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9.6 Option — Organic geology: 5. The environmental impacts of fossil fuel use

Syllabus reference (October 2002 version)
5. The environmental impacts of fossil fuel use - complete versus incomplete combustion	*Student learn to:* analyse and evaluate the types and effects of products of burning fossil fuels - gases, water, particulates analyse the dependence of modern society on fossil fuels and assess attempts to limit emissions describe and evaluate arguments concerning the greenhouse debate	*Students:* identify data sources, select equipment, plan and perform a first-hand investigation to distinguish between the products of complete and incomplete combustion identify data sources, analyse information and use available evidence to determine the effects of fossil fuel combustion products, using a variety of media analyse information and use available evidence to predict scenarios that investigate the effects of removing all sources of fossil fuels

Extract from Earth and Environmental Science Stage 6 Syllabus (Amended October 2002). © Board of Studies, NSW.
[Edit 21 Oct 04]

Prior learning:Science Stages 4–5 Syllabus: Outcome 5.11 (content 5.11.1 b and 5.11.2b)

identify data sources, select equipment, plan and perform a first-hand investigation to distinguish between the products of complete and incomplete combustion

Identify data sources with information on the products of complete and incomplete combustion. Look in text books and on the Internet. If you are using a search engine you could type words such as combustion, carbon monoxide, incomplete.
When you have done the literature search decide what investigation you will do, then select the equipment you will need, keeping in mind any risks involved in the investigation and addressing any hazards that may arise.
Perform the investigation carefully, recording results accurately. Repeat the experiment to see if the results are similar. Make sure that any gases produced are collected satisfactorily and not allowed to escape.

The following information may help you get started with your literature search.

All fuels contain hydrocarbons (C_xH_y).

The general equation for the combustion of a hydrocarbon is;
C_xH_y + O₂ CO₂ + H₂O + energy

To burn completely, any fuel needs a sufficient supply of oxygen.
Incomplete combustion (insufficient oxygen) produces carbon monoxide (CO) and carbon (soot).

identify data sources, analyse information and use available evidence to determine the effects of fossil fuel combustion products, using a variety of media

Identify data sources by looking for CD ROMs on the environment and issues concerning air quality, on the Internet (you could check the EPA, NSW site, the Australian Conservation Foundation or use a search engine) and in books and journals. A table on the EPA web site that might be useful. In the table the initials ROC stands for 'reactive organic compounds'.
Put the information you have gathered in a table, with the first column being the product, and the second column being the effect of the product. You will need to consider the fact that different fossil fuels have slightly different products of combustion. Also consider who they may have an effect on, e.g children’s brains can be affected if they inhale too much lead from the burning of leaded petrol.

analyse and evaluate the types and effects of products of burning fossil fuels - gases, water, particulates

The combustion of fossil fuels for transport, electricity generation and industrial processes can result in the emission of significant amounts of pollution.
The major combustion products of fossil fuels are various nitrogen oxides – (written as NO_x, where _xcan represent several different numbers, depending on which nitrogen oxide gas it is), sulfur dioxide -SO₂, carbon monoxide - CO, carbon dioxide - CO₂ and methane - CH₄.
The 1990s have proved to be the warmest decade since high-quality records commenced in 1910, and contained five of the 10 warmest years on record. The 1980s were the second warmest decade since 1910. It has been estimated that global temperatures increased by approximately 0.58^OC in the 20th century. In its last report, IPCC stated that average surface temperature is projected to increase by 1.4 to 5.8 Celsius degrees over the period 1990 to 2100. Sea level has risen approximately 0.1-0.25 metres in the last hundred years and is projected to rise by 0.1 to 0.9 metres over the same period. The wide range in predictions is based upon several different scenarios that assume different levels of future CO₂ emissions. Each scenario then has a range of possible outcomes associated with it. The most optimistic outcome assumes an aggressive campaign to reduce CO₂ emssions, while the most pessimistic is a "business as usual" scenario. The more realistic scenarios fall in between.
These effects are global and are not confined to national boundaries. Consequently, international responses are required to reduce global greenhouse gas emissions.
SO₂ is produced from the combustion of high sulfur coals. SO₂ reacts with water and sunlight to form sulfuric acid, which produces acid rainfall. Australian coals tend to contain low levels of SO₂.
NO_x is produced as a result of nitrogen reacting with oxygen in the combustion chamber. NO_x contributes to ozone depletion.
CO₂ is a by-product of all combustion of fossil fuels and is thought to trap infra - red radiation that would normally escape into space, thus resulting in the greenhouse effect.
Particulates, mostly dust, soot or unburnt carbon, and smoke are released into the atmosphere as a result of burning of fossil fuels. Particles greater than 10 micrometres (µm) are not inhaled into the lungs and so are not considered a health hazard but fine particles about 2.5 µm and smaller are. These are dangerous as not only can they be inhaled but they penetrate deep into the lungs. They have been known to cause respiratory difficulties and in some cases have resulted in a reduced life expectancy. Particulates are not usually included when the costs of burning fossil fuels are considered but they increase the cost of the health bill for society. These types of issues should be evaluated.
Water vapour is also given off during the burning of fossil fuels. Water vapour is about 60% to 70% of the gas that causes the natural Greenhouse Effect. However the incresed water vapour in the atmosphere due to fossil fuel burning is negligible to the enhanced Greenhouse Effect. Instead increased water vapour in the atmosphere is largely due to warmer suface temperatures causing increased evaporation from rivers, lakes and oceans. Also these warmer temperatures increase the amount of water vapour the atmosphere can hold.

analyse the dependence of modern society on fossil fuels and assess attempts to limit emissions

The use of alternative fuel sources has increased slowly, with incentives from state governments.
Alternative fuel sources are still not economically viable to run as a dominant energy source in comparison to fossil fuels, however as the price of fuel increases and the cost of alterrnative sources goes down, the alternative energy sources become more competitive.
The NSW Environmental Protection Authority (EPA) in conjunction with the other states and the Federal Government is part of a world wide scheme to limit emissions.
The NSW EPA lists in detail all initiatives taken to reduce the amount of emissions from fossil fuel combustion. Scroll down to 'Response to the Issue' and look at the different categories. You could also scroll to the top to read some background information.
A world wide attempt to limit emissions is the Kyoto Protocol. This is an international convention, drawn up in Kyoto, Japan in 1997, in which countries would commit to reduce their greenhouse emissions by 2012. The Australian Government successfully argued that their commitment to reduce emissions shouldn’t be as great as the conference suggested as the government would be planting millions of trees (carbon sinks). In 2001 the Bush administration refused to ratify the protocol as it ‘would harm US businesses’ and in 2004 Australia and the USA are the only two countries that haven't signed.
World energy use in the past and projected to 2025 , Energy Information Administration, Department of Energy, Washington DC, USA.
Do you think attempts to limit emissions have been successful?

analyse information from secondary sources concerning the enhanced greenhouse effect

There is a lot of information on the Internet, on CD ROMs and in books and journals on the enhanced greenhouse effect but many references just refer to it as the greenhouse effect so clarify what the article is referring to when researching. You could put the information you gather into two columns, one for information concerning the harm to the environment caused by the enhanced greenhouse effect and one for evidence that the enhanced greenhouse effect doesn’t exist and so there is no harm. Note the people and/or organisations that are commenting on the for or against arguments. Consider which ones are more reputable and so are more believable.
A separate table could include the different changes the enhanced greenhouse effect could result in and the consequences to different countries if these changes occur.

describe and evaluate arguments concerning the greenhouse debate

The greenhouse effect

Some of the infra -red radiation from the Earth's surface is trapped by Greenhouse gases and is reflected back to the Earth.
This results in a higher average surface temperature and a narrower range of temperatures.
It is a naturally occurring and life-sustaining process.

The enhanced greenhouse effect

Additional infra-red radiation from the Earth's surface is trapped due to an increased concentration of greenhouse gases (CH₄, CO₂, CO, H₂O, NO_x).

Possible consequences

An increase of 0.8 - 2^oC in the Earth's surface temperature by the year 2030.
Changes in the climate.
Rise of sea level (not due to melting of polar ice).
These consequences have been developed by climate modellers.
Some scientists believe that the degree of global warming due to the enhanced green house effect is not solely due to greenhouse gas emissions; but due to a combination of emissions and the Earth's natural greenhouse cycle. Whatever the case most scientists feel strongly that more should be done to reduce greenhouse gases to reduce the impact on people and the environment. What do you think?