Research from the Institution of Mechanical Engineers shows that somewhere in the region of 1.2 to 2 billion tonnes of food is wasted each year, or between 30 and 50 percent of all food produced.

The authors of a report, Global Food: Waste Not Want Not, suggest that, "due to poor practices in harvesting, storage and transportation, as well as market and consumer wastage," up to half of the world's food is being wasted, suggesting that if the problem of waste were addressed, the need to increase production would be dramatically reduced. Such increases have been demanded under the current agricultural paradigm. This includes tackling some regions' lack of infrastructure and communication, as well as other factors associated with poverty and the damaging effects of consumerism in the global North.   

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Global Food was published just days after the Oxford Farming Conference where the Defra secretary, crop research specialists and a former environmentalist argued that genetically modified crops need to be rolled out in order to feed a growing global population. Their comments sparked the ire of food policy experts and sustainable farming advocates who argued that questions of power imbalance, waste and long term sustainability need to be addressed in order to meet food security needs, and claimed GM is largely irrelevant.   

The IME authors' figures demonstrate that huge amounts of other resources, including energy, land, fertilisers and water are also lost "in the production of foodstuffs which simply end up as waste." They commented, "This level of wastage is a tragedy that cannot continue if we are to succeed in the challenge of sustainably meeting our future food demands."

Researchers look at where waste occurs

The researchers found that waste occurs at different points in the supply chain between developed and developing nations. Whereas in developing countries, food is often wasted before it reaches market, as "Inefficient harvesting, inadequate local transportation and poor infrastructure mean that produce is frequently handled inappropriately and stored under unsuitable farm site conditions," in more developed countries, waste occurs at the other end of the supply chain.

The researchers stated that, in developed nations in the global North, "characteristics associated with modern consumer culture mean produce is often wasted through retail and customer behaviour." This includes the catastrophic waste of bloated supply chains, such as the 'just in time' distribution model of supermarket retail and promotions on food items, which lead to increased consumer waste.

"Major supermarkets, in meeting consumer expectations, will often reject entire crops of perfectly edible fruit and vegetables at the farm because they do not meet exacting marketing standards," The study's authors explain. They add that up to 30 percent of the UK's vegetables are never harvested as a result of this, and that globally retailers are responsible for creating an estimated 1.6 million tonnes of food waste due to their policies.  

The authors advised fundamental changes must occur to improve the situation in both developed and developing countries, and that the wastages identified can only be addressed by "creating a political and social environment [that] encourages both transfer and adoption of these ideas to take place." They suggest that governments in developing countries introduce waste minimisation plans into policy decisions and that those in developing countries implement policies to change consumers' wasteful tendencies and prevent retailers' wasteful practices.

Research statistics cause for concern

In addition to expressing concern about the increase in fertiliser and pesticide manufacture, and the associated energy costs, the authors of Global Food said the projected increase in demand for meat and animal products is also worrying. They said, "Per capita calorific intake from meat consumption is set to rise 40 percent by mid-century," which will have serious implications for land, water and energy use.

Animal agriculture is much more resource intensive than plant-based agriculture. For example, beef production, uses 50 times more water than vegetable production. Overall, it takes 20 to 50 times more water to produce one kilogram of meat than one kilogram of vegetables.

Perhaps most shocking are the projections for overall water use. Last year, a global analysis of groundwater depletion revealed that in many of the world's major agricultural regions demand has outstripped supply for groundwater use. Agriculture is responsible for 70 percent of fresh water abstraction, and researchers predict that use will increase in coming decades.

The Global Food authors maintain that this level of use is unsustainable and suggest that in certain areas, such as animal agriculture, excessive demand for water must be curbed. According to the research, 550 billion cubic metres of water are used each year to grow crops which are then not eaten.

One example of this excessive use is biofuel production; it takes 11,397 litres of water to make 1 litre of bio-diesel. Based on data from the UK Environment Agency, which shows average water use per person in UK is 150l/day, it takes the amount of water used by the average UK consumer in one year to manufacture one gallon of bio-diesel (4.5l).

Commenting on the Institution of Mechanical Engineers' findings, Professor Richard Tiffin, Director of the University of Reading's Centre for Food Security, said, "The report is a timely reminder of the sheer size of global food wastage and it is to be applauded. The report's recommendations rightly recognise that engineering solutions combined with behaviour change will contribute to a reduction in the levels of food waste." However, he added, "Consideration should also be given to the economic conditions that give rise to food waste. The growth of urbanised populations in the global south will lead to longer supply chains of the sort that we see in the global north now."

He added that, "There is a danger that reducing food waste to acceptable levels may require storage and transport solutions that are themselves unsustainable."

However, Dr Tim Fox of the IME, cut to the chase. He countered, "The amount of food wasted and lost around the world is staggering. This is food that could be used to feed the world's growing population - as well as those in hunger today. It is also an unnecessary waste of the land, water and energy resources that were used in the production, processing and distribution of this food."

The IME report is available to read here.