conclusions: Solutions
We are developing ideas and technologies to lessen our
impacts.
We can reduce population and consumption.
Sustainability is catching on.
Science helps us understand our world and develop
solutions.
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
Conclusions: Solutions
Environmental science is vibrant and growing.
Ethics evolve, and we may yet develop an ethical basis
for sustainability.
Advances in technology and efficiency can mitigate our
environmental impacts.
Advances have been made toward environmental justice.
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
QUESTION: Review
An anthropocentric worldview would consider the impact of
an action on… ?
a. Humans only
b. Animals only
c. Plants only
d. All living things
e. All nonliving things
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
QUESTION: Review
Which ethic holds that people should use resources “for the
greatest good for the greatest number for the longest time”?
a.
Preservation ethic
b.
Land ethic
c.
Conservation ethic
d.
Deep ecology
e.
Biocentrism
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
QUESTION: Weighing the Issues
Which worldview is closest to your own?
a. Anthropocentric
b. Biocentric
c. Ecocentric
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QUESTION: Review
Which is a nonrenewable natural resource?
a. Sunlight
b. Petroleum
c. Timber
d. Freshwater
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
QUESTION: Review
Which statement is FALSE?
a. Our environment includes living and nonliving
elements.
b. Thomas Malthus favored population growth.
c. Environmental science includes multiple
disciplines.
d. Theories are better supported by evidence than
are hypotheses.
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
QUESTION: Review
Which is NOT an application of science?
a.
Policy decisions
b.
Technologies
c.
Experimental results
d.
Management practices
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
QUESTION: Weighing the Issues
What do you think is the best way to combat
the “tragedy of the commons”?
a. Sell the commons into private hands, so owners
have incentive to manage resources.
b. Have government regulate the amount of
resources individuals take from the commons.
c. Have users work out cooperative systems
among themselves to police resource use.
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings
QUESTION: Interpreting Graphs and Data
What happens if results fail to
reject a hypothesis?
a. The hypothesis is proven to
be true.
b. The hypothesis is supported,
but not confirmed.
c. The hypothesis may be retested
in a different way, with new
predictions.
d. Both b and c are true.
Figure 1.9
Copyright © 2005 Pearson Education, Inc., publishing as Benjamin Cummings