Something about Planes

 
Whilst this is not a subject we will cover in depth it is worth reviewing briefly the increasing use of aviation. Figure 7 shows the figures for the UK market for passenger travel. Although domestic travel has increased, it is far outweighed by the increase in international travel. In addition more freight also travels by plane as shown in figure 8.
Figure 7 Passenger travel by air - 1977-1996
Aviation and the Environment
  • For every 4,000 miles of air travel roughly 2100 pounds of carbon dioxide are generated.(0.15kg per km)
  • Fuel burned by aeroplanes puts nitrogen oxide and water vapour at 30,000 feet (10km) into the atmosphere, which also adds to the greenhouse effect.
  • Airports may sometimes be less regulated than smokestacks and other forms of industrial pollution, yet account for an increasing amount of nitrogen oxides, volatile organic compounds and carbon dioxide
  • In the USA regulations controlling runoff of toxic substances such as de-icing fluids for runways are non-existent. One commonly used de-icing chemical, ethylene glycol, can be fatal to humans in small doses, and is suspected of causing fish kills in some of the waters surrounding airports.
Figure 8 Use of aviation for freight transport in the UK
The US space shuttle releases approximately 265 tons of hydrochloric acid into the atmosphere per launch. The average number of shuttle runs annually is 10, and it has been estimated that these shuttles alone could cause a 10% depletion in the ozone layer by 2010. The chlorine in the hydrogen chloride gas can react with ozone in much the same way that the chlorine from CFC's in aerosols.
 
Task 2: How many trees should you plant this year?

As a rough estimate, 1 gallon of fuel produces 20lbs of CO2, which is equivalent to 1/50th of a tree, i.e. if you use 50 gallons you need one tree to absorb the CO2 produced by 1 gallon of petrol.

a) Calculate your average petrol use in one week. How many trees does this equal?
b) Now calculate your average annual use, and the number of trees you would need to absorb this amount of CO2
c) Finally, calculate the number of trees based on your figures that would be required to absorb the CO2 for your local city, town or street.

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