Carbon impacts of food

We are not cutting emissions from our food fast enough to meet UK climate goals, according to Ethical Consumer’s 2022 Climate Gap Report. Emissions come from every stage of the food system – from deforestation for cattle ranching, to emissions from food waste in landfill.

But food also offers a significant opportunity. By changing the way we eat, we can significantly reduce our carbon footprint.

How does food contribute to climate change?

Greenhouse gas emissions from meat, fish and dairy

When it comes to the emissions from food, there are two main culprits: meat, fish and dairy farming, and what is known as ‘land use’.

The meat industry is responsible for almost 56% of greenhouse gas emissions from our food. Yet it provides just 37% of our protein and 18% of our calories.

There are two big sources of GHG emissions from the animals we eat. Cows and sheep burp large amounts of methane during the torturous process of digesting grass. Methane is a very powerful greenhouse gas. This means that beef and lamb really are the worst of the bunch. A kilo of beef can emit over 20 times more GHG emissions than a kilo of eggs and 200 times more than a kilo of nuts.

In 2018, scientists therefore found that to keep global warming below 2C (let alone 1.5C), the average person may eventually need to eat as much as 75% less beef and 90% less pork.

According to a 2023 report by Feedback, Desmog and the Institute for Agriculture & Trade Policy, the meat and dairy industry is using a number of tactics to greenwash their climate impact. Big Livestock's Big Greenwash report found the total combined livestock emissions of 15 of the world’s largest meat and dairy companies exceed the individual emissions of ExxonMobil, BP and Shell.

Emissions from use of land for farming

Animals also require a large amount of land, both to live on and for their feed. This demand for land can result in massive deforestation, including of the Amazon: in fact, it’s the biggest single cause of deforestation globally.

This is what we mean when we talk about ‘land use’. Our food system drives the conversion of carbon sinks, such as forests, to agricultural land, meaning that they release the greenhouse gas emissions that they previously held into the atmosphere. Another way of thinking about this is that each hectare of land used for farming essentially has an opportunity cost: if we were not using it for food production, we could be reforesting it or leaving it to nature to act as a carbon sink.

Again, the meat and dairy industry is significantly to blame: over twice as much land is used for grazing as growing arable crops.

Greenhouse gas emissions from crops

21% of food related emissions come from growing crops for food. This is significantly lower than meat and dairy, when we consider that it provides 83% of our calories and 63% of our protein globally.

There are several key causes of emissions in arable farming. Land is converted for crops, destroying carbon sinks and releasing CO2. Fossil fuels are also used on site, for example in farm vehicles, also resulting in CO2.

Overuse of fertilisers is another key issue. Most synthetic fertilisers and some pesticides are produced from fossil fuels. Once used, fertilisers release nitrous oxide into the atmosphere, an extremely powerful greenhouse gas, which traps 300 times more heat than CO2.

Greenhouse gas emissions from food packaging, transport, processing and retail

A final 18% of emissions comes after the food leaves the farm, through processing, packaging, transportation and retail.

Eating local food can often be seen as a way to cut carbon. However, food miles account for just 6% of emissions from food production. Compared to other factors, like the amount of meat you eat, then it’s not really the most important issue.

In fact, the importance of transportation very much depends on what you’re going to eat: you might want to avoid air-freighted asparagus, but don’t feel too bad if you can’t find a UK banana! Despite being freighted halfway across the world, bananas are a relatively low carbon food. This is because they are grown in natural sunlight, meaning no intensively heated greenhouses are used. They keep well, so are transported by boats rather than airfreight. And they require little packaging – because they provide their own.

Food waste also accounts for just a small proportion of total emissions (6% globally, or 3.6% in the UK). However, it's worth mentioning as something we can start to tackle at home: 70% of food waste in the UK is from households. WRAP, a UK charity tackling waste, says that 318,000 tonnes of CO2e is emitted each year for bread that we throw away. The UK’s Climate Change Committee, which sets our targets, suggests that by 2030 we need to cut our food waste emissions by 50% compared to 2007 levels.

What is the biggest cause of climate change in the food industry?

Meat and dairy is by far the biggest emitter in the food industry, compared to the energy it provides. Unfortunately, there is no one way of producing meat or dairy that reduces its emissions: we can’t just swap to a more ethical version.

In 2020, a study compared the GHG emissions from organic and non-organic meat. It found that emissions were largely equivalent. Some emissions from organic meat were lower, due to prohibitions on using imported feed and greater use of grazing meaning that fewer feed crops were needed overall. Others were higher, as animals organic animals were found to generally grow slower, live longer, increasing emissions over their lifetime as a whole. Some have even argued that organic, pasture-fed meat may be worse when it comes to the environment, because of the amount of land it requires.

In many ways, the other big problem is not so much to do with farming: it is to do with the way that we trade and distribute food.

We often hear people argue that a growing population means that we must constantly increase food production – leading to more land conversion and other related emissions. In fact, a study by Lancaster University in 2018 found that current global crop production could meet projected nutritional needs in 2050, but only if there were radical societal changes.

Essentially this means we already have enough to go round. But instead we’re converting more land, using more chemicals and farming more animals – and by doing so driving emissions.

What are food companies doing about climate breakdown?

Ethical Consumer expects all companies – including those manufacturing and selling food – to be making commitments on the climate. We want companies to be setting targets for their own emissions reductions in line with the Paris Agreement targets. We want them to be reporting on their emissions right through their supply chains, and we want them to be discussing real, plausible actions they are taking to cut emissions.

Ethical Consumer rates all companies on their carbon management and reporting. Those receiving a Worst rating lose a whole mark in the Climate Change category, and those receiving a Middle lose a half.

Unfortunately, lots of food companies still have a way to go. In our Supermarkets guide, Aldi, Asda, Booths, Co-op, Ethical Superstore, HISBE, Iceland, Morrisons, Ocado, Planet Organic, Sainsbury’s, Spar, Suma and Tesco all received our worst rating for carbon management and reporting.

Others fared slightly better. For example, delivery company Riverford discussed planting trees on its farm in Devon and converting to all electric vans by 2025. It received a middle rating overall.

What can consumers do and food and climate change?

1. Reduce meat and dairy consumption by 20%

Reducing meat and dairy consumption is the single highest impact action consumers can take when it comes to climate breakdown. In fact, scientists say that it is “essential”.

Our 2022 Climate Gap report found that everyone in the UK will need to cut meat and dairy by 20% before 2030 if we are to meet our national carbon reduction goals. This means that either everyone must cut their consumption by 20%, or a significant proportion must cut their consumption significantly more to account for the fact that others may not take action. When deciding on your own climate action, you may want to go beyond 20% to help drive us towards the change needed as a whole.

You could start by focusing on the highest emitters – beef and lamb.

Check out our guide to reducing meat and dairy in your diet.

2. Reduce food waste

The UK throws away around 9.5 million tonnes of food waste every year, and much of this comes from our households. Every apple, yoghurt or packet of ham that gets chucked adds to our carbon emissions.

Reducing food waste can be an immediate and simple way to cut your carbon footprint, and save you money.

New research from WRAP has found that almost 1 in 3 people in the UK say they throw away the equivalent to one shopping bag of food per week, despite food waste costing families approximately £780 per year.

Our guide to cutting food waste gives tips on how to cut back.

3.  Choose better brands of food

Over 80% of emissions come from the production process, rather than packaging, transportation and retail. While we can shift our habits to reduce emissions, much of the change will have to be made by the actual food producers and those who buy from them.

Using our ratings to find better brands means voting with your wallet when it comes to climate breakdown. Your money will fund more change and best practice, while shifting funds away from the worst offenders.

Check out our shopping guides to food and drink, ranging from vegan alternatives to meat and dairy to biscuits, tea, cereals and bananas.

4. Get political about food and the food system

Transforming the food system will require deep political change. You can support this transition by signing petitions, getting involved in a local group or joining protests and demonstrations.

Feedback Global is a great organisation to start with. They have campaigns on everything from industrial meat and farmed fish to food waste and food economies. You could join one of their Gleaning Groups to help save food from waste, or write to your council about its investment in mega animal farming.

If you want to work in your local community, join Sustainable Food Places’ campaign for more sustainable local food systems.

5. Think about where you shop, as well as what you buy

It’s clear that we can’t just focus on carbon. So what will a just transition of the food system look like?

You may want to consider how those who produce our food are being treated, and how both food and profits are being distributed. Not only is this crucial in its own right; fair sharing could cut the amount of food we need to produce and therefore the carbon emissions attached. Thinking about where you’re shopping as well as what you’re buying could therefore be a great action to take.

There are lots of big bad players in the food industry, supermarkets amongst them. Over recent decades, they have driven down prices for farmers and refused to respect workers’ rights.

Check out our supermarkets guide to find better alternatives.