Assessing the Sustainability Implications of Expansions and Innovations in Refrigerated Food Supply Chains

Abstract

Refrigeration transforms food systems. The global integrated refrigerated supply chain, or “cold chain,” impacts numerous sustainability outcomes, from energy consumption and greenhouse gas (GHG) emissions, to consumer diets and producer behavior. This dissertation seeks to understand refrigeration’s systems-level sustainability implications: first, how this technology influences environmental outcomes and human behavior, but also how adoption and use patterns feed back into how this technology impacts its users and the broader environment.

This dissertation begins by building an understanding of the current cold chain’s influence on sustainability. Chapter 2 reviews the existing literature on refrigeration, finding the cold chain remarkably understudied in the sustainability literature. One key environmental tension identified is the trade-off between GHG emissions added from cold chain operation, and the cold chain’s ability to decrease food loss. Chapter 3 compares changes in pre-retail GHG emissions from cold chain operation and food loss rate changes when introducing a refrigerated supply chain into the Sub-Saharan African food system. This study finds cold chain introduction resulting in a net GHG increase of 10% in a scenario reflecting a North American development scenario and 2% in a European development scenario. This analysis also models refrigeration’s influence on food demand and agricultural production: finding an increase of 10% over the baseline when modeling a North American diet, or a 15% reduction with a European diet. Given the substantial influence diet has on food system sustainability, Chapter 4 explores the particular role that refrigeration plays in consumer diet. This study moves beyond Chapter 3’s assumption of convergence to Western diets in development, using data from the Vietnam Household Living Standards Survey and a regression model to isolate the effects of refrigeration from socio-economic variables. In this case study, household refrigerator ownership is statistically significantly associated with lower consumption of starchy staple foods, nuts and seeds, and pulses; and higher consumption of meat and dairy.

Having investigated how refrigeration currently influences emissions and diet, this dissertation’s final chapters examine improvements and innovations in refrigerated supply chains. Motivated by a Chapter 3 finding that the cold chain adds more pre-retail emissions than it saves through food loss reduction, Chapter 5 assesses interventions to decrease cold chain emissions. This study builds a more-refined, process-based cold chain model, reflecting a fully-developed refrigerated food supply chain. The largest decreases result from decarbonized electricity, improved supermarket refrigeration systems, or reductions in pre-consumer food loss. The largest emissions reduction from a single intervention is 1.20 kg CO2e/kg (39%) for frozen fish supplied from using decarbonized electricity, and the largest from a tested combination is 1.61 kg CO2e/kg frozen fish from combining decarbonized electricity with a CO2NH3 supermarket refrigeration system. The final chapter assesses the environmental improvements offered by an innovation in the cold chain: meal kit services. Meal kits are pre-portioned ingredients delivered to consumers, circumventing brick-and-mortar retailing. This study finds average grocery store meal GHG emissions exceeding those for an equivalent meal kit by 33%. Reductions in food waste emissions are found to exceed emissions missions added through extra packaging, and that direct-to-consumer delivery provides additional emissions reductions.

This dissertation examines several key sustainability implications of cold chain expansion and innovation. The complex interactions between cold chain technology and consumer behavior underscores the need to take a systems perspective when examining sustainability outcomes from future food supply chain developments.