Abstract
Food waste is a major problem in modern society and carries considerable social, economic and environmental costs. Food production causes greenhouse gas emissions along the entire food supply chain and wasting food means that those emissions are produced in vain. There is consensus that food waste has to be reduced. For example, the EU and some of its member countries have set concrete targets to reduce the amount of waste. However, in order to achieve the overall goal of a more sustainable economy, not only quantitative but also environmental indicators have to be considered when pursuing waste reduction goals. This study analysed the discrepancies between the waste quantity and wastage carbon footprint (CF) profiles of perishable food products wasted in Swedish supermarkets. The wastage CF, defined as the product CF from cradle up to and including delivery to the retailer times the amount of the product wasted at the store, was calculated for products in the meat, deli, cheese, dairy and fruit & vegetable departments of six Swedish supermarkets. The CF from cradle to retailer of the various products was determined based on existing life cycle assessment (LCA) literature. Emissions due to production and transportation were considered. Data on wasted mass of the products in the period 2010–2012 was provided by the Swedish retail chain Willys. Data on bread waste are mainly held by the bakeries, and were thus not included in the study. Over a three-year period, 1570 t of fresh food (excluding bread) were wasted in the six supermarkets. The associated total wastage CF was 2500 t CO2e. The fruit & vegetable department contributed 85% of the wasted mass and 46% of the total wastage CF. The meat department contributed 3.5% of the wasted mass, while it accounted for 29% of the total wastage CF. The wastage CF of each department tended to be highly concentrated in certain products and thus halving the waste of the top three products in each department could save more than 25 t CO₂e per store and year. © 2014 Elsevier B.V. All rights reserved.
Generated Summary
This research investigates the carbon footprint (CF) of food waste in Swedish supermarkets, focusing on the discrepancies between waste quantity and its environmental impact. The study adopts a life cycle assessment (LCA) approach, calculating the wastage CF for various food products in different departments (meat, deli, cheese, dairy, and fruit & vegetable) across six supermarkets. The methodology involves determining the CF from cradle to retailer based on existing literature and combining this with data on wasted mass from the Swedish retail chain Willys. The research aims to identify hotspots by determining the products and supermarket departments that have the most environmental impact and quantifying the differences between mass and CF profiles of food waste. The study’s scope includes pre-store and in-store waste, providing a comprehensive analysis of the environmental impact of food waste at the retail level. The CF is expressed in terms of carbon dioxide equivalent (CO₂e), considering emissions from production and transportation up to the retailer.
Key Findings & Statistics
- Over a three-year period (2010-2012), a total of 1570 t of perishable food (excluding bread) were wasted in the six supermarkets.
- The total wastage CF for this period was 2500 t CO2e, which translates to 140 t CO2e per store per year.
- The fruit & vegetable department accounted for 85% of the wasted mass and 46% of the total wastage CF.
- The meat department contributed 3.5% of the wasted mass but was responsible for 29% of the total wastage CF.
- The dairy and cheese departments each contributed about 6% to the total wastage CF.
- The total wastage CF of the meat department was 720 t CO2e, or 40 t CO2e per year per store.
- Beef products had a high wastage CF, with beef minced meat contributing 19% of the meat department’s wastage CF. All beef products combined accounted for over 70% of the total CF of wasted meat.
- Poultry had the lowest wastage CF in the meat department, accounting for about 3.5% of the department’s wastage CF.
- The dairy department wasted 100 t of products, with a total CF of 140 t CO2e, or 8 t CO2e per year per store. Cream contributed 15% of the department’s wastage CF.
- In the cheese department, 17 t of cheese were wasted, with a total wastage CF of 150 t CO2e, or 8 t CO2e per store per year. Semi-hard/hard cheese accounted for about 63% of the wastage emissions. Herrgård, Gouda, and Brie cheese had the highest wastage CF.
- The fruit & vegetable department wasted 1340 t, with a total wastage CF of 1140 t CO2e, or 60 t CO2e per store per year. Tomatoes, peppers, and bananas accounted for 47% of the department’s wastage CF.
- The CF of the food wasted in one store during one year (140 t CO2e yr−1 store−1) corresponds to the CF of driving a fully loaded (15 t) heavy truck 71,000 km.
- The top three products in each department (deli, cheese, and dairy) contribute a significant portion of the emissions.
Other Important Findings
- The study highlights a significant difference between the distribution of wasted mass and wastage CF across different departments.
- The wastage CF is highly concentrated in specific products within each department.
- The wastage CF of meat products is primarily due to beef.
- The CF of the food wasted in one store during one year (140 t CO2e yr−1 store−1) corresponds to the CF of driving a fully loaded (15 t) heavy truck 71,000 km.
- Measures to reduce food waste should focus on products with a high wastage CF.
- Prioritizing products with a high wastage CF can provide a way to reduce the climate impact of food waste most efficiently. Halving the food waste of just the top three products in each department could save more than 25 t of CO2e per year per store.
Limitations Noted in the Document
- The study is limited to six supermarkets within the Uppsala-Stockholm region, potentially not fully representing the broader Swedish retail landscape.
- The CF values used in the study are based on existing LCA literature, which may vary in scope, methodology, and data availability.
- The CF of deli products was estimated based on assumptions of meat content and energy requirements, which could introduce uncertainties.
- The study did not include emissions from store operations or packaging.
- The study acknowledges uncertainties inherent in LCA studies, including variations in system boundaries, functional units, and emission factors.
- The study primarily focused on GHG emissions, and did not address other environmental impacts such as resource use, toxic effects, or biodiversity.
- The study’s reliance on data from a single retail chain (Willys) and the exclusion of certain waste streams (e.g., bread) could limit the generalizability of the findings.
- The accuracy of data for unpacked products and the estimated mass assigned to products with broken EAN codes introduce further uncertainty.
Conclusion
The research underscores the significant environmental impact of food waste in supermarkets, emphasizing the importance of considering not only the quantity of waste but also its carbon footprint. The study’s findings reveal substantial discrepancies between the distribution of wasted mass and wastage CF across different departments. While the fruit & vegetable department contributes the most to the wasted mass, the meat department, particularly beef products, has a disproportionately high wastage CF. The study highlights that focusing on products with both high waste quantities and high specific CFs is crucial for effective waste reduction strategies. The research points out the potential for reducing the climate impact by targeting the most impactful products within each department. For example, halving the waste of the top three products in each department could lead to significant environmental benefits. The study emphasizes that measures should consider avoiding simply shifting the waste to other actors and highlights the economic feasibility of addressing waste, especially for high-value animal products. The results highlight the need for a nuanced approach to waste reduction that considers both mass and environmental impact, thereby paving the way for more sustainable practices in the retail sector. The study’s findings suggest that reducing wastage is essential for the climate, equivalent to a truck driving around the Earth. This study provides insights into the discrepancies between wasted mass and wastage CF to identify priority targets in order to establish efficient waste reduction measures.