1. Environment Key Issue #2: Why are resources being polluted?

2. Air Pollution  Definition: a concentration of trace substances at a greater level than occurs in average air  Most common – carbon monoxide, sulfur dioxide, nitrogen oxides, hydrocarbons, and solid particulates  Three human activities that cause pollution: motor vehicles, industry, and power plants  Pollution results from the burning of fossil fuels  Three scales of pollution: global, regional, and local

3. Global Warming  Burning fossil fuels may be causing the earth’s temperature to rise  Carbon dioxide in the atmosphere has risen more than ¼ in the past 200 years  The average temperature of Earth’s surface has increased 2°F during the past 100 years  Greenhouse effect

4. Global-Scale Ozone Damage  The ozone layer (gases) absorbs UV rays from the sun  The ozone layer is threatened by pollutants called chlorofluorocarbons (CFCs)  PEDs were required to stop using CFCs by 2000, and PINGs are supposed to stop by 2010

5. Regional-Scale Acid Deposition  Especially in densely populated areas such as western Europe and eastern North America  Acid precipitation

6. Local-Scale Urban Air Pollution 1. Carbon Monoxide – proper burning in power plants produces carbon dioxide, but improper combustion produces carbon monoxide 2. Hydrocarbons – result from improper fuel combustion as well as evaporation of paint solvents Photochemical smog – formed by hydrocarbons and nitrogen oxides in the presence of sunlight; cause respiratory problems, stinging of the eyes, and an ugly haze over the city 3. Particulates – dust and smoke particles

7. Photochemical Smog in Mexico City

8. Water Pollution

9. Point vs. Nonpoint  Point  Nonpoint

10. Impact on Aquatic Life

11. Wastewater and disease  Drinking this:  Results with this:

12. Land Pollution