11.3 Diet: Vegetarian/Vegan

Author: Alaa Abd-El-Aatty

ABSTRACT: Food’s carbon footprint is the production of greenhouses gas from growing, harvesting, manufacturing, transporting, storing, cooking as well as disposing of food. Avoiding meat and dairy products (becoming vegetarian or vegan) is one of the biggest ways to reduce environmental impact and help fight climate change.

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Image credit: Our World in Data by Hannah Ritchie


Our diet-related environmental burdens are by no means minuscule. This is because food processing is responsible for a quarter of the global greenhouse gas emissions. Feeding large quantities of grain and water to farmed animals and then killing them and processing, transporting and preserving their meat is highly energy-intensive. The U.N. says that raising animals for food is “one of the top two or three most significant contributors to the most serious environmental problems, at every scale from local to global” (Stylianou, 2019). Livestock production contributes to 70% of all agricultural land use, inhabits 30% of the earth’s land surface and is responsible for 18% of greenhouse gases such as methane and nitrous oxide (Anuradha, 2019). Growing animals for food is also unproductive. It takes between five to seven kilograms of grain to make one kilogram of beef (Wolfgang, 2019). They require energy and water to create, process, and transport. As the consumption of meat increases, so does its impact on the climate.

The new study, published in the scientific journal Science, is one of the most detailed evaluations of the harmful environmental effects of agriculture to date. Data from almost 40,000 commercial farms in 119 countries were analyzed. Researchers studied a total of 29 different food products, starting with beef and ending with nuts (Ritchie, 2020). For each product, you can see from which stage in the supply chain its emissions originate. This ranges from shifts in land use on the left to transport and packaging towards the right. In this evaluation, the total greenhouse gas (GHG) emissions per kilogram of food product is assessed. In order to collect all GHG emissions from food production, researchers express them in kilograms of “carbon dioxide equivalents.” This metric takes into consideration not only CO2 but all GHGs.

The most important insights from this research are the massive variations in the GHG emissions of various foods; the production of one kilogram of beef emits 60 kilograms of greenhouse gases. While peas emit just 1 kilogram per kg. Overall, diets based on animals tend to have a larger footprint than those based on plants.

For most foods – and predominantly the principal emitters – the majority of GHG emissions originate from land use reform (shown in green) and farm-stage processes (brown).

Farm-stage emissions comprise processes such as the application of fertilizers – both organic and synthetic; and enteric fermentation (the production of methane in the stomachs of cattle). Collectively, land use and farm-stage emissions account for more than 80% of the footprint for most foods.

Therefore, researchers have found that going vegetarian or vegan can cut your carbon footprint in half. As a result CO2 and methane emissions would decrease and so will the use of fertilizers and water. However, it may not be the most attainable. Instead, a combination of moderated red meat, lamb, and dairy intake along with sustainable farming methods and locally-sourced produce to avoid airfreight would allow for a positive impact to begin to arise.


Varanasi, Anuradha. “You Asked: Should We All Go Vegetarian or Vegan to Reduce Our Carbon Footprint?” State of the Planet, 6 Mar. 2020, https://news.climate.columbia.edu/2019/09/26/vegetarian-vegan-diets-climate-change/

“Fight Climate Change by Going Vegan.” PETA, 19 July 2018, https://www.peta.org/issues/animals-used-for-food/fight-the-climate-crisis/

Jane. “Food’s Carbon Footprint.” Green Eatz, 27 Sept. 2020,  http://www.greeneatz.com/foods-carbon-footprint.html

Martinko, Katherine. “Cutting U.S. Meat Consumption by Half Would Reduce Dietary Emissions by 35% Within Decade.” Sustainability for All , TreeHugger, 6 May 2020, https://www.treehugger.com/cutting-us-meat-consumption-half-would-reduce-emissions-35-within-decade-4847947

Ritchie, Hannah. “You Want to Reduce the Carbon Footprint of Your Food? Focus on What You Eat, Not Whether Your Food Is Local.” Our World in Data, Our World in Data, 24 Jan. 2020, https://ourworldindata.org/food-choice-vs-eating-local; Image: https://ourworldindata.org/grapher/food-emissions-supply-chain?

Stylianou, Nassos. “Climate Change Food Calculator: What’s Your Diet’s Carbon Footprint?” BBC News, BBC, 9 Aug. 2019, https://www.bbc.com/news/science-environment-46459714

Wolfgang, Kraus. “New Study: Vegan Diet Reduces Carbon Footprint by 73% – Vegconomist – the Vegan Business Magazine.” Vegconomist, 19 July 2019, https://vegconomist.com/society-2/new-study-vegan-diet-reduces-carbon-footprint-by-73/


Alaa Abd-El-Aatty is a 3rd year Interior Design student studying at the Ryerson University and lives in Cairo, Egypt. Her passion is stepping back and looking at the world with the purpose of capturing a frame that speaks of culture, beauty, emotions and mold them into an experience. Within her designs, she aims to be as environmentally conscious as possible and tries to create sustainable projects with the purpose of reducing waste.

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