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Science and the Environment. Understanding Our Environment. Section Objectives. List the five major fields of study associated with Environmental Science Describe the major effects of hunter-gatherers, the Agricultural Revolution, and the Industrial Revolution.
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Science and the Environment Understanding Our Environment
Section Objectives • List the five major fields of study associated with Environmental Science • Describe the major effects of hunter-gatherers, the Agricultural Revolution, and the Industrial Revolution. • Distinguish between renewable and nonrenewable resources • Classify environmental problems into three major categories
Environmental Science • The study of air, water, and land surrounding an organism or a community • Included: • Impact of humans • Small areas • Earth’s biosphere
Environmental Science • To understand and solve environmental problems • Studies human use of resources • Studies impact of human use
Environment Through Time • Hunter-gatherers- Obtained food by collecting plants, hunting and/or scavenging animals • Burned grasslands • Killed buffalo in large numbers • Over hunting caused extinctions of: • Giant sloth • Giant bison • Mastadons • Cave bears • Saber-toothed cats
Environment Through Time • The Agricultural Revolution- Growing and raising food for human consumption • Started over 10,000 years ago • Human populations increased dramatically • Concentrations of people affected environment • Domesticated plants from wild plants • Slash and burn • Causes soil loss, floods, and water shortage • Poor farming practice rendered = useless land
Environment Through Time • Industrial Revolution- Shift to using fossil fuels • Efficiency of agriculture, industry, and transportation • Mass production = lower cost • Machinery reduced land and human labor needed • Human populations grew at an extraordinary rate • Urban areas grew = more pollution and habitat loss • Improvements: • Inventions- Light bulb, plastics, pesticides, fertilizers • Sanitation • Nutrition • Medical care
Spaceship Earth • Earth is a closed system • Nothing enters but energy from sun • Nothing leaves except for heat • Some resources are limited • Waste produced faster than disposal
Today’s Problems • Local problems- Landfills • Regional problems- River water shortage • Global problems- Ozone depletion & global warming
Resource Depletion • Resource depletion- Large fractions used up • Natural resources- • Renewable- Can be replaced within a human lifetime • Nonrenewable- Can’t be replaced within a human lifetime
Pollution • Undesirable change in environment caused by introducing harmful substances, excessive waste, heat, noise or radiation • Biodegradable-Can be broken down by natural processes • Build up faster than broken down • Nondegradable-Can’t be broken down by natural processes • Build up at dangerous levels
Loss of Biodiversity • Biodiversity- Variety of organisms in a given area • Genetic variety in a population • Variety of species in community • Variety of communities in ecosystem • Extinction- none left • Preservation important