Human Impact on the Environment

1. Human Impact on the Environment

2. Biodiversity • The variety of different species in an area • What are some benefits of biodiversity?

3. SOME BENEFITS Increases stability of the ecosystem by providing more food for food webs Contributes to the health of the biosphere

4. 3 types of Biodiversity • Genetic Diversity: the variety of genes or inheritable characteristics present in a population • Species Diversity: a number of different species in the community • Ecosystem Diversity: the variety of ecosystems present in the biosphere

5. Threats to Biodiversity • Loss of natural resources: minerals, fossil fuels, nuclear fuels, plants, animals, soil, clean water, clean air, and solar energy • Human Impact: • Pollution • Pesticides • Habitat loss (deforestation) • Global warming vs. greenhouse effect

6. Pollution • Changes the composition of air, soil, and water. • Acid precipitation (acid rain): the burning of fossil fuels releases sulfur dioxide and nitrogen oxides into the atmosphere, forming sulfuric acid and nitric acid when combined with water in the air. • Eutrophication: fertilizers, sewage, wastes rich in nitrogen and phosphorus flow into water, causing extensive algae growth. • Algae uses up the oxygen supply, suffocating the other organism in the water

7. Pesticides • Human made chemicals released into envt. • DDT (dichloro-diphenyl-trichloroethane) • Used as a pesticide in farms to kill of harmful pests • But later found out DDT: • Is nonbiodegradeable (cannot break down) • Animals do not lose it from their bodies, it stays in there

8. Biological Magnification • Concentration of chemicals increase as you move up the food chain or web • By the time you the top of the food chain or web, DDT reached concentration had magnified by 10,000,000!!

10. Habitat Loss • Deforestation: destruction of habitats by clearing large areas of land • In the tropical rainforest, humans are clearing areas of tropical rain forests and replacing the native plants with agricultural crops or grazing land. • More than half of all species on earth live in the tropical rain forest, so what will happen?

11. The reality of deforestation • http://www1.teachertube.com/viewVideo.php?video_id=226836&title=Amazon_Rainforest_deforestation

12. The Greenhouse Effect A natural phenomenon where gases reflect heat back toward the Earth, keeping it warm Caused by an accumulation of greenhouse gases (such as CO2) CO2 is released by burning fossil fuels and breathing!

13. Effects of Greenhouse Gases • Greenhouse gases create a NATURAL heat blanket in the atmosphere increasing the Earth’s temperature • Most people believe this is causing Global Warming! • Can be helped by planting more trees which convert CO2 to O2 during photosynthesis

14. The Ozone Layer • Protects us from harmful UV Rays • Cause of sunburns, eye damage, and cancers • Made of Ozone Molecules (O3) • Destroyed by CFC’s (chloroflourocarbons) • Have caused holes and thinning of the ozone

15. Global Warming • An increase in Earth’s average temperature (UNNATURAL EFFECT) • The Earth is getting warmer, however it fluctuates between warm and cool periods • Do your part to keep the Earth clean and to decrease your carbon footprint!

16. How do you decrease your carbon footprint?