Page 58 - Materials Chemistry, Second Edition

The Australian environment: impact assessment in a sunburnt country

direct domestic use accounts for only about 9%. However, these agricultural practices are driven 45
by the dual needs of food consumption (i.e. human settlements) and export-led economic per-
formance. The use of rainwater tanks is increasing, although there is still little reuse or recycling
of sewage effluent or stormwater. Nearly 50% of household water is used in gardens.
Energy use is increasing and is reliant on fossil fuels such as coal and oil, with little take-up
of renewable energy. Electricity consumption in particular is increasing, partly due to a growth
in commercial and residential air conditioning of 20% per year since 2001. Road transport
consumes almost 40% of all energy used in Australia, and private passenger vehicle travel rep-
resents three-quarters of total road travel. Despite recent attention to urban design to mitigate
energy consumption, Australian governments continue to budget for freeway construction,
particularly in Sydney and Melbourne, at the expense of improving public transport. Mean-
while, in the Australian household, an enduring result of modern consumption patterns is the
production of waste. Australians dispose of about 1 tonne of waste per person per year to
landfill (see Chapter 6 for details on waste management in Australia).

5.4 Bioproduction and capacity in Australia
Given the uniqueness of the Australian environment, the question arises as to exactly what is
the bioproductive capacity of this fragile, arid land. The limited information that does exist
regarding the state of Australia’s biodiversity is weighted towards coastal biodiversity due to
the rising concern over recent decades about the rate of coastal development. Many threatened
species are in the Murray-Darling Basin, south-west Western Australia, populated coastal
regions, and in the Tasmanian Midlands, with more than half of the ecosystems in the devel-
oped coastal areas and the Murray-Darling Basin under severe pressure and significant decline
(NLWRA 2002; Olsen et al. 2006; Tyler 2006, cited in SoE 2006). Of 901 nationally important
wetlands in Australia (as at 2006), a 2001 assessment found that 231 were under pressure from
changes to water regimes.
Annual average bird numbers on floodplains have fallen from 1.1 million in 1983 to
0.2 million in 2004. Four species of frog are already extinct, 15 are endangered and another 12
are listed as vulnerable, with some 14% of frog species threatened (SoE 2006).
Given this dynamic flux in biodiversity, and signs of vulnerability, the question arises as to
whether human settlement is already exceeding its ecological carrying capacity. If it is not,
then what additional capacity remains to enable Australia to absorb a growing population?
Mathis Wakernagel’s thesis on the ‘ecological footprint’ (‘eco-footprint’) (Wackernagel and
Rees 1995) set out to determine the rate at which human beings are consuming the resources of
the Earth and, in particular, the extent to which this rate of consumption exceeds the rate of
accumulation and/or regeneration of resources. A full discussion of the eco-footprint method
of calculation is outside the scope of this book. For the purposes of this discussion, however, it
involves two essential elements:
s a measure of land used per person, according to the different sectors of the economy
and the population’s draw on these economic services
s calculation of the energy used per person, based on a similar calculation converted into
an equivalent land-area unit through an algorithm based on estimates of land required
to produce this quantity of energy.

Following Wackernagel and Rees’ seminal work, subsequent calculations published in the
Living Planet Report (World Wildlife Fund (WWF) 2006) indicate that humans are over-
consuming the bioproductive capacity of the Earth by about 22%. However, beyond this
‘average’, there appear to be large variations between communities. Of particular relevance

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