Understanding our Environment

Includes the natural world as well as things produced by humans. It is a complex web of relationships that connects us with the world we live in.

 The study of how humans interact with the environment  Ecology is the study of how living things interact with each other and with their nonliving environment, so….  Environmental Science = Ecology + Human Interaction

 Area 1:  How we use natural resources such as water and plants  Area 2:  How our actions alter our environment

 Other Sciences:  Biology  Earth Science  Physics  Chemistry  Social Sciences: Geography, Anthropology, and Sociology *Refer to Table 1, pg. 7 to supplement your notes

Environmental Change is not a new issue, wherever humans have hunted, grown food, or settled, they have changed the environment There are three major environmental changes made by humans over the years which we will discuss next

 For most of human history, people were hunter gatherers (people who obtain food by collecting plants and hunting wild animals)

 Set fires to burn the prairies and prevent the growth of trees so the prairies would remain open grasslands where they could hunt bison  Helped spread plants to areas where plants did not originally grow because many of the early hunter- gatherers migrated from place to place  Over hunted many large mammal species possibly leading to extinction

 Allowed human populations to grow rapidly (an area of land can support up to 500 times as many people by farming as it can by hunting and gathering)  The food we eat (the plants we grow and eat descended from wild plants)  As grasslands, forests, and wetlands were replaced with farmland, habitats were destroyed  The replacement of forest with farmland on a large scale can lead to soil loss, floods, and water shortages and was the case of this time period

 In the 1700s, there was a shift from using man or animal powered machinery to using machines powered by fossil fuels such as steam engines.  This shift changed society and greatly increased the efficiency of agriculture, industry, and transportation.

Positive ChangesPositive ChangesNegative ChangesNegative Changes  Invention of the light bulb  Agricultural productivity increased  Sanitation, nutrition, and medical care improved  As the human population grew, many environmental problems such as pollution and habitat loss became more common  The use of plastics, pesticides, and fertilizers began being used which present environmental problems as well

 The concept of Earth being compared to a spaceship traveling through space that cannot dispose of waste or take on new supplies (is a “closed system”)  What problems do you think this causes for our Earth?

 Resources are said to be depleted when a large fraction of a resource has been used up  Any natural material that is used by humans is called a Natural Resource

 A resource that can be replaced relatively quickly by natural processes  Examples:  Air  Fresh Water  Soil Trees  Crops  Sun (energy)  A resource that forms at a much slower rate than the rate that it is consumed  Examples:  Fossil Fuels (oil, coal, natural gas)  Metals such as Aluminum, Iron, and Copper  Salt, Sand, and Clay

 Is an undesired change in air, water, or soil that adversely affects the health, survival, or activities or humans or other organisms  Much of the pollution that troubles us today is produced by human activities

Biodegradable Pollutants Nondegradable Pollutants  Can be broken down by natural processes  Include materials such as human sewage or a stack of newspapers  Cannot be broken down by natural processes  Include materials such as mercury, lead, and some types of plastics  Can build up to dangerous levels in the environment