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Chapter 1: Science and the Environment Section 1: Understanding our Environment ENVIRONMENT ● Everything around us. ENVIRONMENTAL SCIENCE Study of how humans interact with the environment. The Goals of Environmental Science ● Achieving sustainability (when human needs are met in such a way that a human population can survive indefinitely). ● Understanding and solving environmental problems. Environmental scientists study two main types of interactions between humans and their environment. ● How we use resources, such as water and plants ● How our actions alter our environment. Many Fields of Study ●Environmental science is interdisciplinary. ●Important foundation of environmental science: ECOLOGY (Study of how living things interact with each other and their nonliving surroundings. ● Ecologists may study… ● Environmentalists may study… ….the relationship between bees and the plants bees pollinate. ….how nesting behavior is influenced by human behavior (such as landscaping) OUR ENVIRONMENT THROUGH TIME…. Human Impact Wherever humans have hunted, grown food, or settled, they changed the environment. Hunter-Gatherers ● HUNTER-GATHERERS: People who obtain food by collecting plants and hunting animals or scavenging their remains. ● People were hunter-gatherers for most of human history. ● Early hunter-gatherers: ● Small groups ● Migrated from place to place as food became available. How hunter-gatherers affect their environment: ● Hunted bison, and set fires to prairies to prevent tree growth so bison could be seen. ● Helped spread plants to areas where the plants did not originally grow. ● Rapid climate changes and overhunting led to disappearance of some large mammal species. The Agricultural Revolution ● Eventually, hunter-gatherers began ● Collecting seeds of plants they gathered and ● Domesticating animals in their environment. AGRICULTURE: practice of growing, breeding, and caring for plants and animals used for food, clothing, housing, transportation, etc. Effects of the Agricultural Revolution ● Human population grew and became concentrated in smaller areas. ● Pressure on local environment increased. ● Changed food we eat. ● Domesticated plants became different from their wild ancestors. Effects of the Agricultural Revolution ● Habitats were destroyed through slash-and-burn agriculture. ● Soil loss, floods, and water shortages. ● Poorly-farmed land is no longer fertile. The Industrial Revolution ● Began in the mid-1700’s. ● Involved a shift from animal muscle to fossil fuels. ● Increased use of fossil fuels and machines changed society and increased efficiency agriculture, industry and transportation. ● Large-scale production of goods became less expensive. The Industrial Revolution ● Machinery reduced manpower and land needed to grow food. ● Populations in urban areas grew steadily. ● Fossil fuels and motorized vehicles allowed food and other goods to be transported cheaply. Improving Quality of Life ● Positive changes introduced by industrial revolution: ● Inventions ● Agricultural productivity increased, ● Sanitation, nutrition and medical care improved. Environmental Problems Introduced by Industrial Revolution ● Pollution and habitat loss became more common ● Increased use of artificial substances (plastics, artificial pesticides, fertilizers) Spaceship Earth -Earth compared to a spaceship: cannot dispose of waste or take on new supplies. CLOSED SYSTEM ● Isolated system that has no interactions with its external environment. ● Problems with a closed systems ● As the population grows, resources will be used more rapidly. ● Wastes could be produced more quickly than we can dispose of them. What Are Our Main Environmental Problems? ● Resource Depletion ● Pollution ● Loss of biodiversity Resource Depletion ●NATURAL RESOURCE - Any natural material used by humans. ●Two types ● RENEWABLE - Can be replaced relatively quickly by natural processes. Ex: fresh water, air, soil, trees, crops, and energy from the sun. ● NONRENEWABLE - Forms at a much slower rate than it is consumed. Ex: minerals and fossil fuels. Pollution ● POLLUTION: undesirable change in air, water, or soil. ● Industrial revolution produced wastes faster than they could be disposed of. ● Wastes accumulate in the environment and cause POLLUTION. ● Much of the pollution today is produced by human activity. Two Main Types of Pollutants BIODEGRADABLE NONBIODEGRADABLE ● Pollutants that can be broken down by natural processes. ● Pollutants that cannot be broken down by natural processes. ● Examples: human sewage or a stack of newspapers. ● Examples: mercury, lead, and some types of plastic. ● Can become a problem when they accumulate faster than they can be broken down. ● Can build up to dangerous levels in the environment. Loss of Biodiversity ● BIODIVERSITY: variety of species that live in an area. ● Organisms that share the world with us can be considered NATURAL RESOURCES. ● We depend on other organisms for FOOD, OXYGEN, AND MANY OTHER THINGS. ● Species can be considered NONRENEWABLE RESOURCES. “Tragedy of the Commons” (Garrett Hardin, 1968) The difficulty of solving environmental problems is conflict between short-term interests of individuals and long-term welfare of society. Point of Hardin’s Essay ● Someone or group has to take responsibility for maintaining a resource. ● Social pressures influence how we use resources. ● Earth’s natural resources are our modern commons. Economics and the Environment ● Economic forces influence how we use resources. ● LAW OF SUPPLY AND DEMAND: The greater the demand for a limited supply of something, the more the thing is worth. Costs and Benefits ● The cost of environmental solutions can be high. ● COST-BENEFIT ANALYSIS: Balances the cost of an action against the benefit one expects from it. DEVELOPMENT DEVELOPED COUNTRIES ● Have higher average incomes, slower population growth, diverse industrial economies, and stronger social support systems. DEVELOPING COUNTRIES ● Lower average incomes, simple and agriculturebased economies, and rapid population growth. Consumption Trends Ecological Footprints ECOLOGICAL FOOTPRINT: Productive area of Earth needed to support one person in a particular country. -Estimation of land used for crops, grazing, forest products and housing. -Includes ocean area used to harvest seafood, and forest area needed to absorb air pollution caused by fossil fuels. Do Now: PLANT YOUR CORN.