Food Security Discussion Series
Summary by Dr Jane O'Sullivan

11 Aug 2016
Dr Marguerite Renouf

"Research challenges for informing environmentally sustainable food systems for Australia"

Food systems are the sum of all processes that bring food to our tables. Marguerite’s research interests focus on the exchange of resources between the food system and the environment, to what extent the system’s impacts are unsustainable, and how sustainability may be improved. Life cycle assessment (LCA) methodologies attempt to monitor each step in the process, in relation to whichever impacts are the subject of the research. Through agriculture and its inputs to processing, packaging, refrigeration, transport and consumption behaviours, natural resources are converted into wastes. Different studies may measure different types of impact. For instance, carbon footprinting is a type of LCA which is concerned only with greenhouse gas emissions.  

Much of the past LCA research has been focused on agriculture, but attention is gradually moving up through the supply chain. Research challenges include the complexity and variability of supply chain pathways, and juggling the trade-offs between different environmental values. Greater relevance, but also greater complexity, can be attained by evaluating different diets rather than specific products or production processes. Communicating these complexities in ways that are relevant to consumers or policy-makers is a further challenge: there is rarely a straight answer to the questions they pose.

Past LCA research has quantified the impact of food systems across multiple environmental values, including biodiversity, soil health, water resources, chemical contaminants and greenhouse gas emissions. The scale of impacts across these different realms can be surprising. For instance, while organic agriculture may score well on soil health and water contamination, its lower yields can mean greater land-use and energy (greenhouse gas) impacts than conventional farming. A study comparing the footprint of New Zealand dairy products sold in Europe with domestic European products found that the extra distance added little to the footprint, while much lower impacts of New Zealand agriculture made it the “greenest” option. Likewise, the clearing of vegetation needed to grow biofuels can negate their greenhouse gas advantage over fossil fuels. Processing may add to the footprint of fresh vegetables, but if delivering the fresh vegetables to consumers means long periods of refrigeration, greater waste and potentially greater loss of nutritional value, then the processed product may be the preferred option.

Consumers face a range of other questions, such as how my diet or shopping patterns affect environmental impact, and do pre-prepared foods reduce energy and waste compared with preparing food at home? What about eating out? What about food grown at home? Some home-garden crops might be inefficient compared with commercial production, while others like salad and herbs might avoid nutrient losses and refrigeration energy.  

It had been hoped that LCA investigations might result in clear metrics that could be used on food labels to aid consumer choices. What the research has found is that simple answers are almost never sufficient. Individuals and society as a whole needs to decide how they weight different environmental and social values.

Food is an area of environmental impact where individuals can make a difference through their choices, and many are keen to do so. But giving them robust information on which to base those choices remains a challenge.

Browse summaries from the  Food Security Discussion Series here.

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