When shopping for food, how important is it to buy local? This question isn't rhetorical: I no longer know quite what to think about this. Obviously, transporting food long distances requires fossil fuels and creates air pollution, among other ills. So all else being equal, it's better to buy local. But how much better, I'm just not sure.
Studies such as this one (reported on here by the BBC, blogged about here) suggest that, in terms of net environmental impact, it's even more important to buy local than to buy organic. The authors of the study didn't look at human health issues, but did attempt to quantify all sorts of environmental "externalities" -- i.e., costs not borne by the consumer -- resulting from food production. And they found that transportating food was far and away the largest component of external environmental costs. In other words, the closer to home the food is grown, the better it is for the planet.
But then there's this analysis, from the Earth Policy Institute:
The U.S. food system uses over 10 quadrillion Btu (10,551 quadrillion Joules) of energy each year ... 21 percent of overall food system energy is used in agricultural production, another 14 percent goes to food transport, 16 percent to processing, 7 percent to packaging, 4 percent to food retailing, 7 percent to restaurants and caterers, and 32 percent to home refrigeration and preparation.
Wading through all these numbers, it looks as though food transport is not as big a deal as I'd thought. According to the US Energy Information Administration, the US consumes about 100 quadrillion BTUs (or "quads") of energy each year. If the Earth Policy Institute is correct, then transporting farm products takes about 14% of 10 quads, or about 1.4 quads a year. That's a huge amount of energy, admittedly, so buying local certainly helps. But still, transport is only the fourth largest component of the food system -- which means that, as a consumer, you can probably squeeze out just as much energy savings by getting a more efficient refrigerator or stove, or eating more grains and veggies and less meat, as by buying local.
And then there's this, from p. 62 of the Union of Concerned Scientist's venerable Consumer's Guide to Effective Enviornmental Choices:
Transportation accounts for 26 percent of ghg emissions from the fruit, vegetable, and grain category, but only 0.6 percent of all emissions traceable to consumer purchases.
Now, if this is right, then moving food all around the country (as eco-unfriendly as the practice may seem on its face) is a relative drop in the bucket. Or, er, oil barrel. According to the book, personal transportation and household operations -- mostly, what and how far you drive, and how you heat and power your house -- account for more than two-thirds of an individual's GHG emissions. That's about 100 times as much energy as is used transporting fruits, vegetables and grains. So by this reckoning, growing all of your food in your own backyard isn't as important as improving your car's gas mileage by a mere 3 percent. Or, put differently, all else being equal, it may be wiser to choose a home within walking distance of a grocery store than one that's adjacent to the fields where your food is grown.
Obviously, there's a lot to consider here. First of all, the numbers feel, well, squishy to me. When I was researching this post, I found all sorts of estimates of how much energy goes into agriculture; the sources I highlight in this post seem credible and well-reasoned, but I don't think they're in any sense definitive. Second, one shouldn't just consider the global-warming implications when making consumer choices. There are all sorts of good reasons -- practical and emotional, environmental and economic -- to buy locally grown food. But since my time, money, and attention are all limited, I like to concentrate my efforts on the choices that make the biggest difference. The problem is that now I'm just not sure how big an environmental priority to assign to buying local food: Is it the most important choice you can make, or a relatively minor one? What was once clear is now, to me, opaque.
And finally: High oil prices have spawned renewed concern over fuel shortages in the coming decades -- and since modern agriculture certainly requires lots of fuel, some folks seem especially worried whether there will be enough food to go around. That's a reasonable enough thing to worry about. But again and again I hear people argue that the best solution is to go "back to the land" -- to spread out over the landscape, and carve up corporate mega-farms into small homesteads so that the food doesn't have far to go from farm field to table. That could work, I suppose. But that sort of ultra-low-density sprawl runs exactly counter to the examples of the world's most energy-efficient economies, in which people tend to concentrate in compact urban areas where they don't have to drive much to get around.
Which suggests that how much I drive is likely of far greater consequence than how much my food does.
Comments
View as Threaded
biopolitical Posted 8:19 am
21 Jun 2005
More here.
Permalink
odograph Posted 8:38 am
21 Jun 2005
It is probably easy to pick the best and worst examples, but between them is a muddle. FWIW, I think the best would be grains grown in your own state. They have the advantage of using cheap, bulk, slow shipping, and have low wastage on supermarket shelves. At the other extreme, picture some tropical delicacy shipped by air, of which 30% can be sold before it is discarded (and fresh is ordered).
Between that, what do you do? I'd guess for a lot of things price indicates resource load. Chicken is cheaper than beef because it takes less food (indirect energy) and fuel (direct energy).
Anyway, that's my ramble.
ps. you gonna heat those local greenhouses? ;-)
Permalink
CowsEatGrass Posted 10:51 am
21 Jun 2005
It seems that these posts largely (if not intentionally) ignore two of the three pillars of sustainability -- economic and social concerns. Furthermore, I think the energy arguement ends up wrong because it's incomplete (as energy analyses inevitably are). And I don't agree that the energy makes the "biggest difference." I also can't make the numbers any less squishy--there's too many factors to make hard and fast statements about agriculture (all the more reason agriculture can't be run only as a business, it's a lifestyle).
Anyway, the statement that there's probably a huge range of on-farm energy costs across the distance grade is correct. However, it is only with the local that it is so easy to actually find out how much energy is expended on the farm in the production of each commodity (in soft terms, of course). You can ask the farmer, even go to the farm! Further, you can find out what pesticides and fertilizers are used (pollution of air, water, and soil and fossil fuel implications). Smaller farms can easily use less energy than large farms who are bound to huge diesel rigs by using a combination of manual labor, small tractors (possibly using renewables???), and maybe even traction animals (gasp!).
I'm sorry, but this just doesn't add up to me:
So by this reckoning, growing all of your food in your own backyard isn't as important as improving your car's gas mileage by a mere 3 percent. Or, put differently, all else being equal, it may be wiser to choose a home within walking distance of a grocery store than one that's adjacent to the fields where your food is grown.How do you figure?
This one also doesn't cut it:
We lower the environmental costs of food production by growing each kind of foodstuff where it is more efficient (on average) to do so. For example, we tend to match plant varieties to climates and soils. If we grew everything everywhere, so that everybody could always buy local, we would need more pesticides, fertilizer, water, energy and land to produce the same amount of food.
Do you have anything to show that this is actually what we do? Potatoes are from South America, but I believe Idaho is famous for them. How about corn--I think it's more driven by reliable subsidy payments than by being climate-appropriate. "If we grew everything everywhere," a nonsensical notion from the start, there would indeed be some challenges. But how about the option of dietary restraint? Furthermore, growing a wider variety of crops in all areas is possible with current conditions and could easily be advanced with THOUGHTFUL RESEARCH into breeding varieties to thier locales rather than for ease of storage and trasportation. That is to say it could be done with brains (and current technology) rather than with "more pesticides, fertilizer, water, energy and land" as is argued without a trace of support.
Now back to what you're missing-
The social issues cannot be overlooked. Rural communities turning into slums and ghost towns. Not to mention children not knowing what a potato plant looks like (do you?). Then there's the plight of farmworkers on massive farms. Add in the health, taste, and security concerns with this and it begins to look quite remarkable.
Then there's the economic side. Money circulating in a local economy is good for consumers and producers (a.k.a Citizens). Most food dollars funnel into the vertically integrated corporate hands; they supply the seed, fertilizer, pesticide, and machinery, and then by the commodities and process, store, ship, distribute, and sell the "value added products" back to the farmers who feed their families with food they bought at Wal-Mart because they can't afford to shop elsewhere on the margin.
Finally, the references to "back-to-the-land" put a spin of quaintness to the idea of meaningful local economies that is undeserved. It's pretty obvious that every system we have ever had (or tried to have) has failed when held to the standard of "sustainable." I think something much more complex needs to develop from astute imagination if food, economics, and energy are to come into some sort of sane relationship.
Your comments about the inefficiencies of a diffuse population are correct when looking backwards, but not necessarily true when looking forwards. They also fail to recognize the social and environmental costs of concentrated populations who are touted as more efficient.
True local economies will not just be based on food--diffuse populations now rely on centralized supplies of energy, goods, and services. It is when the sources become as diffuse as the sinks that we can mark one in our column in the struggle against entropy.
So it's not just about buying those grains and veggies (and maybe a little meat) locally--it's got to be about locally producing and buying that fridge and stove you mention, too.
Permalink
David Roberts Posted 1:05 pm
21 Jun 2005
One other thing to toss into the mix. Part and parcel of our current food system, which relies on long distances, is heavy processing of foods. Processed, packaged foods last longer and can be transported farther more easily.
As a result, most Americans eat an enormous amount of carb-laden, processed food. In general, Americans are eating more and more, and getting more and more obese, but at the same time getting more and more malnourished, because the foods we eat simply don't have the nutritional content they once did (this is true of non-processed stuff too, like veggies grown on mega-farms).
All of which is by way of saying: There are enormous health costs to our current food system. Diabetes, obesity, heart disease, etc., are all exascerbated by the crappy food we eat.
So that's an external cost that should be factored in the mix, though I admit it's a long thread to follow and difficult to put hard numbers to.
(This assumes that local food, grown on small-scale farms, is healthier.)
www.grist.org
Permalink
jdhlax Posted 3:50 pm
22 Jun 2005
Permalink
odograph Posted 11:35 pm
22 Jun 2005
If we had local food, grown with local water, sure I'd support it.
In much of the southwest though, most food is imported, or grown on an industrial scale with imported water.
I'm afraid the simple rule buying local is clearly better is going to suffer with locale.
Would you want Las Vegas dwellers to buy locally? Is it better to truck in produce, or to pipe in eough water to grow crops in the Nevada desert?
Etc.
Permalink
jdhlax Posted 5:51 pm
23 Jun 2005
However, this is a completely different problem than the one caused by industrial transportation, which consumes oil and pollutes the air, water, and land. Virtually everything should be bought and sold locally in order to reduce the harm from consuming, refining, and burning oil, AND people shouldn't live where they don't belong. If you want to live in the desert, live like Apaches!
Permalink