1. Threat 1: Ozone Depletion  Description: The ozone layer protects us from ultraviolet (UV) radiation from the sun, but it is becoming thinner in places.  Causes: Air pollution such as chlorofluorocarbons (CFCs) from aerosol spray cans.

2. Threat 1: Ozone Depletion  Effects: Increased UV radiation reaches Earth, causing sunburn, skin cancer, and damage to plants.  Solutions: Eliminate the use of CFCs.

3. Threat 2: Global Warming  Description: Earth’s climate is getting warmer.  Causes: Pollution, mostly from CO 2 emissions from fossil fuels.

4. Threat 2: Global Warming  Effects: Altered weather patterns, sea level rise from melting ice caps, plant and animal loss.  Solutions: Use alternative energy sources (solar, wind, hydroelectric) instead of fossil fuels to decrease CO 2 emissions.

5. Threat 3: Habitat Loss  Description: Habitats for organisms, such as the Amazon rainforest and coral reefs, are being destroyed by humans.  Causes: Deforestation to create pastureland for cattle, urban development, pollution, global warming.

6. Threat 3: Habitat Loss  Effects: Loss of biodiversity / extinction of species.  Solutions: Sustainable use of resources, protecting land and species in national parks.

7. Threat 4: Acid Precipitation  Description: Precipitation with unusually high amounts of acid. The pH is below 7.  Causes: carbon dioxide, sulfur dioxide, etc. (from factory or car pollution) mixes with H 2 O to form acid rain.

8. Threat 4: Acid Precipitation  Effects: Harms or kills plants and causes metal in bridges, cars, etc. to corrode quickly.  Solutions: Filter harmful pollution from factories/cars and reduce the use of fossil fuels.

9. Threat 5: Invasive Species  Description: Species not native to a particular area. (kudzu, zebra mussels, etc.)  Causes: Humans carry them to a new area either ON PURPOSE (kudzu) or ACCIDENTALLY (zebra mussels.)

10. Threat 5: Invasive Species  Effects: Harms or kills native species, decreases biodiversity, and negatively affects food webs.  Solutions: Killing or otherwise eliminating the invasive species. Usually, this is difficult!

11. Threat 6: Bioaccumulation  Description: The increasing concentration of harmful chemicals in the bodies of organism in a food web.  Causes: Chemicals such as DDT & mercury are released in ecosystem and absorbed or eaten by plants/animals.

12. Threat 6: Bioaccumulation  Effects: Death by poisoning, low birth rates due to birth defects or thin-shelled eggs, and behavioral changes.  Solutions: Decrease the use of toxic chemicals in ecosystems.