Humans and the Environment

1. Humans and the Environment Standard 4.8

2. New York? Los Angeles? Houston? No, Las Vegas Will Las Vegas run out of resources? How long can Las Vegas keep growing? What is the fastest growing city?

3. Resources • Renewable • Wind, solar and hydroelectric power • Nonrenewable • Exist in finite amounts in Earth’s crust • Coal, oil, natural gas • Will we run out?

4. Resources • Saudi Arabia has 24% of the world’s petroleum reserves • Countries must import all of the oil they use • Developed countries use more than undeveloped countries • US uses about 24% of Earth’s commercial energy although we only have 5% of the population

5. Resources • India • Developing country has 17% of Earth’s population and uses only 2% of the commercial energy • Angola (West Africa) • Country has resources but cannot meet their needs because of political and economic problems

6. Angola • Have rich deposits of oil, diamonds and valuable minerals but most people are poor • Most people will not live past 47 because of malnutrition, unsafe drinking water, and lack of adequate health care • Civil war going on for 25 years

7. Conservation of Resources • Conservation – is the careful use of a resource so that its supply will last longer • How and what can we conserve? • Ways to conserve – source reduction, reuse of products, and recycling, use more energy efficient appliances, purchase cars with better gas mileage, soil conservation, forest conservation

8. Making a Difference • Conservation saves resources and money • Replace incandescent light bulbs with fluorescent bulbs • Cost more initially but uses 75% less energy • Use appliances that are more energy efficient • See house attachment

9. Location, Location, Location • Why were many cities located on the water when they were founded? • In the 1600s and 1700s boats were the main form of transportation • Pittsburgh was extremely important transportation center because of its location on the 3 rivers

11. The Steel City • PA contained numerous coal mines • Coal was an important resource in making steel • By the mid-1800s PA started to use coke for iron and steel making • Coke – almost pure carbon substance made from bituminous coal – the soft coal deposits of western PA • Pittsburgh became a steel center because of the resources needed for steel were nearby

12. PA Resources • By 1900 Pittsburgh steel mills produced 2/3 of the steel produced in the US • PA major resources – coal, iron and steel • Oil – Drake oil company drilled in Titusville and hit oil in 1859

13. Air Pollution • Two main classes • Primary – those that factory smokestacks and motor vehicle tailpipes release into the air • Examples: soot, volcanic ash, dust or sea salt • Secondary – new substances that form as primary pollutants react with each other and with what is already in the atmosphere • Example: Smog • Usually come from three forms – Aerosols, gases and particulates

14. Aerosols – particles so tiny that they remain suspended in the air Gases – compounds that form the basic substance of air Particulates – particles in the air (large or small Air Pollution

15. Acid Deposition • Rain is naturally slightly acidic • In some places rain can be 10x more acidic than normal • Acid deposition – consists of acids or acid-forming substances that fall from the atmosphere to the ground • Commonly caused by plants and factories that release sulfur dioxide and nitrogen dioxide into the air which forms sulfuric acid and nitric acid • Can harm people, ecosystems and animals

17. Greenhouse Gases • Greenhouse gases • Keeps Earth from being a cold hostile environment • Include carbon dioxide, methane, water vapor, ozone, nitrogen oxides and chlorofluorocarbons • Greenhouse effect – natural process in which heat is trapped near Earth’s surface by the atmosphere • Example: think of the way heat is trapped in your car on a hot summer day

18. Global Warming • Increased carbon dioxide into the atmosphere increases the temperature • Global warming – unnatural warming of the average temperature of the atmosphere near Earth’s surface as a result of the increase in atmospheric greenhouse gases such as CO2

19. Effect of Global Warming • Melting of polar ice caps causing a sea level rise • Low-lying islands could flood and disappear • Warmer climate zones could move towards the poles • Plants and animals must adjust or die • Ecosystems would change

20. Ozone Depletion • Ozone – molecule composed of three atoms of oxygen • Forms a protective layer around the planet that stops 99% of the sun’s harmful ultraviolet radiation from reaching Earth’s surface • CFCs release chlorine into the atmosphere, which is broken down by UV radiation, which then breaks down the ozone into oxygen molecules

21. Effects of Ozone Depletion • More severe sunburns • Greater incidence of cataracts and skin cancer • Harm phytoplankton (alter food chains) • Decrease crop yield and damage forests

23. Sewage Discharge • Sewage moves from drain to treatment plant and then it is released into surface waters • In some places storm water drains and sewage pipes are the same – during heavy rainfall the two can combine • Release of raw sewage into surface water can cause the growth of bacteria, viruses and other microorganisms that cause disease • This is why public health experts do not allow swimming near storm water outflow pipes after a heavy rainfall

24. Farm runoff such as fertilizer can flow into surface water and cause algae blooms Algae blooms – huge clumps of algae that are eaten by oxygen-using bacteria when they die Nutrient Runoff

25. Nutrient Runoff • Decomposers will suck all of the oxygen out of an area killing the aquatic life • As a result dead zones are formed • Laundry detergent also contributes to nutrients in sewage because they contain phosphates

26. Nutrient Overload • Can lead to eutrophication • Where nitrates and phosphates also stimulate the excessive growth of algae and other aquatic plants • Also leads to a lack of oxygen

27. Oil – contains toxic substances that kills aquatic life Oil coating destroys the ability of fur or feathers to insulate animas from cold or help them float, causing animals to freeze or drown Petroleum Spills

28. Population Growth • Increased demands for natural resources and increased impacts on the natural environment • Example: Urban area spread into Florida Everglades • Decreased habitat • Increased Pollution • Endangered species – Florida panther and American crocodile as a result

29. Overfishing • Situation in which commercial fisheries take more fish than the population can naturally replace • 70% of the world’s marine stocks are overfished, depleted or fished to capacity • Populations of Atlantic cod, Atlantic swordfish, sharks and blue fin tuna have decreased

30. Offer watershed protection Maintain the atmosphere’s carbon balance Sustain biodiversity Also, provide paper, wood and fuel Forests