Chapter 18 The Environment

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)

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

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

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

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)

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

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

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

Loss of Resources Extinction of species- in last 50 years half of the world’s tropical rainforest have been burned down - 1000s 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

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)

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

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

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.

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