What you eat has a bigger effect on your carbon footprint than most people expect. Food is responsible for a large share of global greenhouse gas emissions, and animal products make up the bulk of it.
The figures are published averages for different diet groups, which is enough to show how big the gaps are.
How to use the Vegan Footprint Calculator#
- Pick your current diet. Choose the group that best matches how you eat now.
- Pick a new diet. Choose vegan, vegetarian or another group.
- Set the days. Use fewer than 7 days if you would only change part of the week.
Where the numbers come from#
The figures are daily averages, in kilograms of carbon dioxide equivalent, for different diet groups in a well-known 2014 study of British adults published in the journal Climatic Change. They put high meat eaters at about 7.2 kg a day and vegans at about 2.9 kg.
| Diet | kg CO2e a day |
|---|---|
| High meat | 7.19 |
| Medium meat | 5.63 |
| Low meat | 4.67 |
| Fish eaters | 3.91 |
| Vegetarian | 3.81 |
| Vegan | 2.89 |
The calculation#
A high-meat diet comes to about 2,620 kg a year, and a vegan diet to about 1,050 kg. Switching saves roughly 1,570 kg, or about 60 percent. Eating the new diet on only some days of the week saves a share of that.
Limits of the estimate#
The figures are averages from one country at one point in time. What you buy, where it comes from, how much you waste and how it’s grown all change the footprint. Food from other regions will differ. Use the result as a rough guide to the scale of the difference, not as a precise measurement of your own emissions.
A worked comparison#
The calculator uses average daily emissions from a UK study of 55,000 people: 7.19 kg of CO₂e a day for high meat eaters, 5.63 for medium, 4.67 for low, 3.91 for fish eaters, 3.81 for vegetarians and 2.89 for vegans. Someone moving from a high-meat diet to a fully vegan one cuts 7.19 − 2.89 = 4.30 kg a day, or 1,570 kg a year, which is about 1.6 tonnes. If they go vegan for only three days a week, the saving is 673 kg a year. A move from medium meat to vegetarian saves 664 kg.
What the figures leave out#
These are averages for a British diet. A diet in Nigeria, India or Brazil has a different mix of foods, and what is grown locally and eaten fresh can have a lower footprint than imported food. Beef and lamb carry the largest emissions per kilogram, followed by cheese, then pork and poultry, while pulses, grains and vegetables are lower. Waste matters too, since food that is thrown away carries all of its production emissions. A vegan diet built on imported processed substitutes may not save as much as one built on beans, grains and vegetables. Treat the result as an estimate of the direction and size of a change, not as a precise number.
Putting a tonne in context#
A return flight from Europe to West Africa produces roughly a tonne of CO₂e per passenger, so the saving from a full diet change over a year is similar to one or two long flights. Home energy, travel and the products you buy usually make up the rest of a personal footprint. If you want to look at one other habit, the bag footprint calculator compares shopping bags. Changing your diet is one of the larger single choices an individual can make, but it works best alongside others.
Frequently asked questions#
Based on this data, a high-meat eater could cut food emissions by about 60 percent. Others would save less.
Yes. Moving from a high-meat to a low-meat diet saves a lot even without going fully vegan.
Carbon dioxide equivalent. It expresses the effect of different greenhouse gases in terms of carbon dioxide.
No. They’re averages from a study and will differ from person to person.
In the study behind these figures, a vegan diet produced about 2.89 kg of CO₂e a day against 7.19 kg for a high meat diet, a difference of roughly 1.6 tonnes a year. The saving is smaller if you start from a lower-meat diet, and it depends on what you eat instead.