WHATS IN OUR AIR? Slide 2 THE STRUCTURE OF THE ATMOSPHERE 78% Nitrogen (N 2 ) 21% Oxygen (O 2 ) 0.035 % Carbon Dioxide (CO 2 ) Rest trace gases such as H 2 O, CH 4, SO X, N0 X, O 3, CO Slide 3 ATMOSPHERIC LAYERS TROPOSPHERE: weather occurs here; birds and planes fly here STRATOSPHERE: contains Ozone MESOSPHERE: Radio waves travel up to here THERMOSPHERE: aurora borealis Slide 4 MAJOR AIR POLLUTANTS AND THEIR SOURCES VOC: Volatile Organic Compounds (incomplete combustion of fossil fuels) PM: Particulate Matter (soot, smoke, metals, dust and dirt) NO X : high combustion temperatures SO X : combustion of sulfur containing fuels such as coal Rn: Rocks and soil as radium and uranium break down Slide 5 WHAT ARE GREENHOUSE GASES? CO 2 : Humans breathing, fossil fuels H 2 0: Water cycle CH 4 : fermentation, rice, cows, wetlands N 2 0: agriculture (major component of fertilizer) Ozone: Sunlight on pollutants creates ozone in the troposphere CFC: aerosol cans, refrigerants, styrofoam (most potent greenhouse gas!) Slide 6 WHAT IS ACID RAIN? Acid rain is formed from sulfuric acid (H 2 SO 4 ) and nitric acid (HNO 3 ) in a ratio of about 2 to 1. Sources include burning of fossil fuels and natural sources such as volcanoes. Slide 7 Massive Volcanism in Human History 1980 Mt St Helens 1883 Krakatau: created a 140 ft high tsunami and killed 34,000 people in South Pacific 1815 Tambora killed 100,000 people in Indonesia and decreased global temperature by 3 C 630,000 years ago Yellowstone National Park left a 45 x 30 mile wide caldera and dumped 2,500 times the ash of Mt St Helens Slide 8 EFFECTS ON HUMAN HEALTH Asthma Cancer Lung Disease Heart Disease Slide 9 EFFECTS ON THE ENVIRONMENT Crop Damage Forest damage Aquatic Ecosystem damage due to rise in pH Visibility (smog) Chemical weathering of rocks, buildings and monuments Slide 10 CLEAN AIR ACT OF 1970 Main goal to regulate emissions of air pollutants Clean Air Act Amendment 1990 (CAAA): Targeted cars, trucks and buses by adding catalytic converters Demands by the year 2010, reduce SO 2 levels by 10 million tons (Title IV) Slide 11 KYOTO PROTOCOL 38 industrial nations met in Kyoto, Japan in 1997 and agreed on reducing greenhouse gases (stabalization at 450 ppm) Developing countries refused to agree to reductions In 2001, 110 parties ratified treaty Two countries pulled out of the treaty, US and Australia Kyoto Protocol will not stabilize GHG, but is an important step Slide 12 WHAT ARE THE OPTIONS FOR MITIGATION OF GHG EMISSION? Place a worldwide cap on GHG emission Invest in renewable forms of energy Stop loss of tropical forests and encourage planting Make energy conservation rules much more stringent Reduce amount of fuel used by raising mileage standards Capture CO2 emission at site, convert to liquid and pump it to deep oceans where high pressure and low temperatures would preserve it as a solid mass Slow down human population
