You want to reduce the carbon footprint of your food? Focus on what you eat, not whether your food is local

Global concern regarding climate change is on the rise, with eight out of ten people now viewing it as a significant threat to their home country.

As I have noted previously, the production of food accounts for one-quarter of all global greenhouse gas emissions.

There is a growing and justified awareness that our dietary habits have a substantial impact on our carbon “footprint.” If you are looking for ways to lower the emissions associated with your meals, you have likely heard the advice to “eat local.” Even prominent voices suggest this, and it feels intuitive—after all, transporting food does generate emissions. However, this is one of the most misguided pieces of advice available.

Eating locally would only be highly effective if transportation were responsible for a large portion of a food item’s total carbon footprint. For the vast majority of foods, this is simply not the case.

Greenhouse gas (GHG) emissions from transport represent a very small fraction of the total emissions generated by food, and the type of food you choose is far more important than the distance it traveled.

Where do the emissions from our food actually originate?

The visualization displays GHG emissions from 29 different food products, ranging from beef at the top to nuts at the bottom.

For every product, you can identify which stage of the supply chain generates its emissions. This spans from land-use changes on the left to transport and packaging on the right.

Producing a single kilogram of beef results in 60 kilograms of greenhouse gases, whereas peas produce only 1 kilogram.

This data comes from the most comprehensive meta-analysis of global food systems to date, published in Science by Joseph Poore and Thomas Nemecek in 2018.

In that study, the researchers analyzed data from more than 38,000 commercial farms across 119 countries.

In this comparison, we examine the total GHG emissions per kilogram of food. While CO2 is the most prominent greenhouse gas, it is not the only one. Because agriculture is a majorof carbon dioxide equivalents. This metric accounts for all greenhouse gases, not just CO2

Explore an interactive version of this chart and download the data.

Greenhouse gas emissions across the supply chain by food product.

The most significant takeaway from this study is the massive disparity in GHG emissions between different food types. Producing a kilogram of beef emits 60 kilograms of CO2-equivalents, while peas emit just 1 kilogram per kilogram.

In general, animal-based products tend to have a larger footprint than plant-based ones. Lamb and cheese both generate more than 20 kilograms of CO2-equivalents per kilogram. Poultry and pork have smaller footprints, yet they still exceed most plant-based foods at 6 and 7 kg CO2-equivalents, respectively.

For most foods—especially those with the highest emissions—the bulk of the impact comes from land-use changes (shown in green) and farm-stage processes (brown). Farm-stage emissions include activities such as the application of synthetic or organic fertilizers and enteric fermentation, which is the methane produced in the stomachs of cattle. Together, land use and farm-stage activities account for over 80% of the footprint for most food items.

Transport is a minor contributor to total emissions. For most products, it accounts for less than 10%, and for the largest GHG emitters, that share is even smaller. In the case of beef from beef herds, transport accounts for just 0.5%.

It is not just transport, but all supply chain processes occurring after the food leaves the farm—such as processing, retail, and packaging—that generally account for a small share of total emissions.

This data holds true when looking at individual food products. Furthermore, studies confirm this applies to entire diets. For example, researchers Vilma Sandström and her colleagues studied the footprint of diets across the EU and found that food transport accounted for only 6% of emissions, while meat, dairy, and eggs were responsible for 83%.

Eating local only provides a marginal reduction in your emissions.

Consuming local beef or lamb still carries a carbon footprint many times higher than most other foods. Whether those products were raised nearby or shipped from across the globe makes very little difference to the total emissions.

Transport typically accounts for less than 1% of the GHG emissions for beef, meaning eating locally has a negligible effect on its total footprint. You might assume this figure depends heavily on your location and the distance the beef must travel, but the example below demonstrates why that factor is largely irrelevant.

Whether you purchase your meat from a neighbor or from a distanttprint high, but the fact that it is beef

Example: how much does distance impact the footprint of beef?

You might assume this figure depends heavily on your location and the distance the beef must travel. If you live in a remote area, you might expect the impact to be much higher than if the beef were produced by a local farmer. However, the crucial point is that the difference in transport emissions is tiny compared to the total footprint of beef. Let’s consider beef from a beef herd, which has an average footprint of approximately 60 kilograms of CO2eq per kilogram. Let’s compare the transport footprint of buying from a local farmer versus someone in the UK buying beef from Central America, roughly 9,000 kilometers away.

Transporting food by boat emits 23 grams of CO2eq per tonne of product per kilometer. Transporting that beef 9,000 kilometers from Central America to the UK emits 0.207 kilograms of CO2eq [9,000km * 23g per tonne-kilometer / 1000 / 1000 = 0.207 kg CO2eq per kg]. This represents just 0.35% of the total 60-kilogram footprint.

If you buy from a local farmer—assuming you walk there and have zero transport emissions—your beef footprint is 59.8 kilograms CO2eq per kilogram [calculated as 60kg – 0.2kg]. It makes almost no difference.

Especially for foods with a high total footprint, the share of emissions attributed to transport is relatively insensitive to the distance traveled.

In a study published in Environmental Science & Technology, Christopher Weber and Scott Matthews (2008) investigated the relative climate impact of food miles versus food choices in US households. Their analysis revealed that replacing less than one day per week of calories from beef and dairy with chicken, fish, eggs, or plant-based alternatives reduces GHG emissions more than buying all of your food from local

They estimated that if the average household replaced their red meat and dairy calories with chicken, fish, or eggs just one day a week, they would save 0.3 tCO2eq. If they replaced those calories with plant-based alternatives, they would save 0.46 tCO2eq. In other words, going “red meat and dairy-free” for just one day per week achieves the same result as having a diet with zero food miles.

There are also instances where eating locally might actually increase emissions. In many countries, certain foods can only be grown and harvested during specific times of the year. However, consumers demand these items year-round. This leaves three options: import goods from countries where they are in season, use energy-intensive methods like greenhouses to grow them locally, or use refrigeration and preservation to store them for months. Many studies show that importing often results in a lower footprint.

Hospido et al. (2009) estimate that importing Spanish lettuce to the UK during the winter results in three to eight times lower emissions than producing it locally. The same logic applies to other foods: tomatoes grown in Swedish greenhouses used 10 times more energy than those imported from Southern Europe, where they were in season.

The impact of transport is small for most products, with one exception: items that travel by air.

Many people believe air freight is more common than it actually is. Very little food is transported by air; it accounts for only 0.16% of food miles. But for the few products that are air-freighted, the emissions can be very high, as air travel emits 50 times more CO2eq per tonne-kilometer than a boat.

To lower your diet’s carbon footprint, avoid air-freighted foods when possible—but the most significant change comes from eating less meat and dairy.

Many foods that people assume arrive by air are actually transported by boat; avocados and almonds are prime examples. Shipping one kilogram of avocados from Mexico to the United Kingdom generates 0.21kg CO2eq in transport emissions. This is only about 8% of the avocado’s total footprint. Even when shipped over great distances, these emissions are much lower than those of locally produced animal products.

Which foods are air-freighted? How do we know which products to avoid?

They tend to be highly perishable items that must be consumed shortly after harvest. In these cases, boat transport is too slow, making air travel the only

Certain fruits and vegetables often fall into this category. Asparagus, green beans, and berries are common air-freighted goods.

It is often difficult for consumers to identify air-freighted foods because they are rarely labeled as such. A general rule is to avoid foods with a very short shelf-life that have traveled a long distance (checking the country of origin on the label can help). This is especially relevant for products where “freshness” is emphasized, as transport speed is a priority for those items.

Therefore, if you want to reduce your diet’s carbon footprint, avoid air-freighted foods where you can. Beyond that, you can make a much larger impact by focusing on what you eat rather than “eating local.” Consuming less meat and dairy, or switching from ruminant meat to chicken, pork, or plant-based alternatives, will reduce your footprint by a significantly larger margin.