Source record
Reducing food's environmental impacts through producers and consumers
Joseph Poore, Thomas Nemecek (2018). Science. University of Oxford; Agroscope.
Key findings
- Food production accounts for roughly a quarter of global greenhouse gas emissions and uses around 43% of ice- and desert-free land.
- Impacts vary enormously between foods: per unit of protein, beef from dedicated herds produces many times the emissions of legumes.
- Impacts also vary widely between producers of the same food, but even low-impact animal products generally exceed the impact of plant substitutes.
Record
- Source type
- Peer Reviewed Study
- Study type
- Meta Analysis
- Topics
- Climate & emissions, Land use, Water, Pollution
- Geography
- Global (119 countries)
- Population
- Approximately 38,700 farms and 1,600 processors covering 40 food products
- Sample size
- ~570 life-cycle assessment studies
- Funding & conflicts
- Academic funding reported; no industry conflicts declared in the paper.
- Source quality
- Strong evidenceLarge, transparent meta-analysis in a leading journal, widely replicated in later work.
Limitations
- Life-cycle assessments depend on system boundaries and allocation choices; results are averages with wide ranges.
- Data coverage is uneven across regions; some low-income farming systems are under-represented.
Statistics we use from this source
- 26%Share of global greenhouse gas emissions from food
- 50kg CO₂e per 100 g proteinBeef (beef herd)
- 20kg CO₂e per 100 g proteinLamb
- 11kg CO₂e per 100 g proteinCheese
- 7.6kg CO₂e per 100 g proteinPork
- 5.7kg CO₂e per 100 g proteinChicken
- 4.2kg CO₂e per 100 g proteinEggs
- 2kg CO₂e per 100 g proteinTofu
- 0.8kg CO₂e per 100 g proteinBeans & pulses
- 0.4kg CO₂e per 100 g proteinPeas
- 83%Share of the world's farmland used for livestock (grazing plus feed crops)
- 18%Share of global calories supplied by animal products
- 33.3kg CO₂e per kgBeef from dairy herds
- 99.5kg CO₂e per kgBeef from beef herds
- 164m² per 100 g proteinBeef
- 185m² per 100 g proteinLamb
- 40m² per 100 g proteinCheese
- 7.1m² per 100 g proteinChicken
- 5.7m² per 100 g proteinEggs
- 7.3m² per 100 g proteinLentils (other pulses proxy)
- 2.2m² per 100 g proteinTofu
Claims this source supports
EnvironmentStrong evidence
Per gram of protein, beef from dedicated beef herds produces roughly 25 times the greenhouse gas emissions of tofu and 60 times those of pulses; the ratio to peas is over 100.
Beef is in a different league from plant proteins on emissions. Chicken and eggs sit in between.
EnvironmentStrong evidence
Poore & Nemecek estimate livestock uses 83% of the world's agricultural land while supplying under a fifth of its calories.
Most farmland feeds animals, not people directly. That land delivers a relatively small share of our food.
EnvironmentStrong evidence
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.
Cite this record
Reducing food's environmental impacts through producers and consumers. The Balance of Health. https://thebalanceofhealth.com/sources/poore-nemecek-2018-reducing-food-environmental-impacts