Does eating less meat actually reduce emissions?
The short answer
Yes. Animal foods produce over half of food's greenhouse gases, and beef and lamb produce the most by far. Eating less of them is one of the biggest dietary changes a person can make.
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Sample data. The figures and sources on this page are demonstration records showing how evidence will be presented. They are approximate and have not yet been through our review process. Read about how we will verify evidence.
- Beef (beef herd)
- Lamb
- Cheese
- Pork
- Chicken
- Eggs
- Tofu
- Beans & pulses
- Peas
kg CO₂e per 100 g protein. Axis starts at zero. Thin lines show the reported range.
Data: Poore et al. (2018). Sample
Global averages. Individual farms vary widely around these figures.
What does the evidence show?
The most comprehensive study of food's environmental impact, covering around 38,000 farms in 119 countries, found that food is responsible for about a quarter of global greenhouse gas emissions.
Within food, animal products dominate. A separate 2021 analysis estimated that animal-based foods account for around 57% of food-system emissions, compared with 29% for plant-based foods.
Ranked per 100 grams of protein, beef from beef herds produces on average around 50 kg of CO₂-equivalent. Tofu produces about 2 kg and peas under 1 kg.Source 1: Reducing food's environmental impacts through producers and consumersSource 2: Global greenhouse gas emissions from animal-based foods are twice those of plant-based foods
Why does this happen?
Cattle and sheep are ruminants. They digest grass through fermentation, which produces methane, a greenhouse gas around 28 times more powerful than carbon dioxide over a century.
Animals also need land. Grazing and feed crops together use most of the world's farmland, and clearing forest or grassland for them releases carbon stored in trees and soil.
Finally, feeding animals is inefficient. Most of the calories in feed are used by the animal to live, not turned into meat, milk or eggs.
- Beef from dairy herds
- Beef, UK average
- Beef from beef herds
- Beef, Brazil average
kg CO₂e per kg. Dots are averages; bars show the reported range between producers. Axis starts at zero.
Data: Poore et al. (2018); studies (2024). Sample
Dots are averages; lines are the range between the lowest- and highest-impact producers reported. Even the best beef sits above almost every plant protein.
kg per person per year. Axis starts at zero. From 1961 to 2020: up about 87%.
Data: Sheets et al. (2024). Sample
Food-balance supply, which overstates intake by the amount wasted. The rise is driven mostly by poultry and by growing incomes in middle-income countries.
Bottom line
If you want to reduce the climate impact of your diet, eating less beef and lamb is the single most effective change. Swapping to chicken helps; swapping to plant proteins helps most.
The strongest counterargument
“Transport is the real problem, so eating local meat is what matters”
Food travels long distances. Surely a locally reared steak beats a plant protein shipped from another continent?
What's true about it
- Food transport does produce emissions, and air-freighted produce can have a high footprint.
- Buying local supports regional farming and can reduce packaging and storage.
What may be misleading
- For most foods, transport is a small share of total emissions, typically under 10%. For beef it is usually a few percent.
- The difference between beef and beans is so large that where either is produced does not close the gap.
What remains uncertain
- Exactly how much local systems reduce emissions depends on the specific supply chain, and good data for many local products is scarce.
Evidence strength
Why this rating: Multiple large, independent global analyses agree on the ranking of foods, and the differences are far larger than the uncertainty in the estimates.
Supported by multiple systematic reviews or large, consistent studies using different methods, with few plausible alternative explanations.
What remains uncertain?Open questions the evidence does not yet settle.
- The best way to compare methane, a short-lived gas, with carbon dioxide is debated. Different metrics change the numbers, but not the ranking.
- How much carbon well-managed grazing land can store, and for how long.
Methodology: how we know thisHow the numbers were produced and what they leave out.
- Figures are drawn from life-cycle assessments, which add up emissions at every stage from land clearing to the supermarket shelf.
- Emissions are expressed as CO₂-equivalents using 100-year global warming potentials, the standard used by the IPCC.
- We compare foods per 100 g of protein rather than per kilogram, so that foods are compared on what they deliver nutritionally.
Read our full evidence methodology.
Claims used on this page2 claims, each with its own record, rating and sources.
Reducing meat and dairy consumption, especially beef and lamb, is one of the largest ways an individual's diet can reduce greenhouse gas emissions.
Yes. Animal foods produce most of food's emissions, and beef and lamb produce the most per gram of protein. Eating less of them lowers a diet's footprint substantially.
Per gram of protein, beef from dedicated beef herds produces roughly 25 to 60 times the greenhouse gas emissions of beans, peas or tofu.
Beef is in a different league from plant proteins on emissions. Chicken and eggs sit in between.
Sources
Each source links to our record of what it found, its limitations and what we used it for, with a link to the original.
- 1Reducing food's environmental impacts through producers and consumers
Joseph Poore, Thomas Nemecek (2018). Science.
- 2Global greenhouse gas emissions from animal-based foods are twice those of plant-based foods
Xiaoming Xu, Prateek Sharma, Shijie Shu et al. (2021). Nature Food.