Bill McCormick, Science, Technology, Environment and Resources
Section
Humans affect the environment in a variety of ways,
including:
- through the consumption of energy and resources
- through the discharge of wastes and pollutants
- through the displacement of plants and animals and the
modification of natural ecosystems by agriculture, and
- by cities, transport systems and industry.
Ecosystem services
Natural and modified ecosystems provide humans with:
- provisioning services such as water, food, fibre, biomass fuel,
genetic resources
- regulating services such as climate regulation, flood and
drought mitigation, water purification, pollination, disease and
pest regulation and control
- cultural services, such as recreation, aesthetic values, and
heritage, and
- supporting services, such as soil formation, nutrient cycling
and primary production.
Modification of these ecosystems can reduce the effectiveness
and amount of these services.
Sustainable population
In June 2010, the Australian Government appointed a
Minister for Sustainable Population to develop a sustainable
population strategy, ’underpinned by respect for the
environment and respect for the needs of Australians requiring good
infrastructure and services’.
There are calls to set population targets for Australia. These
often relate to the number of people that would be the optimal
population, rather than a sustainable population. Estimating the
number of humans that Australia can support without damaging the
natural environment (that is, the sustainable population or
‘carrying capacity’) is not readily possible; it
depends on a number of variables, including:
- the lifestyle and level of per capita resource consumption
- the location of the population around the country
- the quantities of the various pollutants that are discharged
into the air, soil, water and biological systems
- the sources and types of food and how and where they are
produced
- the location (source) and types of energy consumed, and
- the location (source) and types of resources (for example,
water, soil, minerals) used to make products that are
consumed.
While it is difficult to estimate a specific sustainable
population level there is no question that we need to eventually
stabilise Australia’s population. There are limits in terms
of the ability of the environment to supply resources and the
ability of it to absorb waste products. Some commentators argue
that we have already exceeded sustainable population levels for
Australia.
Ecological footprint
The term ‘ecological footprint’ is used to assess
the impact of individuals, cities or countries on the environment.
One definition of ecological footprint is a measure of how much
biologically productive land and water an individual, population or
activity requires to produce all the resources it consumes and to
absorb the waste it generates using prevailing technology and
resource management practices’. Several Australian states and
territories have calculated their ecological footprint.
Victorian ecological footprint
‘The average Victorian resident has an Ecological
Footprint of 6.83 global hectares, more than three times
higher than the world average. This equates to a total Footprint of
33 million global hectares, or 147% of the land area
of Victoria. However, a part of Victoria’s Ecological
Footprint will be located in other parts of the world to provide
the wide range of goods and services consumed by its residents. The
Ecological Footprint consists of both actual (real) land (arable
land, pasture, forests, built land etc.) and “carbon
land” (the land required to absorb the carbon dioxide emitted
through the consumption patterns of a given population)’.
Different levels of consumption between populations will affect
the environmental impacts of those populations. Altering
consumption patterns to reduce the impact may enable the population
of a country to increase, without putting further pressure on the
environment. This may mean consuming less, but alternatively, the
impacts of consumption can be cut by introducing technologies that
reduce energy use, waste products and increase efficiency.
Intensification of agriculture
An increasing population requires more food and other primary
products. Growth without end means that limits will be eventually
reached in terms of the area of suitable agricultural land able to
produce food and fibre needed for consumption and export.
Population growth means growth in agricultural production, a trend
that has been occurring for many years. Such an increase, whereby
more food is produced from less land, is feasible up to a point,
but can have major impacts on the environment if not managed
properly. If practised sustainably, there is the potential to
reduce, or at least minimise, these impacts. Methods of achieving
this include:
- changing farming practices, for example, improved management of
livestock wastes or agro-forestry, to reduce greenhouse gas
emissions
- using improved plant breeds with increased water use efficiency
and genetically modified crops to reduce pesticide use, and
- precision agriculture to deliver water, nutrients and
pesticides to the crops when and where they are needed, thus
reducing consumption and offsite environmental impacts.
Comments
An increasing population will make it more difficult to meet
environmental commitments. For example, to reduce Australia’s
carbon emissions from year 2000 levels by five per cent
by 2020, while the population is increasing to 27 million,
means a reduction in per capita emissions by almost
20 per cent. Thus, population growth means that ways must
be found to reduce individual footprints.
Library publications and key documents
B Foran and F Poldy, Future dilemmas:
options to 2050 for Australia’s population, technology,
resources and environment, report prepared for the Department
of Immigration and Multicultural and Indigenous Affairs, CSIRO,
Canberra, 2002,
http://www.cse.csiro.au/publications/2002/fulldilemmasreport02-01.pdf
T Wiedmann, R Wood, J Barrett, M Lenzen and R
Clay, The ecological footprint of consumption in Victoria,
report prepared for the Victorian Environment Protection Authority
(EPA Victoria) by the Stockholm Environment Institute at the
University of York and the Centre for Integrated Sustainability
Analysis at the University of Sydney, 2008,
http://epanote2.epa.vic.gov.au/EPA/Publications.nsf/2f1c2625731746aa4a256ce90001cbb5/6a4f318c29647984ca2574710004e3ad/$FILE/ATTAD7EZ/1269.pdf