Transcript Chapter 22
Chapter 22 Humans and the Environment Table of Contents Section 1 An Interconnected Planet Section 2 Environmental Issues Section 3 Environmental Solutions Chapter 22 Section 1 An Interconnected Planet Objectives • Explain the importance of the study of environmental science. • Describe Earth’s major layers. • Explain the natural functions of the ozone layer and greenhouse effect. • Summarize the ways in which biologists measure biodiversity. • Discuss the value of biodiversity. Chapter 22 Section 1 An Interconnected Planet Earth’s Layers • Earth’s geosphere, hydrosphere, and atmosphere are interconnected in many ways. • Together, these parts make up the biosphere, the part of the Earth where life exists. Chapter 22 Section 1 An Interconnected Planet Earth’s Layers, continued • Atmosphere – Important parts of the atmosphere are greenhouse gases, which trap heat on Earth, and the ozone layer, which shields Earth from UV radiation. Chapter 22 Section 1 An Interconnected Planet Earth’s Layers, continued • Climate and Atmosphere – The atmosphere’s ability to trap heat in this way is called the greenhouse effect. Chapter 22 Section 1 An Interconnected Planet The Greenhouse Effect Chapter 22 Section 1 An Interconnected Planet Earth’s Layers, continued • Hydrosphere – A very small portion of the hydrosphere is fresh water, and much of this fresh water is not easily usable. Chapter 22 Section 1 An Interconnected Planet Earth’s Layers, continued • Geosphere – The geosphere exchanges materials with the atmosphere, hydrosphere, and biosphere. Chapter 22 Section 1 An Interconnected Planet Earth’s Layers, continued • Biosphere – The biosphere includes all parts of Earth where life exists. Chapter 22 Section 1 An Interconnected Planet Biodiversity • Biodiversity refers to the variety of life found in an area. Chapter 22 Section 1 An Interconnected Planet Biodiversity, continued • Measuring Biodiversity – Biodiversity can be measured in different ways, including by species richness, species evenness, and genetic diversity. Chapter 22 Section 1 An Interconnected Planet Biodiversity, continued • Valuing Biodiversity – Biodiversity is valued for various reasons. Chapter 22 Section 2 Environmental Issues Objectives • Describe major consequences of air pollution. • Relate air pollution to effects on global climate. • Describe how chemical pollutants may undergo the process of biological magnification. • Identify the primary causes of modern extinctions. • Explain why extinctions and ecosystem disruption are of concern to humans. • Relate human resource use to its impacts on ecosystems. Chapter 22 Section 2 Environmental Issues Pollution • Over a short time period, human activities have affected global ecosystems in ways that harm humans and other species. • Human impacts range from local pollution to global change in ecosystems. Chapter 22 Section 2 Environmental Issues Pollution, continued • Ozone Thinning – Industrial chemicals called chlorofluorocarbons (CFCs) act as catalysts in chemical reactions that break down O3 molecules in the ozone layer. – Most countries have banned CFCs, and the ozone layer seems to be recovering. Chapter 22 Section 2 Environmental Issues Ozone “Hole” Over Antarctica Chapter 22 Section 2 Environmental Issues Pollution, continued • Global Warming – The correlation of increasing atmospheric CO2 and rising global temperature suggests a cause-andeffect relationship. – Considering several types of evidence, many scientists have concluded that increased CO2 levels have caused warmer surface temperatures on Earth. Chapter 22 Section 2 Environmental Issues Pollution, continued • Acid Precipitation – Certain air pollutants cause acid precipitation, which harms or kills many organisms. Chapter 22 Section 2 Environmental Issues Pollution, continued • 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. Chapter 22 Biological Magnification of DDT Section 2 Environmental Issues Chapter 22 Section 2 Environmental Issues Ecosystem Disruption, continued • Extinction – Human impacts on the environment are causing an increasing number of extinctions. – Important causes of extinctions are habitat destruction, the transfer of invasive species to new habitats, harvesting, and hunting. – This loss of species has both known and unknown effects on ecosystems. Chapter 22 Section 2 Environmental Issues Ecosystem Disruption, continued • Ecosystem Imbalances – Species such as the sea otter that affect many other species in a community are called keystone species. Chapter 22 Section 2 Environmental Issues Human Resource Use • Current levels of human resource use are probably not sustainable. Chapter 22 Section 2 Environmental Issues World Population Growth Patterns Chapter 22 Section 3 Environmental Solutions Objectives • State the goals of conservation and restoration biology. • Describe examples of efforts to protect species and their habitats. • Summarize international strategies for protecting entire ecosystems. • Discuss the roles of governments and laws in addressing environmental problems. • List several things that individuals can do to help solve environmental problems. Chapter 22 Section 3 Environmental Solutions Conservation and Restoration Biology • Conservation biologists are concerned with identifying and maintaining ecosystems, while restoration biologists are usually involved with repairing badly damaged ecosystems. Chapter 22 Section 3 Environmental Solutions Conservation and Restoration Biology, continued • Species and Habitats – A bioindicator is a species that is especially sensitive to ecological change. Chapter 22 Section 3 Environmental Solutions Conservation and Restoration Biology, continued • Case Study: Saving the Whooping Crane – Populations of many migratory birds, such as the whooping crane, are in decline because of human activities. – However, some populations are recovering as a result of legal protection, breeding programs, habitat restoration, and international partnerships. Chapter 22 Section 3 Environmental Solutions Protecting Ecosystems • Biodiversity Hotspots – International and cooperative efforts to preserve habitat and prevent extinctions include identifying biodiversity hotspots, making debt-for-nature swaps, and promoting ecotourism. Chapter 22 Section 3 Environmental Solutions Governments and Laws • Environmental problems can be addressed through the efforts of governments and laws. Chapter 22 Section 3 Environmental Solutions Private Efforts and Cooperation • Environmental problems can be addressed through the combined efforts of governments, scientists, businesses, and individuals. Chapter 22 Section 3 Environmental Solutions Conservation Case Study: The Everglades • The Everglades restoration project is the most ambitious ecosystem-wide restoration project attempted in the United States. Chapter 22 Section 3 Environmental Solutions Your Role in the Environment • No one can predict our environment’s 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.