1 Chapter 1- Science and the Environment

2 I. Understanding Our Environment A.What is Environmental Science? 1. The study of the impact of humans on the environment. 2. One goal is to understand and solve environmental problems.

3 3.Scientists study two main types of interactions between humans and the environment. 4.Water and plants 5. How our actions alter our environment.

4 6. Ecology is the study of how living things interact with each other and with their nonliving environment.

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6 7. See page 7 in your textbook to see the other major fields that contribute to Environmental science.

7 B.Scientists as Citizens, Citizens as Scientists 1. Everyone can take an active role in our environment

8 C.Our Environment Through Time 1. For most of human history people were known as hunter-gatherers, people who obtain food by collecting plants and animals.

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10 2.Hunter gatherers affected their environment in many ways. 3.Tribes set fires to burn the prairies so they could hunt bison. 4. Over hunting may have led to the disappearance of some species.

11 5. Eventually many hunter-gatherer groups began to use the land as agriculture.

12 B.The agricultural Revolution 1. Agriculture is the practice of growing, breeding and caring for plants an animals than are used for food, clothing, housing, transportation and other purposes.

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14 2. Agricultural revolution allowed human populations to grow very fast. 3. An area of land can support up to 500 times as many people by farming as it can by hunting and gathering. 4. The revolution also changed the food we eat.

15 5. Replacing forests and wetlands with farmland, habitats were destroyed. 6. It caused soil loss, floods, and water shortages. 7. The soil became overworked and it became infertile.

16 C. The Industrial Revolution 1. A shift from energy sources like animals to coal and oil. 2. Machinery reduced the amount of land and human labor needed for farming.

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18 C.Improving Quality of Life 1. The industrial revolution introduced many positive changes. 2. Examples: light bulbs, sanitation, nutrition, medical care, telephone, computer.

19 3.In the 1900’s modern societies began to use artificial substances in place of raw animal or plant products. 4. Plastics and other artificial materials made life easier.

20 D. Spaceship Earth 1. Earth is considered a closed system-the only thing that enters is energy from the sun and the only thing that leaves is heat. 2. There are some problems with this type of system.

21 3. Resources are limited. 4. Waste will be produced more quickly than we can dispose.

22 E.Population Growth: A local Pressure 1. The agricultural and Industrial revolution has allowed the human population to grow much faster than before. 2. Technology, medicine and sanitation increase the human population.

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26 3. The size of the human population in 2000 was more than 10 times larger than I was 400 years ago.

27 F. What are our main environmental Problems? 1. Resource depletion 2. Any natural material that is used by humans is called a natural resource.

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29 3.Natural resource can be renewable or nonrenewable resource. 4.A renewable resource is a resource that can be replaced quickly by natural processes. 5. Examples: fresh water, air, soil, trees and crops.

30 6. A nonrenewable resource is a resource that forms at a slower rate than it is consumed. 7.The most common nonrenewable resources are minerals and fossil fuels. 8. Once they are used up, it might take MILLIONS of years to replenish it!

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34 9. Resources are said to be depleted when a large fraction of the resource has been used up.

35 G.Pollution 1. Pollution is an undesired change in air, water or soil that adversely affects health, survival, or activities of humans or other organisms. 2. There are two types of pollution: biodegradable and nondegradable.

36 3. Biodegradable pollutants are pollutants that can be broken down by natural processes: human sewage or food wastes.

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38 4.Nondegradable pollutants cannot be broken down: mercury, lead, and some plastics.

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40 H.Loss of Biodiversity 1. Biodiversity refers to the number and variety of species that live in an area.

41 II. The Environment and Society A.The Tragedy of the Commons 1. Hardin stated that the conflict between solving environmental issues is the conflict between short-term interests of individuals and the long-term welfare of society.

42 2. His essay basically said that someone or some group has to take responsibility for maintaining a resource. If no one does, the resource can be overused and become depleted.

43 OVER GRAZING

44 B.Economics and the Environment 1. One basic rule of economics is the law of supply or demand. 2. The greater the demand for a limited supply of something, the more the thing is worth.

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46 3. The cost of environmental solutions can be high. 4. A cost-benefit analysis balances the cost of the action against the benefits on expects from it.

47 5. Risk assessment, is a tool that helps to create cost-effective ways to protect our health and the environment.

48 C.Developed and developing countries 1. Developed countries have a higher average incomes, slower population growth, diverse industrial economies, and stronger social support systems. 2. United States, Canada, Japan and countries of Western Europe.

49 3. Developing countries- have lower average incomes, simple agriculture-based economies, and rapid population growth.

50 D.Population and Consumption 1. Most environmental problems can be traced back to two root causes: Human population growing too quickly, people are using up, wasting or polluting natural resources.

51 2. An ecological footprint shows the productive area of Earth needed to support one person in a particular country. 3. Environmental problems are complex and simple solutions are rare.

52 4. Sustainability is the condition in which human needs are met in such a way that a human population can survive indefinitely. 5. A sustainable world is not an unchanging world.

53 THE END