Unit 4 Human Impact on the Environment

1. Unit 4 Human Impact on the Environment

2. Humans depend on their environment for: • Food • Water • Shelter • Clean Air

4. Renewable Resources • Aresource is something that is ready to use if or when it is needed. • Renewable resources can regenerate and are replaceable. • But, they still can be limited in availability • As an example, fresh water is renewable but overuse and drought can sometimes make it scarce.

5. Nonrenewable Resources • Once they’re used they cannot be replaced. • For example, fossil fuels take hundreds of millions of years to form, burning them as an energy source means they are gone. • Fossil fuels include coal, oil , and natural gas.

6. Renewable Resource

7. Nonrenewable Resource

8. Renewable Resource

9. Nonrenewable

10. Renewable Resource

11. Renewable Resource

12. Overconsumption of Resources The U.S. has only 4.6% of the world’s population, yet we consume 40% of the earth’s natural resources.

13. World Population What is the message being conveyed by this cartoon?

14. World Population and Resources What is the this cartoon trying to tell us?

15. Reached on October 31,2011

16. Regents Practice • The trend shown on the graph would most likely result in • a decreased demand for deforestation • an increase in available freshwater • a decrease in air pollution • an increased demand for land use

17. Regents Practice • The trend shown on the graph would most likely result in • a. decreased demand for deforestation • an increase in available freshwater • a decrease in air pollution • an increased demand for land use

18. Which human activity will most likely have a negative effect on global stability? A)decreasing water pollution levels B) increasing recycling programs C) decreasing habitat destruction D) increasing world population growth Regents Practice

19. Which human activity will most likely have a negative effect on global stability? A)decreasing water pollution levels B) increasing recycling programs C) decreasing habitat destruction D) increasing world population growth Regents Practice

20. Regents Practice Which human activity would most likely deplete finite resources? A) use of natural enemies to eliminate insect pests B) development of wildlife refuges C) governmental restriction of industrial pollution D) uncontrolled population growth

21. Regents Practice Which human activity would most likely deplete finite resources? A) use of natural enemies to eliminate insect pests B) development of wildlife refuges C) governmental restriction of industrial pollution D) uncontrolled population growth

22. Destructive Consequences of Human Activity

23. Human activity damages the biosphere and has created serious environmental concerns. • Ozone Depletion • Acid Rain • Global Warming • Biomagnificaiton of Pollutants • Loss of Biodiversity

24. OZONE DEPLETION

25. What is the Ozone Layer? The ozone layer is found in the upper atmosphere and it is composed of O3 Oxygen molecules. It limits the amount of Ultraviolet light energy that reaches the Earth’s surface. The ozone actually absorbs UV radiation and thus prevents it from reaching the surface of the earth where it would damage the DNA of plants and animals which could lead to skin cancer and other diseases.

26. How can the Ozone layer be damaged? • Various air pollutants, such as chlorofluorocarbons (CFCs), enter the upper atmosphere and break down ozone molecules. • CFCs have been used as refrigerants, as propellants in aerosol sprays, and in the manufacture of plastic foams. • When ozone breaks down, the ozone layer thins, allowing more UV radiation to penetrate and reach the surface of the earth.

27. What is meant by an Ozone Hole? Areas of major ozone thinning are called ozone holes. These images of the ozone hole were taken by NASA between September 1981 and September 1999.

29. Regents Practice What will the continued depletion of the ozone layer most likely cause? A) an increase in skin cancer among humans B) a decrease in atmospheric pollutants C) an increase in marine ecosystem stability D) a decrease in climatic changes

30. Regents Practice What will the continued depletion of the ozone layer most likely cause? A) an increase in skin cancer among humans B) a decrease in atmospheric pollutants C) an increase in marine ecosystem stability D) a decrease in climatic changes

32. What is Acid Rain? • Acid Rain is actually any form of precipitation (rain, snow, fog or dew) that contains high concentrations of sulfuric and nitric acids. • The acids can have harmful affects on the environment and the organisms living there.

33. Acid Rain can Damage Forests • Acid rain can be extremely harmful to forests. Acid rain that seeps into the ground can dissolve nutrients, such as magnesium and calcium, that trees need to be healthy. • Trees that are located in mountainous regions at higher elevations, such as spruce or fir trees, are at greater risk because they are exposed to acidic clouds and fog, which contain greater amounts of acid than rain or snow

34. Damage to Forests ! The damage first appears in individual leaves and limbs. It doesn’t take long before the entire tree is damaged and dies off.

35. Acid Rain Damages Buildings and Objects • Acid rain can also have a damaging effect on many objects, including buildings, statues, monuments, and cars. • The chemicals found in acid rain can cause paint to peel and stone statues to begin to appear old and worn down, which reduces their value and beauty.

36. Damage to Buildings and Objects

37. Acid Rain causes Acidification of Lakes and streams • Some types of plants and animals are able to tolerate acidic waters. Others, however, are acid-sensitive and will be lost as the pH declines. • Generally, the young of most species are more sensitive to environmental conditions than adults. At pH 5, most fish eggs cannot hatch. At lower pH levels, some adult fish die. Some acid lakes have no fish. • The chart below shows that not all fish, shellfish, or the insects that they eat can tolerate the same amount of acid; for example, frogs can tolerate water that is more acidic (i.e., has a lower pH) than trout.

38. What is the Water Cycle? • The water cycle or hydrologic is a continuous cycle where water evaporates, travels into the air and becomes part of a cloud, falls down to earth as precipitation, and then evaporates again. This repeats again and again in a never-ending cycle. Water keeps moving and changing from a solid to a liquid to a gas, over and over again. • Would you believe that a dinosaur could have once used your last drink of water? Water on earth today has been here for millions of years. Because of the water cycle, water moves from the earth to the air to the earth again. It changes from solid to liquid to gas, over and over again.

39. Fun Facts • Without water, the earth would look like the moon. • All living things need water to live. People can live several weeks without food, but only a few days without water. We should drink six to eight glasses of water each day! • Water makes up 83% of our blood, 70% of our brain, and 90% of our lungs. Overall, our bodies are 70% water. • A tomato is about 95% water. An apple, a pineapple, and an ear of corn are each 80% water.

41. What Causes Acid Rain? • Burning of fossil fuels (such as coal) and other industrial processes release into the air pollutants that contain sulfur dioxide and nitrogen dioxide. • When these substances react with water vapor, they produce sulfuric acid and nitric acid.

42. The Acid Rain Process

43. What can be done to prevent acid rain? Conserve Energy! • Since energy production creates large amounts of the pollutants that cause acid rain, one important step you can take is to conserve energy. • Turn off lights, computers, televisions, video games, and other electrical equipment when you're not using them. • Encourage your parents to buy equipment that uses less electricity, including lights, air conditioners, heaters, refrigerators, and washing machines. Such equipment might have the Energy Star label. • Walk, ride or carpool.

44. Regents Practice Question • In lakes that are exposed to acid rain, fish populations are declining. This is primarily due to changes in which lake condition? • A) Size • B) temperature • C) pH • D) location

45. Regents Practice Question • In lakes that are exposed to acid rain, fish populations are declining. This is primarily due to changes in which lake condition? • A) Size • B) temperature • C) pH • D) location 45

46. Regents Practice Question: • Which situation is a result of human activities? • decay of leaves in a forest adds to soil fertility • B) acid rain in an area kills fish in a lake • C) ecological succession following volcanic activity reestablishes an ecosystem • D) natural selection on an island changes gene • frequencies

47. Regents Practice Question: • Which situation is a result of human activities? • decay of leaves in a forest adds to soil fertility • B) acid rain in an area kills fish in a lake • C) ecological succession following volcanic activity reestablishes an ecosystem • D) natural selection on an island changes gene • frequencies 47

49. What is a greenhouse? • A greenhouse is made of glass. It traps the Sun's energy inside and keeps the plants warm, even in winter. • It has glass walls and a glass roof. People grow tomatoes and flowers and other plants in them. A greenhouse stays warm inside, even during winter. • Sunlight shines in and warms the plants and air inside. But the heat is trapped by the glass and can't escape. So during the daylight hours, it gets warmer and warmer inside a greenhouse, and stays pretty warm at night too.

50. What is the Greenhouse Effect ? Earth's atmosphere does the same thing as the greenhouse. Gases in the atmosphere such as carbon dioxide do what the roof of a greenhouse does. During the day, the Sun shines through the atmosphere. Earth's surface warms up in the sunlight. At night, Earth's surface cools, releasing the heat back into the air. But some of the heat is trapped by the greenhouse gases in the atmosphere. That's what keeps our Earth a warm and cozy 59 degrees Fahrenheit, on average.