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Environmental Issues. Greenhouse Effect What is it?. Process by which gases in the atmosphere trap and retain heat. Short wavelength radiation penetrates atmosphere; long wavelengths from Earth’s surface trapped. Amount of energy coming in should equal amount of energy going out.
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Greenhouse EffectWhat is it? • Process by which gases in the atmosphere trap and retain heat • Short wavelength radiation penetrates atmosphere; long wavelengths from Earth’s surface trapped • Amount of energy coming in should equal amount of energy going out • Maintains temperature to sustain life
Greenhouse EffectEnhanced • Human actions increase amount of greenhouse gases • Increased gases lead to increased global temperatures
Greenhouse EffectGases • Chlorofluorocarbons (CFC’s) • Carbon Dioxide (CO2) • Burning of oil, coal, and natural gas; deforestation • Methane (CH4) • Digestive process of animals; rice cultivation • Nitrous Oxide (N20) • Burning vegetation, industrial emissions • Refrigerants, aerosols
Greenhouse GasesConsequences Greenland • Increase in temperature from 1.4°C to 5.8°C by 2100 1992 2002 Summer slush expanding • Increase temperatures result in glacier and ice sheet melting • Produce global sea level rise
Sea Level Rise • Global sea level rise estimated to have risen 10-25 cm over last 100 years • The next 100 years average sea level projected 50 cm higher
Sea Level RiseConsequences • The oceans are predicted to rise about 0.5 – 10.0 meter by 2100 • Beach retreat and flooding pose a high risk along east coast and gulf state • Bluff collapse is greatest threat along California
Beach ErosionCalifornia • Beach erosion is a serious problem for coastal communities • 86% of California coasts are classified as actively eroding • 1 in 4 homes within 500 feet of coast will be lost to erosion in 60 years • Some causes: • Sea level rise • Building near coast • Efforts to reduce erosion
2004 2002 2005 Beach ErosionCalifornia Santa Barbara, California
Ocean PollutionSources • Oil spills • Toxic wastes • Debris • Raw sewage
Coral Reefs • Provide natural habitat for 25% of marine life • Serve as breeding ground for marine organisms • Natural breakwater for strong waves
Coral ReefsIssues • Pollution • Human waste, fertilizer, and pesticides • Destructive fishing methods • Dynamite and cyanide • Global warming • Fragile living conditions • At the present rate of destruction, 70% of world’s coral reefs will be gone in the next 20-40 years • Completely gone by 2100