air pollution air pollution atmospheric pollution atmosphere unit 9

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1 air pollution unit 9 air pollution health effects WHO estimates that air pollution killed 7 million people in more than double previous estimates indoor vs. outdoor (ambient) household pollution cooking and heating with solid fuel poor ventilation ambient pollution sources vary greatly with region atmosphere stratosphere troposphere ozone layer greenhouse effect greenhouse gases H2O N2O CO2 CH4 chemical cycles - affect weather patterns and climate carbon cycle - CO2 emissions nitrogen cycle - NO, N2O from heat of combustion sulfur cycle - fossil fuels like coal, oil atmospheric pollution Air pollutants Natural and anthropogenic sources Volcanoes, fires, dust storms Human health impacts acute, chronic, carcinogenic Impacts on plants agriculture, forestry Infrastructure impacts damage to buildings, bridges, statues

2 major air pollutants Sources natural wildfires volcanic eruptions plant emissions anthropogenic industrial (smokestacks) deliberate burning of forests transportation major air pollutants Primary pollutants Volatile organic compounds Particulate Carbon oxides Nitrogen oxides Sulfur oxides Lead Air toxics Secondary pollutants Ozone Peroxyacetyl nitrates Photochemical oxidants indoor air pollution biggest sources burning of solid fuel for cooking/heating wood, coal, dung, crop residuals tobacco smoke building materials formaldehyde asbestos household chemicals particulate smogs Industrial Smog gray industrial fog SO2 and particulates combine with humid air Photochemical Smog brown-air smog Nitrogen oxides and VOCs react with sunlight other pollutants smog may also contain mercury, lead, and other contaminants as particulate

3 south asia south asian smog problem massive persistent smog cloud block out light acid rain acid rain acid deposition causes smokestacks coal-burning, cars dry deposition particulate sulfate and nitrate salts wet deposition acid rain, snow, fog sulfuric, nitric acid acid rain trouble spots associated with coal power plants trends climate change History last million years ice ages and warm trends last 12,000 years pretty warm, stable climate evidence greenhouse effect basic understanding indirect estimates of climate change over 1,000-2,000 years tree rings, corals, ice core samples climate models based on historical data

4 global CO2 emissions atmospheric CO2 concentration solar variation what about the sun? has that changed? effects of climate change projected impacts of climate change 2 C change, 450ppm CO2 3 C change, 550ppm CO2 4 C change, 650ppm CO2 forest fires worsen forest fires much worse forest fires / drought increase sharply prolonged droughts intensify prolonged droughts much worse heat waves more common, fewer winter deaths deserts spread, malaria spreads major heat waves, deaths from heat increase deserts spread more, tropical diseases spread conflicts over water supplies increase irrigation / hydropower decline billion people water shortage some crop increases in temperate zones (decreases in tropics) water wars, refugees, terrorism increase crop pests multiply and spread tropical diseases spread faster and further water shortages for almost all people water wars, refugees, terrorism, economic collapse widespread crop yeilds fall sharply in all regions most mountain glaciers lost half of arctic tundra melts glaciers and ice sheets melt even faster sea levels rise, flood low lying coastal areas sea levels continue to rise many low-lying cities flooded extensive coral reef damage coral reefs severely threatened coral reefs, tropical forests, alpine tundra, coastal wetlands collapse high extinction risk for arctic species 20-30% of plant and animal species face extinction 50% of plant and animal species face extinction slowing climate change what can we do? cut energy waste programmable thermostats insulation more efficient lighting shift to low-carbon energy wind? nuclear? geoengineering carbon sequestration restore natural forests carbon capture and storage global dimming - difficult to know effects legislation / international agreements

5 artificial photosynthesis Berkeley lab nanowire array CO2 reduced to acetyl CoA methane discussion questions Suppose that an incineration facility is to be built near your community and that hazardous wastes currently being disposed of in your landfill will be disposed of in the new facility. Would you support or oppose the proposal? Why? Do you think human activities are having an affect on climate? Do you think there is anyway to prevent catastrophe? Think of three activities you took part in yesterday that used energy inefficiently. (and thus increased pollution) how could you improve the energy efficiency of these activities?