Page 57 - Materials Chemistry, Second Edition

Life Cycle Assessment: Principles, Practice and Prospects
44
Most people live close to the coast, with a trend away from rural communities towards
interlinked coastal cities. Urbanisation is an ongoing phenomenon, and there is a link here to
losses of the natural environment, since most population expansion occurs in greenfield devel-
opments in the outer suburbs of larger cities (see Section 5.3). Hence, coastal environments are
subject to significant pressures, and the rate of natural resource loss in these (often sensitive)
transition ecological zones is therefore a significant and ever-pressing issue.
Across the country, agriculture accounts for 62% of land use. Sheep and cattle grazing con-
tributes in particular to loss of habitat and soils in more fragile arid ecosystems. Soil acidity
due to planting of legume-based crops, and soil salinity due to irrigation, are also significant
problems. Most of Australia’s original vegetation remains, but in many areas is in decline, due
to clearing for agriculture, changed fire regimes, introduction of invasive species, and disrup-
tion of understorey in forests and woodlands. Australia’s remaining forest areas cover only
about 15% of the land they covered when European settlers arrived. Clearly there is tension
over land use in Australia, with demand for agriculture, wood production, natural catchments,
mining and urban development.

5.3 Human settlements and demand for energy and water
In contrast to the natural environment, settlements in Australia are comparable to those in
other modern westernised countries. Most Australians lead highly urbanised lives situated in
large cities that broadly resemble cities in Asia, Europe and the Americas, albeit with distinc-
tive aspects to the urban form, dynamics of development and demographics. Melbourne has a
‘European’ core, with walkable, mixed use, and vertical as well as horizontal streetscapes,
offering ‘24/7’ services combining indoor/outdoor dining, and recreation, as well as retail,
office and commercial spaces. Attempts to integrate and encourage public transport add to the
European feel, with trams and cycle lanes claiming a share of the spaces between buildings.
However, the outer suburban form is more ‘North American’, and is dominated by low density
residential ‘quarter acre blocks’, representing the enduring Australian dream of home owner-
ship in a sprawling, home/backyard, private car-based environment. While there is space here
for trees and ribbons or vestiges of natural environment, this space has often been utilised as
concreted access or yard areas, lawns on the ‘English’ garden model, and exotic garden planting,
requiring considerable watering during dry periods.
The areas of Australia that have seen greatest development in recent decades are on the
eastern seaboard, while in the west, suburbs north and south of Perth are also expanding
rapidly. Australia-wide, some 77% of the coastal development is pre-1980 (SoE 2006); this
figure also indicates that almost one-quarter of coastal development has taken place since 1980
– and the ‘sea-change’ pressure continues, as baby boomers and their offspring seek out the
seaside. Indeed, it is predicted that some 9.2% of the total Australian coastline is likely to be
developed by 2050 (SoE 2006).
Meanwhile, Australia’s population has increased by about one million since 2000, with an
annual growth rate of 1.2%. Australia’s growing cities are taking over productive agricultural
lands and areas of heritage and ecological significance, and this pressure is accentuated by
increasing consumption of energy, land, water and other products dependent on natural
resources. Demand for water, exacerbated by the recent drought, is placing significant pressure
on Australia’s inland water systems, particularly through the use of groundwater. A national
water policy reform process, initiated in 1994, is being implemented. This will eventually sig-
nificantly change the way water is managed in Australia and is likely to have a major impact on
water consumption and the health of waterways. Meanwhile, water consumption continues to
increase. Irrigated agriculture accounts for about two-thirds of Australia’s water use, while

100804•Life Cycle Assessment 5pp.indd 44 17/02/09 12:46:16 PM