Food · emission factor
The Carbon Footprint of Lamb
2,420 g CO₂e / 100g
Lamb carries a footprint of roughly 2,420 g CO₂e per 100 g, making it the second most carbon-intensive common food after beef. That single figure is about 48 times higher than vegetables and roughly four times higher than chicken. For anyone tracking their diet's climate impact, lamb is one of the few foods where a small portion moves the needle significantly.
Why lamb's footprint is so high
Sheep, like cattle, are ruminants: their multi-chambered stomachs ferment grass and feed, and that fermentation produces methane, a greenhouse gas with far greater short-term warming power than CO₂ — around 80 times stronger over a 20-year horizon. Enteric methane is the single largest component of lamb's footprint. Sheep are also less efficient than larger ruminants at converting feed into edible meat, so emissions per kilogram of lamb rival or exceed beef in some production systems. Land use adds more: sheep grazing occupies extensive pasture, and land-use change associated with livestock contributes to the sector's total. The FAO estimates livestock overall account for roughly 14–15% of global greenhouse gas emissions, and small ruminants like sheep and goats are a meaningful slice of that.
How lamb compares to other foods
At 2,420 g CO₂e per 100 g, lamb sits just below beef (2,990 g) and well above every other everyday protein. Cheese comes in at 1,350 g, pork at 1,220 g, chicken at 620 g, and fish at 550 g. Plant proteins are in a different league entirely: tofu is 200 g, beans 100 g, and vegetables just 50 g per 100 g. Put differently, a 200 g lamb chop generates close to 4.8 kg of CO₂e — comparable to driving roughly 20–25 km in a petrol car (231 g per passenger-km). These figures, drawn from Poore & Nemecek's 2018 global meta-analysis in Science, are averages across production systems; grass-fed extensive systems and intensive systems vary, but lamb remains high-impact in nearly all of them.
Does grass-fed or local lamb change the picture?
Less than people expect. Because methane from digestion dominates the footprint, transport and packaging are minor contributors — Poore & Nemecek found transport typically accounts for under 10% of food emissions, so local lamb is not dramatically lower-carbon than imported lamb. Grass-fed systems avoid feed-crop emissions but often involve slower growth, meaning more months of methane per kilogram produced. Some well-managed pastures sequester carbon in soil, partially offsetting emissions, but the science suggests this rarely neutralizes the methane burden. The most reliable lever is simply frequency and portion size: how often lamb appears on the plate matters far more than where it came from.
How lamb compares
How to reduce this footprint
- ✓ Treat lamb as an occasional dish rather than a weekly staple — halving frequency halves its footprint.
- ✓ Swap lamb for chicken (620 g CO₂e/100g) or fish (550 g) to cut the per-meal impact by roughly 75-80%.
- ✓ Use smaller lamb portions in dishes like stews and tagines where vegetables and beans carry the bulk.
- ✓ Track your meals for a few weeks to see how much lamb actually contributes to your food footprint — apps like Decarbonr make this automatic.
Frequently asked questions
Is lamb worse for the climate than beef?
They are close. Beef averages about 2,990 g CO₂e per 100 g versus lamb's 2,420 g, so beef is somewhat higher on average. Both are far above any other common food because both come from methane-producing ruminants.
Why does lamb have a higher carbon footprint than chicken or pork?
Sheep are ruminants, so their digestion releases large amounts of methane, a potent greenhouse gas — chickens and pigs produce almost none. Sheep also convert feed to meat less efficiently, so more emissions accumulate per kilogram. The result is about four times chicken's 620 g CO₂e per 100 g.
Does buying local lamb significantly reduce its footprint?
Not much. Transport usually accounts for less than 10% of a food's emissions, while methane from the animal itself dominates lamb's 2,420 g CO₂e figure. Eating lamb less often has a far bigger effect than buying it locally.
Track this automatically
Decarbonr turns meals and journeys into one clear daily CO₂e number — on your iPhone, on-device, private by design.
Free trial · then subscription · AI scanning optional add-on
Sources & methodology: see Research & scientific references. Figures are averages used by the Decarbonr app; real-world values vary by production system, country, and occupancy.