1. ECOSYSTEMS & HUMAN INTERFERENCES II

2. Carbonification  The destruction of vegetation & burning of fossils are main factors in increasing carbon in the atmosphere Carbon Cycle

3. Greenhouse Gasses & Global Warming  Greenhouse effect: reradiation of solar heat toward the earth caused by certain gasses  Human activities increased the concentration of these greenhouse gasses: CO 2 : from burning of fossil fuels & wood Nitrous oxide (N 2 O): fertilizers & animal wastes Methane (CH 4 ) : oil and gas wells, rice paddies

4. Acid Rain  It is caused by increased levels of Nitrogen oxides (NO x ) & (SO 2 )  Negative effects of acid rain: Destroy forests Pollute water Reduce agricultural yield Increase erosion Health hazard to human (O 3 from HC and NO x )

5. Combustion of fossil fuels is the main cause of acid rain  The burning of fossil fuels releases sulfur oxides and nitrogen that react with water in the atmosphere to produce sulfuric and nitric acids. Field pH  5.3 5.2–5.3 5.1–5.2 5.0–5.1 4.9–5.0 4.8–4.9 4.7–4.8 4.6–4.7 4.5–4.6 4.4–4.5 4.3–4.4  4.3 Average pH in 2002

6.  Toxins produced by human can accumulate in the fatty tissues of animals.  They become more concentrated in successive trophic levels biological magnification. Hazard Waste

7. Nitrogen Cycle  Also, fertilizers and lightening add nitrogen to soil

8.  Eutrophication Runoff containing high phosphate & nitrogen (Fertilizers) Results in (algal bloom). Leads to massive death of aquatic organisms.

9. Lake Neatahwanta, Fulton, NY The Post-Standard, June 4, 2004: Lake algae may be Killing Animals

17. Human activities & ozone  O 3, or ozone protects us from (UV)  Ozone layer has been gradually “thinning” since 1975  Due to use of chlorofluorocarbons, chemicals used in refrigeration and aerosol cans (a) October 1979 (b) October 2000