The value of eating for health is, for many of us, a paramount choice. Nature is part of the equation, but aligning the two presents a unique challenge in our efforts to curb climate change and the impact of our food choices.
In this article by Ellyn Bicknell and Sara Forbes, we look at the potential to create a synergistic food-footprint through an ecological dietary awareness. Can we have our cake and conservation too?
With almost a third of the global greenhouse gas emissions resulting from the inputs and actions required to sustain the current global food system, shifting the dietary choices we make as eaters really can help to meet the goal of under 1.5C post-industrial warming by 2050 (IPCC)¹.
Australia’s current food system contributes the highest per capita greenhouse gas emissions (GHGe) of all G20 countries². However, this does not provide a complete picture of the impact our food consumption has on the environment, as it only considers one measure and includes producing food for export. To help us better understand the environmental footprint associated with food consumption in Australia and New Zealand (NZ), we embarked on a review of relevant Australian and NZ studies. Our findings provide evidence for the upcoming review of the Australian Dietary Guidelines, which currently only refer to sustainability considerations, unlike the recently updated New Zealand (NZ) Eating and Activity Guidelines for NZ adults.
How was the environmental impact of food consumption measured?
We often hear of GHGe in relation to the human impact on the health of the environment and unsurprisingly across the studies reviewed, we found this was the most common metric used to provide evidence related to the consumption of individual foods, food groups or dietary patterns. Other metrics researchers used included the Ecological Footprint, water footprint, and cropland scarcity footprint. Choosing the most appropriate metric (or combination thereof) is important, as it may under-represent the environmental impact of foods. For example, some tools, like life cycle assessment, do not consider differences in agricultural practices and the use of renewable energy³. Regenerative animal farming methods can have positive environmental impacts, such as integrating livestock into agricultural crops for manure. Comparing findings between Australia and NZ also highlighted the importance of using country/region specific data. Beef and lamb production in NZ has one of the lowest affects worldwide on carbon emissions.
What are the key discoveries of your research?
We found that discretionary foods (i.e. pastries, processed meats and sugar sweetened beverages) are consistently one of two highest contributors to environmental stress across multiple metrics: greenhouse gas emissions (GHGe), cropland footprints, Ecological Footprint, and water scarcity footprint. The meat and alternatives group also had a high environmental impact across multiple metrics, although the water scarcity footprint was lower for this group compared to dairy products, cereals, grains, fruit, and vegetables. Modelling of current food consumption in Australia and New Zealand to those dietary patterns recommended as being optimal for health does not necessarily result in an improvement in all environmental indicators.
What can we do?
We think it is important that we learn which foods and dietary patterns are associated with positive health and environmental outcomes in the country/region we live. Then we can take action to change how we interact with food, such as those outlined in this healthy and sustainable diet-related practices infographic⁴.
¹ Intergovernmental Panel on Climate Change (IPCC). Summary for Policymakers. Climate Change 2021: The Physical Science Basis Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. In press: Cambridge University Press.; 2021.
² Drewnowski, A., et al., Shaping Physical, Economic, and Policy Components of the Food Environment to Create Sustainable Healthy Diets. Food and Nutrition Bulletin. 2020. 41(2_suppl): p. 74S-86S.
³ van der Werf HMG, Knudsen MT, Cederberg C. Towards better representation of organic agriculture in life cycle assessment. Nature Sustainability. 2020;3(6):419-25. doi: 10.1038/s41893-020-0489-6.
⁴ Barbour, L.R., Woods, J.L. and Brimblecombe, J.K. (2021), Translating evidence into policy action: which diet‐related practices are essential to achieve healthy and sustainable food system transformation? Australian and New Zealand Journal of Public Health, 45: 83-84. doi: 10.1111/1753-6405.13050.
Forbes S, Bicknell E, Guilovica L, Wingrove K, Charlton K. A Rapid Review of the Environmental Impacts Associated with Food Consumption in Australia and New Zealand. Curr Nutr Rep. 2021 Oct 8. doi: 10.1007/s13668-021-00374-0.