State of the Environment

2001

Human Settlements Theme Report

Australia State of the Environment Report 2001 (Theme Report)
Lead Author: Professor Peter W. Newton, CSIRO Building, Construction and Engineering, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06747 7

Emerging issues (continued)

Waste

Beyond recycling-value addition through better reuse and reprocessing technologies

Secondary products manufactured with recycled materials can often be more expensive than products made with virgin materials. This is because of the additional costs associated with collection, transportation and reprocessing. In addition, there is a general perception that some products made with recycled materials are inferior in quality. Value-adding through better reuse and reprocessing is one approach to increasing the use of recycled materials. There are numerous examples of value-added reuse.

Case 1-Value added re-use of demolished concrete. Concrete rubble from demolition has traditionally been crushed for use as a road sub-base. This is a relatively marginal application where the less stringent specification requirements allow the recycled material to compete on an equivalent performance basis against virgin aggregates. Crushed rubble for road base is also nominally cheaper than virgin aggregates for concrete. However, recent research at CSIRO has resulted in the development of premixed concrete containing recycled concrete aggregate (RCA) for non-structural applications. An example of this value-adding innovation is its application in the recent construction of several recreational facilities with premixed concrete containing RCA. The project was conducted in collaboration with the Victorian Government agency EcoRecycle Victoria, the City of Hobsons Bay, Wyndham City Council and The Alex Fraser Group. With the move towards performance-based specifications, it is anticipated that restrictions on RCA content in new concrete will be restrained only to cautionary recommendations for situations where limited technical data exists to support field performance.

Case 2-New value-adding technology for crumb rubber. In Australia, over 16 million waste tyres are generated annually. About 60% go to landfill and 15% are disposed of illegally through dumping (Atech Group 2001). This leads to landfill pressures as well as the risk of tyre stockpile fires which emit toxic gases. One of the major obstacles that has prevented effective high volume reuse of scrap rubber is its incompatibility with either rubber or polymer matrices. Therefore, crumb rubber could be used only to produce low-performance products such as impact-absorbing mats or garbage bins. New surface engineering technology developed by CSIRO has significantly changed the outlook for scrap rubber. By increasing the chemical reactivity on the surface of crumb rubber, binding properties are significantly improved. This has resulted in the potential to manufacture high-performance products with up to 60% crumb rubber contained in polymer (e.g. polyolefins, ABS, polyurethane) or rubber matrices for value-added applications in the footwear, automotive and building products industries.

Australia's ecological footprint

The ecological footprint methodology provides a tool for measuring human consumption pressures on the environment. Ecological footprint analysis, as applied by Wackernagel and Rees (1996), accounts for flows of energy and matter to and from a defined economy and converts these into the corresponding area of land required from nature to support the flows. Ecological footprint measurement is able to provide an indication of the sustainability of our consumption levels, by comparing the ecological footprint of a population with the area of land available (Petroeschevsky and Simpson 2000). The current global consumption of natural resources is appropriating an area of land 35% larger than the area of ecologically productive land estimated to be available (Wackernagel et al. 1997).

Ecological footprints can also provide an indication of equity in resource consumption between nations. Wackernagel et al. (1997) calculated that there are 1.7 ha of ecologically productive land per capita available globally - this is called the globally available `fair share'. The issue of equity between humans and the rest of the biological world is also raised here: the 1.7 ha per capita allows 88% of ecologically productive land for human use and 12% for other uses.

In a comparative study of 52 large nations (80% of the world's population), Wackernagel et al. (1997) found that Australia has an ecological footprint of 8.1 ha per capita. This far exceeds what is available at a global scale; that is, we are consuming more than our global `fair share'. On the other hand, in Australia there are 9.7 ha per capita of available ecological capacity. This surplus, however, is not available for future increases in Australia's population or to sustain any increase in per capita consumption, as it is being appropriated by other economies as exports.

There have been four major ecological footprint studies undertaken in Australia: Canberra (Close and Foran 1998), south-eastern Queensland, Queensland and Australia (Simpson et al. 1998), and the two most recent studies covering the whole of Australia (Lenzen and Murray 2000, Simpson et al. 2000). The studies take a similar approach to that proposed by Wackernagel and Rees (1996) but with some alterations to account for Australian conditions, so they are not directly comparable with international results. The footprint estimates of these studies range from 4.5 ha per capita for Canberra to one estimate for Australia of 14 ha per capita. Most estimates for Australia are around 4 and 5 ha per capita. In all cases, land for energy and pasture make up the greatest part of the ecological footprint.

Despite the variability in the estimates of ecological footprints in Australia, the results indicate that the average Australian consumes at least more than double their `fair share' of the world's ecologically productive land. While the total area appropriated by the Australian population is (hypothetically) within Australia's geographical boundaries (i.e. our ecological footprint is less than the nation's available ecologically productive land), our heavy economic dependence on the export of rural goods and increasing land degradation means that the capacity for future population growth and increased consumption is limited.

A large range of technologies are available for reprocessing and converting both liquid and solid hazardous wastes (Environment Australia 1997). For domestic wastes, energy recovery is one alternative being considered by various states and territories. In New South Wales, two alternative reprocessing technologies are being implemented to recover energy from organic garden wastes-a bioconversion plant in Port Stephens Council and a gasification facility for Wollongong City Council. The former will also coprocess sewage sludge (Chapman 1999) in addition to garden wastes.

Environmental labelling approach to waste minimisation

Environmental labelling is one approach that may lessen the environmental impact of waste generation and disposal. There are more than 20 countries worldwide with environmental labelling programs. These include the Blue Eco-Angel program in Germany, Green Label in Singapore and EcoLabel in the UK. The German Blue Eco-Angel program provides an 'EcoMark' label for over 4000 products and has been running for over 20 years (Blue Eco-Angel 2000).

Environmental labelling may be provided in different ways:

Since there may be variations in labelling criterion employed in different countries, there have been concerns that environmental labelling can be used as a trade barrier (ASEAN 2000). These barriers may be relevant for international trade or interstate trade. The release of the ISO 14021 standard on environmental labelling is designed to provide generic guidelines on methods to evaluate and verify self-declared environmental claims.