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Human Effect
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Section 1 Global Change Objectives Recognize the causes and effects of acid rain. Evaluate the long-term consequences of atmospheric ozone depletion. Explain how the burning of fossil fuels has changed the atmosphere. Analyze the proposed relationship between the greenhouse effect and global warming. Chapter 18
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Acid Rain Human-induced environmental changes are affecting ecosystems worldwide Sulfur from smokestacks can combine with water vapor to produce sulfuric acid. carried back to Earth’s surface in acidified precipitation is called acid rain. Section 1 Global Change In the United States and Canada, thousands of lakes are “dying” as their pH levels fall below 5.0. Forests in the eastern United States and southern Canada are also being damaged
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The Ozone Hole In 1985 ozone levels in the atmosphere seemed to be as much as 35 percent lower than the average values during the 1960s. disintegration of the Earth’s ozone shield was evident as far back as 1978. Every year since then, more ozone has disappeared, and the ozone hole has grown larger. Section 1 Global Change Chapter 18 decrease in ozone allows more ultraviolet radiation to reach the Earth’s surface, scientists expect an increased incidence of diseases caused by exposure to ultraviolet radiation. In fact, in the United States, the number of cases of malignant melanoma, a potentially lethal form of skin cancer, has almost doubled since 1980
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Global Temperatures global temperature has been steadily increasing for more than a century scientists suspect that human activity may be significantly contributing to global warming Section 1 Global Change
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The Greenhouse Effect Section 1 Global Change Chapter 18
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Atmospheric Temperature and CO2 Levels Section 1 Global Change Chapter 18
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Section 2 Effects on Ecosystems Objectives Describe the effects of chemical pollutants on the environment. Identify three nonrenewable resources. Predict the potential consequences of uncontrolled population growth. Contrast population growth in developing countries with that in industrialized countries. Chapter 18
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Effects of Chemical Pollution important urban environmental problem Example: large oil tanker ran aground off the coast of Alaska in 1989. Oil from the tanker heavily polluted 1,600 km (1,000 mi) of coastline Example: pesticides, herbicides, and fertilizers Many of the most disastrous incidents of pollution involve industrial chemicals that are toxic or carcinogenic (cancer-causing). Section 2 Effects on Ecosystems Chapter 18
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biological magnification. Pesticides like DDT, chlordane, lindane, and dieldrin—break down slowly in the environment. As these molecules pass up through the trophic levels of the food chain, they become increasingly concentrated. This process is called Section 2 Effects on Ecosystems
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Loss of Resources Extinction of Species Earth is losing species 10 percent of well-known species teeter on the brink of extinction. Worst-case estimates are that we will lose up to one- fifth of the world’s species of plants and animals— about 1 million species—during the next 50 years. An extinction of this size has not occurred in at least 65 million years, since the end of the age of dinosaurs. Section 2 Effects on Ecosystems Chapter 18
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Ground-Water Pollution and Depletion Large amounts of ground water are being removed from many aquifers far faster than natural processes can replenish it Ex. Droughts in CA Section 2 Effects on Ecosystems Chapter 18
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Section 3 Solving Environmental Problems Objectives Describe two effective approaches that have been taken to reduce pollution in the United States and abroad. Evaluate the five major steps necessary to solve environmental problems. Determine how individuals can take personal action to help solve environmental problems. Chapter 18
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In the United States Two effective approaches have been taken to reduce pollution in the United States. 1: Pass laws forbidding or reducing pollution 2: Placing a taxes or penalties on pullutors Section 3 Solving Environmental Problems Chapter 18
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Solving Environmental Problems Five Steps to Success There are five components to successfully solving any environmental problem: 1. Assessment: The first stage is scientific analysis of the problem, the gathering of information about what is happening. 2. Risk analysis: Using the information obtained by scientific analysis, scientists predict the consequences of different types of environmental intervention. Section 3 Solving Environmental Problems Chapter 18
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Solving Environmental Problems, continued Five Steps to Success 3. Public education: When it is possible to describe alternative courses of action, the public must be informed. 4. Political action: The public, through its elected officials, selects and implements a course of action. 5. Follow-through: The results of any action should be carefully monitored to see if the environmental problem is being solved. Section 3 Solving Environmental Problems Chapter 18
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Solving Environmental Problems, continued Two Success Stories: The Nashua River Running through the heart of New England, the Nashua River was severely polluted by mills established in Massachusetts in the early 1900s. The Nashua River Cleanup Committee presented bottles of dirty river water to politicians, spoke at town meetings, recruited business people to help finance a waste treatment plant, and began to clean garbage from the Nashua River’s banks. Industrial dumping into the river is now banned, and the river has largely recovered. Section 3 Solving Environmental Problems Chapter 18
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Solving Environmental Problems, continued Two Success Stories: Lake Washington Lake Washington was being polluted with nitrogen and phosphorous from 10 municipal sewage plants. An ecology professor at the University of Washington in Seattle, W. T. Edmondson, became alarmed and began a campaign in 1956 to educate public officials about the danger. After five years, as a direct result of his efforts, joint municipal taxes financed the cleanup of Lake Washington with a massive trunk sewer that rings the lake and carries treated discharge far out into Puget Sound. Section 3 Solving Environmental Problems Chapter 18
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Solving Environmental Problems, continued Your Contribution You can save energy by walking, riding a bicycle, or taking public transportation to work or school. Newspapers, aluminum products, glass containers, and many plastic containers can be recycled. A resource- and energy-use inventory of your home can identify additional ways to help the environment. Section 3 Solving Environmental Problems Chapter 18
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Recycling Section 3 Solving Environmental Problems Chapter 18
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Multiple Choice Use the chart below to answer questions 1–3. Standardized Test Prep Chapter 18
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Multiple Choice, continued 1.How much grain was produced per person in 1990? A.280 kg B.305 kg C.320 kg D.360 kg Standardized Test Prep Chapter 18
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Multiple Choice, continued 1.How much grain was produced per person in 1990? A.280 kg B.305 kg C.320 kg D.360 kg Standardized Test Prep Chapter 18
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Multiple Choice, continued 2. How have world grain production and the human population changed since the early 1980s? F.World grain production has increased; the human population has decreased. G.Both have decreased. H.World grain production has increased more rapidly than the human population. J.The human population has increased more rapidly than world grain production. Standardized Test Prep Chapter 18
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Multiple Choice, continued 2. How have world grain production and the human population changed since the early 1980s? F.World grain production has increased; the human population has decreased. G.Both have decreased. H.World grain production has increased more rapidly than the human population. J.The human population has increased more rapidly than world grain production. Standardized Test Prep Chapter 18
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Multiple Choice, continued 3. What is likely to happen over the next decade if the trends since 1990 continue? A.World grain production will remain stable; grain production per person will decrease. B.World grain production will decrease; grain production per person will increase. C.Both world grain production and grain production per person will increase. D.All grain production will remain at its 1990 levels. Standardized Test Prep Chapter 18
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Multiple Choice, continued 3.What is likely to happen over the next decade if the trends since 1990 continue? A. World grain production will remain stable; grain production per person will decrease. B. World grain production will decrease; grain production per person will increase. C. Both world grain production and grain production per person will increase. D. All grain production will remain at its 1990 levels. Standardized Test Prep Chapter 18
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