How Do Food Choices Affect Climate Emissions?

Food choices affect climate emissions through how a food is grown, not only how far it travels. Animal foods, especially beef and lamb, tend to have a higher footprint than plant foods, but the range between farms is wide. Small changes add up, and no one needs to be perfect.

How big is food in the climate picture?

According to Poore and Nemecek (2018), published in the journal Science and shown by Our World in Data, food production accounts for about 26% of global greenhouse gas emissions. Other studies give a higher share. Crippa and colleagues (2021) put the figure near one third, but they include non-food farm products such as textiles and biofuels.

So the estimate depends on what each study counts. Both agree that food is a large part of the total. Neither one says that food is the only part.

The Poore and Nemecek study looked at data from about 38,700 commercial farms in 119 countries and 40 products. It used life-cycle analysis. This counts land use change, on-farm emissions, inputs, processing, transport, packaging and retail.

Where do the emissions come from?

Most of a food's footprint comes early, on the farm and from the land. For most foods, land use change and farm processes make up more than 80% of the footprint, according to Poore and Nemecek (2018). Farm processes include fertilizer use and the digestion of cattle.

Here are some figures from the same study, as shown by Our World in Data:

• Beef from beef herds is about 60 kg of CO2-equivalent per kg of food.
• Poultry and pork are about 6 to 7 kg per kg.
• Peas are about 1 kg per kg.

The same source reports that livestock and fisheries make up about 31% of food emissions.

Why does the range matter?

These are global averages. Real farms differ a lot. Our World in Data notes that beef emissions range from about 9 to 105 kg of CO2-equivalent per 100 g of protein. That is roughly a tenfold gap.

Even so, the lowest-footprint beef and lamb usually still sit above most plant foods. Land-use numbers are also uncertain. One reason is that it is hard to measure how grazed rangeland is used.

What about food miles?

Many people think the distance a food travels is the main issue. For most foods, it is not. Transport is under 10% of emissions for most products, and less for the highest-emitting ones. For beef from beef herds, it is about 0.5%, according to Poore and Nemecek (2018).

Studies of whole diets agree. Sandström and colleagues (2018) found that transport was about 6% of food emissions in the EU. In the same study, dairy, meat and eggs made up 83%.

This does not mean transport never matters. Air freight is rare, but it is far more intense per tonne and kilometre than shipping by sea. It is more likely for very perishable items, such as berries, green beans and asparagus.

What does this mean for a plate?

The data point to one plain idea. What you eat matters more than where it was grown. Here are some practical steps that follow from that:

1. Notice your most frequent meals. A change in a habit you repeat each week has more effect than a rare switch.
2. Lean on beans, lentils, peas, tofu and whole grains. Their footprints are among the lowest per gram of protein.
3. Cook what you buy. Wasted food carries its full footprint with it.
4. Treat air-freighted perishables as an occasional treat, if you want to be careful.
5. Keep it kind. A good meal that someone enjoys is worth more than a perfect meal that no one eats.

If you are already vegetarian or vegan, you have done the largest part of this. You do not need to count every gram.

Being the only one at the table

Many plant-based people eat with family or colleagues who eat meat. The climate numbers can feel like a heavy topic to bring up over dinner. You do not have to. Most people respond better to a good dish than to a statistic.

Share a recipe. Bring a dish to the table. Let curiosity come from the food. If someone asks why you eat this way, you can answer in one calm sentence and move on.

What the numbers cannot tell us

Footprint figures are estimates. They depend on method, on the year of data, and on how each study draws its boundaries. They also say little about local things, such as soil, water, or jobs on a farm.

Treat the numbers as a compass, not a scorecard. They show a direction. They do not grade a person.

Frequently asked questions

Is eating local better for the climate?

Not usually, on its own. Transport is a small share of the footprint for most foods. What the food is, and how it was grown, usually matters more.

Do plant foods always have a lower footprint?

On average, yes, per kilogram, per calorie and per gram of protein. But there is a spread within every food group. Our World in Data notes that the spread between producers is wide, and that some plant foods, such as air-freighted perishables, can carry a heavier footprint than usual.

Why do studies give different percentages for food emissions?

Studies count different things. Some include only food. Others include non-food farm products such as textiles and biofuels. Methods and years also differ, so the numbers will not match exactly.

Is a vegan diet the only way to lower my footprint?

No. Eating less beef and lamb, wasting less food, and eating more plants all help. Each person can choose the steps that fit their life.

Sources

• Our World in Data, Environmental impacts of food production, citing Poore and Nemecek, Science (2018) and Crippa et al. (2021): https://ourworldindata.org/environmental-impacts-of-food
• Our World in Data, You want to reduce the carbon footprint of your food? Focus on what you eat, not whether your food is local, citing Sandström et al. (2018): https://ourworldindata.org/food-choice-vs-eating-local