Local Versus Non-Local Food: Is The Kind of Food You Eat More Important Than Where it Comes From?

by Cole Mellino

Proponents of local food production have long argued that you drastically decrease your carbon footprint by eating locally-sourced food.

There have been numerous studies in recent years showing that non-local food, especially imported food, which is making up a larger and larger percentage of Americans’ diets, has a much higher emissions impact than locally produced food. A study from the National Resources Defense Council (NRDC) has the numbers to prove it. Here is some of the data on the staggering impact imported food has in California:

  • In 2005, the import of fruits, nuts, and vegetables into California by airplane released more than 70,000 tons of CO2, which is equivalent to more than 12,000 cars on the road. These are all foods that can be grown in California
  • Almost 250,000 tons of global warming gases released were attributable to imports of food products—the equivalent amount of pollution produced by more than 40,000 vehicles on the road or nearly two power plants
  • More than 6,000 tons of smog-forming nitrogen oxides were released into the air— the equivalent of almost 1.5 million vehicles or 263 power plants
  • 300 tons of sooty particulate matter were released into the air—the equivalent of more than 1.2 million cars or 53 power plants
  • Approximately 950 cases of asthma, 16,870 missed schools days, 43 hospital admissions, and 37 premature deaths could be attributed to the worsened air quality from food imports, according to freight transport–related projections by the California Air Resources Board.

These numbers show the major impact that our food choices have on the environment and human health. This heavy reliance on imports is alarming considering that California is the number one state for agricultural production in the U.S. After examining the top six imports to California (table grapes, navel oranges, wine, garlic, rice, and fresh tomatoes — all grown in the state), NRDC discovered a disturbing trend:

Harmful air pollution in California produced from transporting these six foods into California was up to 45 times more than local or regional transport of California grown foods—and global warming pollution went up to 500 times that of locally grown foods when the food was imported by airplane.

In another study comparing the impact of local versus non-local produce, researchers at Virginia Tech conducted an assessment of carbon dioxide emissions of local broccoli and non-local broccoli. Here’s what they found:

The average distance traveled by nonlocal broccoli delivered to Virginia Tech during the month of October 2009 was 2786.0 miles. The total amount of carbon dioxide emitted as a result of this transport was 105,830.0 pounds. This averaged to approximately 11,758.9 pounds carbon dioxide per shipment and 15.3 pounds carbon dioxide per pound of broccoli delivered.

In contrast to the high mileage of non-local broccoli:

The distance traveled per trip by the cargo van transporting the local broccoli was 19.1 miles. The amount of carbon dioxide emitted per trip was 23.2 pounds, which added up to 258.3 pounds of carbon dioxide emitted during all transport occurring in the month of October. Per pound of broccoli, 0.04 pounds of carbon dioxide were emitted.

This is a very specific case study. But it shows how local food can substantially reduce emissions. Just look at this map of the non-local broccoli’s trek across America when it can be grown in Virginia to be eaten in Virginia.

And here’s the much more sensible journey of local broccoli:

There is, however, valid criticism of the idea that local food is always the best. Christopher Weber and H. Scott Matthews, of Carnegie Mellon University did a life-cycle analysis of the average American diet by tracking greenhouse gas emissions through all phases of a food’s production, transport, and consumption. Weber and Matthews found that overall, transport accounts for about 11 percent of the food system’s emissions. Agricultural production accounts for the bulk of greenhouse gas emissions, or 83 percent. They found that the kind of food is much more important than where it comes from. A diet containing meat and dairy products is much more resource intensive than a plant-based diet. The Worldwatch Institute’s article on Weber and Matthews’ report sums it up well:

Weber and Matthews calculated that reducing food miles to zero-an all-but-impossible goal in practice-would reduce the greenhouse gas emissions associated with the food system by only about 5 percent, equivalent to driving 1,000 miles less over the course of a year.

By comparison, replacing red meat and dairy with chicken, fish, or eggs for one day per week  would save the equivalent of driving 760 miles per year. Replacing red meat and dairy with vegetables one day a week would be like driving 1,160 miles less. “Thus,” they write, “we suggest that dietary shift can be a more effective means of lowering an average household’s food-related climate footprint than ‘buying local.’”

So yes, eating less meat and dairy will greatly reduce the impact your diet has on the planet. However, the combination of choosing the right foods with a local approach will have the biggest impact:

Weber acknowledges, “These calculations were done assuming that local foods are no different than non-local foods.” And that’s not usually the case. For example, local-food advocates also emphasize eating seasonal (often meaning field-grown) and less-processed foods. Those qualities, along with shorter distances from farm to table, will also contribute to lower emissions compared to the “average” diet.

Separating the debate into an either/or is a red herring. Ideally, we’d do both.

Cole Mellino is an intern on the energy team at the Center for American Progress

16 Responses to Local Versus Non-Local Food: Is The Kind of Food You Eat More Important Than Where it Comes From?

  1. Larry Gilman says:

    This is a good discussion of a big issue from a very narrow point of view.

    There is more to life than carbon. Local food networks support communities, non-agribusiness rural landscapes, traditions, knowledge, crop landraces, and soils. Importing and exporting food _probably_ entails excessive energy use but it has _certainly_ pushed agricultural economies toward export crops and away from food independence. US industrial corn production accompanied by “free trade” enforcement is stomping on local corn agriculture in Mexico, for example. Thus food globalization increases food insecurity for millions or billions of people. Food networks with a stronger local component will tend to be more equitable and more resilient in the face of high transport costs and the other disruptions related to peak oil, climate change, and global capitalism’s periodic nervous breakdowns.

    The debates about kilojoules per tomato strike me as marginal. Localizing food is a good idea on so many counts, its urgent merit doesn’t stand or fall on the question of whetherit saves large amounts of energy.

    Wendell Berry’s _The Unsettling of America_ remains, for me, the great revelation in this department.

  2. Joan Savage says:

    At least California still has the capability of growing those highlighted food items that are currently imported.

    With increasingly erratic weather conditions and the occurrence of plant pests and polluted environments, food “mobility” takes on a new significance. When Hurricane Irene hit eastern New York with extensive flooding, the well-diversified local agriculture took a hit across nearly all crops.

    In addition to localizing food production as much as possible, can we also move food in ways that don’t have such a big impact on emissions?
    Crop failures and famines in uncertain weather conditions are going to necessitate an answer.

  3. tim quijano says:

    For many people in harsh northern climates, switching to local food would likely be more carbon-intensive due to increased energy requirements for greenhouses and an increase in the amount of fertilizer required.

  4. SecularAnimist says:

    Eat vegan. Eat local. It is by far the easiest and lowest cost (indeed money-saving!) way that the average American can reduce his or her GHG footprint. And it will improve your health, contribute to the well-being of nonhuman animals, and help build community.

  5. Nick Berini says:

    What about local eggs/milk/yogurt? When trying out a mostly vegan diet I found I ended up relying heavily on soy products and wasn’t sure who I was really benefiting there…

    Generally agreed though that a high-veggie, low-animal product diet is; cheaper, healthier, and beneficial to the environment.

    How do we convince Americans that this is a better way (dare I say cooler and more patriotic) than the 4-meat-based-meals-a-day status quo. This might be a tougher fight than climate policy. :) / :/

  6. Several of the numbers used in this article are out of context, and may or may not support various assertions in the words of the piece. We’re used to, and very much appreciate, a norm of somewhat tighter material here at Climate Progress.

  7. M Tucker says:

    Could be grown in California if the water hadn’t run out. Farmers were hit hard during the past drought period. Many were put out of business due to restrictions and higher water prices. California cities, like cities everywhere, will get the water…farmers always suffer. Is it really a good idea to pretend California is the breadbasket of the US given all we know of how California farmers get the water? Please make up your mind.

  8. EDpeak says:

    Agree with SecAnim above..except, if you think you “can’t” go vegan, don’t worry about how ‘pure’ you will or won’t be able to be, just eat as little animal products are you can… this is for our health, the best option, see Physicians Committee for Responsible Mecidine link at the bottom

    (or course one can eat vegan and still eat unhealthy, like eating only greesy food and lettuce..but one can also eat local and eat unhealthy, like greesy food etc..the point is those are two pillars)

    Pillars: Plant-based ; Organic; Local; and unprocessed or minimally processed

    Have you or any friend cut down on salt? At first it’s extra work, but then you discover spices and herbs and flavorings and the food you worried “wouldn’t taste as good” actually tastes _better_ than that old high salt ‘convenience’ food…Same for eliminating (or reducing..) meat and dairy (which is made for baby cows, not for adult cows or baby humans, let alone for adult humans)

    At first it’s a bit extra work to research alternatives and experiment and explore and discover what works..then the next thing you know, like with the person switching from a high salt diet, you discover the plant based food you worried “might not taste as good” actually tastes better than anything you’ve had in the past.

    Same for going from processed to un- (or far less) processed first it’s work, and you worry it might not taste as good as the junk/convenience/fast/processed explore, discover new thing you know, “this stuff tastes _better_ than what I used to eat!”

    The Physicians Committee for Responsible Medicine link including recipes section too, start at:

    Bon apetit :-)

  9. carbon credits. If we had carbon credits on food, the real cost to our environment would show and we would be able to tell local from non-local.

  10. Jason says:

    As usual, the meat study is over-simplistic. The important factor is HOW it is grown. Yes, conventional meat is high CO2 but pastured meats are far, far lower. Pasturing cuts out all emissions from grain production such as fossil fuel based fertilizers and their application, irrigation, insecticides, grain transport, waste disposal, etc. I haven’t seen a study to prove it, but I suspect that methane production may even be reduced as we know that feeding corn to ruminants changes the acidity of their intestinal system in unhealthy ways (e.g. causing the dangerous forms of ecoli to flourish).

    If you can’t get people to eat vegan, try to get them to eat pastured. You’ll get most of the benefit and have a higher success rate (and look like less of a killjoy). Right or wrong, improvement is better than nothing.

  11. Merrelyn Emery says:

    California imports oranges? Must be because all theirs end up over here. What a lunatic system we have set up, ME

  12. Merrelyn Emery says:

    I went to a seminar by Geoffrey Russell (Perfidy) who showed the huge damage being done in Australia by grazing cattle and sheep. It’s not only the methane produced, it’s also the land clearing and the damage to waterways and habitat. Beef is also a major contributor to bowel cancer and other little nasties, ME

  13. Mark Shapiro says:

    Yes, yes, yes, and yes.

  14. M Tucker says:

    “California is the number one state for agricultural production in the U.S.”

    California farmland is some of the most arid, water poor regions in the US. California farmers depend on energy intensive water transport systems that send water through hundreds of miles of pipes and canals. Every state that depends on the Colorado River hates California because California water demand ALWAYS comes first…no matter what; Las Vegas and Phoenix be damned. But please lets continue to speak of the wonderful agricultural production of the blessed Golden State.

    It will not last. It is already declining. Time to work on a truly Sustainable Solution.

  15. As Vaclav Smil says, if you want on a personal level to do things that reduce your carbon footprint, simply eating less (or zero) red meat and ditching the SUV for a Honda Civic will get you far.

  16. Jason says:

    It depends how you do it. I’ve read a few things lately like this,9171,1200759,00.html that show that if rangeland is managed like wild herds treated it, it will thrive. Also google Polyface Farm or Joel Salatin about a guy in Virginia that restored some really depleted land by use of intensive rotational grazing. The important factor is to graze intensively and then rotate the livestock to the next section to rest the grass. This is similar to the way the buffalo herds and grasslands worked until we came along and upset the balance with our destruction and engineering.