Advancing Sustainable Practices in Food Systems: A Life Cycle Assessment Approach to Investigate the Nexus between the Environmental Impacts of Food Waste, Energy, Water, and Carbon Emissions

推進糧食系統的可持續實踐:基於生命週期評估方法的“食物浪費-能源-水-碳排放” 紐帶關係研究

Student thesis: Doctoral Thesis

View graph of relations

Related Research Unit(s)

Detail(s)

Awarding Institution
Supervisors/Advisors
Award date19 Sept 2024

Abstract

Food systems generate significant environmental impacts along their supply chain stages. Researchers must analyze the impacts associated with the supply chain stages holistically to attain sustainable food systems. Based on the three projects conducted, this thesis presents the life cycle assessment of food systems, focusing on food waste, energy, water, and emission along the food production, harvesting, post-harvesting, packaging, transportation, and food preparation and consumption stages.

The first project explores the environmental impacts of two Chinese menus at the Hotel ICON in Hong Kong using the life cycle assessment (LCA) method. The analysis investigated the carbon, energy, and water nexus footprints of the full-course meal, composed of starters, soups, main courses, and desserts. A comprehensive menu-level analysis examined the impacts of meal items in each meal category (starter, soup, main course, and dessert) and the influence of the food type (beef, pork, seafood, vegetarian) and cooking methods (barbecuing, braising, steaming, frying) to the environmental impacts. The findings indicate that the interplay between meal components, food types, and cooking methods significantly impacts the overall environmental footprint. For instance, steamed seafood dishes had a similar impact to stir-fried red meat meals. Conducting life cycle analysis at the menu level can inform sustainable menu design by identifying ingredients and cooking techniques to prioritize for reduction.

In the second project, the life cycle analysis expanded the nexus to address the food waste-energy-water-emission (FEWE) of ingredients sourcing and preparation of a meal item, for this case, pasta. The project investigates and compares the environmental impacts of locally prepared pasta in Hong Kong versus imported ready-to-eat. The analysis guides informed decision-making on sustainable sourcing of ingredients, meal preparation, and consumption in the food service sector. The results indicated that preparing pasta meals locally in Hong Kong has better environmental performance than importing ready-to-eat meals; thus, nexus analysis through LCA guides the informed decision, leading to resource optimization.

The third project investigates if advancing technology use over conventional ones promotes sustainable agriculture production. The study compares the life cycle environmental impacts of spraying ripeners on sugarcane farms using drones or cropdusters. The study found that drones have more significant potential for minimizing impacts, especially if integrated with another technology, such as converting food waste like bagasse into bioenergy, which can charge the drone batteries, optimizing the resources. Thus, LCA enables decision-making regarding selecting a technology that enhances sustainable agriculture.

Generally, this thesis offers valuable insights and advocacy for promoting a more sustainable and resilient food system in the face of growing global challenges by analyzing the associated complexities and trade-offs and integrating emerging technologies.