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Published byDwight Hutchinson Modified over 8 years ago
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Living Resources Environmental Issues
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Resource Use Natural Resource – any living/nonliving thing in the environment that is used by people
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Renewable Resources Naturally replaced in a relatively short amount of time. Examples Sunlight Wind Trees May be used up (cut down trees more quickly than they can grow)
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Nonrenewable Resources Resources that are not replaced as they are used Examples Coal Oil Natural Gas
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Environmental Issues Increased human population = competition for resources Many resources cannot be replaced Types – resource use, population growth, & pollution
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Population Growth Human population grew slowly until about A.D. 1650 Improvements in medicine, agriculture, sanitation decreased death rate. Resource demand increased
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Pollution Change to the environment that has a negative effect on living things. Usually the result of human activity. Examples generating electricity by burning coal creates air pollution Pesticide use
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Types of Pollution wastes, chemicals, noise, heat, and light Affects: Destruction of wildlife Harm to human health Point source – pollution source can be identified Nonpoint source – widely spread; cannot be tied to one origin
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Approaches to Environmental Issues Personal Choices ex. ride in a car, bus, or use a bicycle Local Choices Ex. Build a landfill or use an incinerator for disposing of wastes National Choices Ex. Whether the U.S. should allow oil drilling in a wildlife refuge Global Choices How to protect the atmosphere.
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Environmental Science the study of the natural processes that occur in the environment and how humans can affect them
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Weighing Costs and Benefits Often Economic Provide jobs? Cost too much? Short-term vs. long-term effects Ex. Drilling for oil off of U.S. coastlines Reduce beauty of a landscape?
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Forests and Fisheries
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Logging Methods Clear-cutting cutting down all of the trees in an area at once Quicker, cheaper, safer Changes the ecosystem Soil is exposed to erosion Selective Cutting cutting down only some trees in a forest and leaving a mix of tree sizes and species Less damaging to ecosystem More expensive dangerous
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Sustainable Forestry Sustainable Yield The amount of a renewable resource (ex. trees) that can be harvested without reducing future supply. Ex. Plant a tree for every one cut down. Pines – fast growing; harvested and replanted every 20-30 years Oaks/cherries – may be harvested once every 100 years (slow growing)
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Fisheries - An area with a large population of valuable ocean dwelling organisms Managing fisheries for a sustainable yield Fishing limits Changing fishing methods Developing aquaculture techniques Finding new resources
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Fishing Limits Ban fishing of certain species Limit number or size Ensures that young fish will survive long enough to reproduce Fishing Methods Larger mesh nets to allow small fish out Outlaw practices such as the use of dynamite or poison which kills all fish in an area
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Aquaculture – raising fish and other water dwelling organisms for food Ex. salmon, catfish, shrimp Costly, may cause pollution, or spread disease
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New Resources 9,000 species of fish are harvested for food ½ of the animal protein eaten in the world comes from fish Introduce deep water species (monkfish, tile fish) Use easy to farm freshwater fish such as tilapia
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