Meat footprint calculator

Cattle farming

Hanna Pamua purchased license from DepositPhotos - Order number 170882150. Do not re-use. 

Animal agriculture is the second biggest source of greenhouse gas emissions, and responsible for up to 18 percent of emissions worldwide.


Have you ever wondered about the resources needed to produce a steak or the meat for a BBQ party, or how many miles should be walked instead of driving to offset carnivorous habits?

The Meat Footprint Calculator is the tool for people concerned about the environmental impact of meat. 

Aleksandra Zając and I created the tool for the Omni Calculator Project to show the true cost of meat. While carbon dioxide production and water consumption come to our minds first, there are other things that we don't really think about - the amount of land needed, or the pollution of the air, water, and land. There is also the feed the animals need, which could be used more productively. 

Meat calculator

We made this tool to show the impact of meat and how hugely our individual dietary choices impact the environment. We don't want to convince everybody to become vegan immediately, but to reduce the amount of meat in our diets as much as possible.

Meat consumption has recently soared, as societies around the world get richer. In the last 50 years, the amount of meat eaten globally quadrupled, exceeding 320 million tonnes per year.

Unfortunately, meat is a very inefficient food if you take into account the resources needed for production and the amount of protein obtained. Needless to say, meat production creates pressure on crop and water resources, not to mention the huge demand for land leading to biodiversity loss.

That’s where the Omni Calculator Project comes in. You can choose between five popular meat types: chicken/poultry, beef, pork, lamb, and fish and check their impact. A Science study from 2018 provided data for the four environmental factors: carbon dioxide equivalent, land use, water pollution, and air pollution. 

To make the tool more user-friendly, we’ve implemented the equivalents of those values whenever possible. Thousands of gallons of water or pounds of CO₂ equivalents are not very helpful and imaginable units for most, but water intake per year or trees needed to absorb such CO₂ emissions definitely are. 

We believe that converting scientific units to something down-to-earth can work wonders - people actually start using the tools and are more aware of environmental problems.

Environmental footprint

Animal agriculture is the second biggest source of anthropomorphic greenhouse gas emissions, and responsible for about 13-18 percent of emissions worldwide.

The most significant greenhouse gas associated with meat production is methane. Meat production is the single most important source of this greenhouse gas - livestock produces around 35–40 percent of the global methane emissions

Vast amounts of other greenhouse gases are emitted during meat production, mainly carbon dioxide, CO₂, and nitrous oxide, N₂O. Even though we hear a lot about CO₂, nitrous oxide has a much greater potential for global warming than carbon dioxide, as well as depleting the ozone layer.

In addition, many researchers are warning that water shortages may lead to the next global conflict and great migration of people. There are estimates that over two thirds of freshwater withdrawals go to irrigation for agriculture, and  around 90 percent of global water is used to grow food. Meat production is a great contributor, making up a significant amount of water from these percentages. 

Beef production needs the most water - it requires over 4,000 gallons (15,000 liters) of water to produce 2.2 lbs (1 kg) of meat, making it the most water-intensive protein! Lamb is a bit less greedy (over 2,700 gallons/10,400 liters), and poultry production takes 1100 gal (4,300 l) per kilo of meat. That's a lot, especially when compared to what we drink on a daily basis.

Land use

In today's world, agriculture takes up around 50 percent of the global habitable land (taking all of the Earth's land into account, but excluding deserts and ice-covered regions). From that, approximately 80 percent is associated with animal agriculture, mostly meat production.

To give you some numbers, on average, beef production requires  around 22 times more land than pea production. If the cattle are instead a dairy herd, then "only" 6 times more farmland is used for the same amount of protein from peas. 

Differences in dietary habits are immense - if every person in the world had the UK's meat consumption and average diet, 95 percent of the global habitable area would be needed for agriculture.

Even more terrifying results appear if the whole world chooses an average American diet - 138 percent of the global habitable area would be required. 

Unfortunately, we can't do it - we don't have a spare planet. On the other hand, if everybody changed to a vegan diet, land use could be reduced by more than 75 percent. 


Meat production not only produces greenhouse gases but also a lot of different byproducts. They can be dangerous to our health and may lead to respiratory problems, as well as leading to the deterioration of water, air, and land. Food production is responsible for  around 78 percent of global eutrophication - over-enrichment of nutrients, which may be very harmful to the aquatic ecosystem.

Meat production contributes to a significant part of agricultural eutrophication - for example, red meat production has an environmental impact 10 to 100 times larger than a plant source food.

When it comes to air and land pollution, the ammonia coming from manure is the dominant source of acidifying emissions during livestock production. Overall, the livestock industry is responsible for  around 64 percent of the total ammonia emissions, contributing significantly to acid rain and ecosystem acidification.

According to the latest research, the health benefits of diet change go hand-in-hand with a reduced environmental footprint - that means the products associated with health improvement (such as vegetables, fruits, whole grains) usually have a low impact on the environment. 

As a take-home message, let us paraphrase the slogan from a zero-waste chef Anne-Marie Bonneau: “We don't need a handful of people performing meat reduction perfectly by changing to a vegan or vegetarian diet. We need millions of people doing it imperfectly, reducing meat consumption as much as possible.”

This Author 

Hanna Pamuła, is a Ph.D. candidate at AGH University of Science and Technology, Kraków, Poland, working also as an expert at The Omni Calculator Project, an initiative composed of doctors, scientists, and economists building tools to make math and science more accessible. She is concerned with ecological topics, and the Meat Footprint Calculator is the result of that interest. A nature lover, birdwatcher, photographer and traveler at heart.

Image: License acquired by author.