Is Eating Local Really More Sustainable?

When the U.S. economy and society abruptly shut down in March 2020 due to a global pandemic, food shortages were common as supply chains temporarily collapsed.  For example, most of the beef and pork sold in the U.S. is processed in just a handful of huge plants. When a Covid-19 outbreak shut one or two of them down, retail outlets quickly ran out of meat. A shortage of long-haul truckers made things worse.

Food manufacturers and distributors recovered remarkably quickly, implementing effective safety protocols that allowed them to restore and maintain a highly functional food distribution system throughout the pandemic.  However, the early days of the pandemic revealed a suprising vulnerability in our food supply network.

The U.S. is a large country, both in population and in territory. And yet our food system is highly centralized.  It’s also highly efficient, which makes our food costs among the lowest in the industrialized world. One way the food industry boosts efficiency is through various agricultural technologies that increase the yield or output of every square acre that we farm.  Another is economy of scale.  It is more cost effective for one farmer or company to farm 1,000 acres than it is for 10 farmers to farm 100 acres each.

The American food system is highly centralized. It’s also highly efficient, which makes our food costs among the lowest in the industrialized world.

Another way that we keep costs down is by reducing redundancies in the networks that supply, transport, and sell our food to us.  But another word for redundancy is “back up.”  When a system has no redundancies, the entire system becomes only as strong as its weakest link. 

Eating local by necessity

When our national food systems broke down temporarily, many people sought out new relationships with local growers and supplies.  Participation in Community Sponsored Agriculture — where people buy shares in small local farms in exchange for a weekly box of whatever’s being harvested — shot up.  Small farmers and wholesale vendors quickly set up programs to deliver meat, dairy, and produce directly to consumer’s doorsteps.  A local food economy sprang to life. 

One of the lessons that many people drew from the pandemic was that a less centralized food supply and delivery system would be more resilient when things go awry — and that the benefits of some redundancy would outweigh the costs of reduced efficiency. But while the local food movement may have gotten a big boost from the coronavirus crisis, it’s been around for a long time.  And one of the chief articles of faith among “locavores,” is that eating local reduces the carbon footprint of our consumption and is therefore more sustainable. 

But it’s always wise to test these sorts of assumptions. Just because something seems logical doesn’t mean that it’s true. 

European researchers Alexander Stein and Fabien Santini just published a fascinating paper on the sustainability of local food systems.  “In the political discussion,” they write, “the promotion of local food systems and short supply chains is sometimes presented as a means to increase the resilience of the food system…and it is also suggested as a means to improve the environmental footprint of the food system.”

In their paper, they review the scientific literature on the environmental, social, and economic aspects of sustainability — and reach some suprising conclusions.

Is eating local easier on the environment?

When consumers try to eat local, they often focus on how far their food has to travel from its source to their plates. A popular book entitled the 100 Mile Diet exemplifies this approach. Barbara Kingsolver’s best-selling Animal, Vegetable, Miracle is another example. And one assumption behind this trend is that eating locally will lower the carbon footprint of our diets. However, this is not necessarily the case. 

For one thing, shipping large quantities of food in cargo ships or train may actually burn less fuel than transporting the same amount of food a much shorter distance in hundreds of small trucks. Now consider thousands of consumers driving to farms one by one in their cars to pick up their local food. 

This thinking also assumes that transporting food is the only — or even the primary — factor in how much carbon is emitted in the production of that food. In fact, food production can produce a lot of greenhouse gasses prior to this final leg of the journey. Stein and Santini conclude that the carbon footprint of your diet depends far more on what types of foods you choose to eat than on how many miles they travel to reach your plate. 

Shipping large quantities of food in cargo ships or train may actually burn less fuel than transporting the same amount of food a much shorter distance in hundreds of small trucks.

As a rule, plant foods are less carbon intensive than animal foods — but the same crops may have vastly diffrent carbon footprins depending on the farming methods used.  Highly-processed foods are also more carbon intensive than minimally-processed foods. So, a highly processed plant-based food could potentially rival a minimally-processed animal food in terms of carbon footprint. 

Obviously, reducing the carbon footprint of your diet involves much more than just eating local. Eating more minimally-processed, plant-based foods is at least as important.

Do local food systems protect food security?

Although disruptions in the food supply chain revealed the vulnerabilities of an overly centralized food system, an exclusively local food system is not necessarily more resilient. An urban region, for example, may not be able to produce enough food to feed its local populaion while a more rural area can produce far more than its population can consume.

Different areas of the country also differ widely in their growing conditions, which is why it makes a lot more sense to grow lettuce in Southern California, wheat in Nebraska, and citrus fruit in Florida than it would to try to grow all three in all three locations. In addition, a disaster impacting regional food production is much more likely than what we just experienced, which affected every region of the U.S. at once.

Finally, because local food systems are not always the most efficient or cost-effective, eating local is sometimes out of reach for the poor or food insecure and remains the privilege of the relatively affluent. A diversity of food sources, including both regional and national supply chains, might be the most resilient system, as well as the best way to ensure food security. 

Do local food systems make our communities stronger?

Stein and Santini did find evidence to support the idea that local food systems can make our communities stronger. When consumers buy from local growers, they are more likely to have a personal connection to them and this fosters a greater awareness of the value of the work involved in producing our food, as well as the challenges. Participants in the local food system may be more invested in protecting their environment and the commuinty.  Local food systems can also create local jobs and support the local economy.

But for the farmer, selling locally is not always the best deal. Sometimes, they can make a much better living selling their crops into a national or international marketplace.

The bottom line on local food

I think Stein and Santini have done us all a service by taking a closer look at the intuitive notion that eating locally must be more sustainable.  As they conclude,

“’Local food’ cannot simply be equated with ‘sustainable food’…it neither can ensure food security nor does it necessarily have a lower carbon footprint. In terms of social sustainability, local food systems are not necessarily more resilient, but they can contribute to rural development and a sense of community.” 

Clearly, local farmers play an important role in our food system and in our communities. But there’s a lot more to building a sustainable, resilient, and equitable food system than simply patronizing our local farmer’s markets. 

What do you think? Drop me a line at nutrition@quickanddirtytips.com or come join the discussion on the Nutrition Diva Facebook page.