Go Climatarian!
Three ways to shrink your foodprint
Co-authored by Gwen Rino
If you’re privileged enough to have many choices about food, you already face what Michael Pollan calls the omnivore’s dilemma. Humans can digest everything from abalone to zwieback, so we are continually asking ourselves What should I eat?
And if you’re concerned about the climate crisis, you have another dilemma: How do I reduce my carbon foodprint? You already know that for a livable future, we need to reduce greenhouse gas emissions as quickly as possible. Food production is a major source of heat-trapping gases, accounting for about a quarter of all emissions worldwide. So what would a climate-friendly diet look like?
Information about the climate impact of particular foods can be confusing, even contradictory. You might also be thinking about fair trade, water use, animal welfare, pesticides, health… Meanwhile, every few hours, you’re faced with the choice: What should I eat? If you’ve found yourself overwhelmed in the grocery store or despairing over a menu, you’re not alone. It’s a tough question, so let’s dig in.
Zach Koehn, Early Career Fellow at the Stanford Center for Ocean Solutions and the Blue Food Assessment, analyzed a variety of foods to calculate the greenhouse gas emissions involved in producing them relative to their nutritive value. Based on his research, plus some other studies as noted, we’ll offer three guidelines for a climatarian diet.
1. Mostly plants
You already know this one: Eat plants. It’s part three of Pollan’s eater’s manifesto. But you may be surprised how much it matters. Animal foods have a vastly larger emissions footprint than plant-based foods relative to their nutritional value.
There is some variation among plant foods. Animal foods vary, too. But by far the biggest difference is between plants and animals. We’ve highlighted some common foods in the graph below, but the distinction holds up across categories. Lentils are about the same as soybeans, and lamb is about the same as pork.
If you wanted just one rule for climate-friendly eating, “go vegan” would be it. Project Drawdown lists choosing a plant-rich diet as the fourth most effective way to reduce greenhouse gas emissions. (The first three are wind turbines, large-scale solar, and reducing food waste.)
2. Maybe certain seafoods
But do you have to go vegan to be gentle on the planet? Maybe not.
According to Koehn’s research, bivalves (oysters, mussels, and clams) and small ocean fishes (like anchovies, herring, and mackerel) have a climate impact similar to soy, oats, and almonds and less than corn, broccoli, or tomatoes. When you eat bivalves and small ocean fishes, you’re eating low on the food chain. (Little fish are lunch for big fish. In fact, small ocean fishes are used as bait for halibut and made into feed for farmed salmon.)
Bivalves and small ocean fishes would fit in a climatarian diet. But beware the idea of fish or seafood in general as a kinder, gentler meat. Shrimp must be more climate friendly than steak… right? Nope. Shrimp has almost twice the foodprint of beef.
Fish and seafood vary enormously in their effect on the climate. As you can see in the graph below, farmed catfish has a foodprint over a thousand times larger than anchovies. That’s because aquaculture requires building ponds or tanks, maintaining proper water temperatures, and circulating and aerating the water, all in addition to growing, harvesting, processing, and transporting feed for the fish. In comparison, capturing small, schooling ocean fish with a purse seine net is extremely efficient.
So while it’s generally true that there is a huge difference between plant foods and animal foods, there is an asterisk: in terms of climate impact, bivalves and small ocean fishes are more like plants than like other animal foods. A climatarian diet certainly could include them, as long as we keep an eye on the health of their populations and ecosystems.
Food is intensely personal and also deeply cultural. Many people don’t eat shellfish for religious reasons. It’s also a common food allergy. Oysters, clams, and mussels may be an acquired taste — or should we say an acquired texture. Anchovies might be unfamiliar as anything but a controversial pizza topping. But if you’d like to explore these foods as a climatarian, go ahead. Here are some ways to enjoy mackerel (including ginataang mackerel stew), sardines (including a curry), anchovies, herring, mussels, and oysters.
3. Most of the time
When two options have very different consequences, it matters a lot each time you choose between them. This leads us to the third principle: It’s mostly about what you do most of the time.
You don’t have to give anything up entirely. Just doing something emissions intensive less often makes a big difference. Let’s say you really like hamburgers, and you eat one weekly. Since beef is a high-emissions food, cutting back to once a month reduces your burger-habit foodprint considerably. So one way of being a climatarian is to think of the big-ticket foods as treats, not staples; seasonings, not main dishes.
But when there’s such a huge difference between animal foods and plant foods (plus maybe those certain seafoods), is it okay to eat the emissions-intensive foods at all? Maybe you want to go beyond Meatless Mondays, maybe not; it’s up to you. “Treats, not staples” is a dial you can turn way down without switching off entirely. It leaves you room to be a curious traveler and a gracious guest. But for a climatarian, the habit is to choose from the bounty of low-impact foods.
There are some eerily convincing plant-based burgers on the market these days. What happens if we replace our habitual hamburger with a veggie burger? Given the ten-fold difference between beef and Beyond Burgers, for instance, you can eat a veggie burger every week with less climate impact than a monthly hamburger.
The ultimate effect is the difference in foodprint multiplied by how often you make that choice. You can look at that equation two ways: it can be a rationale for treating yourself occasionally or a reason to skip the high-impact foods entirely.
Don’t worry about the differences among plant foods. Eat those certain seafoods if you like. And if you don’t enjoy agonizing over your food choices, it might just be a relief to avoid the climate culprits. Many people in the world already eat climatarian — that is, lower on the food chain. It’s relatively inexpensive, and it’s healthy.
What about local?
You’ve surely heard that eating local is a way to be kind to the planet. It seems to make sense, since shipping involves burning fossil fuels. But for most foods, transport is responsible for less than a tenth of the foodprint, and for high-impact foods like beef, it’s under one percent. Most of the heat-trapping gas emissions come from land use (deforestation and tilling), ruminant digestion (cow burps), farm equipment (such as tractors and aquaculture pumps), fishing vessels, and production of feed.
How you got to the grocery store and how many items you bought on that trip might make a bigger difference in the foodprint of any given item than its shipping from producer to store! The exception would be items like berries and asparagus, which are so perishable they must be flown if they’re grown far away.
There are other important reasons to eat local, like supporting your regional economy, building community resilience, and feeling your connection to the people and places that produce your food. However, a climatarian diet doesn’t have to be local. If your primary goal is to reduce carbon emissions, what you eat matters far more than where it came from.
Of course there are nuances to all this. Different studies of climate foodprints yield somewhat different results. The sustainability of both fisheries and aquaculture can vary quite a bit depending on how well they are managed, so a climatarian will want to consult a guide like Seafood Watch for the specifics. Koehn’s research looked at mass-produced beef, both pastured and CAFO (concentrated animal feeding operation), but did not include “boutique” beef. Certain ways of grazing cattle on rangeland can sequester a lot of carbon. Even among animals with the highest emissions, such as beef and catfish, there are modes of production that have lower impact and should be encouraged. But the overall picture is clear: most animal foods have an enormous emissions footprint compared to any plant-based food.
We need to feed everyone, not just wealthy Americans. All people deserve healthy food and a livable environment. Yet the people whose ways of life contribute the least to climate change are suffering the worst effects. Some agricultural land is going barren. People are already leaving those places and migrating to regions where the soil is still fertile and there is enough water. Our future ability to grow food at all depends on our taking good care of the climate now.
Some of the most important solutions to the climate crisis will be the ones designed into the background of our lives. Thankfully, we don’t have to ask ourselves Natural gas, hydro, wind, solar, or nuclear? every time we flip a light switch. If our town is on renewable energy, we’re all set. But as long as we have choices about food, diet will be primarily personal. What to eat is an individual decision we will have to make again and again. For a sustainable future, a climatarian diet is our best answer to the omnivore’s dilemma.
Special thanks to Zach Koehn for sharing his research and providing feedback on this article.
