The facts about food miles

If they were air-freighted, they’ll have a higher carbon footprint due to the environmental impact of planes. But if they arrived by boat, their footprint will be a lot lower because sailing has a much smaller carbon impact than flying.

Flying in food generates roughly 47 times more greenhouse gases than using cargo ships. Figures show aeroplanes produce 500g of CO2 per metric tonne of freight per kilometre of travel, while ships only produce 10-40g per km.

Even if two ingredients travel the same distance – and so have the same food miles – the air-freighted goods will have a much greater environmental impact.

Does transport inside the UK count?

Fortunately, most of the food we eat travels by boat rather than plane – globally, only 0.16 per cent of food miles are from air travel. And in 2022, just 7 per cent of the UK’s emissions were from air-freighted goods.

A bigger issue may be what happens to imported food once it gets to the UK. According to government data, transporting food within and around the country produces 109 million tonnes of CO2e annually: that’s 26 per cent of our total greenhouse gas emissions.

Plus, there’s the distance we travel ourselves to buy food. If you regularly drive to large, out-of-town supermarkets, those miles – and carbon emissions – soon add up. In fact, passenger cars are currently the UK’s largest source of transport emissions.

More than miles

So far, transporting food doesn’t sound that great for the planet. But there are lots of other factors that can affect an ingredient’s carbon footprint.

Take tomatoes, for instance. UK tomatoes grown in heated greenhouses in winter have a higher carbon footprint than tomatoes imported from warmer countries, like Spain. Even when you add in the food miles, buying tomatoes from abroad is still better for the planet (although buying UK tomatoes while in season is best of all).

Remember, the biggest portion of any food’s carbon footprint comes from its production, not transport. Beef, for example, has the greatest impact on the planet due to all the resources that go into producing it, such as land, water and animal feed, plus all the methane emissions from the cows themselves.

Which means locally produced beef doesn’t have a much lower carbon footprint than beef flown in from Argentina, say, despite having significantly fewer food miles.

Perhaps it’s no surprise, then, that some experts are questioning the importance of food miles and wonder if the term is more of a distraction than anything else.

‘The food mile message is a little more nuanced than it’s sometimes presented,’ says Professor David Reay, a climate scientist from the University of Edinburgh. ‘When you look at the life cycle of food stuffs, food miles are not a major part. It’s how they were produced… that really matters.’

So, what can I do?

Unless you’ve got an allotment or are buying direct from local producers at a farmer’s market, it’s almost impossible to know how far your food has travelled. But seeing as food miles are only one part of the puzzle, perhaps this is no bad thing.

It would be far more useful to have a label that shows a product’s total carbon footprint, and – after years of false starts – this is now a reality. Similar to the nutrition labels on food packaging, a carbon footprint label shows us the total emissions generated by a product, from beginning to end.

The Carbon Trust has verified more than 27,000 products worldwide, including many different foods. You can now find their carbon footprint label (which is a literal footprint) on foods from Quorn, Yeo Valley, Danone, and many more.

Other brands use their own carbon footprint labelling scheme; there’s currently no standardised carbon label in use in the UK. This can make it even tougher to work out which ingredients are best for the planet, but this environmental impact calculator (launched by the BBC in 2019) can help.

Until an industry-wide carbon footprint label is introduced, can we do anything right now?

Shopping local vs shopping global

If you want to shop locally, one extreme option is to stop eating anything we can’t rear or grow on our own shores. But it’s worth noting that – if we stopped importing food altogether – we’d take away a valuable source of income from communities all over the world.

In sub-Saharan Africa alone, around 1.5 million people depend on exporting food to the UK. Records show that 40 per cent of all our air-freighted fresh fruit and vegetable imports are from this region. But ending this relationship would only reduce UK total greenhouse gas emissions by less than 0.1 per cent – not much of a trade-off in the long run.

You can cut down on eating certain foods, such as meat and dairy, and avoid goods that are more likely to have been flown in. These are often fruits and vegetables that need to be eaten soon after harvesting: asparagus, green beans, berries and cherries are common culprits.

Professor Reay says that one of the best things to do is buy locally produced food, but food that’s also in season; sunlight is an incredibly efficient use of resources. It also saves you having to do numerous carbon calculations during the weekly shop.

It will take time to move towards a more sustainable global food system, but focusing on food miles alone isn’t the answer. Following a local, seasonal and plant-based diet can have a much greater impact on the planet than simply checking out the air miles on your avocado.

More on sustainability

10 ways to eat out sustainably
How to reduce food waste
Is a vegan diet better for the environment?
How to compost food at home
Sustainability hub page

Paul Allen is a former BBC environmental editor and a director at Lark. Find him on X @larkingly

This article was updated on 8 March 2024. If you have any questions or suggestions for future content, please get in touch at goodfoodwebsite@immediate.co.uk.