In medium- and high-income countries food is to a great extent wasted, meaning that it is thrown away even if it is still suitable for human consumption. Significant food loss and waste do, however, also occur early in the food supply chain. In low-income countries food is mainly lost during the early and middle stages of the food supply chain; much less food is wasted at the consumer level (Gustavsson, Cederberg et al. 2011).
For milk (Fig. 2): waste at the consumption level makes up approximately 40-65% of total food waste in all three industrialized regions. Losses in agricultural production are significant since dairy cow illness (mostly mastitis infections) causes an approximate 3-4% decrease in milk yield. For all developing regions, waste of milk during postharvest handling and storage, as well as at the distribution level, is relatively high (Gustavsson, Cederberg et al. 2011).
Food Losses - Dairy Products
In the UK, we waste 363,598 tonnes of milk per year, all of this is classified as avoidable (Chapagain, James 2011).
The government funded Waste Resources Action Programme (WRAP) has estimated that UK householders waste 30% of the food they buy and of this approximately 60% is edible, or would have been were it eaten within its sell-by date. It finds that we waste 8.3 billion tonnes of food, the avoidable fraction of the food and drink waste would cost people in the UK a total of 12 billion per year, an average of 480 per household per year.
The greenhouse gas emissions associated with avoidable food and drink waste is the equivalent of approximately 20 million tonnes of carbon dioxide per year. This is roughly 2.4% of greenhouse gas emissions associated with all consumption in the UK. The most significant contributors to avoidable carbon emissions are milk waste, coffee waste and wheat products (bread, cake etc.) (Chapagain, James 2011).
Out of the total carbon footprint of the UKs household waste of food and drink, 78% is related to waste under the avoidable category and 22% under the possibly avoidable category. The average carbon footprint of avoidable household food waste is 330kg CO2 eq per person per year. This is equivalent to approximately one third of the emissions of CO2 (rather than CO2 eq) associated with household electricity use per person in the UK (Chapagain, James 2011).
The products with the greatest share in the carbon footprint of household food waste are presented in Fig. 3. Data limitations mean that few processed foods were able to be identified, and subsequently limited emissions have been attributed to these(Chapagain, James 2011).
In addition to the direct emissions associated with the life cycle of food, WRAP also estimate that avoidable food waste generated in the UK is responsible for emissions associated with Land Use Change totalling 7.6 million tonnes CO2 eq per annum (Fig. 4) (Chapagain, James 2011).
Carbon Footprint of Household Food Waste in the UK ('000 Co2 eq. t/yr)
(Westhoek, Rood et al. 2011) carried out a meta anlaysis of 44 LCA studies and looked at a set of possible production and consumption oriented scenarios on environmental benefits (GHGE, biodiversity). Global implementation of increased livestock efficiency, and a reduction in food waste (20% to 5%), resulted in the largest reduction in GHGE emissions and increase in biodiversity.
The water footprint is an indicator of freshwater use that looks not only at the direct water use of a consumer or producer, but also at the indirect water use.
The total water footprint of food waste in UK households is 6,262 million cubic metres per year, of which 5,368 million cubic metres per year is attributed to avoidable food waste, and a further 894 million cubic metres to possibly avoidable waste. These figures represent 5% and 1% of the UKs total food water footprint respectively. In per capita terms, the water footprint of total avoidable and possibly avoidable household food waste in the UK is 284 litres per person per day. By comparison, the daily average household water use in the UK (i.e. water from the tap) is about 150 litres per person per day. Out of the total household food waste, 243 litres per person per day (86%) is completely avoidable and the remainder is possibly avoidable.The products with the largest share of the water footprint of household food waste are presented in Fig. 5. It is seen that beef and cocoa products are the top two products in the list of water footprint of household food waste. They also rank in the top list of products in the external water footprint of the agricultural products in the UK.
Water Footprint of Household Food in the UK (Million m3 Per Year)
CHAPAGAIN, A. and JAMES, K., 2011. The water and carbon footprint of household food and drink waste in the UK. WWF, WRAP.
GUSTAVSSON, J., CEDERBERG, C., SONESSON, U., VAN OTTERDIJK, R. and MEYBECK, A., 2011. Global food losses and food waste: extent, causes and prevention. FAO.
WESTHOEK, H., ROOD, T., VAN DEN BERG, M., JANSE, J., NIJDAM, D., REUDINK, M. and STEHFEST, E., 2011. The protein puzzle: The consumption and production of meat, dairy and fish in the European Union. PBL Netherlands Environmental Assessment Agency.