2. I. Earth’s Increasing Population Population: What is Population? All of the individuals of one species occupying a particular area. Can population size vary? A population could be the residents of Minersville or all of the residents of Pennsylvania. The area defined could be small or large.
3. I. Earth’s Increasing Population Population Growth What is our current population? The Global Population is approximately 6.8 billion (May 1, 2010). Does our population change? Each day the population increases between 200,000 to 300,000 people per day. What is currently happening to our population? Earth is currently experiencing a population explosion. Explosion is used because the rate at which the population is growing has increased rapidly in recent history.
4. I. Earth’s Increasing Population Figure2: Human Population growth remained relatively steady until the beginning of the nineteenth century. The growth rate then began to increase rapidly. Why do you think this occurred?
5. I. Earth’s Increasing Population Why the population growth? Many years ago few people lived on Earth. Took thousands of years for the population to reach 1 billion. After mid 1800’s population increased much faster. Changes in society and the advances in civilization helped create the population explosion.
6. I. Earth’s Increasing Population Three Major Reasons for Population Explosion Modern Medicine (Better Medicine) Reduced infant deaths dramatically. Increased the ability to reproduce (fertility drugs). Allows people to live longer. Modern Sanitation Drinking water cleaned before use. Wastes disposed of more safely. People have better hygiene. (cleaner)
7. I. Earth’s Increasing Population Three Major Reasons for Population Explosion Better Nutrition Food better distributed and more readily available. Aid given to areas in famine. (3rd world countries)
8. I. Earth’s Increasing Population Future Predictions About Population How fast will the population grow? By the year 2050 there will be 9 Billion people on Earth. About 1.5 times more than today. What is the biggest problem facing the planet today? Biggest question is will Earth have enough resources to support such a large population? Not if we continue at our current pace of pollution and wasting resources.
9. I. Earth’s Increasing Population Population Limits Population size depends upon the amount of available resources and how members of the population use them. If resources become scarce or if the environment is damaged, members of the population can suffer and population size can decrease.
10. I. Earth’s Increasing Population Population Limits Earth An Endless Supply of Resources? People once believed that Earth had an endless supply of resources such as fossil fuels, metals, rich and fertile soils, and clean water. We now know that is NOT TRUE! Earth’s resources are LIMITED. What is Carrying Capacity? Carrying Capacity is the largest number of individuals of a particular species that the environment can support. Unless Earth’s resources are treated with care, they could disappear and the human population might reach its carrying capacity!!
11. II. People and the Environment How will you affect the environment over your lifetime? How much Garbage will you produce? By the time you are 75 years old, you will have produced enough garbage to equal the mass of eleven African Elephants. 53,000 kg or 116,600 pounds How much water will you use? You will have consumed enough water to fill 68,000 bathtubs. 18 million Liters. How much energy will you use? United States Citizens use 5X more energy than anyone else.
12. II. People and the Environment Daily Activities that affect the Environment Electricity May be created by burning fossil fuels; polluting the environment. Fossil Fuels Fossil Fuels are mined causing damage to the environment. Fossil Fuels are burned, polluting the environment. Water: Drinking and Waste Water Many people waste water; a valuable resource. Water must be treated correctly before it is put back into rivers/streams. Raw sewage used to be released directly into rivers and streams without being treated.
13. II. People and the Environment Daily Activities that affect the Environment Food We Eat Grown in soil, using valuable nutrients and minerals. Pesticides and Herbicides used to kill insects and weeds; these chemicals can get into water supplies and threaten health of living things if the chemicals become too concentrated. Plastics/Paper Products Plastics begin as oil; the process of refining oil can cause pollutants that contaminate the environment. Paper; products come from the foresting of trees, oil is used to transport the materials to paper mills, and water and air pollutants are given off in the papermaking process.
14. II. People and the Environment Packaging Produces Waste Packaging foods for single servings uses more paper and plastic than buying food in bulk. After the products are consumed the packaging must be discarded using up valuable land resources. The land is changed when resources are removed from it, then further damaged when they must be discarded.
15. II. People and the Environment Our Future? Greater Population means more resources will be used. Greater population means more waste will be created. Greater population means more environmental problems for our planet. People need to conserve more resources, recycle more materials, and help lessen the negative impact our current society places on our environment.
18. I. Using Land (Ch 19: Section 2) How Land is Used Land is a natural resource used by man. Used for agriculture, logging, garbage disposal, urban development, and as a fuel source. These activities often impact Earth’s land resources. How Agriculture affects our environment How much land can be used for agriculture? About 16 million square kilometers of Earth’s total land surface is used as farmland. The Earth has about 145 million square kilometers of land. Only about 11% is used for food.
19. I. Using Land (Ch 19: Section 2) How Does Agriculture Affect Our Environment? Feeding the growing population. Farmers use higher yielding seeds and chemical fertilizers. These methods help increase the amount of food grown on each square kilometer. The use of these chemicals can contaminate the soil and local drinking water. The use of Herbicides and Pesticides. These chemicals help reduce weeds, insects, and other pests that can damage the crops. The use of these chemicals can damage the crops and the water table.
20. I. Using Land (Ch 19: Section 2) How Does Agriculture Affect Our Environment? Organic Farming Use of natural fertilizers, crop rotation, and biological pest control methods. Help farmers grow crops without using chemicals. Unfortunately this type of farming CANNOT currently produce enough food to feed all of Earth’s people.
21. I. Using Land (Ch 19: Section 2) How Does Agriculture Affect Our Environment? Removing Vegetation for Crops Exposes soil to wind, water, and gravitational erosion forces. In some areas it can take up to 1000 years for topsoil to be replaced.
22. I. Using Land (Ch 19: Section 2) How Can We Reduce Erosion? No-Till Farming, Cover Cropping, and Strip Cropping. Terracing, Retaining Walls, Planting Vegetation. Windbreaks and Shelter Beds. a. All of these are a review!!
23. I. Using Land (Ch 19: Section 2) Does the Land Affect Livestock? Land used for feeding livestock. Livestock used as source of food for humans. Farmers use corn and hay as livestock crops. Used to feed their cattle/livestock. These crops provide nutrients for cattle and improve the quality of the meat.
24. I. Using Land (Ch 19: Section 2) What are Forest Resources? Resources found in forests for medicine, fuel, and other materials. ¼ of land on earth is covered with forests. 55% in developing countries; 45% in developed countries.
25. I. Using Land (Ch 19: Section 2) What is Deforestation? Deforestation is the clearing of forests for agriculture, grazing, development, or logging. Amount of forested land in the world decreased by 0.24% (94,000 km2) each year between 1990 and 2000. a. Most of this deforestation has occurred in tropical climates.
26. I. Using Land (Ch 19: Section 2) Why the Concerns about Deforestation? Tropical rain forests contain diverse populations of plants and animals that don’t live in other places. Many of these plants might be important for developing new medicines. Some worry that removing too much of these forests could lead to the extinction of some animals. Cutting too many trees down could have a regional affect on climate. Water from tree leaves evaporates into the atmosphere where it can condense to form rain. If too many trees are cut down, less water enters the atmosphere and the region receives less rainfall.
27. I. Using Land (Ch 19: Section 2) How Does Development of Land Change Our World? From 1990 to 2000 the amount of urban roadways in the United States increased by more than 13% Paving land prevents water from soaking into the soil. Instead it runs off into sewers or streams. This increases the STREAMS DISCHARGE. Stream Discharge is the volume of water flowing past a point per unit of time. During heavy rainstorms in paved areas, rainwater flows directly into streams, increasing stream discharge and the risk of flooding.
31. I. Using Land (Ch 19: Section 2) How Does Development of Land Change Our World? Many communities use underground water supplies for drinking. Covering land with roads, sidewalks, and parking lots reduces the amount of rainwater that soaks into the ground to refill underground water supplies. a. This increases the chance and rate of flooding.
32. I. Using Land (Ch 19: Section 2) How Does Development of Land Change Our World? Some businesses, communities, and private groups now preserve areas rather than pave them. Preserving space beautifies the environment, increases area into which water can soak, and provides space for recreation and other outdoor activities. See Figure 8
33. I. Using Land (Ch 19: Section 2) Sanitary Landfills A waste-disposal area that is excavated and lined with plastic, concrete, or clay; and filled with layers of waste and dirt. Because of this design, the landfill is able to prevent liquid wastes from draining into ground water below. About 60% of our garbage goes into Sanitary Landfills Since many materials do not decompose in landfills, or they decompose slowly, landfills fill with garbage and new ones must be built. Type of soil, depth of groundwater, and neighborhood concerns must be considered when choosing an acceptable location for a landfill.
35. II. Hazardous Waste (Ch 19: Section 2) Hazardous Wastes Wastes that are poisonous, cause cancer, or that can catch fire. Previously, everyone-Industries and individuals-put hazardous wastes into landfills along with household garbage. EPA passed laws banning hazardous wastes into sanitary landfills.
36. II. Hazardous Waste (Ch 19: Section 2) How are some Household Wastes Hazardous? Unlike Industries, individuals discard hazardous wastes in the trash. Insect Sprays, batteries, drain cleaners, bleaches, medicines etc. This garbage remains unchanged for many years and pollutes the land and water. Hazardous wastes can also cause cancer and other disorders. a. Affects humans and animals that interact with the land.
37. II. Hazardous Waste (Ch 19: Section 2) What is Phytoremediation? Hazardous substances can contaminate the soil. These contaminants may come from nearby industries or leaking landfills, Water filters into the ground and leaves toxic substances in the soil. Some plants can help fix this problem in a method called PHYTO-REMEDIATION. Phyto- means plant Remediation- means to fix or remedy a problem.
38. II. Hazardous Waste (Ch 19: Section 2) What is Phytoremediation? During phytoremediation, roots of certain plants such as alfalfa, grasses, and pine trees can absorb metals, including copper, lead and zinc from contaminated soil just as they absorb other nutrients.
39. II. Hazardous Waste (Ch 19: Section 2) What is Phytoremediation? What happens to these plants after they absorb metals? If livestock were to eat the contaminated alfalfa, the harmful metals could end up in your milk or meat. Contaminated plants must be harvested and either composted to recycle the metals or burned. If the plants are destroyed by burning, the ash residue contains the hazardous waste that was in the plant tissue and must be disposed of at a hazardous waste site.
41. II. Hazardous Waste (Ch 19: Section 2) How are organic pollutants broken down? Living things also can clean up pollutants other than metal. Substances that contain carbon and other elements like hydrogen, oxygen, and nitrogen are called organic compounds. Examples include gasoline, oil, and solvents.
42. II. Hazardous Waste (Ch 19: Section 2) How are organic pollutants broken down?. Organic pollutants can be broken down into simpler, harmless substances, some of which plants use for growth. Some plants release enzymes into the soil. Enzymes are substances that make chemical reactions go faster. Enzymes from plant roots increase the rate at which organic pollutants are broken down into simpler substances used by plants for growth.
43. II. Hazardous Waste (Ch 19: Section 2) Natural Preserves Not all land is used to produce materials or for storing wastes. Some land remains mostly uninhabited by people. National Forestlands, Grasslands, and National Parks in the United States are protected from many problems stated in this chapter. Many other countries also have Nature Preserves.
45. III. Conserving Resources Resource Use Petroleum and metals are important for making the products you use every day at home and in school. Petroleum is used to make plastics and fuel. Minerals are used to make automobiles and bicycles. If these resources are not used carefully, the environment can be damaged.
46. III. Conserving Resources Resource Use Conservation is the careful use of earth materials to reduce damage to the environment. a. Conservation can prevent future shortages of some materials, such as certain metals.
47. III. Conserving Resources Reduce, Reuse, Recycle U.S. uses more natural resources than other regions. Ways to conserve resources include reducing the use of materials, and reusing and recycling materials. Ways to reduce the consumption of materials. Use both sides of notebook paper. Take lunch in a non-disposable container.
48. III. Conserving Resources Reduce, Reuse, Recycle Ways to reduce the consumption of materials. Use both sides of notebook paper. Take lunch in a reusable container. Reuse old clothes by giving them to someone else. Reuse old clothes as rags for cleaning jobs.
49. III. Conserving Resources Yearly Consumption of Resources a. A person in the US uses more resources than the average person elsewhere. Figure 12
50. III. Conserving Resources Reusing Yard Waste Composting: piling yard wastes where they can decompose gradually. Grass, Leaves, any other yard debris. Decomposed material provides needed nutrients for your garden, grass, or flower bed. Some cities no longer take yard waste to landfills, they take them to large compost piles. If everyone in the US composted, it would reduce the trash put into landfills by 20%.
51. III. Conserving Resources Recycling Materials Using material again is called recycling. Recycling helps conserve Earth’s resources, energy and landfill space. a. Wastes that can be recycled: Glass, paper, plastic, steel, or tires.
52. III. Conserving Resources Recycling Materials Recycling Paper Paper makes up about 40% of the mass of trash. Recycling paper in the US would use 58% less water and generate 74% less air pollution than producing more paper from trees. Figure 13 (next slide) does not even include newspapers. More than 500,000 trees are cut every week just to print newspaper.
53. III. Conserving Resources Recycling Materials Recycling Paper
57. III. Conserving Resources Recycling Methods Many states or cities now have some form of recycling laws. Some places people who recycle pay lower trash collection fees. Other places refundable deposit is made on all beverage containers. This means paying extra money at the store for a drink, but your get the money back if you return the container to the store for recycling.
59. III. Conserving Resources Recycling Methods Several disadvantages to recycling More trucks are needed to haul materials separately from your trash. Materials must then by separated at special facilities like the one in figure 15. Demand for things made from recycled materials must exist, and items made from recycled materials often cost more.
60. III. Conserving Resources Population Outlook Human population explosion already has had an effect on the environment and the organism that inhabit Earth. It is unlikely that the population will begin to decline in the near future. To make up for this, resources must be used wisely. Conserving resources by reducing, reusing, and recycling is an important way that every person can make a difference.
