Dozens of studies identify beef as among the most egregious greenhouse gas emitters. Emissions from beef herd production alone typically range from about 79 to 101 kilograms of carbon dioxide equivalent per kilogram of edible weight, according to one paper. That compares with 3 to 21 kilograms of CO2e for the full supply chain of chickens, including production. 

There are several reasons for beef’s high carbon footprint. It takes a lot of land to raise cows and their feedstock and clearing forests releases emissions. There are emissions associated with fertilizer use. The unique digestive process of cows and other ruminants also generates methane, a greenhouse gas 80 times more potent than CO2 in the short term.

 Findings, published in a 2022 study in the American Journal of Clinical Nutrition, were clear: What differentiated people whose diets had a higher carbon footprint was “one or two items of beef on a given day,” Rose says. The highest-impact foods “were all beef items.”  They found that ditching beef for one meal could halve a person’s dietary carbon footprint that day. 

Take a burger. A beef patty’s footprint is 4.21 kilograms of carbon dioxide equivalent (CO2e) per 100 grams, according to follow-up research published in Nature Food last year.

The non-red meat alternatives don’t even come close. Ground turkey’s footprint is 0.4 kg CO2e, and a veggie burger’s footprint is only 0.2 kg CO2e.

Food systems are responsible for roughly 30% of human-caused emissions globally, and nearly 60% of that comes from animal-based products.  Ditching beef for one meal could halve a person’s dietary carbon footprint that day.  Focusing on one meal at a time, and swapping out beef as often as you can, is one way to square the circle between lowering the climate impact of your diet and giving up steak on your birthday. The more people who embrace such swaps, the bigger the dent in food-related emissions.

Data source: 2023 Nature Food study.  Excerpts from "One Simple Change to Reduce Your Climate Impact? Swap Out Beef" by Zahra Hirji, published in Bloomberg on Feb. 21, 2024.