Abstract
Global greenhouse gas (GHG) emissions from food loss and waste (FLW) are not well characterized from cradle to grave. Here GHG emissions due to FLW in supply chain and waste management systems are quantified, followed by an assessment of the GHG emission reductions that could be achieved by policy and technological interventions. Global FLW emitted 9.3 Gt of CO2 equivalent from the supply chain and waste management systems in 2017, which accounted for about half of the global annual GHG emissions from the whole food system. The sources of FLW emissions are widely distributed across nine post-farming stages and vary according to country, region and food category. Income level, technology availability and prevailing dietary pattern also affect the country and regional FLW emissions. Halving FLW generation, halving meat consumption and enhancing FLW management technologies are the strategies we assess for FLW emission reductions. The region-specific and food-category-specific outcomes and the trade-off in emission reductions between supply chain and waste management are elucidated. These insights may help decision makers localize and optimize intervention strategies for sustainable FLW management.
Generated Summary
This research article, published in Nature Food, presents a comprehensive analysis of greenhouse gas (GHG) emissions from food loss and waste (FLW) across the global food system. The study quantifies emissions from cradle-to-grave, encompassing supply chain and waste management systems, to assess the potential for emission reductions through policy and technological interventions. The methodology involves constructing a material balance model for FLW with country-level and regional details, estimating GHG emissions across different supply chain activities and waste management stages. The research identifies key areas for emission reduction, specifically in post-farming and waste management stages. The study also examines emission reductions under various policy and technological interventions, considering socio-economic factors such as income level, diet, and technology availability. This approach allows for a detailed examination of regional variations and the impacts of different strategies.
Key Findings & Statistics
- The global food system generated 18.6 ± 12.6 Gt of CO₂ equivalent (GtCO₂e) GHGs in 2017.
- Meat and animal products led to the highest GHG emissions (11.53 ± 8.12 GtCO₂e), followed by cereals, pulses, and others (5.76 ± 3.49 GtCO₂e).
- Roots and oil crops (0.80 ± 0.70 GtCO₂e) and vegetables and fruits (0.47 ± 0.36 GtCO₂e) accounted for only 6.8% of the GHG emissions from the entire food sector.
- Supply-embodied FLW GHG emissions (FLWCS) were approximately 6.45 ± 4.82 GtCO₂e in 2017.
- The GHG emissions from FLW management (∑FLWCT) were 2.84 ± 1.03 GtCO₂e.
- Supply-embodied FLW GHG emissions and waste-management-related GHG emissions sum up to reach half of the total GHG emissions from the global food system.
- China, India, the United States, and Brazil generate 44.3% of the global supply-embodied GHG emissions and 38.0% of the global waste-management-related GHG emissions.
- The FLW logistic GHG emissions were calculated by summing the average energy consumption of all the logistic activities related to FLW incurred in the eight post-farming stages from harvest to retail and amounted to 2.65 ± 1.81 GtCO₂e.
- The global FLW at the consumer stage contributes to 35.5% of the total supply-embodied FLW GHG emissions.
- Meat and animal products dominate with 56.9% of the food logistic emissions, while vegetables and fruits generate only 4.2% (Supplementary Fig. 5e).
- The energy consumed in processing bovine and lamb meat (1.4 kg CO₂e kg⁻¹) generates 13 times more GHG emissions than processing tomatoes (0.1 kg CO₂e kg⁻¹) (Supplementary Table 1).
- Halving FLW generation will achieve an annual reduction of 3.23 GtCO₂e in supply-embodied emissions.
- Halving meat consumption will result in less reduction of the supply-embodied emissions (2.13 GtCO₂e).
- Halving meat consumption will result in an emission reduction of 4.27 GtCO₂e from the global food system.
- EA + SEA, where the staple food is cereals, will maximize the emission reduction after halving FLW generation, accounting for 33.4% of the global reduction.
- Regions with higher meat preference (mainly EU + NAM + OC) will dominate the FLW GHG emission reductions after halving meat consumption, accounting for 38.4% of the global reduction.
- If halving meat consumption and halving FLW generation are achieved together, the reduction will be 42.8% of the global GHG emissions.
- Enhancing FLW management technology with 50% AD or 50% COM supplementing LFD will lead to 13.7% or 14.8% emission reductions.
Other Important Findings
- The global food system accounts for a substantial portion of global anthropogenic greenhouse gas emissions, with a significant amount originating from food loss and waste (FLW).
- FLW emissions are not well-characterized from cradle to grave, and this study aims to address this gap.
- Income level, technology availability, and prevailing dietary patterns influence FLW emissions.
- Halving FLW generation, halving meat consumption, and enhancing FLW management technologies are assessed for FLW emission reductions.
- Regional differences in farming, processing, distribution, dietary patterns, and consumer behavior significantly impact FLW generation.
- Food logistic activities generate GHG emissions and affect food loss and wastage, leading to additional FLW GHG emissions.
- Consumer-stage FLW contributes significantly to supply-embodied FLW GHG emissions.
- Waste management technologies are crucial for managing waste-related emissions.
- The study highlights the importance of considering differences between food categories when managing GHG emissions.
- Dietary patterns and regional variations significantly influence FLW GHG emissions.
- Technological advancements, particularly in logistics and waste management, can play a key role in reducing emissions.
- The study underscores the need for localized intervention strategies tailored to specific regions and food categories.
Limitations Noted in the Document
- The study acknowledges that the GHG emission per unit weight of each food commodity carries uncertainty due to regional system boundaries, socio-economic status, and agro-environmental characteristics.
- The analysis relies on the best-estimated values from the literature, assuming normal distributions for GHG emissions.
- The interventions assessed do not account for all potential changes, such as potential decreases in food production due to less FLW generation or the increase in infrastructure investments due to technological advancements.
- The study’s findings are based on data from FAOSTAT and other sources, which may have inherent limitations.
- The study does not address the complexities of combined interventions fully, which may lead to potential synergies or antagonisms.
- The analysis is limited by the availability of data, particularly regarding waste management practices across different regions.
- The study did not consider the potential changes in food production and infrastructure investments due to the interventions assessed.
Conclusion
The study emphasizes that food loss and waste (FLW) generates a significant portion of greenhouse gas (GHG) emissions, with meat and animal products contributing the most. The research underscores the importance of reducing FLW through various interventions, including halving FLW generation and meat consumption, and improving waste management technologies. The findings reveal that different regions and food categories have varying contributions to emissions, necessitating tailored strategies. The study highlights the potential of technological advancements in logistics and waste management, such as the adoption of AD and COM. The research suggests that reducing meat consumption could significantly lower GHG emissions, with the impacts varying across regions. The study points to the need for a balanced approach, combining technological improvements with changes in dietary patterns to achieve effective emission reductions. The importance of regional and time-sensitive interventions is stressed, along with a call for integrated strategies that consider the trade-offs between different interventions. In conclusion, this study strongly suggests that reducing FLW and meat consumption will lower emissions and that further studies could be done to refine existing methods of assessment. Ultimately, the effective management of the food system requires a localized approach to reduce the global impact of FLW and its impact on GHG emissions. Furthermore, the findings advocate for a holistic strategy that combines various interventions to reduce FLW and related emissions effectively. Further study is recommended to refine strategies and implementation methods on a global scale, and to implement the local variations needed for effective implementation.