Making packaging greener – biodegradable plastics

Box 1 | Life cycle analysis

Life cycle analysis seeks to identify the true environmental impact of a product by considering its environmental effect at every stage of its ‘life cycle’. This includes the impact of extracting the raw materials, processing them into a product, transporting that product, using it and then disposing and/or recycling it. It attempts to quantify all of the material and energy inputs and all of the outputs of a product or process.

Environmental costs

Many environmentalists believe the price we pay for a product should reflect its 'life cycle' cost. Traditional plastic packaging is an example where the environmental cost is not reflected in the price we pay for the product. It is relatively cheap to manufacture and this is reflected in its inexpensive price. But this doesn’t factor in the costs of disposing of the plastic, its impact on wildlife or the large volume of landfill it takes up.

Recycling

Recycling schemes sound good, but are they economic when you take into account the resources consumed in transporting, processing and reworking the material to be recycled? At this stage there are no rigorous environmental studies on plastic that take into account greenhouse gas emissions, air pollution or energy consumption.

Quantitative or qualitative analysis

Life cycle analysis, often referred to as ‘cradle to grave’ analysis, is great in concept, and central to any sound approach in ecodesign. In practise, however, it’s difficult to apply quantitatively because there are no universal standards of comparison and many of the costs are impossible to define precisely. For example, what is the long-term impact of generating more carbon dioxide when we still don’t know the basic mechanics of global climate change.

However, even when applied qualitatively, and acknowledging our imperfect knowledge, life cycle analysis quickly demonstrates that the price we pay for a product often bears no relation to the environmental cost of creating it. Sustainability is all about taking this into consideration.

Related sites
Life cycle analysis and assessment (Global Development Research Center, Japan)
Environment management tools – life cycle assessment (United Nations Environment Programme)

External sites are not endorsed by the Australian Academy of Science.
Posted February 2002.