Living Resources Environmental Issues

Resource Use  Natural Resource – any living/nonliving thing in the environment that is used by people

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)

Nonrenewable Resources  Resources that are not replaced as they are used  Examples Coal Oil Natural Gas

Environmental Issues  Increased human population = competition for resources  Many resources cannot be replaced  Types – resource use, population growth, & pollution

Population Growth  Human population grew slowly until about A.D Improvements in medicine, agriculture, sanitation decreased death rate. Resource demand increased

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

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

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.

 Environmental Science the study of the natural processes that occur in the environment and how humans can affect them

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?

Forests and Fisheries

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

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 years  Oaks/cherries – may be harvested once every 100 years (slow growing)

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

 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

 Aquaculture – raising fish and other water dwelling organisms for food Ex. salmon, catfish, shrimp Costly, may cause pollution, or spread disease

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