APES CH 19 & 20

• • Troposphere
  • Lowest layer
  • Where all the weather happens (Greenhouse gasses stays here; H2O, CO2, CH4, N2O)
  • Highest gas density (75%-80% of Earth’s air mass; 78% N2 and 21% O2)
  • Supports life
• • Stratosphere (17-48 km above surface)
  • Ozone Layer (Filters 95% of harmful UV radiation)
• Layers of the atmosphere

  1. Troposphere
  2. Stratosphere
  3. Mesosphere
  4. Thermosphere
• Natural Sources -

  • Wind blown dust (soil erosion)
  • wildfires
  • volcanic eruption pollutants
  • volatile organic compounds released by plants
• Human Sources - Industrialized and Urban pollutants
• Industrial Smog

  • Primarily from burning Coal
  • Consists of SO2, H2SO4, and solid particulates
  • Combustion of oil and coal forms CO, CO2, and Soot
  • Common in industrialized areas
• Photochemical Smog

  • Caused by emissions from motor vehicles, industrial facilities, and power plants
  • Formed under the influence of the sun’s UV radiation
  • VOCs + Nitrogen Oxides + Heat + Sunlight yields:
  • Ground level O3, Aldehydes, and other secondary pollutants
• • Primary pollutants - Emitted directly to the atmosphere
• • Secondary pollutants - formed from primary pollutants reaction with air
• • Stationary Sources - power plants, industrial facility
• • Mobile Sources - Motor vehicles
• Types of indoor air pollutants

  • Less developed countries: 
  • Biofuel that produces soot, smoke, an CO 
  • Prominent use of biofuel indoor for heating and cooking
  • Coal, wood, dung, charcoal, crop residue
• Types of indoor air pollutants

  • More developed countries:
  • Chemical use for cleaning and building 
  • Smoking
  • Radon-222 gas
• Indoor Air Pollution Health hazards

  • Air pollution is about 2-5 times higher inside US houses and buildings than outdoors (could go up to 100x)
  •  Pollution inside cars can go up to 18x higher than outside
  • Most people in more developed urban areas spend 70%+ of their time indoors or in their vehicles
• Radon-222

  • Radon-222 from underground deposits
  • Radon-222 undergoes radioactive decay into Polonium-210 which can expose lung tissues to radiation 
  • Radon tests for detection
• • Acid Deposition
  • Cause and Sources
  • Human generated Sulfur Oxides and Nitrogen Oxides gets into the atmosphere
  • Wet Deposition: Acid Rain, snow, fog, or cloud vapor
  • Dry Deposition: Acidic particulates
  • Ammonia in the atmosphere and some soil particles neutralizes acids which in turn produces Sulfates and Nitrates
  • Remains in the atmosphere for 2-14 days
  • Buffers - keeps the pH stable 
• 1. Wet Deposition: Acid Rain, snow, fog, or cloud vapor
  2. Dry Deposition: Acidic particulates
  3. Buffers - keep the pH stable
• Acid Deposition Effect

  • Respiratory disorder
  • Releases toxic metals from soil → biomagnification
  • Lowers pH in aquatic systems
  • Leeches soil nutrients and minerals
  • Damages forests
  • Damages stoneworks
• Clean Air Act 1970/77/90 created regulations and enforced by states and cities
• EPA established air quality standards for six outdoor air pollutants (CO, NO2, SO2, Suspended particulate matter, Ground level O3, Lead)
• National emission standards for hazardous air pollutants (HAP)

  • 188 hazardous air pollutants
• The Toxics Release Inventory (TRI) is a resource for learning about toxic chemical releases and pollution prevention activities reported by industrial and federal facilities
• New US regulation limits CO2 emissions from coal-fired power plants
• New air quality standards for China ban high-sulfur, high-ash content coal in major cities
• Air Pollution Treaties

  1. Kyoto Protocol
  2. 1997: Treaty to slow climate change
  3. USA did not sign
  4. 2014: USA and China agreed to cap carbon emissions within 15-20 years
  5. 2015: Paris Meeting
  6. Countries pledged to meet certain goals
  7. No financial assistance for poor countries to reach goal
  8. Countries are not legally bound to comply (unenforceable)
  9. Long term VS Short term
• • ChloroFluoroCarbons (CFC): Ozone depleting chemical
• Ozone Depletion

  • Thinning of layers in Antarctica and the Arctics
  • ChloroFluoroCarbons (CFC): Ozone depleting chemical
  • Takes 11-20 years to reach stratosphere so there will be a long delay between banning CFC and the recovery of the ozone
  • Will take 60 years to recover back to 1980s level
  • Copenhagen Amendment
  • Accelerated phase-out of CFCs
• • Montreal Protocol
  • Cut emissions of CFCs
• Climate Change Natural Factors

  • Volcano eruptions
  • Solar input
  • Earth’s orbit and tilt
  • global air circulation pattern
  • changes in albedo
  • greenhouse gas
  • ocean currents
• Climate Change Human Factors

  1. Fossil fuel use, deforestation, agriculture
  2. Basically more Carbon footprint and lesser carbon sink
• Climate Change

  1. Between 1906 and 2016, earth’s temperature rose by 0.94°C
  2. 10 warmest years on record since 1861 have taken place since 2005
  3. Arctic ice has been shrinking since 1979
  4. Glaciers are melting
  5. Permafrost is melting, rising sea levels reducing coast
  6. Carbon dioxide and methane levels have risen sharply
  7. Terrestrial organisms have migrated towards poles and up mountains where it is cooler
• • Carbon Footprint -the total amount of greenhouse gasses (including carbon dioxide and methane) that are generated by our actions.
• •  Carbon Sink - anything that absorbs more carbon from the atmosphere than it releases – for example, plants, the ocean and soil. 
• • Carbon Sequestration -the process of capturing and storing atmospheric carbon dioxide -1 method of reducing the amount of carbon dioxide in the atmosphere with the goal of reducing global climate change.
• • Carbon Neutral - the balance between emitting carbon and absorbing carbon emissions from carbon sinks. Or simply, eliminate all carbon emissions altogether. Ex: Costa Rica - Carbon neutral by 2030
• • Carbon source is anything that releases more carbon into the atmosphere than it absorbs – for example, the burning of fossil fuels or volcanic eruptions
• Feedback Loop

  In climate change, a feedback loop is something that speeds up or slows down a warming trend.

  A positive feedback accelerates a temperature rise, whereas a negative feedback slows it down.
• • Albedo

  Albedo is the fraction of light that a surface reflects. 

  The albedo of Earth's surface (atmosphere, ocean, land surfaces) determines how much incoming solar energy, or light, is immediately reflected back to space.
• Role of Ocean 

  • Carbon and Heat Sink
  • Algae, corals, vegetation, bottom sediments
  • Ocean acidification from too much carbon
• Role of Clouds

  • Cumulus clouds reflect lights back to space
  • Cirrus clouds insulate Earth thus cooling it