1. Chapter 18
The Environment

2. Sections 1-3
Section 1: Global Change (The atmosphere & ecosystems/ Ozone Layer/ Global temps)
Section 2: Effects on Ecosystems (Effects of Chemical Pollution/Loss of Resources/ Growth of Human Population)
Section 3: Solving Environmental Problems (A Worldwide Effort/Solving Environmental Problems)

3. Global Change
Human-induced environmental changes are affecting ecosystems worldwide
Acid Rain: acidified precipitation-caused by coal-burning power plants that release sulfur into environment

4. The Ozone Layer
In 1985 Scientists found that the ozone layer was depleted
Decreased ozone allows more UV rays to reach the surface
Increased rates of skin cancer, cataracts and cancer of the eye

5. What is Destroying the Ozone Layer?
Chlorofluorocarbons (CFC’s) are the major destroying factor
Found in coolants of refrigerators and air conditioners, in aerosol cans, and in foaming agents of styrofoam cups

6. Global Temperatures
Since the 1950’s the average temperatures have been increasing (global warming)
Greenhouse Effect: additional carbon dioxide in the atmosphere due to burning fossil fuels (CO2 traps heat)

7. Is Global Warming Occurring?
There is a correlation between increasing CO2 levels and increasing temps
This correlation does not prove cause/effect. This topic is a controversial subject among scientists

8. Effects on Ecosystems
Chemical Pollution:ex dumping of industrial chemicals into Lake Erie
Oil Spill in Alaska - injured/killed 1000s of animals
Most incidents of pollution involve chemicals that are toxic or carcinogenic

9. Agricultural Chemicals
Pesticides, herbicides, and fertilizers pollute areas around farms
Agricultural chemicals pollute water sources and land
DDT - pesticide that accumulates in fatty tissue of animals (Banned)
Birds - thin eggshells

10. Loss of Resources
Extinction of species- in last 50 years half of the world’s tropical rainforest have been burned down s of species are lost
Loss of topsoil - excessive farming is causing topsoil to be lost
Ground-Water Pollution/Depletion- aquifers are areas b/w porous rock that hold ground water
Water is being removed faster than it is being replaced into the aquifer

11. Growth of Human Population
Decreased death rates b/c of better sanitation and increased medical care
World population annual increase is 94 million people
Most industrial countries have lower rates of pop. increase (US/Japan/ Europe/New Zealand)

12. Solving Environmental Problems
In 1990’s an international agreement stopped CFC production
Many dangerous industrial and agricultural chemicals have been restricted in US

13. Reducing Pollution
Sewage treatment plants remove chemicals/bacteria from sewage
Scrubbers reduce sulfur emissions from smokestacks
Carpool lanes to promote sharing rides
The US has passed laws forbidding pollution
All cars must have catalytic converters to reduce emissions
Gas tax - extra money collected helps to rid pollution from air

14. Solving Environmental Problems
5 steps to success
Assessment - gather information, collect data
Risk Analysis- scientists predict consequences of different types of environmental intervention
Public Education- present alternative actions, explain costs and results
Political Action- politicians try to implement action
Follow-through- monitoring of problem to see if problem is being solved.

15. Your Contribution
Conserve energy by walking, riding bike, or taking public trans
Learn about your environment
Reduce/Reuse/Recycle
Create compost in your backyard