By Orna Herr, Communications Officer (Education) at the British Science Association


Earlier this year, in a move unprecedented among supermarkets, Morrisons announced that they’ll be removing the ‘use by’ date on their milk. Containers will instead have a ‘best before’ date, encouraging customers to use the “sniff-test” to decide if the milk is still good.

This is an attempt to try to reduce the huge amount of milk that is wasted in homes (490 million pints a year!) as it is poured down kitchen sinks across the UK. People strictly adhering to ‘use by’ dates may believe that the milk still in their fridge after the date must have gone off, despite research showing this is often not the case.

The issue of prematurely disposing of milk is sadly just the tip of the iceberg of the problem of food waste. Bread and potatoes are wasted at an even higher rate than milk, and in total the UK throws a shocking 9.5 million tonnes of food away a year. It’s estimated that 60% of this waste happens in homes.

Waste not – protect the planet

One of the reasons that this is such a big problem is that dumping food in landfills is contributing significantly to the climate crisis.

When food rots, it emits a greenhouse gas called methane (the same gas cows produce when they break wind). Methane is 25 times more harmful than carbon dioxide as it is that much more effective at trapping heat in the atmosphere. If we stopped wasting food, human-caused greenhouse gas emissions could be reduced by around 6-8%.

Shocking statistics around food waste and the climate crisis are in no short supply. According to Wrap, a UK-based charity tackling food waste, “If every UK household stopped wasting food for one day, it could do the same for greenhouse gas emissions as planting 640,000 trees per day (around 230 million per year).”

But not a drop to drink

Food waste also contributes to water shortages. Food production requires great quantities of water; 70% of the world’s accessibly freshwater is used for agriculture. Freshwater is actually very rare, and while scientists are trying to discover ways to water crops with seawater, that is not yet possible. In the meantime, it’s predicted that two thirds of the world’s population will face water shortages by 2025.

So water is a precious commodity, and food is very greedy for it. It takes 100 buckets of water to produce one loaf of bread and 54 buckets to rear one chicken breast. When we throw food away, the water used to produce it was used in vain. Globally, 24% of all the water used for agriculture is wasted.  

The immorality of waste

Aside from the environmental implications, there is a clear moral quandary around throwing away good food when there are people around the world and in the UK who don’t have access to enough food to feed themselves and their families.

In 2020, 8% of households in the UK regarded themselves as food insecure, with half of these reporting very low food security. (Food insecurity is defined as: “A lack of the financial resources needed to ensure reliable access to food to meet dietary, nutritional, and social needs.”) In February 2021, a government report showed that there were over 1,300 Trussell Trust food banks in the UK, and over 900 independent food banks.

Educating the next generation

Children and young people who are growing up in food secure households may not be aware of the importance of avoiding food waste, and are too young to take responsibility for it. But time flies. Today’s generation of school students will be taking their next steps and living independently before we know it, so instilling in them an understanding of how human actions impact the planet now could help create a more eco-aware population.  

We have multiple free resources in both our CREST Awards and British Science Week activity packs that encourage primary and secondary students to think about issues surrounding food waste.

We recently produced Silver and Gold level CREST projects focused on hydrology which include activities which encourage students to research how much water is used in agriculture, and to think about methods farmers could employ to use less water.

Secondary students could also look at ‘Conscious consumers’ in the 2022 British Science Week Secondary activity pack to learn about the different types of food we produce, from meat to grains, and where humans sit in the food web.

For younger children, ‘Planet-friendly burgers’ in the 2022 British Science Week Primary activity pack is a great starting point to get them asking questions about where their food comes from, how it’s grown, and how they can make environmentally-friendly choices.

Food waste is a big problem in the UK with far reaching implications, but it is one that is within our reach to solve. Thinking about what we put in our weekly shop, using leftovers wherever possible, donating dried and tinned food to food banks if we suspect it will end up in the bin otherwise, and of course using the sniff test are steps we can all take to make sure food ends up in bellies, not landfills.