Human Impact on Ecosystems
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This slideshow is intended for students in Mr. Hildebrandt's biology classes.
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Human Impact on Ecosystems
- 1. Human Impact on Ecosystems 1
- 2. It’s complicated! 2
- 3. Air Pollution • Over the past 20 years, developed countries have made progress in improving air quality. • Unfortunately, air quality in the developing world has been getting worse. 3
- 4. Major Outdoor Air Pollutants • Sulfur dioxide - acid rain, health damage, visibility reduction • Nitrogen oxides - acid rain, eutrophication, growth of weedy species • Carbon monoxide - inhibited respiration • Lead and mercury - neurological damage • Chlorofluorocarbons - ozone depletion • Particulate matter - lung damage, cancer • Volatile organic compounds – that attach to CO2 in the atmosphere; carcinogens? 4
- 5. Acid rain caused by air pollution (2000) 5
- 6. Los Angeles: famous for “smog” created by air pollution 6
- 7. Indoor Air Pollution • Smoking - diseases related to smoking responsible for 20% of deaths in the U.S. • Poorly ventilated heating and cooking fires are the greatest source of indoor air pollution. • Radon gas (a radioactive decay product of uranium): the most harmful indoor pollutant 7
- 8. Land Pollution •Litter & Landfills - garbage on the ground •Mining - lands are disturbed in an effort to obtain minerals •Deforestation - trees are cut and harvested •Industrial wastes – nuclear & chemical dumped into ground 8
- 9. Water Pollution •Runoff - pesticides, herbacides, and fertilizers concentrate in open waters •Litter - garbage thrown dumped into water (“The Great Pacific Garbage Patch”) • Chemicals – industrial wastes and sewage dumped into water 9
- 10. Wildlife Destruction •Threatened - Species that have massive population declines. •Endagered - Species that are dangerously close to extinction. • Extinct – A species that has been wiped out. They no longer exists on Extinct: Dodo bird & earth. Wooly Mammoth 10
- 11. Governmental Role: Legislation • Endangered Species Act (1973) – provided protection for threatened and endangered species • Clean Air Act (1963) - First national air pollution control. • Clean Air Act (1970) rewrote original Act. Identified critical pollutants Established ambient air quality standards . 11
- 12. Current Conditions and Future Prospects Developed vs. Developing Countries 12
- 13. CURRENT AND FUTURE CONDITIONS • In the United States, air quality has improved dramatically in the last decade in terms of major large-volume pollutants. – Cities where pollution is largely from traffic still have serious air quality problems. • Major metropolitan areas of many developing countries are growing at explosive rates, and environmental quality is very poor. 13
- 14. Circumpolar winds transport air pollution from heavily industrialized regions to the Arctic, where atmosphere is damaged. 14
- 15. The Great Pacific Garbage Patch 15
- 16. Long range transport of pollutants 16
- 17. Total Suspended Particulates (TSP) Tend to be much higher in large cities in developing countries than in developed countries
- 18. Some Good Trends U.S. emissions of six major air pollutants in 1970 compared with 2002. 18
- 19. Production of chloroflurocarbons (CFCs) Montreal Protocol passed in 1987 19
- 20. Antarctic Ozone Hole seems to be recovering 20
Notes de l'éditeur
- The International Geosphere-Biosphere Programme ( IGBP ) is a research program that studies the phenomenon of Global Change
- For instance, figure 9.29 in the text shows reductions in carbon monoxide, volatile organic carbon, particulate matter, and sulfur dioxide since 1970-. Note also, that Pb the emissions into the air had been reduced almost completely to zero due primarily to the removal of lead as an additive to gasoline. In old figure it showed that nitrous oxide emissions had actually increased during that period of time because it is very difficult to adjust automobiles to reduce these emissions, and the number of automobiles and the actual miles driven has greatly increased during that period of time throughout the United States.
- Figure 9.25 shows the reduction in production of chlorofluorocarbons since the Montreal Protocol was passed in 1987, which largely banned their production. Notice that developing countries continue to produce increasing levels of chlorofluorocarbons (mostly India), though not nearly at the rate that the industrialized countries (France is still relatively high) of the world produced 15 years ago.