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Chapter 10 The Atmospheric Environment

Chapter 10 The Atmospheric Environment. Air Pollution: Long Distance Traveler. Winds distribute pollutants Developing countries lack regulations Global distillation effect Canadian Arctic accumulates high levels of toxins Inuit people High levels of PCBs Why?. The Atmosphere.

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Chapter 10 The Atmospheric Environment

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  1. Chapter 10 The Atmospheric Environment

  2. Air Pollution: Long Distance Traveler • Winds distribute pollutants • Developing countries lack regulations • Global distillation effect • Canadian Arctic accumulates high levels of toxins • Inuit people • High levels of PCBs • Why?

  3. The Atmosphere • Gaseous envelope surrounding Earth • Mostly oxygen & nitrogen (99%) • Four layers • Troposphere • Stratosphere • Mesosphere • Thermosphere

  4. The Atmosphere

  5. The Atmosphere

  6. What’s In Our Atmosphere • Nitrogen 78% • Oxygen 21% • Argon 0.93% • Carbon dioxide 0.04% • Other Gases 0.03%

  7. The Atmosphere • Ecosystem services • Protects Earth from UV radiation • Allows visible light and some infrared to penetrate • We depend on the atmosphere • Oxygen balance

  8. Solar Radiation & Atmospheric Circulation • The sun makes life on Earth possible: • Primary determinant of climate: amount of sunlight received • Solar radiation powers • Earth’s cycles

  9. Solar Radiation and Atmospheric Circulation • Electromagnetic spectrum • Entire range of electromagnetic radiation • Includes gamma, x-ray, ultraviolet, visible, infrared, microwave, and radio • 43% of incoming solar radiation peaks in visible light wavelengths • Gamma, x-rays and most UV rays are absorbed by the stratosphere • Plants use portions of visible light for photosynthesis

  10. Earth’s Energy Budget

  11. The Sun & Latitude • Sun does not reach all places uniformly: why? • Temperature varies locally

  12. The Seasons • Inclination on its axis determines Earth’s seasons • N. and S. hemispheres are opposite

  13. The Atmosphere • Temperature differences drive circulation • Continuous circulation moderates surface temperature on the Earth

  14. Atmospheric Circulation • Winds • Small-scale, horizontal movements • Result of atmospheric pressure and Earth’s rotation • Prevailing winds • Major surface winds; blow continuously • Polar easterlies, westerlies, trade winds

  15. Atmospheric Circulation • Coriolis effect • Earth’s rotation from west to east • Moving air or water is deflected • N. hemisphere: deflected right • S. hemisphere: deflected left • Influences wind direction

  16. Oceanic Conveyor Belt • Transfer of warm water from Pacific ocean to the Atlantic as a surface current • Cold dense water sinks and slowly flows from Atlantic to the Pacific Ocean as a deep water current

  17. Weather & Climate • Weather • Atmospheric conditions at a specific place and time • Rapid changes • Climate • Average weather conditions • Changes over hundreds/thousands of years • Important factors: temperature and precipitation

  18. Air Quality & Air Pollution • Various chemicals present in the atmosphere in levels high enough to cause harm • Natural & human sources • Seven important types • Two categories • Primary: enter directly into atmosphere • Secondary: form in the atmosphere

  19. Primary and Secondary Air Pollution

  20. Carbon Oxides • Gases • Carbon monoxide • Colorless, odorless, tasteless • Reduces blood’s ability to transport oxygen • Carbon dioxide • Produced in very large quantities • Major greenhouse gas

  21. Sulfer Oxides • Gases • Acid deposition • Corrode metals, damage stone • Damage plants, respiratory irritant

  22. Nitrogen Oxides • Gases • Inhibit plant growth • Aggravate health problems • Photochemical smog • Nitrous oxide: greenhouse gas, depletes ozone • Nitrogen oxides: corrode metals & textiles

  23. Particulate Matter • Different solid and liquid particles • Suspended in the atmosphere • Soil particles, soot, lead, etc… • Corrodes metal, erodes buildings, soils clothing • Can be microscopic! • Inhaling can be hazardous

  24. Hydrocarbons • Contain only carbon and hydrogen • Methane, benzene, paraffin • Many different kinds! • Varying effects • Some have no effect • Some cause respiratory damage • Some cause cancer

  25. Sources of Sulphur and Nitrogen Oxide Emissions

  26. Volatile Organic Compounds • VOC’s: unburned hydrocarbons and vapors that evaporate easily in the atmosphere • VOC concentration may be 10 times higher indoors, why? • Toxic effect on humans

  27. Ozone • Essential component of stratosphere • Filters out harmful UV radiation • Pollutant in the troposphere • Most harmful component of photochemical smog • Reduces visibility, causes health problems • Reduces plant vigor

  28. Sources of Air Pollutants • Natural: • Erupting volcanoes • Forest fires (lightening) • Ocean spray and salt particulates • Volatile organic compounds from coniferous forests • Natural process from other vegetation

  29. Air Pollution • Human Activities: • Fossil fuels (coal, natural gas) • Transportation (mobile) • Industrial (stationary)

  30. Human Health Effects • Eye and respiratory tract problems • Suppresses immune system • Chronic respiratory disease • Cancer • Birth defects • Neurological damage

  31. Effects of Air Pollution • Injures organisms • Reduces visibility • Corrodes metals, plastics, textiles • Harms respiratory tracts • Reduces plant production • Ozone depletion, climate change

  32. Managing Air Pollution • Difficult due to long-range transport • Nations have to work together • Emissions trading – “cap and trade” • EU ETS – one of the largest programs • Kyoto Protocol uses emissions trading system for six major greenhouse gases • Carbon credit trading – two types • COC’s • CRC’s

  33. Canada’s Response • Clean Air Act • Includes air pollutants and greenhouse gases • Controversial • Federal and provincial governments need to work together • Incentive-based regulation • Kyoto Protocol • Signed in 1997 • Conservative government dropped it in 2006 • Second Clean Air Act introduced

  34. Urban Air Pollution • Smog • Industrial smog • Sulphur oxides, particulate matter • Worst in winter…why? • More problematic in developing countries…why?

  35. Urban Air Pollution • Photochemical smog • Brownish-orange haze • Chemical reactions • Worst in summer…why? • Sources?

  36. Urban Air Pollution

  37. Weather and Topography • Temperature change  air circulates  pollutants dispersed • Temperature inversion • Cold air layer trapped near the ground by warm layer • Traps pollutants close to ground • Cities in valleys: more temperature inversions

  38. Temperature Inversion

  39. Commitments to Reduce Smog • Smog has serious impacts on Canadian economy • 1990, Canadian Council of Ministers of the Environment developed regulations, guidelines and education initiatives • Targeted automobile emissions and commercial emission restrictions

  40. Los Angeles • Very bad smog…why? • 1969: California is first state to enforce vehicle emission standards • Every pollutant regulated today • Should meet federal standards by 2010

  41. Acid Precipitation • Sulphur and nitric acids in precipitation • Dry acid particles in air • Around since Industrial Revolution • Causes much damage • Kills fish, damages structures • Affects forest ecosystems

  42. How Acid Deposition Develops • Sulphur dioxide and nitrogen oxides released • Where do these pollutants come from? • Wind carries these pollutants • React with water in atmosphere • Form dilute acids • Sulphuric • Nitric, nitrous

  43. How Acid Deposition Develops

  44. Ph Scale • Ph Scale runs from zero (most acidic) to fourteen (most alkaline) • A one unit change on the Ph scale represents a 10 fold unit change in acidity

  45. Effects of Acid Deposition • Corrodes metals and building materials • Decline in some fish species • Birds lay eggs with thinner shells • Damaging to forests

  46. Impacts of Acid Percipitation • Research at ELA on lake 223 • Reduction in Ph • Reduction in biodiversity • Ph lower than 4.0 may mean no fish at all

  47. Impacts of Acid Precipitation • Damage to forests • Overall tree weakening • Increase in UV radiation • Insect infestation • Changes in soil chemistry

  48. Impacts of Acid Precipitation

  49. The Politics of Acid Deposition • Difficult to control • Who should pay for the pollution? • Acids are released in one place • Returned to Earth’s surface hundreds of miles from source

  50. Combating the Effects ofAcid Precipitation • Over past 15 years, Canada has committed to reducing sulphur dioxide • 1985, Eastern Canadian Acid Rain Program • 1991, Canada-United States Air Quality Agreement • Canada Wide Acid Rain Strategy for Post-2000 • Reduction achieved by: • Scrubbers installed in smoke stacks • Low sulphur coal (but other problems arise)

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