Chapter 19

Section 1: Population Impact on the Environment

I. Earth’s Increasing PopulationA. Population:

1. What is Population?a. All of the individuals of one species occupying a particular area.

2. Can population size vary?a. A population could be the residents of Minersville or all of the

residents of Pennsylvania.

b. The area defined could be small or large.

I. Earth’s Increasing PopulationB. Population Growth

1. What is our current population?a. The Global Population is approximately 6.8 billion (May 1, 2010).

2. Does our population change?a. Each day the population increases between 200,000 to 300,000

people per day.

3. What is currently happening to our population?a. Earth is currently experiencing a population explosion.

b. Explosion is used because the rate at which the population is growing has increased rapidly in recent history.

I. Earth’s Increasing PopulationFigure2: 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?

I. Earth’s Increasing PopulationC. Why the population growth?

1. Many years ago few people lived on Earth. a. Took thousands of years for the population to reach 1 billion.

2. After mid 1800’s population increased much faster. a. Changes in society and the advances in civilization helped create

the population explosion.

I. Earth’s Increasing PopulationD. Three Major Reasons for Population Explosion

1. Modern Medicine (Better Medicine)a. Reduced infant deaths dramatically.

b. Increased the ability to reproduce (fertility drugs).

c. Allows people to live longer. 2. Modern Sanitation

a. Drinking water cleaned before use.

b. Wastes disposed of more safely.

c. People have better hygiene. (cleaner)

I. Earth’s Increasing PopulationD. Three Major Reasons for Population Explosion

3. Better Nutritiona. Food better distributed and more readily available.

b. Aid given to areas in famine. (3rd world countries)

I. Earth’s Increasing PopulationE. Future Predictions About Population

1. How fast will the population grow?a. By the year 2050 there will be 9 Billion people on Earth.

b. About 1.5 times more than today.

2. What is the biggest problem facing the planet today?a. Biggest question is will Earth have enough resources to support

such a large population?

b. Not if we continue at our current pace of pollution and wasting resources.

I. Earth’s Increasing PopulationF. Population Limits

1. Population size depends upon the amount of available

resources and how members of the population use them. 2. If resources become scarce or if the environment is damaged,

members of the population can suffer and population size can decrease.

I. Earth’s Increasing PopulationF. Population Limits

3. Earth An Endless Supply of Resources?a. People once believed that Earth had an endless supply of

resources such as fossil fuels, metals, rich and fertile soils, and clean water.

b. We now know that is NOT TRUE!

c. Earth’s resources are LIMITED.

4. What is Carrying Capacity?a. Carrying Capacity is the largest number of individuals of a

particular species that the environment can support.

b. Unless Earth’s resources are treated with care, they could disappear and the human population might reach its carrying capacity!!

II. People and the EnvironmentA. How will you affect the environment over your

lifetime? 1. How much Garbage will you produce?

a. By the time you are 75 years old, you will have produced enough garbage to equal the mass of eleven African Elephants.

b. 53,000 kg or 116,600 pounds

2. How much water will you use?a. You will have consumed enough water to fill 68,000 bathtubs.

b. 18 million Liters.

3. How much energy will you use?a. United States Citizens use 5X more energy than anyone else.

II. People and the EnvironmentB. Daily Activities that affect the Environment

1. Electricity

a. May be created by burning fossil fuels; polluting the environment.

2. Fossil Fuels

a. Fossil Fuels are mined causing damage to the environment.

b. Fossil Fuels are burned, polluting the environment.

3. Water: Drinking and Waste Water

a. Many people waste water; a valuable resource.

b. Water must be treated correctly before it is put back into rivers/streams.

i. Raw sewage used to be released directly into rivers and streams without being treated.

II. People and the EnvironmentB. Daily Activities that affect the Environment

4. Food We Eata. Grown in soil, using valuable nutrients and minerals.

b. 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.

5. Plastics/Paper Productsa. Plastics begin as oil; the process of refining oil can cause

pollutants that contaminate the environment.

b. 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.

II. People and the EnvironmentC. Packaging Produces

Waste1. Packaging foods for

single servings uses more paper and plastic than buying food in bulk.

2. 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.

II. People and the EnvironmentD. Our Future?

1. Greater Population means more resources will be used.

2. Greater population means more waste will be created.

3. Greater population means more environmental problems for our planet.

4. People need to conserve more resources, recycle more materials, and help lessen the negative impact our current society places on our environment.

CHAPTER 19: SECTION 1 REVIEW

Chapter 19

Section 2:Using Land

I. Using Land (Ch 19: Section 2)

A. How Land is Used1. Land is a natural resource used by man.

2. Used for agriculture, logging, garbage disposal,urban development, and as a fuel source. a. These activities often impact Earth’s land resources.

B. How Agriculture affects our environment1. How much land can be used for agriclulture?

a. About 16 million square kilometers of Earth’s total land surface is used as farmland.

b. The Earth has about 145 million square kilometers of land.

c. Only about 11% is used for food.

I. Using Land (Ch 19: Section 2)

B. How Does Agriculture Affect Our Environment?2. Feeding the growing population.

a. Farmers use higher yielding seeds and chemical fertilizers.

b. These methods help increase the amount of food grown on each square kilometer.

c. The use of these chemicals can contaminate the soil and local drinking water.

3. The use of Herbicides and Pesticides. a. These chemicals help reduce weeds, insects, and other pests that can

damage the crops.

b. The use of these chemicals can damage the crops and the water table.

I. Using Land (Ch 19: Section 2)B. How Does Agriculture

Affect Our Environment?4. Organic Farming

a. Use of natural fertilizers, crop rotation, and biological pest control methods.

b. Help farmers grow crops without using chemicals.

c. Unfortunately this type of farming CANNOT currently produce enough food to feed all of Earth’s people.

I. Using Land (Ch 19: Section 2)

B. How Does Agriculture Affect Our Environment?5. Removing Vegetation for Crops

a. Exposes soil to wind, water, and gravitational erosion forces.

b. In some areas it can take up to 1000 years for topsoil to be replaced.

I. Using Land (Ch 19: Section 2)

C. How Can We Reduce Erosion?

1. No-Till Farming, Cover Cropping, and Strip Cropping.

2. Terracing, Retaining Walls, Planting Vegetation.

3. Windbreaks and Shelter Beds.

a. All of these are a review!!

I. Using Land (Ch 19: Section 2)

D. Does the Land Affect Livestock?1. Land used for feeding livestock.

a. Livestock used as source of food for humans.

2. Farmers use corn and hay as livestock crops. a. Used to feed their cattle/livestock.

b. These crops provide nutrients for cattle and improve the quality of the meat.

I. Using Land (Ch 19: Section 2)

E. What are Forest Resources?

1. Resources found in forests for medicine, fuel, and other materials.

2. ¼ of land on earth is covered with forests.

3. 55% in developing countries; 45% in developed countries.

I. Using Land (Ch 19: Section 2)

F. What is Deforestation?1. Deforestation is the clearing of forests for

agriculture, grazing, development, or logging.

2. 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.

I. Using Land (Ch 19: Section 2)

G. Why the Concerns about Deforestation?1. Tropical rain forests contain diverse populations of

plants and animals that don’t live in other places.

2. Many of these plants might be important for developing new medicines.

3. Some worry that removing too much of these forests could lead to the extinction of some animals.

4. Cutting too many trees down could have a regional affect on climate.

a. Water from tree leaves evaporates into the atmosphere where it can condense to form rain.

b. If too many trees are cut down, less water enters the atmosphere and the region receives less rainfall.

I. Using Land (Ch 19: Section 2)

H. How Does Development of Land Change Our World?1. From 1990 to 2000 the amount of urban roadways in the

United States increased by more than 13%

2. Paving land prevents water from soaking into the soil. a. Instead it runs off into sewers or streams.

b. This increases the STREAMS DISCHARGE.

3. Stream Discharge is the volume of water flowing past a point per unit of time.

4. During heavy rainstorms in paved areas, rainwater flows directly into streams, increasing stream discharge and the risk of flooding.

Chapter 19 Section 2: Blog Question #1

Chapter 19 Section 2: Blog Question #2

Chapter 19 Section 2: Blog Question #3 and #4

I. Using Land (Ch 19: Section 2)

H. How Does Development of Land Change Our World?5. Many communities use underground water supplies for

drinking.

6. 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.

I. Using Land (Ch 19: Section 2)

H. How Does Development of Land Change Our World?

6. Some businesses, communities, and private groups now preserve areas rather than pave them.

a. Preserving space beautifies the environment, increases are into which water can soak, and provides space for recreation and other outdoor activities.

b. See Figure 8

I. Sanitary Landfills1. A waste-disposal area that is excavated and lined

with plastic, concrete, or clay; and filled with layers of waste and dirt.

a. Because of this design, the landfill is able to prevent liquid wastes from draining into ground water below.

2. About 60% of our garbage goes into Sanitary Landfills

3. Since many materials do not decompose in landfills, or they decompose slowly, landfills fill with garbage and new ones must be built.

a. Type of soil, depth of groundwater, and neighborhood concerns must be considered when choosing an acceptable location for a landfill.

I. Using Land (Ch 19: Section 2)

I. Using Land (Ch 19: Section 2)

II. Hazardous Waste (Ch 19: Section 2)

A. Hazardous Wastes

1. Wastes that are poisonous, cause cancer, or that can catch fire.

2. Previously, everyone-Industries and individuals-put hazardous wastes into landfills along with household garbage.a. EPA passed laws banning hazardous wastes into sanitary

landfills.

II. Hazardous Waste (Ch 19: Section 2)

B. How are some Household Wastes Hazardous?1. Unlike Industries, individuals discard hazardous

wastes in the trash. a. Insect Sprays, batteries, drain cleaners, bleaches,

medicines etc.

b. This garbage remains unchanged for many years and pollutes the land and water.

2. Hazardous wastes can also cause cancer and other disorders.

a. Affects humans and animals that interact with the land.

II. Hazardous Waste (Ch 19: Section 2)

C. What is Phytoremediation?1. Hazardous substances can contaminate the soil.

a. These contaminants may come from nearby industries or leaking landfills,

b. Water filters into the ground and leaves toxic substances in the soil.

2. Some plants can help fix this problem in a method called PHYTO-REMEDIATION.

a. Phyto- means plant

b. Remediation- means to fix or remedy a problem.

II. Hazardous Waste (Ch 19: Section 2)

C. What is Phytoremediation?3. 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.

II. Hazardous Waste (Ch 19: Section 2)

C. What is Phytoremediation?4. What happens to these plants after they absorb

metals? a. If livestock were to eat the contaminated alfalfa, the

harmful metals could end up in your milk or meat.

b. Contaminated plants must be harvested and either composted to recycle the metals or burned.

c. 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.

Figure 10:

Phyto-remediation

II. Hazardous Waste (Ch 19: Section 2)D. How are organic pollutants broken down?

1. Living things also can clean up pollutants other than metal.

a. Substances that contain carbon and other elements like hydrogen, oxygen, and nitrogen are called organic compounds. i. Examples include gasoline, oil, and solvents.

II. Hazardous Waste (Ch 19: Section 2)D. How are organic pollutants broken down?.

2. Organic pollutants can be broken down into simpler, harmless substances, some of which plants use for growth.

a. Some plants release enzymes into the soil. i. Enzymes are substances that make chemical reactions go

faster.

b. Enzymes from plant roots increase the rate at which organic pollutants are broken down into simpler substances used by plants for growth.

II. Hazardous Waste (Ch 19: Section 2)E. Natural Preserves

1. Not all land is used to produce materials or for storing wastes.

2. Some land remains mostly uninhabited by people.

3. National Forestlands, Grasslands, and National Parks in the United States are protected from many problems stated in this chapter.

a. Many other countries also have Nature Preserves.

Chapter 19 Section 2 Review