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How Humans Affect the Atmosphere: Air Pollution and its Impacts Weather & Atmosphere – Meeting the Benchmarks CCISD, Hancock, MI Feb 15, 2002 Richard E.

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Presentation on theme: "How Humans Affect the Atmosphere: Air Pollution and its Impacts Weather & Atmosphere – Meeting the Benchmarks CCISD, Hancock, MI Feb 15, 2002 Richard E."— Presentation transcript:

1 How Humans Affect the Atmosphere: Air Pollution and its Impacts Weather & Atmosphere – Meeting the Benchmarks CCISD, Hancock, MI Feb 15, 2002 Richard E. Honrath Dept. of Civil & Environmental Engineering Michigan Technological University

2 The major air pollutants Carbon monoxide (CO) Nitrogen oxides (NOx) Ozone (O3) Particulate matter (PM-10, PM-2.5) Sulfur dioxide (SO2) Lead (Pb) Greenhouse gases (CO2 and others)

3 Carbon Monoxide Impacts: Blood oxygen levels Hb + O2 HbO2 K1 = Equilibrium constant Hb + CO HbCO K2 = 210 x K1 Headaches, alertness, death Sources: Vehicles (plus others) Source: Ref. (1)

4 Carbon Monoxide CO levels are improving, but still a problem in many colder urban areas. Source: Ref. (1)

5 Nitrogen Oxides NOx = NO + NO2 Impacts: Respiratory irritant (NO2) (but AQ standard seldom violated) -Leads to ozone formation -Leads to acidic deposition of HNO3

6 Nitrogen Oxides NOx = NO + NO2 Impacts: Respiratory irritant (NO2) -Leads to ozone formation -Leads to acidic deposition of HNO3 Sources: High-temperature combustion N2 + O2  2NO Source: Ref. (1)

7 Ozone Impacts: - Respiratory irritant - Plant damage (forest, crops) (FACE site) - Oxidizes C=C double bonds: rubber Sources: -Produced in the atmosphere NOx + VOCs + sunlight -> NOx + O3

8 Ozone A major urban and regional pollution problem Source: Ref. (1)

9 Particulate Matter Definitions: - PM10 = PM < 10 um - PM2.5 = PM < 2.5 um Impacts: - Lung irritation - Visibility

10 Particulate Matter Impacts: - Lung irritation - Visibility Sources: Depends on particle size Source: Ref. (1)

11 Particulate Matter Impacts: Visibility at Shenandoah Nat’l Park Source: Ref. (2)

12 Sulfur Dioxide Impacts: - Eye and lung irritation (but seldom > standard) - Acidic deposition of H2SO4. - Damage to limestone and concrete. Sources: S in fuel is emitted as SO2 Source: Ref. (1)

13 Sulfur Dioxide Impacts: Acidic deposition of H2SO4. Pure water pH = 5.6 Source: Ref. (3)

14 Lead Impacts: Brain and kidney damage. Sources: Leaded gasoline was dominant, but Pb is no longer in U.S. on-road gasoline Source: Ref. (1)

15 Lead Impacts: Brain and kidney damage. Sources: Metals processing, battery mfr, etc Source: Ref. (1)

16 Greenhouse Gases Impacts: Global climate change Gases: Sources: See : Ref. (4)

17 The Greenhouse Effect What determines the average temperature of the earth?

18 The Greenhouse Effect What determines the average temperature of the earth? 1. Source: Ref. (5)

19 The Greenhouse Effect What determines the average temperature of the earth? 2.

20 The Greenhouse Effect What determines the average temperature of the earth? 3.

21 The Natural Greenhouse Effect Average solar radiation in: 236 W per square m

22 The Natural Greenhouse Effect Average solar radiation in: 236 W per square m Without the atmosphere, temperature would be: -2 F

23 The Natural Greenhouse Effect Average solar radiation in: 236 W per square m Without the atmosphere, temperature would be: -2 F Greenhouse effect of natural water and CO2: 148 W per square m (1 lightbulb every 2 feet) Result: Average temperature = 57 F

24 The Human Contribution Source: Ref. (6)

25 The Human Contribution Total effect until now: about 2.3 W / m 2 (1 light bulb every 15 feet) Predicted effect by 2050: Up to 7 W / m 2 (1 light bulb every 9 feet)

26 What happens if we add 3 to 7 W / m 2 to the earth’s atmosphere?

27 Recent Trends in Temperature Source: Ref. (6)

28 Expected Impacts: More precip, more energy in weather More extreme weather events are predicted On average, more precipitation, but region-by-region, some will be wetter, some drier.

29 Long-term Impacts: Models predict changes in climate Two climate models predict Illinois climate in 2030 and Source: Ref. (7)

30 CO2 Emissions by Nation Developing nations will soon be the largest CO 2 producers, but most CO 2 in the atmosphere today came from to industrialized nations Source: Ref. (8)

31 CO2 Emissions by Nation Easiest mitigation measure = energy efficiency Emissions by Sector Household emissions See : Ref. (4)

32 Particulate Activities 1. Light scattering - Particles most effectively scatter light of wavelength ~ particle diameter. - Uncontrolled car exhaust scatters blue light. - Atmospheric gases also scatter, blue more than red. - Large concentrations of particle mixtures scatter all colors  white haze

33 Haze in Los Angeles Source: Ref. (9)

34 Particulate Activities 1. Sky Blue, Sunset Red - Start with jar of clean water. - Demonstrate no scattering: -Shine light beam through – cannot see it from the sides, color at exit is white. -Add milk a little at a time -Observe effect on scattering: beam becomes visible, color at exit reddens, color from sides becomes bluish. -View an object through the jar: -Starts visible, becomes invisible: Haze. See Ref. (10)

35 Particulate Activities 1. Sky Blue, Sunset Red Key points: -Why is the sky blue? -Why is the sunset red? -Why does the sunset get redder when there are fires or pollution? -Why are far-away objects invisible in smoggy places?

36 Particulate Activities 1. Air Strips -Obtain samples of particles and observe using magnifying glasses or microscopes. -Discuss local particle sources. Notes - Will only be able to see larger particles, like plant materials, dusts, or major smokes - Best to do during fall when more large particulates are in the air. See Ref. (10)

37 Local Issues 1. Vehicle emissions -Sources of CO, CO2, particulates, NOx, VOCs -Strategies for reducing emissions  Fuel economy (all, proportional to fuel use)  Catalytic converters and no exhaust system leaks (CO, NOx, particulates, VOCs – no effect on CO2)

38 Local Issues 1. Vehicle emissions -Activity: Let’s Sock Car Exhaust -Use tube socks to collect particles from vehicle exhaust. -Notes: -Connect when vehicle is cold, run 5 min, let cool 5 min, remove, turn inside out. -Fuel is incompletely burned, and catalytic converters do not function, during 1 st 5 minutes with cold engine. -Observe the socks outside (fuel on them) See Ref. (10)

39 Local Issues 1. Vehicle emissions -Activity: Let’s Sock Car Exhaust -Key points: -Emissions will relate directly to engine size (amount of fuel burned in 5 min). -Emissions will vary with age and maintenance. -Only particles are collected: CO, NOx, gaseous VOCs, CO2, water vapor are not.

40 Local Issues 2. Snowmobiles and wood stoves -Snowmobiles: 2-cycle engines are light, but of the C burned, -~1/3 is fully burned and emitted as CO2. -~1/3 is emitted as CO. -~1/3 is not burned at all and released as gasoline.

41 Local Issues 2. Snowmobiles and wood stoves -Wood stoves: -Newer wood stoves have catalysts or secondary combustion; -those without emit more particles and VOCs -Can compare by viewing chimney exhaust (don’t be fooled by water fog) -Wood stoves can be a major source of indoor air pollution when smoke is pulled in from outdoors.

42 Local Issues 3. Indoor air pollution Key issues: -Radon -Molds -Particles and smokes

43 Local Issues 4. Atmospheric Dispersion -Radiative cooling on clear nights -> cold ground under warmer air. -Air flow over Lake Superior during summer -> cold water under warmer air.

44 The Effect of Temperature on Air Mixing Temperature increasing with height

45 Warm Air over Cold Water Source: Ref (11)

46 Cold Air over Warm Water Source: Ref (11)

47 Lake Superior Average Temperatures Percent Ice- free Source: Ref (12)

48 Fog forming over warm Portage Lake

49 Inversions over L.A. Source: Ref. (9)

50 Local Issues 5. Airborne pollutants and fishing advisories PCBs: “PolyChlorinatedBiphenyls” Chemically stable, thermally stable, high dielectric constants. Used in transformers, as hydraulic fluids, …

51 PCBs “PolyChlorinatedBiphenyls” Used in transformers, as hydraulic fluids, … Chemically stable, thermally stable, high dielectric constants. Not broken down in the environment. Accumulate in animal fats. Cause birth defects. Manufacture in U.S. banned in 1977.

52 PCBs in the Environment Source: Ref. (13)

53 PCBs in Lake Superior The atmosphere is the main source. The atmosphere is also a main sink.

54 Impacts in the Great Lakes Wildlife effects (fish-eating birds): –crossed beaks, –embryo deaths, –… Human effects (children of mothers who ate large amounts of Great Lakes fish): –behavioral and developmental defects –sperm counts Fish advisories

55 Stratospheric Ozone Strat vs Trop O3 Source: Ref (12)

56 Stratospheric Ozone Ozone destruction Source: Ref (12)

57 Stratospheric Ozone Antarctic ozone hole Source: Ref (12)

58 Stratospheric Ozone Antarctic ozone hole Source: Ref (13)

59 Stratospheric Ozone Declining outside of Antarctica Source: Ref (5)

60 Stratospheric Ozone Impact on UV radiation Source: Ref (5)

61 Stratospheric Ozone Success of the Montreal Protocol Source: Ref (18)

62 Stratospheric Ozone Some common questions CFCs are heavier than air, so cannot reach the stratosphere. The ozone hole is natural, and is caused by volcanoes and oceans. Ozone depletion occurs only over Antarctica.

63 Tropospheric Ozone Chemistry in Los Angeles air NO x + Hydrocarbons + sunlight = Ozone (O 3 ) This photo shows haze – ozone is invisible but haze commonly occurs at the same time as high ozone levels.

64 Roles of Ozone in the Lower Atmosphere Human health effects (urban and rural). Causes forest and crop damage (regional).

65 Ozone is an issue in urban areas and in large regions Source: Ref (17)

66 Sources 1)EPA, National Air Quality and Emissions Trends Report, EPA 454/R , March )U.S. National Park Service, March 2001, 3)National Acid Deposition Program (NRSP-3)/National Trends Network, NADP Program Office, Illinois State Water Survey, 2204 Griffith Dr., Champaign, IL, 61820, 4)Data available in U.S. EPA,Inventory of U.S. Greenhouse Gas Emissions and Sinks: , USEPA 236-R , 5)Our Changing Planet: The FY 1996 U.S. Global Change Research Program, A Report by the Subcommittee on Global Change Research, Committee on Environment and Natural Resources Research of the National Science and Technology Council, A Supplement to the President’s Fiscal Year 1996 Budget (see 6)Ledley et al., Eos Transactions, 80, 39, p. 453, )Climate Change Impacts on the United States: The Potential Consequences of Climate Variability and Change, National Assessment Synthesis Team, US Global Change Research Program, (See Chapter 6 at 8)B. Hileman, Global Climate Dchange, C&E News, p. 11, Nov 17, )O. E. Allen, Atmosphere, Time-Life Books, )Environmental Resource Guide, Air Quality, Grades 6-8. Air and Waste Management Association (see 11)W. A. Lyons, Turbulent diffusion and pollutant transport in shoreline environments, in Lectures on Air Pollution and Environmental Analyses, American Meteorological Society, pp , Boston, Mass, )R. E. Honrath, C. I. Sweet, and C. J. Plouff, Environ. Sci. & Tech., , )F. Wania and D. Mackay, Environ. Sci. & Tech., 390A-396A, )EPA Ozone Science web site: 15)NOAA Climate Prediction Center, 16)British Antarctic Survey, 17)NOAA Aeronomy Laboratory; J. Geophys. Res., 101, D22, cover, )Our Changing Planet: The FY 1997 U.S. Global Change Research Program, (see


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