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Read up on: food waste

A summary of the sustainability issues around food waste and its impact on the environment.
© University of Reading
If food loss and waste were a country, it would be the third largest emitter on Earth, after USA and China.1
The amazing efficiency and productivity of the modern food system you looked at in Step 2.6 has kept pace with the growing population but there is a drawback. Food has become a product that we buy rather than something we are involved in producing, and we have become distanced from those that produce our food so that we no longer recognise the value of the precious resources that are poured into creating things we like to eat. In High Income Countries, government subsidies and market forces have led to this value becoming invisible; food is cheap, we buy too much, store it badly, prepare portions that are too large and don’t know how to use leftovers. The result is, too much of it goes in the bin.
You may like to watch this optional video ‘Today I learned: We Waste One-Third of Food Worldwide’ (National Geographic).

This is an additional video, hosted on YouTube.

The scale of the food waste problem

It’s difficult to calculate exactly how much food is lost or wasted and it can be measured in different ways: by fraction of weight produced or by calorific value. A report in 2011 estimated that a third of the food produced by the world is either lost or wasted (food loss and food waste are two different concepts and depend on where in the food supply chain the loss occurs). When you work that out per person in the world, it’s roughly equivalent to the weight of a giant panda EACH, every year.
Working out how much food is wasted globally is an ongoing task, but the UNEP Food Waste Index Report 2021 indicates that however you look at it, food waste has an enormous impact on both the planet and humans with nearly a fifth (around 17%) of the food that’s available to consumers not making it into anyone’s mouth.

The impact of the food waste problem1

One way to measure the impact of food waste on our world is through its environmental footprints.

Carbon footprint

This measures all greenhouse gases (GHGs) emitted during food production, processing, distribution, and consumption, as well as the emissions from waste disposal.
Adapted from Waste to Value © EIT Food
If every person in the UK wasted no food at home for one day, it could have the same impact on greenhouse gases as planting half a million trees. (WRAP, October 2020)

Land and water footprint

The amount of food we produce uses 70% of the world’s fresh water and requires intensive farming practices, yet a third of this food production is lost or wasted placing unnecessary pressure on the soil and causing pollution.
In 2007, a land area as big as Canada and India put together and water equivalent to three times the volume of Lake Geneva was used to produce food that wasn’t eaten.1
Lake Geneva taken by Sentinel-2 Satellite
Try this animated card game to sort foods according to their environmental footprint (Carbon, Land and Water) or download this PDF if you want to play it offline.

Biodiversity loss

The expansion of the environmental footprints of food production has a knock-on effect on biodiversity. In order to produce food we never eat, farmers expand into wild areas and fishing operations over-exploit marine habitats.
9.7 million hectares are deforested annually to grow food – a land area nearly as big as the whole of Scotland and Wales put together.1
You can also measure the impact of food waste financially and in terms of its effect on humans:

Financial loss

The global cost of food waste in 2011 was approximately equal to the GDP of Turkey or Switzerland.
WRAP reports that in the UK, an average family with children wastes the equivalent of £700 every year.

Human loss

There are over 800 million hungry people in the world.
A quarter of the calories intended to feed humans are lost or wasted along the food chain2.

Although the problem of food waste seems enormous, consumer behaviour is a large part of the cause and can therefore also be a large part of the solution. In the video in the previous Step you saw Patrick demonstrate the value in the waste from school meals to the children, and watched the children make their own compost. As with food production, taking the time to understand the issue results in innovative ways to address the problem. In the next Step you’ll find further resources to explore for ideas that may be relevant to your own teaching context.

1 Food Wastage Footprints (FAO)
2 Reducing Food Loss and Waste: Creating a sustainable food future II (World Resources Institute)
© University of Reading
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