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OK! Visual representation of the 10-level FSC and the 4-level FSC, as well as the mass flows of food (F) and losses (L) that can be included in the models developed in this study. Credit: Environmental Research Letters (2024). DOI: 10.1088/1748-9326/ad4c7b
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Visual representation of the 10-level FSC and the 4-level FSC, as well as the mass flows of food (F) and losses (L) that can be included in the models developed in this study. Credit: Environmental Research Letters (2024). DOI: 10.1088/1748-9326/ad4c7b
According to the Food and Agriculture Organization of the United Nations, roughly one-third of the food produced in the world is wasted each year, leaving around 800 million people suffering from hunger.
A new study from the University of Michigan suggests that fully refrigerating the global food supply chain could reduce food waste by nearly half – about 620 million tons.
At the same time, a fully refrigerated supply chain, or “cold chain,” could reduce climate-warming greenhouse gas emissions associated with food waste by 41% globally, according to a study published in Environmental Research Letters.
Sub-Saharan Africa and South and Southeast Asia have the greatest potential to reduce both food waste and associated emissions through greater adoption of the cold chain, according to the study.
In South and Southeast Asia, food waste could be reduced by 45% and associated emissions by 54% under an optimized refrigeration scenario. In sub-Saharan Africa, the study found that both food waste (47%) and emissions (66%) could be significantly reduced under optimized refrigeration conditions.
And developing a more localized and less industrialized farm-to-table food supply chain could deliver food savings comparable to an optimized cold chain, the study said.
“We were surprised by the amount of potential we have to reduce food loss and waste on a global scale,” said Aaron Friedman Hyman, a master's student at the University of Michigan's School of Environment and Sustainability and Ross School of Business and lead author of the study. “Of the roughly 1.3 billion tons of food wasted each year, roughly half could be addressed by optimizing the food supply chain.”
The other author is Shelley Miller, a professor in the University of Michigan's School of Environment and Sustainability and School of Engineering.
Food waste is estimated to account for about 8 percent of man-made greenhouse gas emissions, and UM's new study focuses on food loss from the post-harvest to retail stage of the food supply chain, not on-farm or at-home losses.
The study looks at greenhouse gas emissions produced during food production — it doesn't include emissions associated with refrigeration and other supply chain operations, or from food waste in landfills.
As a result of our investigation, we found the following:
The biggest opportunity to improve food waste in less industrialized economies is the supply chain between farms and consumers. But in North America, Europe, and other more industrialized regions, the majority of food waste occurs at the household level, so cold chain improvements would not have a significant impact on overall food waste. The UM study reinforces previous research by highlighting the importance of meat-related food waste. Although fruit and vegetable waste is very high globally by weight, climate-related emissions associated with meat waste are consistently higher than any other food type, primarily due to the high greenhouse gas intensity of meat production. Unlike previous studies on this topic, the UM researchers compared the benefits of a globalized, technologically advanced food supply chain to the benefits of a localized farm-to-table food system. “Hyperlocalized food systems waste less food than optimized global refrigerated supply chains,” says Friedman Hyman. “These results help quantify the value of maintaining and supporting local food chains.”
For the study, the researchers built a food loss estimation tool to assess how improved access to the cold chain would affect food loss and associated greenhouse gas emissions for seven food types in seven regions. They used data from the Food and Agriculture Organization of the United Nations and other sources.
By modeling food loss at each stage of the supply chain, the study identifies where the cold chain can be optimized to reduce food loss and emissions. The researchers analyzed the impact of moving from the current state of cold chains, which are inconsistent and of variable quality around the world, to an optimized system, defined as one with high-quality refrigeration at all stages.
The study estimates that poor cold chain infrastructure causes up to 620 million tons of food loss annually worldwide, resulting in 1.8 billion tons of carbon dioxide equivalent emissions – the equivalent of 28% of annual U.S. greenhouse gas emissions.
The researchers say their adaptable and easy-to-use tool will be useful to everyone involved in the food supply chain, including farmers, grocery retailers, government officials and non-governmental organizations.
“Cold chain infrastructure is expanding rapidly around the world, but optimized cold chains will likely develop at different rates and in different ways around the world,” Miller said. “This analysis shows that while increased refrigeration should improve both food waste and associated greenhouse gas emissions, there are important trade-offs in cold chain improvements for different food types and regions.”
She said investment decisions need to be prioritized to maximize desired outcomes and impacts: for example, if an NGO’s top priority is eradicating hunger, then that objective may best be met by cold chain upgrades that maximize overall food waste reduction.
However, organizations that prioritize climate action may choose to focus on reducing meat loss specifically, rather than food loss overall.
The study found that meat accounts for less than 10% of global food waste by weight, but more than 50% of greenhouse gas emissions associated with food waste. Optimizing meat refrigeration could reduce emissions associated with meat waste by more than 43%, the study found.
The researchers stress that climate emissions associated with refrigeration can be substantial, so the actual greenhouse gas emissions reductions will depend on the efficiency of the cold chain technology and the carbon intensity of the local power grid.
Further information: Aaron Friedman-Heiman et al., “The impact of refrigeration on food waste and associated greenhouse gas emissions throughout the supply chain.” Environmental Research Letters (2024). DOI: 10.1088/1748-9326/ad4c7b
Journal information: Environmental Research Letters
