Thursday, 26 November 2009

The clock is ticking as fuel reserves run out

Adelaide Advertiser
Tuesday 24/11/2009 Page: 30

SINCE August, at least 400 barrels of oil have leaked from the Montara drilling platform and polluted the Timor Sea. This, combined with emissions trading scheme discussions and the Copenhagen climate change conference next month have heightened Australian awareness of energy and environmental issues.

Moderately priced energy underpins our high standard of living, and care of the environment is a major facet of any discussion of our future. Australia is the world's eighth largest producer of energy, of which more than three-quarters is exported. Two-thirds of this exported energy is contained in fossil fuels, mainly coal, and the rest in uranium oxide. Because energy is central to every activity, its production, export, import and use are carefully monitored by the Australian Bureau of Agricultural Resource Economics. This is collectively referred to as the national energy flow.

So that solid, liquid and gaseous fuels can be compared on the same basis, the energy they contain is measured in petajoules, a quantity infrequently encountered in everyday life. A petajoule is the amount of energy required to heat 2.4 million tonnes of water from OC to 100C. It is a million million times larger than the kilojoule which is used to indicate the energy in food. In the 2006-07 financial year, total Australian energy production was 17,055 petajoules which together with 1860 petajoules of imported energy made 20,775 petajoules available. Of this, 13,055 petajoules were exported, leaving 5687 petajoules for domestic use - 282 petajoules of which came from renewable energy sources and the rest from fossil fuels.

Our efficiency of energy use is poor, with only an average 33% of the energy in coal being converted into electricity in our power stations. In our cars only about 15% of the energy in petrol is converted into motion. Overall, of the energy available for domestic use, almost 60% is lost due to inefficient conversion. Australia's 95% dependence on fossil fuels for domestic energy use is high by comparison with the world average of 80%. This is largely because our fossil fuels are readily accessible and relatively cheap to produce, and we do not have access to substantial hydroelectric power because of a the lack of large steadily flowing rivers and we do not use nuclear energy.

Our 2008 emission of carbon dioxide from fossil fuels was 18.75 tonnes per person which, together with those of Canada and the United States, is one of the highest by far. However, due to our small population, our contribution to increasing atmospheric carbon dioxide levels and global warming is only 1.4% of the total. Nevertheless, during global emission reduction negotiations this is unlikely to impress either the emerging economic giants China and India, whose carbon dioxide emissions per person are 4.57 and 1.18 tonnes respectively, or the Europeans whose per person emissions are half ours.

Because of international pressure to reduce carbon dioxide emissions, a review of our energy use is unavoidable. Our possession of 38% of the world's high-grade uranium deposits, our great wind energy potential and our abundant sunshine for solar and biofuel energy production together with improved efficiency will be major considerations. Another reason for such a review is that the known world reserves of economically accessible oil, gas and coal will be exhausted in 42 years, 60 years and 122 years respectively (and Australia's will be exhausted in 20 years, 65.6 years and 190 years or earlier) if energy use continues to grow.

Stephen Lincoln is a professor in the School of Chemistry and Physics and the author of Challenged Earth.