APPENDICES
133G3 Complexities of measuring the sustainability of the food supply
Historically, dietary guidance has been based on experimental evidence from nutritional science and epidemiology,
with sustainability often referred to in the context of ‘triple bottom line’ considerations of economic, social and
environmental factors.^1058 understanding the environmental implications of food choices involves considering
new, often non-empirical evidence drawn from assessment of the relationship between the food system, food
choices and environmental outcomes. This requires evidence from research in environmental science, agricultural
science and economics. Government reports are also useful, especially in areas with policy implications, such as
carbon accounting.
The food system comprises many stages from inputs on-farm to waste management following consumer use.
As shown in Figure G1, these include agriculture and aquaculture, processing, manufacturing, transport, retail,
preparation, consumption and waste management. The complexity of the system challenges the development
of standardised methodologies for measuring the environmental consequences of producing particular foods.^1060
As well, some current analyses do not consider the process through to the consumer and the subsequent
disposal of waste.
The environmental consequences of food production depend on the agricultural system used and the particular
environmental aspect examined, as these differ in impact, with implications for yield, quality and affordability.^1042
Given this, the consequences cannot be assessed solely on a commodity basis but are dependent on where
and how the product is grown. For example, it is estimated that in NSW, the amount of water used in beef cattle
production ranges broadly from 3.3 l to 221 l H2Oe kg−1 live weight at farm gate.^1061 As well, it is important
to ensure that focussing on one outcome (e.g. emissions) does not have an unfavourable effect on another
(e.g. soil degradation) and consequently add further pressure to the food system.
New technologies will play an important role in developing sustainable food systems, but the extent depends
on consumer acceptance and economic constraints.^1040 There is a need for more Australian data on many
components of the food system and further research and development is required.
Two methodologies – process life cycle analysis (Process-lCA) and input-output analysis – are increasingly
used to critically analyse the environmental impact of various components of the food system:
• Process-lCA considers the environmental impact of all processes involved in bringing a product to the
consumer, including the way it is used and the impact of disposing packaging and waste. lCA methodologies
are highly standardised, however the complexity of analysing sustainability at the food supply level means that
many different questions are asked and models used which can limit meaningful comparisons.^1060 Additionally,
to obtain an overall perspective, the same process must be completed across the entire life cycle. lCA
methodologies are complex, time consuming and expensive, which inhibits their use for data collection.
• Input-output modelling is a useful tool for assessing the environmental impact of consumption. It was originally
developed for economic analysis, but has been applied to environmental analysis since the late 1960s.
It can be used to assess environmental indicators such as land disturbance, water and energy use, and total
indicator intensities (the total amount of an indicator required to produce and deliver a value unit of a particular
commodity).^1062 This can be used in decision making to predict and forecast the impact of future performance
of an economy and the effect of changes to relevant systems.
In developing an evidence-base for sustainable food choices, different methodological approaches limit the
comparability of findings. For example, scope and definitions vary according to the stage of the food system being
considered. Some studies incorporate the environmental impact of manufacturing on-farm machinery and the
production of all other on-farm inputs such as fertiliser, while others include only fertiliser production. Much of the
environmental impact evidence for specific foods is based on primary production and on-farm effects, with less
information on aspects of the food supply chain such as processing, distribution, retail, consumption and waste
management. However, the environmental impact of the life cycle of a particular food cannot be considered only as
a characteristic of the food, but of all the specific and local aspects of its production, movement, storage, preparation
and ultimate fate.
While overseas studies are not always generalisable to the Australian context, the body of Australian evidence
is steadily growing, and the interest in this field may serve to stimulate more research. Despite the above
challenges, enough evidence exists to suggest pragmatic guiding principles on how dietary patterns and home
practices can contribute to reducing the environmental consequences of the food system.