5.6.1 Food waste is a global problem
Approximately 1/3 of the food produced globally is not eaten
Globally around 1/3rd of the food we produce is not eaten. Put into context, if food production requirements are to nearly double by 2050, then wasting a third of our existing food output is a luxury we can ill afford.
Food waste and losses contribute to GHG emissions both directly and indirectly. Direct emissions are in the form of methane and are generated when organic matter decomposes (e.g. in landfill). Food losses and waste contribute indirectly since, for a given level of consumption more food needs to be produced than is consumed since a proportion of it is wasted. The emissions from this additional production can be seen as avoidable GHG emissions (and avoidable use of water, land and so forth).
When all of the environmental impacts from food systems are considered – GHG emissions, water use, deforestation and both terrestrial and marine biodiversity loss – and taking into account existing world nutritional challenges (see Chapter 1), then food waste presents an important focal issue to be addressed (see Chapter 4 for more on mitigation of food system GHGs).
5.6.2 Food losses and waste occur throughout the food system
Food waste hotspots vary regionally
In developed countries food waste occurs at the production and consumption stages.
In poorer countries, almost all food waste arises at the production, post-harvest and storage stages.
Problems with food waste are not equally distributed across regions.
In this report, production refers to agricultural production, post-harvest handling and storage, processing and distribution to retailing. Consumption refers to food waste by consumers.
In poorer countries, per capita losses are higher at the production, harvesting, transport and storage stages (i.e. up until the point of sale and consumption.). One of the reasons for this is a lack of infrastructure and technology for safe storage and efficient transport from farm to market. Hungrier populations also tend to waste less food at home, resulting in relatively lower consumer-stage waste (around 4%–16% of the total).
In wealthier countries, food waste per capita is in general higher, and more evenly distributed across all food system stages, but levels of waste at the consumption stage are particularly significant.
Waste at the consumption stage in middle and high-income regions ranges from 31%–39%.
5.6.3 Food waste contributes significantly to GHG emissions
Avoidable GHGs of wasted food are very significant
Graph produced from data in FAO (2014)
The GHG emissions required to produce the food that is wasted would make food waste the third highest GHG emitting country.
The blue water used to produce the globe’s wasted food is more than any individual country’s agricultural blue water usage (see earlier in this chapter information on blue water usage).
The environmental burden of producing so much food is very high.
The estimated GHGs emissions from producing food that is not eaten would make ‘food waste’ the third highest GHG emitting country in the world.
The estimated blue water usage (see earlier in this chapter) of food waste is higher than the food-related blue water usage of any country.
In terms of land-use, the land required to produce this food represents 28% of the total available agricultural land.
While these are estimates, they clearly show that, the environmental and societal cost of food waste is high. At the same time, efforts to reduce food waste could yield both social and environmental benefits.
However, the rebound effect does need to be taken into account. For example at the consumer stage, if consumers buy less food because they are wasting less, they save money. This money could be used on other energy using, and GHG-emitting goods and activities – from new electronic goods to shoes to holidays. For a discussion and an estimate of its significance in the UK see Chitnis, et al. (2014). (For more about the similar concept of the ‘substitution effect,’ see Chapter 9)