The question of how far food should travel between its production and consumption points is a frequent matter of passionate debate. The popular rule of thumb is that the more local the food, the better it is, and we've all heard of the many purported benefits that eating locally has on local economies, the environment and one's health.
Concern for greenhouse gas emissions created by food transport often frames the discussion, with the presumption that local foods result in less carbon being burned. But there are actually many instances where importing something from a faraway market is more climate-friendly than trying to produce it locally. One example: lamb imported to the U.K. from New Zealand, where pasture-raised practices and hydroelectric power prove greener than local grain-fed production houses, even when 11,000 miles of travel factors into the equation.
If you want to do right by the climate without getting bogged down by details, there are a few simple rules that can help cut through the nuances and guide your purchasing decisions. One category of food that's pretty hard to justify shipping is food from a different hemisphere that's out of season at home, such as tomatoes and berries during the wintertime.
This isn't simply a matter of a carbon footprint: In demanding to eat them year-round, you abandon your relationship to where you are. This relationship offers one of the most important benefits of eating locally, influencing other important choices we make.
Climate activist Bill McKibben once told me that his personal rule-of-thumb for making food purchasing decisions is the Marco Polo exception. It states that if a food is non-perishable enough that Marco Polo could have brought it home from China in a sailboat, then we don't need to worry about eating it, even if it's not local. But if a food is so perishable that it must be shipped refrigerated and quickly, then it's off the table.
We can't know whether or not a package of dried noodles was flown across the ocean by plane, but most likely it was carried by a cargo boat, which burns a lot less carbon. Even so, maritime shipping accounts for about 4 percent of global carbon emissions, on par with Japan's carbon footprint. Pursuing a local foods diet, with flexibility provided by the Marco Polo exception, prepares your eating habits for a day when certain international foods might be shipped carbon-free, by sailboats similar to Polo's.
That day may be closer than you think.
Jorne Langelaan co-owns a shipping company called Fairtransport Shipping, which operates two vessels, with plans for two more. For someone who derives his income from shipping and trade, Langelaan has a surprising take on the practice.
"It is complete nonsense that we are transporting anything and everything across the planet," he says in an interview with Port of Rotterdam Perspectives. But Langelaan points out that not all ships emit equally. One of his ships, the Tres Hombres, is currently en route to Europe laden with coffee, rum and chocolate from the Caribbean. No carbon will be burned in the transport of these indulgences because the Tres Hombres is a sailboat, and the only engine-free transatlantic cargo ship in the world.
While the Tres Hombres and its sister sailboat the Nordlys are inspirational and beautiful ways to ship cargo, Langelaan and his partners at Fairtransport harbor no illusions that such old-fashioned technology is the key to countering global warming. But they do provide reminders that fuel-based shipping doesn't have to be the only game in town, while being useful for motivating and educating people.
And Fairtransport has its sights set on a goal that's both more realistic and more ambitious. It is designing a new, hybrid cargo ship that will run primarily on wind-filled sails, only hosting an engine for use when necessary. Dubbed the Ecoliner, the boat aims to travel as fast as a conventional cargo ship, while using only half the petroleum.
Despite these promising improvements over conventional cargo ships, Langelaan still views the Ecoliner as more of a crutch than a real solution, fearing that a more fuel-efficient vessel will simply encourage more long-distance shipping.
"Only products that are not available locally should be transported," he says, "and in a sustainable way." The rum, chocolate and coffee on board the Tres Hombres are perfect examples of such products. They can't be produced in Europe, and they can handle a slow passage on a sailboat.
In the grand scheme, food transport's greenhouse gas emissions are not a massive threat to the climate. Transportation of food only makes up between 4 and 10 percent of the total carbon emissions created by the food system, adding up to much less than the carbon burned in the production, processing and packaging of food. Animal products tend to have especially large carbon footprints, which dwarf the amount of carbon used in their transport.
Tracking the impacts of various foods on a case-by-case basis can be overwhelming, but thinking about your food choices is akin to a meditation practice for self-improvement. Or riding your bike instead of driving — or volunteering on a wind-powered cargo ship. None of these actions alone will save the world, but they add up, are contagious and create good habits.
So say you want strawberries this winter — then now is the time to plan for that. First, figure out how to stockpile a large strawberry stash this summer, either by planting a bunch, or more realistically, finding a local farmer to purchase from. Then, focus on storing those berries. Dry them or make jam, leather, sauce or syrup. Doing so will connect you with the culinary texture of where you are and ground you in traditions that rely on preserved foods in winter.
Someday you might end up with some products that could be transported by the Tres Hombres, and perhaps traded for a bottle of 10-year-old balsamic vinegar to drizzle on fresh strawberries next year. At that point the Marco Polo exception will become an exceptional treat, and a worthy voyage.