Each year, more than 17 billion metric tons of greenhouse gas emissions are created due to food production around the world. In a new study published in the scientific journal Nature Food, researchers find that 57 percent of those emissions are linked specifically to the production of what they term “animal-based human food.” While previous studies have always indicated an environmental impact of animal agriculture, this study finds numbers even higher than previous examinations.
The study, titled Global Greenhouse Gas Emissions for Animal-Based Foods Are Twice Those of Plant-Based Food, was authored by Xiaoming Xu, Prateek Sharma, Shijie Shu, Tzu-Shun Lin, and Atul K. Jain of the University of Illinois, Urbana, Philippe Ciais of the Laboratoire des Sciences du Climat et de l’Environnement in France, Francesco N. Tubiello of the FAO in Rome, Pete Smith of the University of Aberdeen, and Nelson Campbell of PlantPure Communities, Inc.
In their research, the scientists looked at the carbon footprint of 171 plant-based foods and 16 animal-based ones produced in 200 countries. In their analysis, beef was the commodity linked to the largest share of emissions, accounting for 25 percent of the global total, followed directly by cow milk. The largest emitter among plant-based crops was rice, accounting for 12 percent of global greenhouse gases.
What the team found suggests an even larger environmental impact of food production than earlier results, in part because of an effort to address gaps in earlier studies. Here, they include a look at factors like the emissions related irrigation, transportation, logistics, and packaging required to bring food products to market – facets of the production cycle that have historically been difficult to accurately calculate.
“We needed to calculate a good baseline” to be able to really grapple with the issue, climate scientist Jain told Scientific American.
In a comparison of plant-based to animal-based foods, the environmental impact of animal agriculture becomes particularly clear. The scientists broke out the causes for carbon emissions related to the production of each, noting that creating human food from animals requires creating grazing lads, managing manure, and a significant amount of emissions associated with what the study politely terms “fermentation in animal guts.” On the plant-based food side, product processing accounts for a larger share of the emissions than it does for animal-based foods, but the overall totals are far lower, so your processed plant foods still have a smaller footprint on the planet than a beef burger.