Making cattle more productive would help with another emissions problem: The fewer cows you have, the less land you have to clear for them to graze. In Brazil, for instance, ranchers are burning swaths of the Amazon rainforest to make room for cows. An investigation by the NGO Global Witness last year found that in just one Amazon state, over the course of three years, beef companies bought cattle from ranches responsible for 20,000 football fields’ worth of illegal deforestation. “That disturbance is going to release carbon to the atmosphere,” says University of Illinois ​​climate scientist Atul Jain, a coauthor on the Nature Food paper. Plus, growing grain for your cows requires tilling the land. “That also would release carbon from the soil, because soil is one of the major reservoirs for carbon dioxide,” Jain says.

You might be thinking that it would be easier to solve the problem if we all just consumed less meat and milk. The answer is that some people can—but some can’t. Americans have plenty of alternative proteins, like the Impossible Burger. (A recent analysis by the Good Food Institute, which promotes the alternative protein industry, calculates that compared to regular meat, producing plant-based meat uses between 47 and 99 percent less land and between 72 and 99 percent less water, and emits between 30 and 90 percent less greenhouse gas.) But to many people around the world, a cow is much more than food. A cow can be an asset—not only as a critical source of protein and nutrients like iron, but as a working animal and a kind of currency. 

As more people ascend into the middle class, the demand for meat will increase globally, and Jillian Fry, a public health scientist at Towson University, says that people in industrialized nations should forgo meat more often to help strike a balance. “That makes it even more urgent for us to shift our diets toward plants—not 100 percent, but toward plants—so that we’re freeing up resources so that folks who don’t have the food to meet their basic needs and health will have access to that,” she says. “We’ve known for a long time that our Earth does not have the resources to support the world eating the way that Americans do.” 

Mitloehner doesn’t think this is the most efficient way to go. The market share of alternative proteins remains small, he says, even after years of hype. “All of that considered, neither the production nor the consumption of animal-sourced foods in the US play anywhere close to the role that the fossil fuel sectors—transport, power, and cement—play, which make up 80 percent of our nation’s carbon footprint,” says Mitloehner. “We will do what we can with livestock, but let’s be real about the elephant in the room.” That’d be fossil fuels.

For her part, Fry thinks there’s a danger of using methane-cutting feed additives to prop up a business-as-usual food system. Additives might reduce emissions, but they won’t fix the fact that ranchers are mowing down forests to make way for cows. “The expanding desire for meat, and especially production of cattle, is a major driver of this deforestation,” says Fry. “And there’s no way to reverse that impact on the climate by adding seaweed to feed.” 

She worries that the meat and dairy industries might choose additives over making other changes. “If the industry can hold up one strategy about reducing methane emissions, that’s their shiny object to distract people from multiple larger issues that need to be addressed,” she continues.

A lot of hot air, if you will.

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