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Ecolog 2
DAY 1
Chapter 1Science and the Environment
Section 2: The Environment and Society
“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 short-term 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 agriculture-based 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 controversial data.
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”
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?
DAY 1
Chapter 1Science and the Environment
Section 1: Understanding Our Environment
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 hunter-gatherers may have led to the disappearance of some large mammal species, including:1) giant sloths2) giant bison3) mastodons4) cave bears5) 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.
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.
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
Over-hunting caused extinction of some species
Habitats were destroyed because grasslands, forests, and wetlands were replaced with farmland.
Introduced artificial substances into the environment that cannot be recycled like plastic.
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?
DAY 2
Chapter 1: Science and the EnvironmentSection 1: Understanding Our Environment
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 Depletion2) Pollution3) 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 non-degradable 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
DAY 1
Chapter 2Tools of Environmental Science
Section 2: Statistics and Models
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
DAY ONE
Chapter 2 Tools of Environmental Science
Section 3: Making Informed Decisions
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 decision-making 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.
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Scientific Method - Controls and Variables
Steps in the Scientific Method
• Problem• Observation• Hypothesis• Experiment• Conclusion• Retest
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POHEC
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Scientific Experiments Follow Rules.
• An experimenter changes one factor and observes or measures what happens.
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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.
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What is the Purpose of a Control?
• Controls are NOT being tested• Controls are used for COMPARISON
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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.
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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.
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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.
Study Questions
• None for this power point.• Make a foldable for POHEC
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