Transcript Ecolog 2 - Laurens County Schools

Ecolog 2
Chapter 1
Science and the Environment
Section 2: The Environment and Society
DAY 1
“The Tragedy of the Commons”
• In his essay, ecologist Garrett
Hardin argued that the main
difficulty in solving environmental
problems is the conflict between
the short-term interests of the
individual and the long-term
welfare of society.
• The example he used was the
commons, or the areas of land
that belonged to the whole
village.
“The Tragedy of the Commons”
• It was in the best interest of
the individual to put as many
animals in the commons as
possible.
• However, if too many animals
grazed on the commons, they
destroyed the grass.
• Once the grass was
destroyed, everyone suffered
because no one could raise
animals on the commons.
“The Tragedy of the Commons”
• The commons were eventually replaced
by closed fields owned by individuals.
• Owners were now careful not to put too
many animals on their land, because
overgrazing wouldn’t allow them to raise
as many animals next year.
• Hardin’s point being that someone or
some group must take responsibility for
maintaining a resource or it will become
depleted.
“The Tragedy of the Commons”
• Hardin’s point can be applied to our
modern commons, natural resources.
• Humans live in societies, and in societies,
we can solve environmental problems by
planning, organizing, considering the
scientific evidence, and proposing a
solution.
• The solution may be to override the shortterm interests of the individual and
improve the environment for everyone in
the end.
Supply and Demand
• The Law of Supply
and Demand is a law
of economics that
states as the demand
for a good or service
increases, the value
or the food or service
also increases.
• An example is the
world oil production.
Costs and Benefits
• The cost of environmental solutions can be
high.
• A cost-benefit analysis balances the cost of the
action against the benefits one expects from it.
• The results depend on who is doing the
analysis.
• For example, pollution control may be too
costly to an industry, but to a nearby
community, the price may well be worth it.
• Often, environmental regulations are passed
on to the consumer or taxpayer.
Risk Assessment
• One of the costs of any action
is the risk of an undesirable
outcome.
• Risk assessment is a tool that
helps us create cost effective
ways to protect our health and
environment.
• To come up with an effective
solution to an environmental
problem, the public must
perceive the risk accurately.
Developed and Developing Countries
• The unequal distribution of wealth and
resources around the world influence
the environmental problems and
solutions a society can make.
• Developed countries have higher
incomes, slower population growth,
diverse industrial economies, and
stronger social support.
• Developing countries have lower
average incomes, simple agriculturebased communities, and rapid
population growth.
Population and Consumption
•
Almost all environmental problems can
be traced back to two root causes:
• The human population in some
areas is growing too quickly for the
local environment to support.
• People are using up, wasting, or
polluting many natural resources
faster than they can be renewed,
replaced, or cleaned up.
Local Population Pressures
• When the population in an area grows rapidly,
there may not be enough natural resources
for everyone to live a healthy, productive life.
• In severely overpopulated regions, forests are
stripped bare, topsoil is exhausted, and
animals are driven to extinction.
• In these areas, malnutrition, starvation, and
disease can be constant threats.
Local Population Pressures
• In developing countries, millions of people are
starving.
• Yet these human populations tend to grow the
fastest.
• Food production, education, and job creation
cannot keep pace with the population growth,
so each person gets fewer resources as time
goes by.
Consumption Trends
• To support the higher quality of life,
developed countries are using much more of
Earth’s resources.
• Developed nations use about 75 percent of
the world’s resources, although they make up
only 20 percent of the world’s population.
• This rate of consumption creates more waste
and pollution per person then in developing
countries.
Consumption Trends
Ecological Footprints
• Ecological footprints are calculations that
show the productive area of Earth needed
to support one person in a particular
country.
• An ecological footprint estimates the land
used for crops, grazing, forests products,
and housing.
• It also includes the ocean area used to
harvest seafood and the forest area needed
to absorb the air pollution caused by fossil
fuels.
Ecological Footprints
• An ecological footprint
is one way to express
the differences in
consumption between
nations.
Critical Thinking and the
Environment
• People on either side on an
environmental issue may
feel passionately about
their cause and can distort
information to mislead
people about the issue.
• Research done by scientists
is often used to make a
political point or is
misinterpreted to support
Critical Thinking and the
Environment
• In addition, the economic dimension of an
environmental issue may be oversimplified
and to complicate matters still, the media
often sensationalizes environmental issues.
• For these reasons and others, you must use
your critical thinking skills when making
decisions about environmental issues.
Critical Thinking and the
Environment
• Remember a few things as you explore
environmental science further:
• First, be prepared to listen to many viewpoints
over a particular issue.
• Second, investigate the source of the information
you encounter.
• Third, gather all the information you can before
drawing a conclusion.
A Sustainable World
• Sustainability is the
condition in which human
needs are met in such a
way that a human
population can survive
indefinitely.
• Sustainability is a key goal
of environmental science.
A Sustainable World
• A sustainable world is not unchanging as
technological advances and human
civilizations continue to be productive.
• However, our current world is not sustainable
as the developed countries are using
resources faster than they can be replaced.
• Achieving a sustainable world requires
everyone’s participation including individual
citizens, industry, and the government.
“The Tragedy of the Commons”
http://www.youtube.com/watch?v=M
LirNeu-A8I
Study Questions
• What is the tragedy of the commons?
• Define a developed country? A non developed
country?
• What is an ecological footprint?
• What is sustainability?
Chapter 1
Science and the Environment
Section 1: Understanding Our Environment
DAY 1
What Is Environmental Science?
• Environmental science is
the study of the air, water,
and land surrounding an
organism or a community,
which ranges from a small
area to Earth’s entire
biosphere.
• It includes the study of the
impact of humans on the
environment.
•
What is the Goal of Environmental
Science?
A major goal of environmental
science is to understand and solve
environmental problems.
• To accomplish this goal,
environmental scientists study two
main types of interactions between
humans and their environment:
1) How our actions alter our
environment.
2) The use of natural resources like
water, coal, and oil.
Many Fields of Study
• Environmental science is an interdisciplinary science,
which means that it involves many fields of study.
• Important to the foundation of environmental science is
ecology.
• Ecology is they study of interactions of living organisms
with one another and with their environment.
• Biology is the study of living things.
• Chemistry is the study of chemicals and their
interactions.
• Physics is the study of matter and energy.
Many Fields of Study – Page 7 in Text
•
Scientists as Citizens, Citizens as
Scientists
Governments, businesses, and cities
recognize that studying our environment
is vital to maintaining a healthy and
productive society.
• Thus, environmental scientists are often
asked to share their research with the
world.
• However, the observations of
nonscientists are the first steps toward
addressing an environmental problem.
Our Environment through Time
• Wherever humans have hunted, grown food,
or settled, they have changed the
environment.
• For example, the environmental change that
occurred on Manhattan Island over the last
300 years was immense, yet that period was
just a “blink” in human history.
First Impact: Hunter-Gatherers
•
•
Hunter-gatherers are people who obtain
food by collecting plants and by hunting
wild animals or scavenging their remains.
Hunter-gatherers affect their environment
in many ways:
1) Native American tribes hunted buffalo.
2) The tribes also set fires to burn prairies
and prevent the grow of trees. This left
the prairie as an open grassland ideal
for hunting bison.
First Impact: Hunter-Gatherers
• In North America, a combination of rapid
climate changes and overhunting by huntergatherers may have led to the disappearance
of some large mammal species, including:
1)
2)
3)
4)
5)
giant sloths
giant bison
mastodons
cave bears
saber-toothed cats
The Agricultural Revolution
• Agriculture is the raising of crops and
livestock for food or for other products
that are useful to humans.
• The practice of agriculture started in
many different parts of the world over
10,000 years ago.
• The change had such a dramatic impact
on human societies and their
environment that it is often called the
agricultural revolution.
The Agricultural Revolution
• The Agricultural Revolution allowed
human populations to grow at an
unprecedented rate.
• As populations grew, they began to
concentrate in smaller areas placing
increased pressure on the local
environments.
The Agricultural Revolution
• The agricultural revolution changed the food we
eat.
• The plants we grow and eat today are descended
from wild plants.
• However, during harvest season farmers
collected seeds from plants that exhibited the
qualities they desired, such as large kernels.
• These seeds were then planted and harvested
again. Overtime, the domesticated plants
became very different from their wild ancestors.
The Agricultural Revolution
• Many habitats were destroyed as grasslands,
forests, and wetlands were replaced with
farmland.
• Replacing forest with farmland on a large scale
can cause soil loss, floods, and water
shortages.
The Agricultural Revolution
• The slash-and-burn technique was one of the
earliest ways that land was converted to
farmland.
• Much of this converted land was poorly
farmed and is no longer fertile.
YouTube!
Agriculture Revolution
The Industrial Revolution
• The Industrial Revolution involved a shift
from energy sources such as animals and
running water to fossil fuels such as coal
and oil.
• This increased use of fossil fuels changed
society and greatly increased the efficiency
of agriculture, industry, and
transportation.
• For example, motorized vehicles allowed
food to be transported cheaply across
greater distances.
The Industrial Revolution
• In factories, the large-scale
production of goods became less
expensive than the local
production of handmade goods.
• On the farm, machinery reduced
the amount of land and human
labor needed to produce food.
• With fewer people producing
their own food, the populations
in urban areas steadily grew.
YouTube!
Industrial Revolution Clip
Hunter-Gatherers
The Agricultural
Revolution
The Industrial
Revolution
Characteristics Get food by
collecting plants
and hunting wild
animals
Practiced growing
food, breeding, and
caring for plants
Started using
fossil fuels such
as coal and oil
(Energy Shift)
Effects on
Environment
Habitats were
destroyed because
grasslands, forests,
and wetlands were
replaced with
farmland.
Introduced
artificial
substances into
the environment
that cannot be
recycled like
plastic.
Over-hunting
caused extinction
of some species
Study Questions
• Define Environmental Science.
• What is the goal of Environmental Science?
• How is Environmental Science
Interdisciplinary?
• Who are the hunter gatherers?
• What is the agriculture revolution?
• What is the industrial revolution?
Chapter 1: Science and the Environment
Section 1: Understanding Our Environment
DAY 2
Our Environment Through Time
Continued:
Improving the Quality
of Life
• The Industrial Revolution
introduced many positive
changes such as the light
bulb.
• Agricultural productivity
increased, and sanitation,
nutrition, and medical
care vastly improved.
Improving the Quality of Life
• However, the Industrial Revolution also
introduced many new environmental
problems such as pollution and habitat
loss.
• In the 1900s, modern societies began to
use artificial substances in place of raw
animals and plant products.
• As a result, we know have materials
such as plastics, artificial pesticides, and
fertilizers.
Improving the Quality of Life
• Many of these products
make life easier, but we are
now beginning to understand
some of the environmental
problems they present.
• In fact, much of
environmental science is
concerned with the problems
associated with the Industrial
Revolution.
Spaceship Earth
• Earth can be compared to a
spaceship traveling through
space as it cannot dispose of its
waste or take on new supplies.
• Earth is essentially a closed
system.
• This means that the only thing
that enters the Earth’s
atmosphere in large amounts is
energy from the sun, and the
only thing that leaves in large
amounts is heat.
Spaceship Earth
• This type of closed system
has some potential
problems.
• Some resources are limited
and as the population
grows, the resources will be
used more rapidly.
• There is also the possibility
that we will produce wastes
more quickly than we can
dispose of them.
Spaceship Earth
• Environmental problems can occur on
different scales: local, regional, or global.
• A local example would be your
community discussing where to build a
new landfill.
• A regional example would be a polluted
river 1000 miles away affecting the
region’s water.
• A global example would be the
depletion of the ozone layer.
Population Growth
• The Industrial Revolution, modern medicine,
and sanitation all allowed the human
population to grow faster than it ever had
before.
Population Growth
• In the past 50 years, nations
have used vast amounts of
resources to meet the worlds
need for food.
• Producing enough food for
large populations has
environmental consequences
such as habitat destruction
and pesticide pollution.
Population Growth
• Most scientists think that the
human population will almost
double in the 21st century before
it begins to stabilize.
• Because of these predictions, we
can expect the pressure on the
environment will continue to
increase, and the human
population and its need for food
and resources grow.
What are our Main Environmental
Problems?
• Environmental problems can generally be
grouped into three categories:
1) Resource Depletion
2) Pollution
3) Loss of Biodiversity
Resource Depletion
• Natural resources are any
natural materials that are
used by humans, such as,
water, petroleum,
minerals, forests, and
animals.
• Natural resources are
classified as either a
renewable resources or a
nonrenewable resource.
Resource Depletion
• Renewable resources
can be replaced
relatively quickly by
natural process.
• Nonrenewable
resources form at a
much slower rate than
they are consumed.
Resource Depletion
• Resources are said to be
depleted when a large fraction
of the resource has been used
up.
• Once the supply of a
nonrenewable resource has
been used up, it may take
millions of years to replenish it.
• Renewable resources, such as
trees, may also be depleted
causing deforestation in some
areas.
Pollution
• Pollution is an undesirable change
in the natural environment that is
caused by the introduction of
substances that are harmful to
living organisms or by excessive
wastes, heat, noise, or radiation
• Much of the pollution that
troubles us today is produced by
human activities and the
accumulation of wastes.
Pollution
• There are two main types of
pollutants:
• Biodegradable pollutants, which
can be broken down by natural
processes and include materials
such as newspaper.
• Non-degradable pollutants,
which cannot be broken down by
natural processes and include
materials such as mercury.
Pollution
• Degradable pollutants are a
problem only when they
accumulate faster than they
can be broken down.
• However, because nondegradable pollutants do
not break down easily, they
can build up to dangerous
levels in the environment.
Loss of Biodiversity
• Biodiversity is the variety of organisms
in a given area, the genetic variation
within a population, the variety of
species in a community, or the variety of
communities in an ecosystem.
• The organisms that share the world with
us can be considered natural resources.
• We depend on them for food, the
oxygen we breathe, and for many other
things.
Loss of Biodiversity
• Yet, only a fraction of all the species that once
roamed the Earth are alive today and many are
extinct.
• Scientists think that if the current extinction rates
continue, it may cause problems for the human
population.
• Many people also argue that all species have
potential economic, scientific, aesthetics, and
recreational value, so it is important to preserve
them.
Study Questions
•
•
•
•
•
•
•
•
What is spaceship Earth?
What is an effect of the industrial revolution?
What are our main environmental problems?
Compare renewable and non-renewable
resources.
Define Biodiversity
Define Pollution
Define biodiversity.
What is loss of biodiversity?
Ecolog
Chapter 2
Tools of Environmental Science
Section 2: Statistics and Models
DAY 1
How Scientists use Statistics
• Statistics is the collection and
classification of data that are in
the form of numbers.
• Scientists rely on and use
statistics to summarize,
characterize, analyze, and
compare data.
• Statistics is actually a branch of
mathematics that provides
scientists with important tools for
analyzing and understanding their
data.
Statistics Works with Populations
• Scientists use statistics to describe statistical
populations.
• A statistical population is a group of similar
things that a scientist is interested in learning
about.
What is the Average?
• Statistical populations are composed of
similar individuals, but these individuals
often have different characteristics.
• A mean is the number obtained by adding
up the data for a given characteristic and
dividing this sum by the number of
individuals.
• The mean provides a single numerical
measure for a population and allows for
easy comparison.
Distribution
• Distribution is the relative
arrangement of the members of a
statistical population, and is usually
shown in a graph.
• The graphs of many characteristics of
populations, such as the heights of
people, form bell-shaped curves.
• A bell shaped curve indicates a
normal distribution where the data is
grouped symmetrically around the
mean.
Distribution
What is the Probability?
• Probability is the likelihood that a
possible future event will occur in
any given instance of the event.
• Probability is usually expressed as a
number between 0 and 1 and
written as a decimal rather than as a
fraction.
• However, there must be a large
enough sample size in order to
obtain accurate results.
Understanding the News
• The news contains statistics everyday.
• For example, a reporter might say, “A
study shows that forest fires increased air
pollution in the city last year.”
• This could lead you to gather and then
graph data on the pollution levels for last
20 years, and looking to see if this years
seem unusually high.
• Paying attention to statistics will make
you a better consumer of information.
Thinking About Risk
• Risk is the probability of
an unwanted outcome.
• People often worry
about big oil spills, but
as the pie chart shows,
there is a much greater
risk of oil pollution from
everyday sources.
Thinking About Risk
• The most important risk we consider is the risk
of death.
• Most people overestimate the risk of dying
from sensational causes, such as plane
crashes, but underestimate the risk from
common causes, such as smoking.
• Likewise, most citizens overestimate the risk
of sensational environmental problems and
underestimate the risk of ordinary ones.
Thinking About Risk
Models
• Models are patterns, plans,
representations, or
descriptions designed to
show the structure or
workings of an object,
system, or concept.
• Scientists use several
different types of models to
help them learn about our
environment.
Physical Models
• Physical models are three-dimensional models
you can touch.
• Their most important feature is that they
closely resemble the object or system they
represent, although they may be larger or
smaller.
• The most useful models teach scientists
something new and help to further other
discoveries.
Physical Models
• One of the most famous physical models
was used to discover the structure of
DNA.
• The structural model was built based on
the size, shape, and bonding qualities of
DNA.
• The pieces of the model put together
helped the scientist figure out the
potential structure of DNA.
• Discovering the structure led the
understanding of DNA replication.
Graphical Models
• Maps and charts are the
most common examples
of graphical models.
• Scientists use graphical
models to show things
such as the position of the
stars, the amount of forest
cover in a given area, and
the depth of the water in a
river or along a coast.
Conceptual Models
• Conceptual models are verbal or
graphical explanations for how a
system works or is organized.
• A flow-chart diagram is an example
of a conceptual model.
• A flow-chart uses boxes linked by
arrows to illustrate what a system
contains, how those contents are
organized, and how they affect one
another.
Conceptual Model
Conceptual Models
• Conceptual models can also be verbal
descriptions or even drawings.
• For example, one conceptual model of the
structure of an atom describes the atom as one
large ball being circled by several smaller balls.
• This illustrates another point, that a model can be
more than one type.
• An atomic model made using plastic balls is both
a conceptual and physical model.
Mathematical Models
• Mathematical models are one or more
equations that represent the way system or
process works.
• Mathematical models are especially useful in
cases with many variables, such as the many
things that affect the weather.
Mathematical Models
• Although mathematical models use number and
equations, they are not always right.
• People are the ones who interpret the data and
write the equations.
• Therefore, if the data or the equations are wrong,
the model will not be realistic and will provide
incorrect information.
• Like all models, mathematical models are only as
good as the data that went into building them.
Mathematical Models
• Scientists use mathematical models to create
amazing, as well as useful images.
• “False color” satellite images are created using
mathematical models.
• Scientists use the models to relate the amount
of energy reflected from objects to the
objects’ physical condition.
Study Questions
• None for this PPT
Bellringer
Chapter 2
Tools of Environmental Science
Section 3: Making Informed Decisions
DAY ONE
Values and the Environment
• Scientific research is an essential first
step in solving environmental
problems.
• However, before research can begin,
an examination of values is usually
needed.
• Values are principles or standards that
an individual considers important.
• Many values that affect environmental
decision-making.
Values that Affect Environmental
Decision Making
An Environmental Decision-Making
Model
• A decision-making model is a
conceptual model that provides
a systematic process for making
decisions.
• Decision-making models can be
used to help you make decisions
about environmental issues,
which can be very difficult.
Decision-Making Model
A Decision-Making Model
• The first step in the model is to
gather information. This includes
things such as watching news
reports, and talking to experts.
• Second, consider which values
apply to the issue.
• Next, explore the consequences of
each option.
• Finally, evaluate all of the
information and make a decision.
A Hypothetical Situation
• The golden-cheeked warbler population is
declining in Valley County.
• The town of Pleasanton, in Valley County,
is growing rapidly, and much of the new
development is occurring outside the city
limits.
• Biologists who have been studying the
warbler warn county officials that if they
do not take action, the state fish and
wildlife service may list the bird as an
endangered species.
A Hypothetical Situation
• Several groups join
together to propose
that the county buy
several hundred acres
of land where the
birds are known to
breed and save the
land as a nature
preserve.
A Hypothetical Situation
• The group also proposes
limiting development on
land surrounding the
preserve.
• The group obtains
enough petitions to put
the issue to a vote, and
the public begins to
discuss the proposal.
A Hypothetical Situation
• People who own property within the
proposed preserve oppose the plan.
• These property owners have an
economic interest in the situation.
They believe that they will lose
money if they are forced to sell their
land to the county instead of
developing it.
• Other residents do not like the idea of
more government regulations on how
private property can be used.
A Hypothetical Situation
• Other landowners support the plan and fear that
without the preserve the warbler will be listed as
an endangered species.
• Once listed as endangered, the state will impose
a plan to protect the bird that will require even
stricter limits on land development.
• People who have land near the preserve think
that their land will increase in value.
• Many residents also look forward to hiking and
camping in the preserve.
How to Use the Decision-Making
Model
• The hypothetical situation in Pleasanton can
be used to illustrate how to use the decisionmaking model.
• Michael Price is a voter in Valley County who
will vote on whether the county should create
the nature preserve.
• The steps Michael took to make his decision
follow.
Gather Information
• Michael studied the warbler issue thoroughly by
– watching local news reports
– reading the newspaper
– learning more about the golden-cheeked
warblers from various websites
– attended forums where the issue was
discussed.
• Several of the arguments on both sides made
sense to him.
Gather Information
• Michael also gathered
scientific information
that included graphs of
the decline of the
warbler population.
Consider Values
• Michael made a table to help
him clarify his thoughts and
values.
• Michael considered the
environmental, economic, and
recreational values of the
preserve.
• He believed these to be
important, but someone else
might have thought other values
were more important to
consider.
Should the Valley County Set Aside a
Nature Preserve?
Explore Consequences
• Michael decides that in the short term, the
positive and negative consequences listed in
his table were almost equally balanced.
• For example, some people would suffer
financially from the plan, but others would
benefit.
• In addition, taxpayers would have to pay for
the preserve, yet all residents would have
access the previously private property.
Explore Consequences
• The long-term consequences that allowed
Michael to make his decision.
• Michael realized that the environmental
values were an important factor in his
decision.
• The thought of the warbler becoming extinct
distressed him, and protecting the habitat
now would be less costly that protecting it
later under a state imposed plan.
Explore Consequences
• Michael considered that
there were long-term
benefits as well.
• He had read that property
values were rising rapidly
in counties where land was
preserved for recreation.
• He also found that people
would pay more to live in
counties that have open
spaces.
Explore Consequences
• Because the county
contained little preserved
land, Michael thought
that creating the preserve
would bring the county
long-term economic
benefits.
• He also highly valued the
aesthetic and recreational
benefits of the preserve,
such as walking trails.
Make a Decision
• Michael chose to vote in
favor of the nature
preserve.
• However, someone else
who looked at the same
table of pros and cons
might have voted
differently.
• If you lived in Valley
County, how would you
have voted?
Make a Decision
• As you learn about issues
affecting the environments,
use this decision-making
model as a starting point to
making your decisions.
• Be sure to consider you
values, weigh the pros and
cons, and keep in mind both
the short-term and long-term
consequences of your
decision.
Study Questions
• None for this power point.
• See your study guide.
Scientific Method - Controls
and Variables
113
Steps in the Scientific Method
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Problem
Observation
Hypothesis
Experiment
Conclusion
Retest
P
O
H
E
C
114
Scientific Experiments Follow Rules.
• An
experimenter
changes one
factor and
observes or
measures what
happens.
115
The Control Variable
• The experimenter makes a
special effort to keep other
factors constant so that they
will not affect the outcome.
• Those factors are called
control variables.
116
What is the Purpose of a
Control?
• Controls are NOT being tested
• Controls are used for
COMPARISON
117
Other Variables
• The factor that is changed is
known as the independent
variable.
• The factor that is measured or
observed is called the dependent
variable.
118
Example of Controls &
Variables
• For example, suppose you want to figure
out the fastest route to walk home
from school. You will try several
different routes and time how long it
takes you to get home by each one.
• Since you are only interested in finding
a route that is fastest for you, you will
do the walking yourself.
119
What are the Variables in
Your Experiment?
• Varying the route is the
independent variable
• The time it takes is the
dependent variable
• Keeping the same walker
throughout makes the walker a
control variable.
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One more thing… it is best to
make several trials with each
independent variable.
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Study Questions
• None for this power point.
• Make a foldable for POHEC
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