The Air/ The Atmosphere

• SO₂, gas
• can get by burning sulfur S + O₂ --> SO₂
• sharp, unpleasant smell, toxic
• lung irritation, serious at 10 ppm levels
  • used to treat wine (kills unwanted mold)
• mostly we get from fossil fuels
  • coal 0.2-2% Sulfur
  • crude oil about the same
• if you burn coal, oil, gasoline-- get some SO₂
  • all the S ends up as SO₂
• Not a recent problem
  • London, 1700's nearly unlivable air
  • when winds stopped, 10-1000 deaths/day
    • mostly due to CO and SO₂
  • Once burning coal was a capital offense

• one coal fire is minor
• collectively, many cars and fires =
  • community disaster

Can reduce the problem/ solutions are obvious

• select fuel low in Sulfur
• treat fuel to remove the sulfur
• use alternative fuels/energy sources
• trap the SO₂ before it gets away
• avoid concentrations of SO₂ producers
  • taller smokestacks
  • cut back activity when no wind

Still, not easy solutions

• low sulfur coal--
• abandon coal industry in Ohio, W Va, Penn
  • increased unemployment
• force everyone to use coal from Wy, Montanta
  • high shipping costs
• treat crude oil to remove most of the sulfur
  • costs a bit more, but effective
• treating coal
  • expensive, not very effective
• alternative energy sources
  • nuclear,
  • solar, geothermal, hydroelectric
    • hydro often destroys fisheries
    • nuclear has it own problems
• trap the SO₂
  • has been effective
  • only economical for large unit
    • electrical power plants
• can pass exhaust over limestone
  • smokestacks and wind patterns
  • just moves the material to someone
    • else's neighborhood
    • ... return to this under Acid Rain

Nitrogen Oxides, NOx

• Actually a number of different compounds
• NO, NO₂, N₂O₄, N₂O₅, N₂O
• change back and forth, similar problems
• simpler, to select one to (NO) discuss
• or lump them together as NO_x (x varies)
• Again, tough on lungs if enough is present
  • dissolves, forms nitric acid in the lungs
  • produces edema-- water in the lungs
  • can lead to death
• Nature provides some of this
  • N2 + O2 ---lightning---> 2 NO
  • often reacts with water, dissolves in rain
  • plants use it as N-fertilizer
  • level is too low to be a problem
• Any hot object causes air to form NO
  • N₂ + O₂ ---heat---> 2 NO
  • car engine, coal fired power plant, welder
• Enough to become a real problem

• change operating temp of engine or fire box
  • unfortunately... cooler car engines
    • produce more CO and unburned
    • hydrocarbons
    • hotter engines, less CO but more NOx

Carbon Dioxide, CO₂

• Somewhat safer material it seems
• We drink CO₂ rich beverages
• We can breathe 1-2% CO₂ little trouble
  • get a bit sleepy, but usually safe
• Plants need it for photosynthesis
  • CO₂ + water + sun ---- (green plant) ---> O₂ and sugar
  • sugar + O₂ ---(people)---> CO₂, H₂O and our energy source

• wait and you get coal, petroleum

The problem with CO₂ is more subtle, long term

CO₂ absorbs infrared light

• traps the energy
• called Greenhouse Effect

• air temperature rises

• world temperatures are rising (0.5-2 ^OC)
• effect tracks the increase in CO₂ levels
• global warming, climate shifts

• Methane is also a green house gas
• Leaking natural gas
• Some bacterial fermentation
  • (landfills = methane source)
• Cows and others--
  • most intestinal gas = methane
• but CO₂ is largest, most identifiable species

• we can't create another test world
• we don't want experiments with this one
• weather is a very complex problem

• results vary from bad to disastrous
• time varies from 10-100 years away
• solutions take 10-100 years to have effect
• best evidence says risk is very real

• Do cigarettes cause cancer?

• be careful -- perhaps risk of cancer and tendency to smoke are linked
• but, could it be people likely to smoke are at higher cancer risk
• but an unknown link -- not cause and effect

• in absence of Causal link...
  • would it be wise to act on the very
  • strong statistical evidence?
    • wise as an individual
    • wise as a social policy

Despite claims from "leaders" like Jesse Helms, there is causal evidence

• A major component of smoke is benzopyrene
• Benzopyrene leads to cancer in test animals
• The same group of animals have very low cancer if left alone
• Can show cause an effect

many variables

Harder if you can't construct control experiment

• can't feed people toxins to find unsafe level

• you form a trade group opposed to it
  • (get the money)
• you focus only on the costs, distort costs,
  • belittle the risks
• you hire a few expert witnesses
  • (someone's always willing to take the money)
• you spend money on PR and political elections
• form a few mock scientific groups as a front
• hire lawyers to tie up every proposed activity
  • (litigate to stall)
• pick flaws in every study ever done
  • (inconclusive, need more evidence)
• line up against everyone else; challenge motives
  • (misguided, conspiracy, political agenda)
• you encourage no action until we get
  • more proof
  • newer technology
    • that will surely solve the problem
  • more studies

This is now the official US Policy on CO₂ and Global Warming

• we signed treaties
  • (under a past president of course)
• we know that the best evidence says this is a real, serious problem
• we will officially pretend we need another study or two or more
• we will take no action that addresses the problem
• let every other nation in this world deal with CO₂ reduction