Tangerines per Gallon

In a meeting with environmentalists, Elizabeth Edwards talked about the importance of buying locally-produced foods:

“We’ve been moving back to ‘buy local,'” Mrs. Edwards said, outlining a trade policy that “acknowledges the carbon footprint” of transporting fruit.

“I live in North Carolina. I’ll probably never eat a tangerine again,” she said, speaking of a time when the fruit is reaches the price that it “needs” to be.

Being the kind and considerate person that I am, I don’t want the Edwards family to unnecessarily forego the pleasures of tangerine-eating. Therefore, I’ll try to help them out by calculating a vital economic and environmental parameter which shall be known as tangerines per gallon.

This is a very rough and preliminary analysis; tangerine experts and transportation experts are invited to chime in with more data.

Tangerines weigh about 1/4 pound each. As near as I can tell, the tangerines consumed in the U.S. come mostly from Florida, California, and Spain. There are four possible ways for them to get to market: truck, train, ship, and air.

According to the Association of American Railroads, trains move freight with an average efficiency of 423 ton-miles per gallon. The AAR also puts railroad fuel efficiency at 3-4 times that of trucking. I’ll use 400 tmpg for rail, and 100 tmpg for truck.

The Edwards residence is near Chapel Hill, NC. Let’s move some tangerines to his local store–first, from Florida. For this simplistic analysis, assume the shipment originates in La Belle, FL, which is 763 miles away from Chapel Hill–I’ll round it up to 800. So we have 8 gallons of fuel used per ton of tangerines, or 1000 tangerines per gallon.

If the shipment goes by rail, the TPG number will be much higher. The rail haul will consume only 2 gallons of fuel per ton, but I’ll assume 100 miles of truck shipment to get the fruit to and from the railheads, adding 1 more gallon. We’re now up to more than 2600 tangerines per gallon.

For West Coast tangerines, I calculate 266 TPG by truck and 941 TPG by rail. (This company is making a major push to get a higher proportion of the west-to-east fruit/vegetable traffic moved to the rails.)

But what if the Edwards tangerines come from Spain? We’re now talking ship or plane, and the fuel consumption estimates for these modes are harder to pin down. Combining estimates from several sources, I feel we can conservatively estimate 500 ton-miles per gallon for sea transportation and 7 tmpg for air freight.

According to an analysis from 1998, virtually all U.S. tangerine imports from Spain come by sea. So let’s ship the Edwards tangerines from Valencia and bring them in at Wilmington, NC. This should be about 5000 miles, consuming 10 gallons per ton, and haul them 160 miles to Chapel Hill, for another 2 gallons. Result: 666 tangerines per gallon.

If the tangerines do go by air–which seems unlikely–then fuel consumption from Valencia to Charlotte will be about 714 gallons, with another gallon for trucking to Chapel Hill. Result: 11 tangerines per gallon,.

So, it seems likely to me that the Edwards family is getting somewhere between 400 and 1000 tangerines per gallon. (Truck from Florida, blended truck/rail from West Coast, or ship from Spain.) Worst case–air freight from Spain–they’re still using less than a tenth of a gallon per tangerine consumed.

It’s interesting to compare these results with the “local” case. Suppose that a miracle occurred and tangerines began to grow in North Carolina. Even then, though, it’s doubtful that there would be tangerine groves adjacent to the Edwards place. If the tangerines are raised by a farmer 60 miles away, and he brings 500 lb of them to market in a pickup truck getting 20 mpg, then he is using 3 gallons of fuel each way–6 for the round trip–which equates to 333 tangerines per gallon. This is worse than truck from Florida, worse than rail from California, and worse than ship from Spain. Obviously, the numbers for the local alternative would improve–a lot–if we assume that the pickup truck is actually filled to capacity, or nearly so, but that’s not always easy to do under conditions of small-scale production and distribution.

39 thoughts on “Tangerines per Gallon”

  1. A fascinating and illuminating post! Thank you, David!

    On the other hand, I would like to think of preachy, self-righteous Mrs Edwards never eating another tangerine. It warms the cockles of my heart.

  2. And I suppose that she will take time out from the campaign soon so she can stay home canning peaches, tomatoes, green beans, etc., as well as overseeing the construction of a root cellar in the stately Edwards manse.

    Does this remind anyone else of Marie Antoinette playing shepherdess? Or did anyone else think of David Ricardo?

  3. Upon hearing the story of Mrs. Edwards giving up tangerines in favor of locally-grown produce, I immediately ran to my local grocery and purchased a crate of Clementines. In West Michigan our tangerines usually come from either Spain or Israel, but this year, to my surprised delight, they came all the way from South Africa!

    I wonder if any others were driven to buy tangerines because they heard that drivel.

  4. For the air-freight from Spain, you forgot that it could be shipped to RDU airport, which is *much* closer to Chapel Hill. OTOH, I’m pretty sure neither airport has direct flights to Valencia for passengers, and I’d be surprised if the did for freight. OTOH, a layover in the NY area would hardly change the results of the analysis.

  5. Tom – Ha ha ha ha! V good!

    Robert, I see you got your tangerines from S Africa and they came all the way to MI. This is what we call “global trade” and it gives a living wage to a lot of people. In fact, when I think what it took to get those tangerines planted, grown, harvested, packed – in specially manufactured crates, taken to a port, loaded on transport, protected on the voyage, cross the world, be unloaded in the US, picked up at the dock,loaded on trucks and taken to Michigan, the mind boggles.

  6. I just had a terrible thought.

    What if, years from now, when it’s too late, scientists find that massive tangerine intake cures cancer?

    Elizabeth Edwards can have my share of tangerines. I hate ’em.

  7. alas, another snippy wise acre attempt to put down “” associated with “that” party.
    Support local when you can; buy worldwide if you must…simple, right?

  8. “Support local when you can; buy worldwide if you must…simple, right?”

    Why? Buy the product you want, based on quality, price, whatever. Why is there any principle involved at all?

    Why is it “progressive” to be bigoted against someone who wants to sell you something just because they live farther away?

  9. dvid…no, actually it’s not that “simple.” Locality is not the only thing that matters. As the analysis shows, 1000 miles via an efficient transportation mode may use less energy than 50 miles via an inefficient transportation mode.

    An energy is not the only important resource. Making effective use of the time of human beings, for example, is important too.

  10. Do the Luddites realize that their packet-switched emails and phone conversations to nearby destinations often travel thousands of miles “out of the way”?

    The extreme Luddites, the ones who really believe the stupid ideas, are ignorant fools. But for the rest, talk about “local” this or that is mostly posturing: they care little about the empirical validity of their slogans. Like today’s fad diet, today’s economic and political buzz-phrases will soon be put aside in favor of next year’s fashions. The ideas don’t make sense? No matter, they will soon enough be forgotten. The big mistake, aside from the sheer wrongness of some of the ideas, is the assumption that bad ideas don’t have costs in the real world.

  11. I suspect that part of the reason we don’t realize they have costs is that we have taken the gains for granted. For instance, the world market makes us healthier in the variety of nutrients.

    One of my husband’s colleagues described to her class her reaction when she returned to America from a semester in one of the more deprived of Russia’s satellites; she apparently (or at least she told them) started crying in Target at the immense selection of shampoos. The person who told me this believed that the teacher saw this as a bad thing. I’ve thought about that every once in a while for the last dozen years or so; I still haven’t figured out why that is a bad thing.

  12. I read a news about me in your blog(site)


    Thank you for support me. You can know too more about me with reading this text:
    Best Regard Arash Sigarchi

    Arash Sigarchi the Iranian Journalist and blogger was born in Rasht City center of Gilan province in north of IRAN that have 300 Km distance from Tehran (capital of IRAN)
    He fond very soon to reporter and he started this job with a sport newspaper in only 16 years. Thereupon , He went to Tehran for study in university. He activity in Reporter of political and social proficiency in Tehran `s professional newspapers. “Sigarchi” have presence in reformist newspapers as a journalist Simultaneous with come president Mr. Khatami .

    Sigarchi was a analyzing and author for reformist newspaper. He owned very experiences in that years. He wined in Iranian press festival 10th and 11th in branch of Interview and political article.
    The forty newspapers arrested by the Iranian leaders`s injunction in a day at 2000. Sigarchi was unemployed as others journalists. He comeback to his birthplace Rasht City and he operated a new newspaper with 16 pages ; that name was “Gilan e Emrooz” (means Gilan Today). He used his experiences in this newspaper and it extended to more sale at the country in during his Editorship. His newspaper between local newspaper of IRAN was the best for Three years.

    Sigarchi in the 5 years editorship of GilanToday instructed journalism to 60 persons at two method : scientific and tentative. They are active in many newspaper in IRAN now.
    “Sigarchi” operate a blog at 1999 befor start brunt of censorship on the Iranian press. he written in his blog Until he cant published his article or news in his newspaper ; Hereinafter he encounter with brunt of censorship. After this accidence , he was a famous Iranian blogger in Internet. Iran `s intelligence service decided For Confliction with “Sigarchi” for this reason.
    They sallied to his home in first time , for Activity in blogging and try for promotion of “freedom of expression” and prevalence of “professional journalism” in IRAN by “Arash Sigarchi”. They removed his computer , books , handwritten and other personal tools. after this conflict , they prisoned “Arash” in desember of 2004 and sentence he to 14 years prison in 4 January 2005.

    Iran `s reign was be impel for freedom of “Arash” from jail in march 2005 after remonstrance of many Iranian and universal journalists and bloggers and world liberals like Ms. “Shirin Ebadi” (peace Nobel Prizewinners in 2003) too . she was attorney of “sigarchi” in court.
    After 9 month , in December 2005 , revision court lessened “Arash” condemnation from 14 to 3 years and they sended “Arash” to jail. Don’t long time from presence of “Arash” in prison , yet that his brother , “AShkan Sigarchi” deceased in a accident. He was a famous Iranian musician and pursued case of “Arash”.
    This Shock and pressures of prison afforded Arash was be sick after a year. He had a bad tumor in his tongue. That was a bad cancer!
    Arash become to leave from prison for remedy With protest of bloggers and journalists. He do chemotherapy , surgery and radio therapy in last six month. He is ok now and he wait for end of his condemnation. He have many program for future .
    “Arash Sigarchi” is a poet and auther. He has a poem book as namely “Inebriety Vainglory”. He has e two collection of story that cant published in IRAN. “Arash” has not permit for publish. Don’t let censorship!
    Arash Sigarchi Go to others country for lecture about “freedom of expression” and “free flow of information” now. His email Address is sigarchi@gmail.com or arash_sigarchi_s@yahoo.com .

  13. …she apparently…started crying in Target at the immense selection of shampoos.

    I was similarly overcome with emotion, and I had only returned from Australia. Where they have Targets of their own.

  14. You’d do everyone a favor by calculating how many tangerines or humvees we could enjoy at the same carbon footprint that is claimed by the popping out of yet another Amerikan kid. Why are we subsidizing the breeders when we should be subsidizing the tangerine growers and truckers at the expense of the breeders?

  15. Angie Schultz – I had something of the same sensation the first time I went to Delhi and saw the abundance of incredibly handsome men. I almost burst into tears of happiness,but I was too busy looking.

  16. Each to her own, Verity.

    …yet another Amerikan kid.

    That would be “AmeriKKKan”, for maximum Moral Outrage.

    I looked up the agricultural products of North Carolina, to discover what sorts of foods the Edwards family could consume while remaining true to their locally-grown ethos.

    Turns out they can have all the tobacco they can eat.

  17. Here in Australia there has been a lot of Chinese garlic – very white not very hot for some time. The hotter red variety was grown locally and cost a lot more. Suddenly they are the same price and some of the cheap red garlic is also Chinese but most of it in Mexican…this is Western Australia I’m talking about. So how can the garlic farmers in Gilroy California compete – even if they use Mexican labor to pick the stuff?

  18. Verity, you have a cute product idea there. How about bathmats with little footprints on them and the motto–“Watch your carbon footprint. Keep your showers short.”

    I bet they’d sell very well, at least in certain venues.

  19. David- Actually … hmmmm …. yes.

    Or some way of making a carbon footprint on a bathmat grow larger! Personally, I favour profligacy.

  20. Fetching idea – for a dog. Where I live we are strangers to house slippers and Saquatches. By a really amazing coincidence,I am allergic to handcrafts and folk art.

    Couldn’t we just subcontract out to a a factory in Indonesia? This way, the Indonesians get trained in the important art of contributing to the world economy and cash in on carbon footprints before they become yesterday’s fad.

  21. Pingback: Newmark's Door
  22. But wait.

    Where I live the local grocery store is just about as far as the local farms. So when I go to the local farm to get tangerines rather than to the supermarket there is 0 (zero) gallons of additional fuel used. I get an infinity of tangerines per gallon by buying from a local producer. (I also support local neighborhoods and communities and get fresher produce besides.)

    As far as I am concerned your argument is full of soot!

  23. Gosh, Lm, are tangerines all you eat? Where do your wheat-based products come from? Corn-based? Eat any potatoes? Tell you what, why don’t you figure out how much driving you’d have to do to buy each food product you currently consume from the nearest ‘local grower’? And do you buy *any* processed foods at all? After all, they have to be transported *from* the ‘local grower’ *to* the processor and then *to* the end-seller’s location. Do you drive to the processor’s plant to pick this stuff up? How much home-canning do you do, anyway? (I, by the way, do quite a lot, not because I’m worried about the eco-nazis drive to screw with my lifestyle so much as I grew up that way and think it tastes better.)

  24. Let’s see. We just canned our first tomato sauce of the season; the tomato crop is just ripening. We’ve got beans, zucchini and cabbage frozen from our earlier harvests. We grow lots of our own food because we think it tastes better and it’s a kick to get the stuff to grow.

    It must have been a long time since you’ve been out to a farm because , you know, they do grow more than one crop at a time.

    The tangerine/gallon argument leaves out lots of stuff: carbon footprint of the manufacturing process, of the local cost to transport the tangerines to the train/truck/airport stations, carbon footprint of the workers getting to the train/truck/airport stations. So I’ve left out lots of stuff, too.

    So I say to you chill.

  25. The “buy local” sentiment can be understood in terms of signalling. What you’re doing is telling your local tribe members that you’re on their side, an ally not a enemy. From an evolutionary perspective this was a valuable human trait. Distinguishing and signalling ally versus enemy provided a selective advantage. That’s my guess as to the popularity of such otherwise impoverishing behavior.

  26. I sense a lot of closedmindedness here. Instead of assuming the worst, why not try to understand what motivates people?

    In my case, I understand that buying local is becoming quite popular. The reasons are probably two:

    1) Some people probably do it because they value local farmers more than remote farmers. I don’t subscribe to that philosophy. As commenters have said, remote farmers are just as deserving.
    2) Many people do it because they believe they are reducing their carbon footprint. OK, a few issues here.
    a) First, I generally feel that a carbon tax would do the trick here.
    b) But, buying local is not just “an inefficient approximation” to a carbon tax. It is about changing people’s value system in a way that will change their demand curve. If people get some moral value out of buying local (or conserving home energy, or whatever) then the resulting consumption switch can be an efficient result. The value system of people can change, and when that happens, it can change the equilibrium.
    c) I agree that people who buy local to reduce CO2 had better be sure they are actually doing that. I’ve seen some mixed evidence here, but (i) I think the environmentalist community is sufficiently self-critical to “get the message” once definitive research comes out in either way, (ii) I’m sure some food gets freighted by air, and it would make sense to target that per David Foster’s great analysis; (iii) Efficiency happens with economies of scale. As local-farmer demand increases, the local-food supply chain will increase in efficiency. (iv) It is excellent to point these things out so people can be mindful of them. For example, one could imagine a food-transportation business, targeted at locally-grown foods, which emphasizes high CO2 efficiency (hybrids, electric vehicles, railways). (v) Note that the tangerines in David Foster’s example are not grown at the seaport, and they are not grown at the train station. Presumably the very beginning of the supply chain, which moves foods to the high-efficiency transportation hubs, is CO2-inefficient. That is left out of David’s otherwise excellent analysis.

  27. It seems that it would be fair to assume that the distance from production farms to distribution centers is roughly equivalent to the distance from local farms to local stores. In other words, we should add the global rail/boat/plane costs to the pickup truck cost, not compare it. Unless, that is, all farms are at rail stations or ports or what have you, which I somehow doubt.

  28. For rail shipment, I added 100 miles of truck transport to get the goods to & from the railheads. For sea transport, I assumed 160 miles of trucking from Wilmington (NC) to Chapel Hill.

  29. Thanks for the reply David. If I’m not mistaken, you have accounted for high-efficiency trucking to and from the railheads (and “from” the domestic seaport). A few remaining questions:

    1) What about transportation “to” the overseas seaport?
    2) Is the assumption of high-efficiency trucking valid? Probably it is most valid for large farms that can benefit from big trucks.

    What I get out of your helpful analysis is this:

    1) Carbon-emission-wise, don’t worry too much about the efficient parts of the supply chain.
    2) Do worry about air freight. (perhaps uncommon)
    3) Do worry about low-efficiency trucking.
    4) Usage level of low-efficiency trucking is probably, roughly proportional to
    a) how much we rely on small farms and
    b) how far away small farms are from high-efficiency transportation hubs.

    I am not sure if we should be too concerned about low-efficiency trucking. In the long run, we will use it less and less — note that even small farms are close to other small farms, and these folks have incentive to aggregate their production in local transportation hubs that can use high-efficiency trucking.

  30. The analysis is too limited to be anything but misleading. For instance, the basis for these calculations is way off because the 423 ton-miles-gallon that you started with is an average that is primarily based upon moving heavy bulk commodities long distances (i.e. coal, steel, aggregates). It doesn’t apply to a light commodity such as packaged tangerines.

    For example, your model would indicate that if rail tracks ran the 60 miles from the local farm to my doorstep that would be the most efficient transportation mode. A commodity like this would move in a boxcar. The load would cube out without reaching the weight limit. The lading weight may only be ~60,000 lbs. The tare weight on a 50’ boxcar is approximately 65,000 lbs. Common sense should tell you it wouldn’t be efficient to move 0.27 lb of steel railcar for each 0.25 lb tangerine. Not to mention I don’t need 240,000 tangerines. You’re also ignoring a bunch of other things such as all of the energy costs associated with building and supporting a transportation network.

Comments are closed.