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TOWARDS SUSTAINABLE CONSUMPTION: ASSESSING THE ENVIRONMENTAL IMPACTS OF FOOD CONSUMPTION AND THE EFFECTIVENESS OF ECOLABELS
Promoting sustainable consumption is critical to meet the United Nation’s Sustainable Development Goals. Food systems can cause considerable environmental impacts, which are exacerbated by the rapidly increasing global population and urbanization. Policy makers are seeking strategies to promote sustainable food consumption to reduce food-related environmental footprints. However, literature assessing environmental implications of food consumption has several gaps: first, studies using national average diets or one-day dietary recall data are likely to neglect the heterogeneous food purchasing patterns in different households and over longer time spans; second, few studies have considered reducing the overall food-emissions-water-land (FEWL) impacts and the FEWL impact reduction potentials have not been fully examined due to lack of considering changing consumption patterns of food items within food groups. Additionally, knowing the environmental impacts of food consumption is only the first step towards sustainable consumption. Providing the information to consumers to guide their decision making is also critical. Ecolabels are increasingly used to inform consumers about the environmental performance of products. However, the effectiveness of ecolabels is unclear because methods used in existing studies may not show consumers’ naturalistic behavior.
This dissertation aims to address these research gaps to provide better understanding of the reduction potentials and trade-offs of food environmental impacts, and the effectiveness of ecolabels to facilitate consumer decision making for sustainable consumption. To achieve the objective, a variety of models and methods are used: (1) detailed food purchasing records from 57,578 U.S. households were analyzed and a process-based life cycle assessment (LCA) model is developed to evaluate the food carbon emissions and identify reduction pathways; (2) the LCA model was then expanded to also quantify food-related blue water footprint and land footprint. The FEWL impact reduction potentials were evaluated in two dietary change scenarios: (a) only adjusting intake in each food group to the recommended amount and (b) in addition to adjusting food group intake amount, changing consumption patterns to shift towards the food item that minimizes the overall FEWL impacts within each group). A food-item level analysis was also conducted to examine the FEWL impact trade-offs associated with food item substitutions; and (3) survey and attention data were collected from 156 participants in a naturalistic shopping environment using eye tracking glasses to evaluate the effectiveness of ecolabels on informing consumers’ product selection for sustainable consumption.
By assessing the environmental impacts of food consumption and the effectiveness of ecolabels, this dissertation proposed pathways to reduce food-related environmental impacts (i.e., through identifying target households and food groups for impact reduction) and strategies to improve ecolabels’ effectiveness in consumers’ decision making. The results can provide insights to policy makers to promote sustainable consumption.