Go figure: one swig costs buckets of water

By Deborah Smith Science Editor
May 25, 2005

You're feeling good: you've been for a run and you've had a very quick shower to save water. But you might want to think before you gulp down that sports drink.

While a shorter stint in the bathroom could save 25 litres of water, about 200 litres of water are needed to make a $2 soft drink, according to a study of the Australian economy.

But 21,000 litres of water are needed to produce a kilogram bag of rice worth $2.50 - a venture that generates only six minutes of work.

The study examined the environmental, social and financial impact of 135 different industries and, according to its author, Barney Foran, of the CSIRO, could help people decide how to better spend their money. An environ-mentally conscious jogger, for example, might decide "a cup of water out of the tap is all you need". A socially conscious one might might weigh the jobs the soft drink industry contributes to the economy against the money it provides government coffers.

Balancing Act, which Mr Foran wrote with two physicists, Christopher Dey and Manfred Lenzen, of Sydney University, is also aimed at helping businesses and governments set priorities and identify areas for improvement.

It took three years using complex mathematics for the team to condense vast amounts of information into a simple representation of the impact of different goods and services on 10 areas. They are: water use, land disturbance, greenhouse gas emissions and energy use; employment, worker income and government revenue; and profits, exports and imports.

Rice growing, for example, needs 200 times more water and produces four times more greenhouse gases than the average calculated for the whole economy. However, it generates 50 per cent more jobs than the average, most of them in regional areas.