Carbon in the Atmosphere

Carbon Dioxide

When we study the carbon cycle, we typically focus in carbon dioxide when we look at the atmospheric portion of the cycle. This is simply because carbon dioxide is the major carbon containing component of the atmosphere even though it constitutes less than 0.04% of the atmosphere. How can such a small amount be important?

Carbon dioxide is a greenhouse gas which means that it has the ability to act like a blanket around the earth and trap heat. (For an extreme example of carbon dioxide causing a greenhouse effect read about the atmosphere of Venus.) However, carbon dioxide is not the only natural substance to do that. Water vapour is also responsible for contributing to the greenhouse effect, but of course we would not want to reduce the amount of water vapour in the atmosphere to significantly because we would risk another problem - less rainfall. This has happened too often already when areas have become arid because of too much land clearing.

What can you do as an individual to reduce carbon dioxide emissions?

Methane

Carbon is also present in methane, another of the gases implicated for increasing the greenhouse effect. While the quantity of methane in the atmosphere is much less than that of carbon dioxide, one tonne of methane has the effect of 20 to 25 tons of carbon dioxide. SO where does the methane come from?

Some methane is produced by decomposition, such as marsh gas. Some is produced by industry but a significant amount is produced by livestock. "According to a new report published by the United Nations Food and Agriculture Organization, the livestock sector generates more greenhouse gas emissions as measured in CO2 equivalent – 18 percent – than transport." (FAO Newsroom, 2006).

A vegetarian diet has been shown to have significant health benefits but now there is another good reason to eat less meat, or none at all. It helps the environment! (See National Vegetarian Week: Environmental Benefits.) The typical Aussie who loves his steak probably won't like this idea too much but it will also save money.

Carbon Monoxide

Fortunately, there is no one likely to oppose efforts to reduce carbon monoxide emissions. Even though it is important for a variety of industrial processes, there is a strong incentive to ensure that it is not released to the atmosphere because we don't like poisons. How can we reduce carbon monoxide production?

Carbon monoxide is produced by incomplete combustion so we need to ensure that cars are well tuned and that furnaces are correctly adjusted. This in ceases the heat efficiency of the combustion as well as reducing carbon monoxide production.

Solid Carbon

These days, we don't hear a lot about solid carbon in the atmosphere but there are both health and environmental concerns about the levels of soot in the atmosphere. See Scientists warn of soot effect on climate. One of the most infamous episodes involving smog occured in the northern winter of 1952 and was called the Great London Smog when about 4000 deaths were attributed to the effects of the soot, sulphur dioxide and other pollutants from burning coal.

Industries using combustion of coal and other fossil fuels have been forced to clean up their act in industrialised countries but unfortunately, there are many places where there is still much to be done in this regard. As final preparations are put in place for the Beijing Olympic Games, there is still concern about the smog. (See Beijing Olympics: 1.15m cars banned from roads in last-ditch smog effort.)

Questions

1. The information above suggests that carbon in the atmosphere is responsible for many problems. Is this a balanced view?
   
2. List some things that you can do to reduce the amount of greenhouse gases resulting from your daily activity. Explain why your ideas will be benficial. Try and list them in decreasing order of importance. ie Start with the most important ones.
3. A common response is, "What I do will not make a difference." How would you respond to someone who says this.
4. The carbon cycle suggests recycling of carbon in the environment. Explain which parts of the carbon cycle have true recycling and where the system has been upset.
5. Former prime minister John Howard said he wanted to avoid responding to the greenhouse issue in a way that would upset the economy. How would you respond to this?