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UNIT 1: CHAPTER 1SCIENCE AND THE ENVIRONMENT
Section 1: Understanding our Environment Environmental science studies the impact of humans on the environment.
goals: understanding and solving environmental problems
2 focus areas: (1) how we use natural resources and (2) how our actions alter our environment
branches/fields of study (w/i env. science): ecology, geology, chemistry, botany, zoology, paleontology, social sciences...INTERDISCIPLINARY!
ENVIRONMENT...A LOOK THROUGH TIME
Hunter-Gatherers:
fires, overhunting…strategies!
Led to: Agriculture (collecting seeds—artificial selection, domesticating animals); began ~10,000 years ago in various parts of the world.
Dramatic impact on societies and the environment…called the agricultural revolution.
Lasting Effects
• Due to the replacement of forests, grasslands, and wetlands with farmlands, long-lasting effects resulted:
• Habitats were lost
• Soil loss (due to replacement of forests with farms)
• Floods (due to replacement of forests with farms)
• Water shortages (due to irrigation)
• Infertile soil (due to overfarming)
Next…Industrial Revolution
• Up until the mid 1700s, societies were powered primarily by the work of humans or animals—then began the switch to fossil fuels (coal and oil).
• Result: increased efficiency and productivity of agriculture, industry, and transportation
• Less land needed for agriculture—fewer people grew their own food and urban populations increased
• Positive changes in quality of life: invention of the light bulb, telephone and the portable computer; sanitation, nutrition and medical care improved
• Negatives: replacement of natural animal and plant products with artificial substances (ex. plastics, pesticides); most of environmental science is concerned with the problems associated with the IR.
Earth’s Problems?
• Earth is a closed system: only energy from the sun can enter and only heat energy can leave.
• b/c some resources are limited, as the population grows, resources will be used
• more wastes are produced more quickly than we can dispose of them (i.e. pollution)
• Different scales of env. problems: local (property owners dispute about land use or pest problem), regional (polluted drinking water), or global (ozone depletion)
3 Main Environmental Problems
1. Resource depletion: occurs when a large fraction of natural resources has been used up (renewable vs. nonrenewable)
2. Pollution: an undesired change in air, water, or soil that negatively affects the health, survival, or activities of humans OR other organisms (biodegradable vs. non-degradable)
3. Loss of biodiversity: extinction, species are considered to be a non-renewable resource
• Biodiversity: the number and variety of species in a given area.
Section 2:The Environment and
Society• “The Tragedy of the Commons” by ecologist
Garrett Hardin published in 1968
• The problem in solving environmental issues is the conflict that results from short-term interests and long-term interests
• Someone/group has to take responsibility for mainatining a resource---otherwise the resource(s) can become overused and then depleted.
• Long-term solutions and improvements have to take precedence
Economics and the Environment
• Factors that influence how we use resources:
• Social Pressures
• Supply and Demand (ex. production of oil and price…choices: increase price, decrease use, find new sources of energy)
• Costs and Benefits
• risk assessment—important that the risk is perceived accurately
Developed vs. Developing
• Developed: countries having higher avg. incomes, slower population growth, diverse industrial economies, and stronger social support systems (UN)
• US, Canada, Japan, and the countries of Western Europe
• Use about 75% of the world’s resources but only make up about 20% of the world’s population! Why?...support quality of life
• Developing: countries having lower avg. incomes, simple and agriculture-based economies, and rapid population growth (UN)
• Haiti, India, Chile, Mexico, Libya, Thailand
• ~5.2 billion people live in developing countries; fewer than ½ have access to enough food, safe drinking water, and proper sanitation. Result: malnutrition, starvation, disease, soil infertility, animal extinction.