Let’s get this out of the way: You don’t have to turn vegetarian to make a meaningful dent in your carbon emissions. You don’t have to start
eating insects or experiment with precision-fermented plant-based proteins. You don’t even have to eat less meat, necessarily. Just eat less beef — or, if you prefer the idea of “more” to the idea of “less,” you could even say: Eat more chicken.
Either way, the reason comes down to some of the simplest carbon accounting we have. Cows are, by far, our most carbon-intensive protein source. Every kilogram of beef produced in the U.S. emits about 38 kilograms of carbon from cradle to slaughterhouse, according to Gillett. Compare that to roughly 3.8 kilograms of CO2 per kilogram of chicken, and even 4.9 kilograms of CO2 per kilogram of pork, and you can start to see why even such a small change can have a big impact. A chicken needs to eat just 1.6 kilograms of feed to produce a kilogram of meat.
“1.6 is basically magic, right?” Arthur Gillett, chief research officer at HowGood, an emissions research and data service for the food sector, told me. “Why are we messing with crickets?”
Beyond that, though, the picture gets murkier. Because here’s the thing: Even if you wanted to track every single ounce of carbon related to your food intake, you couldn’t, at least not with any meaningful degree of accuracy. Of all the many systems operating in the global economy, the food system is perhaps the most complex, involving processes we’re still trying to understand, let alone track.
For example: dirt. Essentially all the food we eat depends, at some point in its life cycle, on dirt. One reason beef is such a high-emission product is that it takes a lot of dirt to grow all the feed a typical cow eats over the course of its life — which runs to the thousands of pounds (including
byproducts from other agricultural production) — plus a lot more to grow the cow itself. Even in the U.S., where cows are mostly finished on feedlots, livestock occupy 41% of available farmland, but are raised on just 30% of farms. In Brazil, the world’s largest exporter of beef, where cows are mostly grass-fed, cattle graze on somewhere between 189 million and 253 million acres of what used to be the Amazon rainforest, depending on whose estimate you use.
But back to dirt: Climate scientists still don’t really understand how it works, from a carbon perspective. How much carbon is stored in the Earth’s soil? Estimates vary
pretty widely, biogeochemist Rose Abramoff told me. How much is it emitting each year? That’s even less clear. Does it make a difference whether that soil is planted with genetically modified soy versus heirloom squash? No idea.
Until seven or eight years ago, it was accepted practice in the life-cycle analysis world to resolve these uncertainties by assuming soil-related emissions were stable and therefore marking them at zero, according to Gillett, “which is incredibly wrong,” he told me. Analyses are starting to be able to account for those emissions now, he said, but to be really meaningful, they would have to be recalculated every year. “So then every LCA, to be worth its salt, has to be a multi-year LCA. That’s impossible.” Gillett said.
In other words, the science is very much still changing, and you could drive yourself crazy trying to keep up with it. These days, Gillett is excited about the potential for regenerative agriculture practices like no-till farming and co-locating livestock with crops to transform dairy into one of our most carbon-efficient sources of protein, he told me — something he never would have expected to say a year or two ago.
Similarly, “Maybe 10 years ago, all of us were talking about food miles,” i.e. the distance from farm to table, according to Minnie Ringland, manager of climate and insights at ReFED, a food waste reduction advocacy group. You may have experienced this in the form of admonishments to “eat local.” Since then, however, cold storage supply chains have gotten a lot better, particularly in the Global South, which means that we’re losing a lot less food to spoilage — compared to the agricultural process itself, shipping represents a negligible portion of the emissions related to just about any given product.
It's also important to remember that not all farming regions are created equal. California, for instance, is a great place to grow lots of things; Arizona, less so. “Depending on the geography where the food is being produced, it can be super intensive in terms of land use change, if land is being deforested in order to make way for agricultural fields or for grazing,” Ringland said. Another factor is the use of nitrogen fertilizer, which is both emissions-intensive to produce and generates carbon dioxide from its use, the environmental effects of fertilizer run-off on nearby land and waterways notwithstanding.
That’s not to say there aren’t other important benefits to eating locally: contributing to your local economy, supporting biodiversity, encouraging holistic farming practices. The farmers at your weekend farmers market are a whole lot more likely to be practicing regenerative techniques and fertilizing with compost instead of industrial chemicals. But they’re also not going to be there at 7:48 p.m. on any given Tuesday when you’re midway through cooking a batch of chicken cacciatore and realize that you forgot the bell peppers.
Speaking of compost, though, here’s a bonus trick to reduce your food-related carbon emissions: Collecting and composting your food scraps is good, but wasting less food is even better. The reason why is pretty obvious: Before it can be composted, food still has to go through the entire supply chain. And while composting food produces fewer emissions than landfilling food waste, it’s not an entirely emissions-free process, and can be more or less carbon-intensive depending on where and how it’s made. Reducing your food waste requires a bit more planning, but it will also save you money and send a more accurate demand signal down the farm-to-grocery-store supply chain.
I could go on and on about things like the relative carbon impact of plant-based proteins and the emissions reduction potential of standardizing expiration dates on food labels, but all of that is still being worked out. If you
are fake meat-curious, you can check out our guide on that here. And if you’re already a vegetarian or curious about it for reasons of health, ethics, etc., that’s great. The most important thing you, as a consumer, can do to reduce emissions from the food system is hold companies accountable for their carbon claims, which means not getting sucked into the stuff that sounds too good to be true. There’s plenty of delicious food out there that doesn’t take elaborate math to justify eating.
So to recap: Eat less beef, waste less food. You can make it more complicated than that if you want, but everything else is gravy.
