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Changes in Energy Use and Water Stress Caused by the Emergence of the Cold Chain


A critical yet unexplored dimension of the food-energy-water nexus is the expansion of the "cold chain" into developing countries. The cold chain is defined as access to climate-controlled environments (i.e. refrigeration) throughout the entire food supply chain. There is not a good understanding of how adoption of the cold chain in emerging economies will affect food consumption patterns, energy use, or water stress. This research will examine the influence of the cold chain on the life cycle impacts of meat, dairy, and produce in the context of the Chinese food system. The hypothesis driving this work is that the introduction of a fully-integrated cold chain will lead to significant increases in global energy use and water stress without achieving substantial decreases in food waste. In addition to testing this hypothesis, the research will seek to identify potential technical or policy interventions that are likely to reduce the anticipated energy and water impacts of an expanded cold chain.

First, the project team will construct a system dynamics model that quantifies baseline greenhouse gas (GHG) emissions, energy use, and water stress of the interlinked food, energy, and water systems when refrigeration is not present. Second, elements of the cold chain related to physical system properties will be integrated into the model, including extended shelf life of food, direct energy required for refrigeration, GHG emissions from coolants, changes in transportation modes and distances, and changes to infrastructure such as refrigerated warehouses and modern grocery stores. Third, elements of the cold chain related to behavior and consumption will be integrated into the model, including shifts in consumption to more water and energy intensive foods, increased bulk purchasing (and subsequent waste generation) due to household refrigeration, and a shift in demand for convenience foods such as prepared and frozen meals. The system dynamics model will be integrated with an economic input-output model to determine the spatial extent of water consumption to quantify water stress. Finally, a variety of scenarios will be tested to determine how interventions or alternative development scenarios will affect system dynamics. In particular, a case study will be constructed to quantify the life cycle energy and water use of a direct-to-consumer meal kit compared with the same meal purchased from a brick-and-mortar supermarket. Direct-to-consumer food systems have the potential to leapfrog traditional supermarkets in emerging economies and may significantly reduce energy use due streamlined logistics and also reduce food waste, lowering overall energy and water use associated with an expanded cold chain. The work will advance sustainable systems modeling capabilities by coupling multiple modeling techniques and integrating socio-economic factors into analysis of emerging technologies. Due to the emerging nature of the cold chain, the research will also advance methods in prospective LCA, using scenario analysis to determine potential interventions that have the greatest potential to mitigate undesirable consequences. The project will work directly with relevant cold chain industries to help improve the sustainability of the food supply chain. Outreach activities will be coordinated through established industry partnerships to share the results of the work. The PI is part of a larger effort to redesign sustainability-related curriculum through integration of case-based learning in sustainability education, where each case tells a story that presents a real-world problem with a challenging decision. The cold chain will be the basis of a new Michigan Sustainability Case and integrated into course modules.

National Science Foundation (NSF)
Research Areas
Food & Agriculture