As farmers markets and CSAs burst to life in shades of springy green, the chance to snag seasonal favorites and support local growers is back. If that bunch of arugula with serious pep in its step is any indication, eating local also tastes great. But a common sustainable eating trope also springs up alongside all this fresh goodness: Advocacy groups, universities, and food writers have championed the idea that eating grub grown closer to home is also a boon for the climate. Reducing food miles, or the distance between where food is produced and where it’s consumed, they say, can substantially slash the emissions of what we eat.
Want more Earth-saving tips?
SUBSCRIBE to the one5c newsletter here
The logic makes sense, but does it stand up to scrutiny? There’s a dash of nuance worth unpacking, but the main thing to digest here is that there are far more impactful ways to decarbonize your diet than sweating where your food comes from.
How much of food’s footprint comes from transport?
A bit, but nowhere near as much as some might think. The idea of minimizing food miles seems intuitive at first blush: The less distance something travels, the fewer fossil fuels get burned, and the lower emissions must be, right? The first problem with this idea, says Laura Enthoven, a postdoctoral researcher in environmental economics at the University of Antwerp who co-authored a 2021 review of common beliefs about local food systems, is that transportation is only responsible for a relatively small portion of emissions.
Studies have generally estimated food miles at less than 10% of food’s total carbon footprint. In 2018, an analysis in the journal Food Policy put the number at around 5%, and that same year the go-to study of grub’s greenhouse emissions in Science put it at 6%. Some headlines, however, glommed onto an outlier study published in Nature Food in 2022 that arrived at a larger figure—nearly 20%—when it defined food miles more broadly. Those researchers considered not just the greenhouse gases emitted by moving vittles from farm to fork (which they calculated at 9%), but also those from transporting farming inputs like fertilizers, pesticides, and machinery.
“Local can be better than global, or it can be worse. It depends on the supply chain.”
Laura Enthoven, University of Antwerp
It’s a potentially important finding, but one that eating locally wouldn’t necessarily solve. If the farms you bought from imported things like fertilizers or machinery, Hannah Ritchie, deputy editor and science outreach lead at Our World in Data, wrote about the study, “you could source all of your food locally…and still have high ‘food miles.’” And regardless, Enthoven emphasizes, transportation “is still not the major issue.”
Still, eating local must make some difference?
That depends. Eating local doesn’t always guarantee the modest carbon savings it seems to promise. “Local can be better than global, or it can be worse. It depends on the supply chain,” says Enthoven. Several elements determine a given food’s transport emissions. For instance, how full the vehicle moving the food around is matters: A truck packed with pallets of lettuce from a large-scale producer could be more fuel-efficient per bundle of romaine than a panel van from a local purveyor with just a few crates tucked in the back.
A food’s main mode of transport to get to the shop or market also factors in, which brings us to an important asterisk. Goods that travel by plane are hugely carbon intensive. Air travel emits 50 times more emissions than shipping by boat, which is the most common way food moves around the world. Luckily, just 0.16% of grub hitches a ride in the sky—mostly highly perishable things like berries and farmed salmon.
So, what can I do to cut the footprint of my diet?
For low-carbon eating, locavorism is more like a seasoning than a main ingredient. It might notch your grocery emissions down a tad, but it’d be wishful thinking to imagine a local diet is any match for bigger climate wins. Think of optimizing your diet around where food comes from—and seasonality, for that matter—as an amuse-bouche, while broader changes to what you actually eat are the entrée. Here’s what you can do, in ascending order of climate impact:
Focus on seasonal over local
Eating foods that are in-season could help you steer clear of items grown in energy-intensive greenhouses. That’s right: Depending on where you live, a local tomato in February might be worse than one shipped in from Mexico. Studies conducted in Canada, the U.S., and Europe have found that ’maters farmed in heated greenhouses have 6 times the impact of those from the field. And a study in China found that greenhouse cherries are 2 to 16 times worse than those from outdoor orchards. Check out what’s ripe in your state on the Seasonal Food Guide, and remember that what’s bountiful is often also cheap—and at peak deliciousness.
Avoid frequent fliers
“Substituting one of those exotic fruits for a local apple could make a difference,” says Becca Jablonski, the co-director of the Sustainable Food Institute at Colorado State University and an associate professor in the department of agriculture and resource economics. So could an apple variety from across the country or another fruit of any kind and provenance, so long as it’s never seen the inside of a plane. Spotting these well-traveled goods can be tricky, but here are a few things to look out for.
Waste less food
One of the most impactful ways to cut food emissions is to stop pitching perfectly good grub. According to Project Drawdown, reducing food waste is among the top climate solutions individuals can take part in. In the U.S., nearly half of waste happens in homes. If all that got eaten instead of tossed it would save the average American household more than $1,500 a year (which is a lot of asparagus).
Eat less meat
Food carbon footprints are primarily determined by the type of food (like an animal protein versus a plant protein) as well as the farming practices used and any deforestation involved in growing it. “So land use and production at the farm level are way more important than just looking at how many miles you have between the producer and the consumer,” Enthoven explains. When you look at the biggest emitters, getting meat from a nearby farmer doesn’t have much carbon benefit. Transportation emissions account for less than 2% of the footprint of lamb, and less than 0.5% for beef. That’s pretty small potatoes compared with, say, swapping beef for tofu, which is up to 31 times less carbon-intensive through its entire lifespan.