Natural Gas and the Environment
Natural gas can be considered to be the cleanest of all of the fossil fuels as combustion by-products are primarily carbon dioxide and water vapour, however, coal and oil are composed of much more complex molecules with greater carbon ratios, higher nitrogen content and sulphur. Therefore, when oil and coal are burnt, they release much more harmful emissions which include high levels of carbon emissions, nitrogen oxides, and sulphur dioxide. In addition coal and oil can leave harmful by products when combusted such as ash or soot. Natural gas on the other hand release no or very little of the harmful emissions that coal and oil do when combusted.
By promoting the use of natural gas for energy production in place of coal or oil, we would be helping to reduce the harmful pollutants that are released into the atmosphere when coal and oil are burnt. Using natural gas can help to promote the reduction of greenhouse gases, improve air quality (reducing smog), reduce the possibility of acid rain, and reduce the emissions from transportation.
In generating a given quantity of energy through combustion, natural gas will produce approximately 30% less carbon dioxide than oil and just under 45% less carbon dioxide than coal. The main greenhouse gas is carbon dioxide. However, another greenhouse gas is methane, which is the principle component of natural gas. Although methane from natural gas is only thought to make up 1% of all greenhouse gases in the atmosphere, methane can trap heat over 20 times more effectively than carbon dioxide, so it is a potentially dangerous greenhouse gas (even in small quantities). Due to the methane content in natural gas, there have been studies into whether the reduction of carbon dioxide from natural gas is in fact offset by the increase in methane. A study by the Environmental Protection Agency (EPA) and the Gas Research Institute (GRI) in 1997 concluded that the reduction in harmful emissions from natural gas far outweighed the negative effects from the release of methane from natural gas.
Using natural gas does not contribute significantly to the formation of smog because it emits low levels of nitrogen oxides, and hardly any particulate matter. One of the main contributors towards causing smog is the petrol powered automobile. If there was a larger switch towards gas powered LPG vehicles the risk of smog would be lessened. Recent EPA statistics suggest that natural gas powered cars cut carbon monoxide emissions between 90% – 97% and reduce carbon dioxide emissions by 25% when compared with petrol/gasoline or diesel based transport.
With a greater use of natural gas there would also be a lessened chance of acid rain. Acid rain is caused when sulphur dioxide and nitrogen oxides react with water vapour and causes acidic compounds in the air which fall as acid rain. Coal fired power plants are the main contributor to acid rain, however, as natural gas produces virtually no sulphur dioxide and 80% less nitrogen oxides than coal, there would be less chance of acid rain when using natural gas as an energy source.