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Why Does A Vegetarian Leave A Smaller Ecological Footprint Than An Omnivore?

If you are searching for ways to make your carbon footprint smaller, try to eat less meat.  That was a key finding from a major recent study conducted on diets in the US.

Researchers discovered that vegetarians had approximately half as small of a food-related carbon footprint compared to meat eaters.  Even lower was the carbon footprint for vegans. However, if you would prefer to not entirely give up steak, simply reducing the amount of meat you eat can help to reduce your diet’s footprint by a third.

Approximately 25 percent of all greenhouse-gas emissions that heat the planet up comes from food production. And scientists have know for quite some time that meat has a larger climate footprint compared to vegetables and fruits – partly due to the fact that it takes more energy to produce meat, but also due to cows having a tendency to burp lots of methane up. (In turn, cows have a greater impact compared to chickens and pigs.) 

That is why a US nutritional panel last year recommended that for environmental reasons that Americans should consider consuming less meat. The Dietary Guidelines Advisory Committee stated that a diet with a higher level of plant-based foods, along with lower amounts of animal-based foods and calories, promotes better health and is also associated with a lower environmental impact compared to the current US diet.

However, the panel did not attempt to calculate the difference that consuming less meat may actually make.  This is where the study comes into play.

Peter Scarborough, along with his Oxford University colleagues published a paper based on a study examining the diets of 2,041 vegans, 8,123 pescatarians (vegetarians who eat fish), 15,751 vegetarians, and 29,589 meat eaters, ages 20 to 79 in the UK. Then they calculated the greenhouse-gas emissions that were associated with the specific foods that each of the groups ate.  A couple of key findings:

The lightest footprint comes from the vegans, but just eating less meat can make a real difference

1) In Britain, the “high-meat” average diet produced an equivalent of 15.9 pounds of carbon-dioxide on a daily basis.  The study notably defined “high-meat” as anything over 3.5 ounces a day, or around one chicken breast.  This is a very low bar (with the average British individual eating about twice this much meat), and individuals who consume more meat will have a footprint that is even larger.

2) By contrast, the average vegetarian diet, product the equivalent of around 8.4 pounds of carbon-dioxide on a daily basis – or only about half as much. 

3) At 6.4 pounds of carbon-dioxide a day, vegan diets were lighter.  The carbon footprint for the average vegan diet was around 60 percent lighter compared to the average heavy meat diet.

4) There were a couple of surprise findings.  The average pescatarian diet (fish with vegetarian) was about as climate-friendly as an average vegetarian diet.  There was only around 25 percent difference. 

5) The difference between a light meat eater and heavy meat eater was larger than the difference between a vegetarian and light meat eater.  This underscores the concept that eating less meat can make a significant impact – even when the individual doesn’t completely give it up. 

A couple of caveats: It was a survey only of UK diet.  It is likely that American diets are different (Around 12 ounces of meat are consumed by the average American on a daily basis).  However, it has been suggested by other surveys that US vegetarian diets still have around half of the carbon foot that a meat-heavy diet has.

Also, it doesn’t guarantee that adopting a vegetarian diet will cut your carbon emissions from your food exactly in half. It will depend on what and how much you eat.  For example, if you give up chicken and then replace it with cheese, that could actually increase the amount of emissions at the margins, given that cows have a greater impact compared to chickens.