Lesson 1: Understanding Science
Section 1: Understanding Our Environment
Objectives:
❑ Define environmental science, and compare environmental science with ecology
❑ List the five major fields of study that contribute to environmental science
❑ Describe the major environmental effects of hunter-gathers, the agricultural revolution, and the Industrial Revolution
❑ Distinguish between renewable and nonrenewable resources
❑ Classify environmental problems into three major categories
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.
Simple definition:
Environmental science is the study of how humans interact with the environment.
2. A major goal of environmental science is to understand and solve environmental problems.
3. To accomplish this goal, environmental scientists study two main types of interactions between humans and their environment:
1. One area of study focuses on how we use natural resources, such as water and plants.
2. The other area of study focuses on how our actions alter our environment.
4. Many Fields of Study
❑ Environmental science is an interdisciplinary science, which means that is involves many fields of study.
❑ Important to the foundation of environmental science is ecology.
❑ Ecology is the study of interactions of living organisms with each other and with their nonliving environment.
For example, an ecologist might study the relationship between bees and the plants bees pollinate. However, an environmental scientist might investigate how the nesting behavior of bees is influenced by human activities such as the planting of suburban landscaping.
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5. 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.
❑ The first step toward addressing an environmental problem is often the observations of nonscientists. For example, when deformed frogs started appearing in lakes in Minnesota, middle school students noticed the problem first.
6. Our Environment Through Time
Hunters-gathers Agriculture Industrial Revolution
❑ Environmental change is not a modern issue. Whenever humans have hunted, grown food, or settled, they have changed the environment.
❑ Example: The environmental change that occurred on Manhattan Island over the last 300 years was immense, yet that period of time was just a “blink” in human history.
7. Hunter-gathers: For the most part of our history people were hunter-gathers.
❑ Definition: people who obtain food by collecting plants and by hunting wild animals or scavenging their remains.
8. Are there hunter-gathers in the world today? If so, where?
Yes, there are modern day hunter-gathers and they live in New Guinea, a tropical island off the north coast of Australia.
9. What did the Native Indians do to the land to keep the grasslands and why did they do this?
The tribes set fires to burn prairies and prevent the growth of trees. This left the prairie as an open grassland ideal for hunting bison.
10. What may have led to the disappearance of some large mammal species?
In North America, a combination of rapid climate changes and overhunting by hunter-gathers may have led to the disappearance of some large mammal species.
11. Agricultural Revolution:
❑ Define agriculture: is the raising of crops and livestock for food or for other products that are useful to humans
❑ Define agricultural revolution: refers to the dramatic impact caused by the practice of agriculture on human societies and their environment.
❑ The agricultural revolution allowed human population to grow at an unprecedented rate.
❑ What happen as populations grew? As populations grew, they began to concentrate in smaller areas placing increased pressure on the local environments.
12. Dramatic changes due to 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 harvest again. Overtime, the domesticated plants became very different from their wild ancestors.
13. What was destroyed because of the Agricultural Revolution and why were they destroyed?
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.
14. What was one of the earliest ways that land was turned into farmland and what did this method do to the land?
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.
15. Industrial Revolution:
❑ Definition: a shift from energy sources such as animals and running water to fossil fuels such as coal and oil.
❑ Ways it changed society:
1. increased use of fossil fuels
2. increased the efficiency of agriculture, industry, and transportation
16. Examples of ways it changed:
❑ Motorized vehicles could allow food to be transported cheaply across greater distances.
❑ 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.
17. Why did population in urban areas increase? The population grew in urban areas because fewer people were needed to produce their own food.
18. How did the industrial revolution improve the quality of life? The Industrial Revolution introduced many positive changes such as the light bulb and increased agricultural productivity. Also sanitation, nutrition, and medical care vastly improved.
19. How did the industrial revolution hurt our quality of life? The Industrial Revolution introduced many new environmental problems such as pollution and habitat loss.
❑ Example: In the 1900’s, modern societies began to use artificial substances like plastics, artificial pesticides, and fertilizers in place of raw animals and plant products.
❑ 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.
20. The Agricultural and Industrial Revolutions caused the population on Earth to increase at a rapid rate.
21. Spaceship Earth
❑ Some people refer to the earth as a spaceship because it cannot take on new supplies nor dispose of its waste as it travels through the solar system.
❑ This is a closed system with some potential problems. This means that the only thing that enters Earth’s atmosphere is large amounts of energy from the sun, and the only thing that leaves in large amounts is heat.
❑ 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.
22. 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. Ozone depleting chemicals release in one country can destroy the ozone layer for everyone on Earth.
23. Main environmental problems are: resource depletion, pollution, and loss of biodiversity
❑ Define natural resource: are any natural materials that are used by humans, such as, water, petroleum, minerals, forests, and animals.
❑ The two classifications of natural resources are renewable resources and nonrenewable resources.
❑ Define renewable resource and give examples:
Renewable resources can be replaced relatively quickly by natural process. Examples are energy from the sun, water, wood, soil, and air.
❑ Define nonrenewable resource and give examples:
Nonrenewable resources form at a much slower rate than the rate that they are consumed. Examples are metals such as Fe, Al, and Cu; nonmetallic materials such as salt, sand, and clay; and fossil fuels.
24. When does resource depletion occur?
It occurs when a large fraction of the resource has been used up.
❑ Examples of resource depletion:
1. Once the supply of a nonrenewable resource has been used up, it may take millions of years to replenish it.
2. Renewable resources, such as trees, may also be depleted causing deforestation in some areas.
25. Pollution:
❑ Define: 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.
26. Two types of pollution:
❑ Biodegradable pollutants are pollutants that can be broken down by natural processes and include materials such as newspaper.
❑ Nondegradable pollutants are pollutants which cannot be broken down by natural processes and include materials such as mercury.
27. Are degradable pollutants a problem? Yes they can be a problem, but only when they accumulate faster than they can be broken down.
28. Are nondegradable pollutants a problem? Yes they are a problem because they don’t break down easily and they can build up to dangerous levels in the environment.
29. Loss of Biodiversity:
❑ Definition of 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.
❑ This biodiversity of organisms that shares the world with us can be considered natural resources.
❑ We depend on them for food, the oxygen we breathe, and for many other things.
❑ Yet, only a fraction of all the species that once roamed the Earth are alive today, and many are extinct.
30. Scientists think that if the current extinction rates continue, it may cause problems for the human population.
31. Scientists think that if the current extinction rates continue, it may cause problems for the human population.
32. Many people also argue that all species have potential economic, scientific, aesthetics, and recreational value, so it is important to preserve them.
Section 2: The Environment and Society
Objectives:
❑ Describe “The Tragedy of the Commons”
❑ Explain the law of supply and demand
❑ List three differences between developed and developing countries
❑ Explain what sustainability is, and describe why it is a goal of environmental science
1. In 1968, ecologist Garrett Hardin published an essay on how to share common resources titled “The Tragedy on the Commons,” which became the theoretical backbone of the environmental movement.
❑ Hardin observed that when land was held in common, individuals tended to graze as many animals as possible (best interest of the individual).
❑ Overgrazing led to the destruction of the land resources.
❑ When enclosed fields owned by individuals replaced commons, people tended to graze only the number of animals that the land could support (best interest for the society).
2. The point of Hardin’s essay is that someone or some group has to take responsibility for maintaining a resource.
3. Hardin’s point can be applied to our modern commons, Earth’s natural resources.
4. Humans live in societies, and in societies, we can solve environmental problems by planning, organizing, considering the scientific evidence, and proposing a solution.
5. The solution may override the short-term interests of the individual, but improves the environment for everyone in the long run.
6. The Law of Supply and Demand is a law of economics that states as the demand for a good or service increases, the value of the good or service also increases.
❑ An example is the world’s oil production. In general, when the production of oil declines, the price of a barrel of oil increases.
7. 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.
8. 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 be well worth it.
9. Often, environmental regulations are passed on to the consumer or taxpayer.
10. One of the costs of any action is the risk of an undesirable outcome.
11. Risk assessment is a tool that helps us create cost effective ways to protect our health and environment.
12. To come up with an effective solution to an environmental problem, the public must perceive the risk accurately.
13. 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 economics, and stronger social support. (United States, Canada, Japan, and other Western European countries)
❑ Developing countries have lower average incomes, simple agriculture-based communities, and rapid population growth. (Mexico, Brazil, Malaysia, and other middle-income countries)
14. 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.
15. When the population in an area grows rapidly, there may not be enough natural resources for everyone in the area to live a healthy, productive life.
16. In severely overpopulated regions, forests are stripped bare, topsoil is exhausted, and animals are driven to extinction.
17. In these areas, malnutrition, starvation, and disease can be constant threats.
18. 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.
19. To support the higher quality of life, developed countries are using much more of Earth’s resources.
20. Developed nations use about 75% of the world’s resources, although they make up only 20% of the world’s population.
21. This rate of consumption creates more waste and pollution per person than in developing countries.
22. Ecological footprints are calculations that show the productive area of Earth needed to support one person in a particular country.
23. 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.
24. An ecological footprint is one way to express the differences in consumption between nations.
25. People on either side of an environmental issue may feel passionately about their cause and can distort information to mislead people about the issues.
26. Research done by scientists is often used to make a political point or is misinterpreted to support controversial data.
27. Also, the economic dimension of an environmental issue may be oversimplified. And to complicate matter 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.
28. 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.
29. Sustainability is the condition in which human needs are met in such a way that a human population can survive indefinitely.
30. Sustainability is a key goal of environmental science.
31. A sustainable world is not unchanging as technological advances and human civilizations continue to be productive. However, our current world is not sustainable as developed countries are using resources faster than they can be replaced.
32. Achieving a sustainable world requires everyone’s participation including individual citizens, industry, and the government. Two examples demonstrating that we can move toward sustainability:
❑ Seattle’s Lake Washington is cleaner and healthier now than it was 30 years ago.
❑ The bald eagle, which was once on the brink of extinction, is making a comeback because of efforts to preserve their habitat and to reduce pollution due to DDT pesticides.
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