Why You Should Go Meat-Free For One Day A Year, According To Science


Robin Andrews

Science & Policy Writer

Go veggie, fight climate change. kazoka/Shutterstock

Today – Monday June 12, 2017 – is World Meat-Free Day, which celebrates an initiative that hopes to get everyone to adopt a vegetarian diet for just 24 hours. The aim is to promote healthier diets, living sustainably, and cutting our carbon footprint.

As we’re sure you know, the federal government is withdrawing from the Paris climate agreement, but at least one-third of the US is sticking to the accords come hell or high water. Governors and businesses are cutting their carbon emissions, but as individuals, you can act to show your support too.


So, as its World Meat-Free Day, we wanted to show you how much carbon dioxide you could save by going vegetarian for just one single day – and we’re confident the numbers will surprise you.

Right – let’s do the math, as they say. We’ll be sticking to SI units for now, but we’re nice, so we shall convert things to Imperial units right at the end.

The average meat consumption in the US per person – which also takes into account vegetarians – is 90 kilograms per year, as of 2014. That’s about 0.25 kilograms per day, which across the entire population of the US is 80.4 million kilograms of meat per day. (That’s far higher than the global average, by the way, but we digress.)

Producing meat takes quite a lot of energy. You have to provide either feed to the animals or let them graze on open pastures. Either way, you need to grow that food, as well as water the land and keep the cattle from getting parched – all of which generates carbon dioxide emissions.


You need electricity for all this too, and the upkeep, transportation, and processing all bring with them an additional carbon footprint. The methane emissions that escape out of the mouths and butts of these animals – particularly cows – is also a major contributing factor to the carbon footprint.

Sheep take a lot of resources to farm. N-Sky/Shutterstock

A report by the nonprofit, US-based Environmental Working Group (EWG) calculated, using the best available data, the total amount of carbon dioxide produced per kilogram of meat product, for both farming and post-farming environments, for a variety of livestock.

For the sake of simplicity, we’ve gone with the most common types of meat: beef, chicken, pork, and lamb. We aren’t taking into account fish, dairy, eggs, turkey nor veal – which means these numbers are a very conservative estimate.

Per kilo of beef, you get 39.25 kilos of carbon dioxide; the same goes for lamb. Pork produces 12.12, and chicken just 6.8.


According to the North American Meat Institute, 37 percent of meat consumed by the average American is poultry and 55 percent is red meat. Assuming Americans eat the same proportion of beef, pork, and lamb, and using those carbon dioxide values, you can get a rough estimate of how many kilograms of carbon dioxide meat production and consumption produces on an average American day.

1 – Beef = 576,965,000 kilograms of CO2

1 – Lamb = 576,965,000 kilograms of CO2

2 – Chicken = 202,640,000 kilograms of CO2


3 – Pork = 178,164,000 kilograms of CO2

Total = 1.53 million tonnes (1.69 million tons) of CO2 per day. If everyone stopped eating meat for just one day per year, and the livestock numbers changed to reflect this, this is how much CO2 would be saved. It’s a truly remarkable number.

As a point of comparison, if everyone went meat-free for one year, this equates to 558 million tonnes of CO2, which according to our calculations is 10 percent of America’s total carbon emissions, as of 2015. The Environmental Protection Agency estimates that all of America's agriculture produces 9 percent of the country's total emissions, which happily suggests that our calculations are broadly correct.

So is it worth going meat-free for just one day per year? For environmental reasons, it absolutely is. Imagine going meat-free once per week then, as an increasing number of people are doing!

Avoid this for one day per year, or even once per week, and it'll make a huge difference. vikuschka/Shutterstock

According to the most comprehensive plan to combat climate change yet, if 50 percent of the world adopted a more plant-based diet by 2050 – and cut back on agriculture-related deforestation too – then 66 billion tonnes (about 73 billion tons) of CO2 could be prevented from reaching the atmosphere.

This makes a plant-based diet the fourth-most effective way for the planet to cut its carbon footprint, according to that analysis. So what are we waiting for?


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