Air Quality in Australia

Air Quality

a. Air pollution is the build up of contaminated particles in the air, which negatively affects the air quality. The following paragraphs will explore the spatial dimensions of air pollution including where it is found, how it is affected by weather, how it is affected by time and how much we produce.

Air pollution is mostly found around the urban and industrial areas of Australia, as this is where most emissions are produced. Australia is fortunate in being an isolated continent as this largely protects it from air pollution from other countries, unlike in Europe -where Norway has complained about air pollution which has blown across the sea from Britain's power stations and poisoned their lakes with acid rain.

Seasonal changes can greatly affect the concentration of air pollution. In the warmer, less windy months in Australian cities, the sunlight reacts with the pollutants in the air, creating a dense photochemical smog. In winter months in country towns, more people use wood heaters which produce a high level of air pollution. This can result in large country towns such as Armidale having levels of air pollution higher than those of Sydney in cooler months. The diagram to the left demonstrates how time and weather conditions can influence air pollution on a smaller scale.

In 2007, Australia produced 597.2 million tonnes of carbon dioxide equivalent . Carbon dioxide equivalent is all of the greenhouse gases (such as carbon dioxide, methane and nitrous oxide) converted into the carbon dioxide equivalent. The air pollutants that we can see and taste in cities are nitrogen oxide (NOx) and ozone. Urban air generally has 35 more parts per million then clean air of NOx and 65 more parts per billion then clean air of ozone.

b. Air quality has ecological dimensions. Air pollution is caused by a number of factors, some human and some natural. Examples of how human activity causes air pollutants are; emissions from transport, power generation, agriculture and woodfire heating. Some examples of natural causes are bush fires and dust storms. The following paragraphs will take a look at three human causes of air pollution: transport, power generation and agriculture. They will also look at how Australians contribute to the natural causes of bush fires.

Australians population density is 3 people per square kilometre. This is small, especially when compared to countries like Singapore (7,023 people per square kilometre) or Monaco (16, 923 people per square kilometre.) This allows Australians to live in low density housing. Living spread out makes people more dependent on motor vehicles. In 2003, there was a private vehicle owned for every two people in Australia. While cars are a quick and easy way to get around, the fossil fuels they burn make a substantial contribution to air pollution. They are the main source of air pollution in Australian cities. In 2005, transport was responsible for 14% of Australia's green house gas emissions. Between 1990- 2005 the carbon dioxide equivalent emissions for motor vehicles increased by 30%, or 18.5 million tonnes .

We hear often about how Australia is starting to get a lot of its energy from renewable sources, but in reality Australia is still 96% dependant on fossil fuels such as coal and gas for electricity- as demonstrated in the graph to the left. Power generation stations create up to 50% of Australia's greenhouse gas emissions. Coal burning power stations do not cause as much air pollution as they used to, due to the introduction of scrubbers which heavily filter the gases. They are still major contributors to air pollution however.

In 2007, Agriculture caused 15%, or 88.1 million tonnes of carbon dioxide equivalent. There are many ways that Australian agriculture produces air pollution. Overgrazing on marginal land can produce dust storms which release pollutants into the air. An extreme example of this was the creation through bad farming practices of the dust bowel in America in the 1930s. The resulting dust storms not only probably released a lot of pollutants into the air, but also had major social affects. The farming of cattle also causes air pollution through the cow's emission of gases. A 2006 report released by the United Nations revealed that 18% of the world's greenhouse gas emissions came from cattle farming. Cattle farming is a major industry in Australia, in 2006 Australia was the world's greatest exporter of beef. Another way agriculture contributes to air pollution is through the use of some pesticides and fertilizers and the burning of plants, which all release dangerous gases into the air.

With the temperatures heating up and the land drying out, it is believed that in Australia's future there will be more bushfires, which will cause air quality levels to worsen for a longer number of days. Bushfires produce a lot of smoke which worsens the air quality with increased levels of fine particles. During the 2006-2007 Great Divide bushfires, thick smoke that travelled to Melbourne caused the air quality to peak at four times the National Environment Protection Measure 24-hour standard. The graph to the right demonstrates how humans can cause bushfires.

c. Air quality -or rather- air pollution, has huge impacts on both the environment and human beings. The following paragraphs will look at how air pollution impacts the environment through acid rain, global warming and ozone depletion. It will also look at how air pollution impacts on humans through health and mortality rates.

Air pollution can impact on the environment in a number of ways. It can go into the atmosphere and form acid rain or snow or mist, (as shown in the diagram to the left), which can in turn poison waterways, harm wildlife and make soil impossible to grow things in. It can also damage buildings and statues. Australia is fortunate in not having many problems with acid rain yet, due to its isolated location and relatively low air pollution emissions. It is a problem overseas though. For example, in Germany, all of the forests are believed to be dying because of acid rain harming them.

Certain air pollutants such as carbon dioxide, methane and nitrous oxide are called greenhouse gases and contribute to global warming. Global warming is when greenhouse gases trap the sun's rays inside the atmosphere, causing the earth to heat up. Some of the predicted impacts of global warming on Australia are; temperatures will increase 1-7ºc by the year 2070, Australia's coastal lines will suffer erosion from an expected 8-88cm rise in the world's sea level and natural disasters will be more