1. Environmental Science 1

2. Lesson 7: Human Use of resources  People, like many other organisms, rely on the environment for resources such as water, air, and fertile soil.  People also need raw materials to make all the products they use. Without resources, people would not be able to meet their needs for food, water, clothing, shelter and energy. 2

3.  Non-renewable resources include: fossil fuels such as coal, oil, and natural gas are found on Earth in limited supplies.  Renewable resources can be replaced in our lifetime but are often damaged by pollution. 3

4. Resource Use Challenges  Fossil Fuels  To obtain coal, people create mines. Miners can become trapped & coal dust can cause health problems.  Humans pump oil and natural gas from the ground or ocean floor. Can break, causing oil to pollute the oceans and land.  By burning fossil fuels, we release useful energy  Carbon dioxide, sulfur, and nitrogen- an excess of these gases in the atmosphere can harm the environment 4

5.  The overuse of natural resources can also cause resource depletion  The continued reduction in the supply of natural resource  When people use resources faster than they can be replaced, resources are depleted  Examples: overfishing, and deforestation 5

6. Chapter 8: Natural and Human-Made Changes to ecosystems  Most organisms have adaptations for the natural changes that take place. (seasons)  Most common natural changes:  Temp., length of day, and precipitation.  Organisms that do not have the proper adaptation migrate during the fall and spring.  Ensures they will find food throughout the year.  Animals that use less energy, therefore requiring less food, hibernate in the winter.  Body temp. and heart rate drop becoming inactive for weeks or months. 6

7.  Populations can be drastically decreased or even become extinct due to various changes.  Natural disaster (earthquake, severe storm)  Natural occurrence (disease)  Many sudden ecosystem changes are due to humans.  Cutting trees (destroys habitats)  Introduce new species (no natural predators causing overpopulation) 7

8.  Biodiversity- different populations living in an ecosystem allowing it to function.  Very important in maintaining the function of the ecosystem.  A meadow ecosystem can survive losing one population because of the various other populations. 8

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10. Agriculture  You must copy anything written in BLACK!!! 10

11.  Agriculture is the main source of food for us  As human population grows, people need more land to live on, and more land for agriculture  Agriculture depends on fertile soil  It has nutrients that crops need to survive and grow  Can’t plant each year in the same place. Why not?  Farmers apply chemical fertilizers to crops but this can cause water pollution. 11

12.  Farmers are finding ways to keep soil fertile without causing water pollution  Farmers rotate the crops each year  It involves planting different species in a field in different years or at different times of the year  Some crops add nutrients to the soil 12

13. Resources and Agriculture  Farmers rely heavily on water resources in the area to water their plants  Precipitation isn’t always enough  Farmers irrigate their crops  May use wells or nearby rivers  There are cons to irrigation  Irrigation often uses up water needed for other purposes Can also take water away from other organisms in the ecosystem 13

14. Waste Management  Much of the solid waste that we produce ends up in landfills  In a landfill, trash is dumped into a large hole and buried, decomposers allow the matter to be recycled in the ecosystem.  The goal of landfills is to allow decomposition to occur in an area away from where people live. 14

15.  Older landfills are hazardous because they can have harmful materials leak from the landfill trash and into the groundwater, polluting it.  Newer landfills are lined with clay or plastic to prevent the pollution of the ground water  Scientists are transforming old landfills into healthy ecosystems by covering with soil and planting trees. 15

16. Decomposition Rates  Apple core: 1 to 2 months  Glass bottles: tens of thousands of yrs. (made from sand, can outlast most anything)  Plastic bags: up to hundreds of years; newer plastic bags can photo-degrade, but most aren't exposed to sunlight when in a landfill  Plastic milk jug: 500 years  Aluminum can: 80-200 years  Milk carton: 5 years  Styrofoam: no sign of breaking down  Cigarette butt: 1-5 years  Newspaper: 2-4 weeks, will decompose much faster when wet 16

17.  Two ways to alleviate the landfill problem:  1. Recycle: People use materials from old products to make new products  2. Composting: breaking down organic wastes such as fruits, vegetables, leaves, and wood by mixing it with soil and letting decomposers such as bacteria break down the materials 17

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19. Lesson 5: Energy Transfer and conversion  Law of conservation of energy- energy cannot be created or destroyed.  Energy can be transferred from one object to another (changed or converted)  Ex. You push a box. You lose your energy, box gains energy. Evens out.  Machines allow people to transfer energy to do useful work. (pulley/lever=simple machine) 19

20.  Chemical Energy- the bonds holding molecules together.  Nuclear Energy- energy holding neutrons and protons together. The atom is split and energy is released. (fission)  Electrical Energy- Using electrons (charged particles) sent through wires to produce energy.  Light Energy- comes from the sun and other sources (electricity). Travels in the form of Electromagnetic waves (able to travel through vacuum)  Sound Energy- vibration of objects causes air molecules to vibrate and transmit the wave. 20

21.  Sun = main source of energy  Solar Energy- drives the water cycle and other Earth processes. Can also be used to generate electricity.  The sun is a renewable source of energy like water and wind. 21

22.  Heat flows from hot to cold.  3 types of energy transfer:  Conduction: transfer of energy by physical contact.  Energy transferred from constant particle movement (always from hot to cold)  Convection: transportation of energy from one place to another in flowing matter.  Only in fluids (anything that can flow: liquid, gas)  Radiation: transfer of energy through waves that do not require matter (medium).  Ex. Heat and Light 22

23.  Energy conversion- change from one type to another.  Food gives you energy, sun gives plants energy  Electricity turned to light or sound  Kinetic and Potential energy are a common form of energy conversion.  Ex. Roller Coaster  Some energy is lost as heat due to friction making the appliance less efficient. 23

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25. Alternative Energy Sources  You must copy anything written in BLACK!!! 25

26. Lesson 6: Energy Resources  Main use of energy = generate electricity.  Non-renewable form very slowly and cannot be replaced in our lifetime.  Fossil fuels (coal, oil, natural gas) are non- renewable.  Form from the remains of animals and plants.  Burning releases chemical energy, however they produce pollutants of air and water. 26

27.  Excess CO 2 gets trapped on Earth from the burning of fossil fuels causing the global temp. to rise (Global Warming/Greenhouse Gases)  Power Plants use generators to convert kinetic energy into electricity.  Turbines (spinning blades) drive the generators.  Nuclear Power Plants use nuclear fission (releasing the energy from the nucleus by splitting the atom)  No CO 2 production but radioactive waste. 27

28.  Solar Power- use solar cells to store and convert into electricity.  Need many cells, do not produce large amounts of energy – very expensive.  Wind Power- use turbines to generate energy from the wind.  No pollution but very noisy.  Biomass- used in developing countries. Refers to the use of living things (plants and animal products) to produce energy.  Burn dung from animals as fuel, or use of wood. 28

29.  Hydroelectric Power- electricity produced by running water.  Dams are built with turbines.  No pollution but disrupts aquatic ecosystems.  Geothermal Energy- heat from the Earth’s crust to produce energy.  Steam turns turbine. 29

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