Air
Climate and Pollution
Chapter 9
The Ocean of Air
Weather – daily temperature and moisture conditions in a
place
2.
Climate – long-term weather patterns
1.
The Atmosphere
1.
Layers to the atmosphere
1.
2.
3.
4.
Troposphere
Stratosphere
Mesosphere
Thermosphere
Stratosphere
Stratosphere = global sunscreen
Ozone layer – 1000 time more O3 than in troposphere – screens 95% of UV light
Ozone – troposphere vs. stratosphere
Ozone shield
Stratospheric Ozone
5.
6.
Allows humans and other organisms to exist on land
Helps protect humans from sunburn, skin and eye cancer, cataracts,
and damage to the immune system
7.
Prevents much of the oxygen in the troposphere from being converted
to ozone, which in the troposphere is a harmful air pollutant.
Greenhouse Effect
8.
The natural warming of the lower atmosphere (troposphere) because
of the presence of certain atmospheric gases.
9.
Greenhouse gases
10. H2O, and CO2 are the primary gases
11. Ozone, O3,
12. Methane, CH4
13. Nitrous oxides, N2O
14. Chlorofluorocarbons, CFC’s
15. Perflurocarbons, PFC’s, such as CF4 (carbon tetra fluoride)
Greenhouse effect
16. Latent heat – H2O vapor
Albedo
17. Reflectivity of surface of earth.
General Air Circulation
18.
19.
Coriolis Effect
Jet Stream
Ocean Currents
Season Winds
20. Monsoons
Climate Changes
21. Milankovitch Cycles
1. 100,000 year cycle earth’s orbit = Eccentricity
2. 40,000 year cycle, rotation change = Obliquity
3. 26,000 year cycle, wobbling on axis = Precession
Southern Oscillation
4.
5.
El Nino
La Nina
Air Pollution
6.
The presence of one or more chemicals in the atmosphere in
sufficient quantities and duration to cause harm to humans, and
other forms of life, and materials.
Primary Pollutants
Major Classes of Air pollutants
7.
8.
9.
10.
11.
12.
13.
14.
Carbon oxides – CO, CO2
Sulfur oxides – SO2
Nitrogen oxides - NOx
Volatile organic compounds (VOC’s) – methane, CFC’s
Suspended particulate matter (SPM) – dust, asbestos, liquid droplets
Photochemical oxidants
Radioactive substances
Hazardous air pollutants (HAP’s)
Brown-Air Smog
Gray-Air Smog
15. Industrial smog
16.Form from the burning of coal
17.Droplets of sulfuric acid and sulfur dioxide
18.Donora, PA – Oct. 26, 1944 – 20 died, 6000 affected. Thermal
inversion.
19.London, England – Dec. 1892 – 1000 deaths plus Dec. 4, 1952 The
Great Pea Souper – over 4000 deaths
Solution to Acid Deposition
20. Reduce energy use and thus air pollution by improving energy
efficiency
21. Switching from coal to cleaner-burning natural gas and renewable
energy resources
22. Removing sulfur from coal before it is burned
23. Burning low-sulfur coal
24. Removing SO2, particulates and nitrogen oxides from smokestack
gases
25. Removing nitrogen oxides from motor vehicle exhaust
26. Taxing emissions of sulfur dioxide
Kyoto, Japan Agreement
27. 161 nations met, negotiated a new treaty
28. Require 38 developed countries to cut greenhouse emissions to an
average of 5.2% below 1990 levels between 2008 and 2012.
29. Not require developing countries to make any cuts in their greenhouse
gas emissions
30. Allow emissions trading, in which a country that beats its goal for
reducing greenhouse gas emissions can sell its excess reductions to
countries that fail to meet their reduction goals.
31. Show Global warming Real Time - 47
Estimated long-term variations in mean global surface temperature and average Tropospheric carbon
dioxide levels.
The Ozone Hole - The Players
32. Chlorofluorocarbon (CFC) – discovered in 1930 by General Motors
chemist – Freons
33. Used for coolants in air conditioners and refrigerators
34. Propellants in aerosol spray cans
35. Cleaners for electronic parts such as computer chips
36. Sterilants for hospital instruments
37. Fumigants for granaries and ship cargo holds
38. Bubbles in plastic foam used for insulation and packaging.
39.
Stratospheric Ozone (Show Real Time – 48)
The premise
40. CFC’s migrate up into the Stratosphere and chemically
degrade and destroy the ozone in the stratosphere.
41.1974 Sherwood Rowland and Mario Molina calculated that CFC’s are
destroying the ozone layer.
What happens
Polar Vortex over the poles
The requirements for ozone loss are:
1.
2.
The polar winter leads to the formation of the polar vortex, which isolates the air within it.
Cold temperatures form inside the vortex; cold enough for the formation of Polar Stratospheric
Clouds (PSC’s). As the vortex air is isolated, the cold temperatures and the PSC’s persist.
3.
Once the PSC’s form, heterogeneous reactions take place and convert the inactive chlorine and
bromine reservoirs to more active forms of chlorine and bromine.
4.
No ozone loss occurs until sunlight returns to the air inside the polar vortex and allows the
production of active chlorine and initiates the catalytic ozone destruction cycles. Ozone loss is rapid.
The ozone hole currently covers a geographic region a little bigger than Antarctica and extends nearly
10km in altitude in the lower stratosphere.
5.
For more information http://www.atm.ch.cam.ac.uk/tour/index.html
Other chemicals the deplete Stratospheric ozone
Halons and HBFC’s, both used in fire extinguishers
Methyl bromide (CH3Br), widely used fumigant
Carbon tetrachloride (CCl4), a cheap, highly toxic solvent
Methyl Chloroform, or 1,1,1-trichloroethane (C2H3Cl3), used as a cleaning solvent
for clothes and metals and as a propellant in more than 160 consumer products such as
correction fluid, dry-cleaning sprays, spray adhesives, and other aerosols.
5.
Hydrogen chloride (HCl) emitted into the stratosphere by U.S. space shuttles.
1.
2.
3.
4.
So What?
6.
The ozone layer filters out UV-A and UV-B radiation. These
UV radiation cause:
7. Worse sunburns
8. More cataracts (a clouding of the eye’s lens that reduces vision and
can cause blindness if not corrected)
9. More skin cancers
Montreal Protocol
10. 1987, 36 nations developed a treaty to cut emission of CFC’s
by 35% between 1989 and 2000.
11. 1990 – London 93 countries
12. 1992 – Copenhagen – adopted protocol, phase-out of key
ozone-depleting chemicals
CFC substitutes
Radon-222
13. Intermediary Daughter product of radioactive decay of U-238, found
in granite, phosphate deposits, and black shales
14. Alpha particle emitter – damages lung tissue
15. In the Atlanta area closer to Stone Mountain or area of bedrock
exposed home should be tested every 5 to 10 years. Should be contingent
of sale of older home.