Nature Food 2023 data

Vegan vs Vegetarian: Which Diet Is Better for the Planet? (2026)

Q: Which is better for the environment: vegan or vegetarian?

Vegan diets have a significantly lower environmental footprint than vegetarian diets. The key reason is dairy: cheese and butter production generates substantial greenhouse gas emissions and requires significant land and water. A 2023 Nature Food study found that vegans produce 75% fewer greenhouse gas emissions than high-meat eaters, while vegetarians produce about 55% fewer. The gap between vegan and vegetarian is primarily driven by dairy consumption.

Q: What is the carbon footprint of a vegan diet?

Based on the 2023 Scarborough et al. Nature Food study, vegan diets in the UK generate approximately 0.7 kg CO2e per day, compared to 2.2 kg for high meat-eaters (more than 100g meat per day). Vegetarian diets generate approximately 1.2 kg CO2e per day. Switching from a high-meat diet to vegan saves approximately 550 kg CO2e per year, equivalent to flying from London to New York and back.

Q: Is local meat better than imported plants for the environment?

No. This is a common misconception. Transport typically accounts for only 5-10% of food's total carbon footprint. The production method accounts for 80-90%. A locally raised beef steak has a far higher carbon footprint than imported lentils or tofu, because methane from cattle digestion and land use for grazing vastly outweigh transportation emissions.

For the first time, a large-scale UK study published in Nature Food (Scarborough et al., 2023) quantified the environmental difference between vegan, vegetarian, fish-eating, and meat-eating diets across five environmental metrics. Here is what the data shows.

Vegan diet vs high-meat diet (100g+ meat/day) -- Scarborough et al., Nature Food, 2023

75%

Lower greenhouse gas emissions

75%

Less land use

66%

Less biodiversity impact

54%

Less water use

73%

Less eutrophication

Visual comparison of environmental impact: plant-based farm on left with clear skies and small footprint, livestock farm on right with larger environmental impact

Five-Metric Environmental Comparison

Environmental Metric	Vegan	Vegetarian	Fish-eater	Low meat (<50g/day)	High meat (100g+/day)
GHG emissions (kg CO2e/day)	0.70	1.16	1.35	1.71	2.73
Land use (m2/day)	1.0	1.8	2.2	2.9	5.1
Water use (L/day)	0.67	1.14	1.19	1.26	1.44
Biodiversity impact (sp·yr)	0.22	0.37	0.45	0.59	0.92
Eutrophication (g PO4e/day)	0.15	0.30	0.33	0.41	0.73

Source: Scarborough et al. (2023). Vegans, vegetarians, fish-eaters and meat-eaters in the UK show discrepant environmental impacts. Nature Food, 4, 565-574.

Why Dairy Matters More Than People Think

The environmental gap between vegan and vegetarian is largely explained by dairy. This surprises many people who assume dairy farming is relatively benign compared to meat production.

Cheese carbon footprint

Hard cheese produces approximately 8-10 kg CO2e per kg. For comparison, chicken is around 6-7 kg CO2e/kg. Per calorie, cheese often has a higher impact than poultry.

Dairy land use

Dairy cattle require grazing land plus land for growing feed crops. UK dairy farming uses approximately 3.5 times more land per kg of protein than tofu production.

Methane from cattle

Dairy cows produce methane through enteric fermentation (digestion). Methane is 28-34x more potent than CO2 over a 100-year period, making cattle a significant climate concern.

The Food Miles Myth

Key insight: Transport is responsible for approximately 5-10% of food's total carbon footprint. Production method accounts for 80-90%. Local beef has a dramatically higher footprint than imported lentils.

A commonly cited argument is that local and seasonal meat is more environmentally friendly than imported plant foods like quinoa or avocados. While it is true that air-freighted produce has a higher impact, the overwhelming majority of plant foods are transported by sea or road, not air. The methane from a single cow's digestion over its lifetime outweighs the transport emissions of the lentils that would feed a person for months.

The Honest Nuance: Not All Plant Foods Are Equal

While plant-based diets are generally far better for the environment, some specifics matter:

Avocados require significant water (approximately 2,000 litres per kg in some regions). Their widespread popularity has environmental costs at scale.
Almonds are water-intensive: approximately 12 litres per almond. California's almond industry uses 10% of the state's total water supply.
Rice paddies produce methane. Rice has a higher GHG footprint than other grains.
Air-freighted berries and asparagus can have a surprisingly high carbon footprint. Frozen berries are more environmentally friendly than fresh air-freighted ones.
Organic farming is not always lower-impact. Organic dairy, for instance, can have higher land use per litre of milk than conventional dairy due to lower yields.

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Environmental Questions Answered

Which is better for the environment: vegan or vegetarian?

Vegan diets have a significantly lower environmental footprint than vegetarian diets. The key reason is dairy: cheese and butter production generates substantial greenhouse gas emissions and requires significant land and water. A 2023 Nature Food study found that vegans produce 75% fewer greenhouse gas emissions than high-meat eaters, while vegetarians produce about 55% fewer. The gap between vegan and vegetarian is primarily driven by dairy consumption.

What is the carbon footprint of a vegan diet?

Based on the 2023 Scarborough et al. Nature Food study, vegan diets in the UK generate approximately 0.7 kg CO2e per day, compared to 2.2 kg for high meat-eaters (more than 100g meat per day). Vegetarian diets generate approximately 1.2 kg CO2e per day. Switching from a high-meat diet to vegan saves approximately 550 kg CO2e per year, equivalent to flying from London to New York and back.

Is local meat better than imported plants for the environment?

No. This is a common misconception. Transport typically accounts for only 5-10% of food's total carbon footprint. The production method accounts for 80-90%. A locally raised beef steak has a far higher carbon footprint than imported lentils or tofu, because methane from cattle digestion and land use for grazing vastly outweigh transportation emissions.

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