Roughly one-third of food produced for human consumption, about 1.3 billion tonnes per year, gets lost or wasted globally—the equivalent of 6 to 10 percent of human-generated greenhouse gas emissions.

Gustavsson et al., 2011; Vermeulen et al., 2012 for the calculation on emissions

Neil Palmer, CIAT

Extra facts

  • Per-capita consumer waste is estimated to be 95 to 115 kilograms per year for Europe and North America, but only 6 to 11 kilograms per year in Sub-Saharan Africa and South Asia (Gustavsson et al. 2011).
  • Food waste is a huge problem globally, but the underlying reasons differ between regions.
    • Food waste in high-income countries is dominated by consumer waste.
    • Developing countries have high losses at the post-harvest and processing stages due to spoilage. Factors leading to spoilage include lack of modern transport and storage infrastructure, as well as financial, managerial and technical limitations in difficult climatic conditions (Venkat 2011; Gustavsson et al. 2011).
  • The total avoidable food waste in the United States is 55.41 million tonnes per year for 2009, which amounts to 28.7 percent of total annual production by weight (Venkat 2011).
  • Using 2011 retail prices, the avoidable food waste in the United States (for the year 2009) has a total retail value of 197.7 billion USD. Consumer waste alone amounts to 124.1 billion USD, or nearly 63 percent of the total retail value of wasted food (Venkat 2011).
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Methods, caveats and issues

Assumptions

  • Venkat (2011: 437) estimates that the total avoidable food waste in the United States is 55.41 million metric tonnes per year for 2009, which amounts to 28.7 percent of total annual production by weight. This translates to 180 kilograms per year of total avoidable waste on a per-capita basis. This is less than the 280 to 300 kilograms per year for Europe and North America reported by Gustavsson et al. (2011) because it excludes both production losses and unavoidable consumer waste.
  • Consumer waste dominates the total waste, accounting for just over 60 percent of the total avoidable waste. Per-capita consumer waste is 110 kilograms per year, which is within the 95 to 115 kilograms per year range estimated for Europe and North America by Gustavsson et al. (2011).
  • When calculating financial losses, Venkat uses current United States retail prices for all the food commodities.
  • Disposal cost is excluded from the calculation of the economic impact of food waste.

Methods and definitions

  • From Gustavsson (2011):
    • The total amount of food is calculated using the following formula: A+B+C-D=E-(F+G+H+I) = J=K+L, where A = production, B = imports, C = stock variation, D = exports, E = domestic supplies, F = feed, G = seed, H = processing, I = waste, J = food, K = fresh food and L = processed food.
    • The different commodities addressed are grouped according to FAOSTAT’s Food Balance Sheets. (Available from http://www.fao.org/corp/statistics/en/). Estimated/assumed waste percentages for each commodity group in each step of the food system chain for each world region are accounted for. These can be found in the appendices to the report by Gustavsson et al. (2011). Conversion factors determine the part of the agricultural product that is edible. Allocation factors determine the part of the agricultural produce that is allocated for human consumption. For more info, see Gustavsson et al. (2011: 23pp).
  • From Venkat (2011):
    • Venkat uses a Life-Cycle Food Waste Model based on standards set by the International Organization for Standardization (ISO).
    • Greenhouse gas emissions from agricultural processes and waste disposal are modelled based on the Intergovernmental Panel on Climate Change (IPCC) tier 1 guidelines.
    • The spatial boundary for the Life Cycle Assessment of the food commodities is cradle to grave: starting with the extraction of raw resources from the ground and ending with the disposal of uneaten food.
    • The system boundary includes the production, processing and packaging of food products, transport and storage through typical distribution networks, storage at retail locations and landfilling of waste.
    • Food waste is considered at the distribution, retail and consumer levels for which data exist, but not at the farm or processing level. All energy used at the consumer level – including shopping trips, refrigeration and cooking – is excluded from this analysis because of uncertainties and lack of adequate data. Therefore, Venkat estimates that the total climate change and economic impacts of food waste as calculated in the study represent conservative lower bounds of the actual impacts (Venkat 2011: 435).
    • The avoidable consumer waste represents uneaten food that is wasted at the consumer level. This definition excludes unavoidable waste in consumed foods, such as non-edible parts (skins and shells), as well as fat or moisture losses in cooking. For more information, see Venkat (2011: 433).
  • The GHG emissions attributed to food waste are calculated by dividing by three the total GHG emissions contributed by the food system, which is estimated as 9,800-16,900 MtCO2e/year (Vermeulen et al. 2012).
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Sources

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