GEOGRAPHY 101

1
GEOGRAPHY 101

• Environ-mental
• Geography
• Day 15....

2
Housekeeping Items

• Just a reminder that, if you are interested in
  learning more about climate change, see the
  lecture by Jeff Lewis on the web site.
• I got the answers to the two questions from
  Tuesday regarding methane from permafrost and
  nitrogen in the atmosphere.
• Unless you got an extension, the LCAs are due
  today.
• We will start off today by doing the debate on
  BC's carbon tax.

3
Air Pollution

• Air pollution has existed for a long time, but
  has grown a lot worse since the Industrial
  Revolution. Why would it have existed in
  pre-industrial times, and why would it have
  tended to be less severe (there were exceptions)?
• In addition to a population much larger than in
  ancient times, the human population has become
  highly urban, and consumption rates have risen
  dramatically.
• Also in the last 100 years, we have brought
  thousands of new synthetic chemicals into use in
  modern agricultural and industrial applications,
  with waste residues entering respiratory systems,
  food chains and ecosystems.

4
Types of Air Pollution

• Air pollutants enter the atmosphere both as gases
  and as particles. Primary pollutants include
  cigarette smoke, auto exhaust, forest fires,
  discharge gases and particles.
• Secondary pollutants arise from mixing higher in
  the atmosphere and chemical alteration and
  change, an example of which would be acid rain
  (the primary contributors being sulfur dioxide
  and nitrogen oxides).

5
Major Air Pollutants

• Sulfur dioxide- from fossil fuels (e.g. coal
  plants) harmful to buildings human health, and
  a source of acid rain
• Nitrogen oxides- from high temperature combustion
  (cars and power plants) harmful to human health
  and source of acid rain
• Carbon monoxide- by-product of fossil fuel
  combustion colourless, odourless gas that
  inhibits of absorption of oxygen by the blood
• Carbon dioxide- released from burning of fossil
  fuels, forests and other vegetation contributes
  to climate change
• Particulates- includes soot, lead, ash and
  pollen solid liquid airborne particles that
  contribute to a variety of diseases, including
  asthma, emphysema lung cancer.

6
Major Air Pollutants

• Hydrocarbons- carbon-based gases emitted from
  cars, home heating industry when combustion is
  incomplete health hazard as primary pollutant
  and contribute to ground-level ozone
• Oxidants- caused by interaction of sunlight and
  hydro-carbons causes everything from eye
  irritation to cancer
• Acid deposition- rain, snow, or dry dust lowers
  pH in freshwater lakes and streams and damages
  forests
• Synthetic compounds- manufactured organic
  compounds such as CFCs, DDT, PCBs, and dioxins
• Radioactive substances- radon from coal-burning
  plants and waste from nuclear plants, causing
  cancer genetic alterations.

7
Sources of Air Pollution

• The chart on p. 225 shows the contributions that
  humans make to the different types of pollution
  3 (or more) of the carbon dioxide to 100 of
  synthetic compounds. Sulfur dioxide has both
  natural and human sources. Natural sources
  include gas exchanges involving phytoplankton.
• Most pollutants have harmful consequences when
  absorbed by ecosystem components, for obvious
  reasons. Carbon dioxide is the exception.

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Sources of Air Pollution

• If natural uptake of pollutants doesn't increase,
  then an imbalance occurs. Some people have
  described pollution as a resource in the wrong
  place. Their strategy resource recovery
  involves finding ways to avoid expelling
  pollutants into the environment, and instead
  treating them as valuable resources.
• One such strategy is called eco-industrial
  networking. This involves clustering industries
  together and using the wastes from one industry
  as a raw material for another.

9
Sources of Air Pollution

• Both developed and developing nations contribute
  significantly to air pollution from motor
  vehicles, power plants, and industrial plants in
  the wealthy nations. Most of this is from fossil
  fuel combustion the less complete the
  combustion, the more the pollution.
• The U.S. is the leading producer of CO2, both in
  total and on a per capita basis, though China
  will overtake it on a total output basis in the
  not-too-distant future.

10
Sources of Air Pollution

• Photochemical smog is a major problem in cities
  with large numbers of vehicles. The current
  number of cars in the world is 600 million, but
  the number is rising quickly. China is expected
  to have gone from 350,000 in 1985 to 140 million
  by 2020!
• In Canada, studies have attributed 5800 premature
  deaths annually in Ontario to air pollution
  (mainly from cars), 17,000 hospital admissions
  and 60,000 emergency room visits. In addition,
  there is 1 billion in lost productivity. In
  Atlanta, Georgia, when cars were banned from the
  center of the city during the Olympics, asthma
  admissions to local hospitals dropped by almost
  half. Worldwide air pollution kills over 4
  million people per year.

11
Not Everyone Sees the Proliferation of Cars as a
Good Thing...
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Sources of Air Pollution

• In addition to brown smog attributable to cars
  and trucks, there is also grey smog deriving
  from industry and power plants. It is a mixture
  of sulfur dioxide, droplets of sulfuric acid, and
  particulates.
• In addition, tiny particles from the burning of
  diesel fuels (trucks, buses, etc.) so-called
  PM-10 (10 micrometers or less) are extremely
  hazardous to human health.

13
Sources of Air Pollution

• One particularly serious air pollutant was and is
  CFCs chlorofluorocarbons. These were used as
  propellants in spraycans of various kinds, as
  solvents and as cooling agents. It was
  discovered, beginning in the '80s, that they were
  the main cause of the decline in the ozone layer
  over the poles. The ozone shield high in the
  atmosphere is essential for protecting us from UV
  rays. Each molecule of CFCs can destroy 100s of
  1000s of ozone molecules, and they remain in the
  atmosphere for 75 to 110 years.

14
Sources of Air Pollution

• CFCs also contribute to climate change.
  Fortunately, at a meeting in Montreal in the late
  1980s, more than 70 countries agreed to phase
  them out, though there is still an active black
  market in the substance. (For more details on
  CFCs and ozone depletion, see p. 228.)
• DDT is another controversial organic chemical.
  Banned in the U.S. And other developed nations
  after Rachel Carson's Silent Spring, it still has
  value in the battle against malaria, though it
  concentrates in food chains.

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Sources of Air Pollution

• In addition to industrial and transportation
  sources for air pollution, agriculture also
  contributes (through livestock, soil erosion and,
  secondarily, fertilizer application), as does
  forestry activity.
• The most prominent air pollution regions in the
  world are displayed on p. 229. Mexico City and
  major Chinese cities have some of the worst urban
  air pollution in the world. And in Athens,
  nitrogen oxides and sulfur dioxides are eroding
  precious ancient monuments.

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Urban Thermal Inversion(warm air over cool,
keeping pollutants in)
17
Thermal Inversions

• The London smog episode of 1952, brought on by an
  inversion, and fueled by car exhaust, factory
  pollution, and coal heat in homes, led to the
  deaths of 4000 people in less than a week.

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Long-Range Transport of Pollutants

• Another way in which climate and weather interact
  with air pollution is in the long-range transport
  of contaminants.
• Examples include the movement of CFCs to
  Antarctica, the transport of air pollutants and
  toxic chemicals from Asia (China and India) to
  North America, the movement of industrial toxins
  from the Midwest to the Arctic and Quebec, and
  the spread of radioactivity from the Chernobyl
  disaster around Europe. Pollution does not stop
  at national borders!

19
Urban Air Pollution

• Because of the use of toxic materials in
  buildings, indoor air quality is a concern.
  Another problem can be the leakage of radon from
  the ground into buildings through basements.
  Also the closed nature of many buildings (with
  automatic heating and air conditioning) means
  that some buildings suffer from sick building
  syndrome bad air from building materials, but
  also the circulation of germs.
• More broadly, urban sprawl exacerbates urban air
  pollution and can be partly remedied through more
  investment in transit and more cluster
  development.

20
Urban Air Pollution

• Cities with the lowest density and most
  automobile dependence in North America (L.A.,
  Houston, Atlanta) often have the worst air
  pollution. The Clean Air Act, and actions by the
  Clinton administration, forced some urban regions
  to clean up their act and to invest in light
  rail and other forms of transit, and to consider
  air pollution and energy consumption issues in
  how they planned and managed their environments.
• By clustering land uses together and considering
  land use and transportation together, the number
  of trips can be reduced and the mode can be
  altered.