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Human Impact. Charting a Course for the Future. Charting A Course. Key Concept : As We Enter The 21 st Century, Many Biologists Are Concerned About The Biological Effects Of Global Change To: Resources Air Water Biodiversity. Oxygen Gas. Ozone Molecule. Ozone Depletion. Ozone layer
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Human Impact Charting a Course for the Future
Charting A Course Key Concept: As We Enter The 21st Century, Many Biologists Are Concerned About The Biological Effects Of Global Change To: • Resources • Air • Water • Biodiversity
Ozone Depletion • Ozone layer • 20/50 km above earth (12 – 31 miles) • Oxygen = O2 • Ozone = O3 • Ozone at ground level is a pollutant • In the upper atmosphere it is VERY important
Ozone Layer • Absorbs Ultraviolet Radiation (UV) • UV Radiation Can Cause: • Sunburn • Cancer • Eye Damage • Cataracts • Decreased Resistance To Disease • Destruction of Plants & phytoplankton
Ozone The Universal Sunscreen
Ozone Hole - South Pole
Ozone Depletion • Discovered in 1970’s over Antarctica • Hole is growing larger • Now occurring over the Arctic • 1995 • grew large enough to expose U.S.
Ozone Hole Caused By CFC’s Chlorofluorocarbons CFC’s act as a catalyst CFC’s have a long half-life 2O3 + CFC’s 3O2
Where Do CFC’s Originate? • CFC’s found in • aerosol cans • coolants used in • refrigerators • freezers • automobile air conditioning
Montreal Protocol 1987 46 Nations Agreed to end use of CFC’s by 2000
Climate Change • Any Climate Change will have profound effects on the Biosphere. • Over past 120 years average global temperature has increased 0.5 degrees Celsius (0.9 degrees F) • Rise between 1980-2000 fastest in over 100 years.
Climate Change • Ice caps are melting • Arctic Sea Ice may be gone in 50 years
Why is it happening? • CO2 Methane (Greenhouse Gases) • Burning Fossil Fuels, Forests • Project Increase of 1 – 2 degrees Celsius by 2050
Global Warming Effects • Polar Ice Melt • Rising Sea Levels • Increase in number & severity of storms • North American droughts • Shifts in plant & animal species distribution
Ways to Help the Biosphere • Decrease energy consumption • Insulate Homes • Energy Efficient Appliances • High Mileage Cars • High Efficiency Energy Production • Alternate Fuel Sources • Fuel Cells • Wind