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Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 An Interconnected Planet Chapter 22 22-1 Humans and The.

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1 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 An Interconnected Planet Chapter 22 22-1 Humans and The Environment The study of the interaction between humans and their own environment is environmental science. Humans, like all other organisms, depend on their environment for food, water, air, shelter, and other resources. The ability of humans to understand, manipulate, and possibly damage ecosystems exceeds that of other organisms. Therefore environmental science may be critical to our own survival.

2 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 An Interconnected Planet Chapter 22 Biodiversity Biodiversity refers to the variety of life found in an area. A measurement of Biodiversity is: –1. Species richness refers to the number of unique species in an area. –2. Species evenness refers to the relative number of individuals of each species in an area. Another type of biodiversity is genetic diversity. –Genetic diversity is the amount of variation within the genetic material of a given population (gene pool). –Genetic diversity affects a populations ability to adapt when faced with environmental change. –Evolution by natural selection acts on genetic variation.

3 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 An Interconnected Planet Chapter 22 Valuing Biodiversity Scientists have named and described about 2 million species. Some believe there may be 100 million total species.

4 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Biodiversity provides important benefits to people. –Food. –Homes, fuel from trees. –Medicine and useful chemicals. –Undiscovered species may provide other benefits. Biodiversity provides important benefits to the survival of Earth.

5 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Environmental Issues Chapter 22 22-2 Environmental Issues As the human population increases, so does the human impact on the environment. Humans often cause pollution by putting substances that cause unintended harm into air, water, or soil. Many human activities disrupt ecosystems.

6 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Environmental Issues Chapter 22 Pollution Air pollution is blamed for causing: –Ozone thinning –Global warming –Smog –Acid precipitation

7 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Ozone OzoneA gas molecule made of 3 oxygen atoms. –Harmful in the lower atmosphere –The ozone layer floating 20 km above earth in the stratosphere. It shields earth from harmful ultraviolet radiation (UV radiation).

8 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Destruction of Ozone Layer Human-made chemicals such as chlorofluorocarbons (CFCs) float up to the stratosphere and break down the ozone layer. –CFCs were found in aerosol sprays and coolants in air conditioners and refrigerators. –Since 1995 most countries have banned CFCs, but it will take many years for the ozone layer to recover. Destruction of Ozone Layer

9 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Global Warming May be correlated to increased amounts of CO 2 in atmosphere Cutting down rain forests and burning fossil fuels lead to an increase in CO 2 in the atmosphere. Global Warming

10 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Smog Smog is a visible type of air pollution. –Happens when water vapor mixes with pollutants from the burning of fuels and use of chemicals in homes and industries. –May contain nitrogen oxides, sulfur oxides, organic chemicals, small particles, and ozone. –Animals and plants are harmed by respiring pollutants in smog.

11 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Acid Precipitation All rain is slightly acidicCO 2 in the air dissolves in the rainwater, creating carbonic acid. Certain air pollutants such as nitrates and sulfur compounds cause an increase in the normal acidity of rainwater. Acid rain can destroy forests, damage buildings, and kill fish and other organisms in lakes and ponds.

12 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Environmental Issues Chapter 22 Land and Water Pollution –The release of toxic chemicals, such as DDT, into the biosphere can impact ecosystems in many ways, especially when chemicals undergo biological magnification. –Biological magnification is a process in which chemicals become more concentrated in organisms that are higher on a food chain.

13 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 22 Biological Magnification of DDT Section 2 Environmental Issues

14 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 22 Bald Eagles Return to the Channel Islands in California Visual Concept Biological Magnification of Toxins Section 2 Environmental Issues

15 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu 22-3 Conservation and Restoration Biology Our planets air, water, land and organisms are interconnected. Environmental problems connect across national boundaries, so solutions may require world wide efforts.

16 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Environmental Solutions Chapter 22 Conservation biologists are concerned with identifying and maintaining ecosystems, while restoration biologists are usually involved with repairing badly damaged ecosystems. Environmental problems can be addressed through the combined efforts of governments, scientists, businesses, and individuals.

17 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Environmental Solutions Chapter 22 Your Role in the Environment No one can predict our environments future, but it is clear that individuals can make a difference in its fate. Thus, it is important for you, as an individual, to understand your role in the environment and to take responsibility for that role.

18 Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 22 Click below to watch the Visual Concept. Visual Concept Conservation Section 3 Environmental Solutions


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