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How much better is local food for the environment?
Local food can consume more energy, especially when it is shipped -- even short distances -- by truck. Here is from The Boston Globe:
...a gathering body of evidence suggests that local food can sometimes consume more energy -- and produce more greenhouse gases -- than food imported from great distances. Moving food by train or ship is quite efficient, pound for pound, and transportation can often be a relatively small part of the total energy "footprint" of food compared with growing, packaging, or, for that matter, cooking it. A head of lettuce grown in Vermont may have less of an energy impact than one shipped up from Chile. But grow that Vermont lettuce late in the season in a heated greenhouse and its energy impact leapfrogs the imported option. So while local food may have its benefits, helping with climate change is not always one of them.
And more:
Judged by unit of weight, ship and rail transport in particular are highly energy efficient. Financial considerations force shippers to pack as much as they can into their cargo containers, whether they're being carried by ship, rail, or truck, and to ensure that they rarely make a return trip empty. And because of their size, container ships and trains enjoy impressive economies of scale. The marginal extra energy it takes to transport a single bunch of bananas packed in with 60,000 tons of other cargo on a container ship is more than an order of magnitude less than that required to move them with a couple hundred pounds of cargo in a car or small truck.
Yes even grapes from Chile end up on a truck but perhaps on a more efficient truck. Why is there no talk of how they are transported from the Chilean vine to the Chilean port? Here is a previous post on this topic.
Posted by Tyler Cowen on July 25, 2007 at 06:45 AM in Food and Drink | Permalink
Comments
And the energy to run the big cranes to get them off the boat and too the train, and off the train and onto *GASP* the truck to get it too the store.
Posted by: Jacob at Jul 25, 2007 8:37:15 AM
Though this raises a good point that these things should be concidered and hypothetically it could happen but I don't see a lot of hard evidence that this is actually happening. I don't see a lot of heated greenhouses in Vermont nor a lot of new greenhouse construction.
Unfortunately, though shippers would like return containers to be full they often aren't. There's a lot being shipped from Asia to North america but there's not a lot to ship back. Usually the company shipping from Asia pays for the return trip. If the shipping company can find something to ship back then it's free money for them.
Posted by: asiequana at Jul 25, 2007 9:30:03 AM
From Earth Day 2006, when Yahoo! decided to offer 10 poorly considered suggestions for how to save the Earth:
7. Buy Local. According to Yahoo!, produce grown in the U.S. travels 1500 miles, on average, to reach your grocery store. Yahoo! goes on to say that you can "save on fuel by buying from local growers," or by creating "your own community garden."
This suggestion shows why Yahoo!'s climate change reducing suggestion Number 2 doesn't compute. Even if it travels 1500 miles, produce travels by the foodstuff equivalent of public transportation. Replacing this transportation with the thousands of trips that the fellow members of your community would need to make to support local growers really doesn't make a whole bunch of sense - especially when you multiply those thousands by thousands of communities. Plus, you need to consider that all of you are getting city mileage instead of eco-friendly highway mileage! Unless, that is, you're driving that hybrid from suggestion Number 4.
The community garden idea is a nice one though, and you should give it serious consideration when deciding what crop to put in the space that your community is currently using to grow trees for paper production for its junk mail.
Will buying local reduce climate change? No. At least, not in any measurable way.
***
Yes, we were having fun that day....
Posted by: Ironman at Jul 25, 2007 9:30:37 AM
When determing my annual carbon output at esurance.com the other day, the "buy local?" option surprised me. It immediately occured to me that the "Buy Local, Save the Environment" could be little more than a grassroots/local organic/yuppie marketing tactic piggy-backing on global warming.
Posted by: Captain Hook at Jul 25, 2007 10:03:54 AM
[ on a truck but perhaps on a more efficient truck. ]
That seems to be what this idea hinges on. How much more efficient can this truck be? Unless it can overcome the inefficiencies of an older truck in Chile, the energy to load it into boxes, the energy to put it on to the boat, the starting of the boat, going thousands of miles, and then unloading of the boat and then to a distribution center and then on to this amazingly efficient local truck.
Posted by: BlogReader at Jul 25, 2007 10:48:18 AM
Replacing this transportation with the thousands of trips that the fellow members of your community would need to make to support local growers really doesn't make a whole bunch of sense - especially when you multiply those thousands by thousands of communities.
Huh? Maybe I'm misunderstanding you, but it seems to me that a trip to the local grower wouldn't be that much further than a trip to the supermarket. I guess the argument could be made that stocking the fridge would require a trip to the local grower *and* to the supermarket.
One more point: the option of importing food from great distances doesn't speak to the spoilage issue. I don't know if that even is an issue.
Posted by: fustercluck at Jul 25, 2007 10:51:53 AM
Fustercluck,
Assume no one uses more energy intensive farming than anyone else.
Imagine a farmers market 5 miles outside of town. Imagine 1000 trips a day to that farmers market.
Imagine two grocery stores in town where everyone is on average 1 mile from one of the stores. Imagine 1000 trips a day to one of those grocery stores. (This will actually be less than 1000 because some live in walking or biking distance. I walk to my closest grocery store whenever I am buying stuff I can carry home by myself).
Which option uses more energy? Answer: It depends on the average energy transportation usage of the food in your grocery store.
Now if you can manage to persuade your local grocery store to buy overpriced local produce (relative to that grown on cheap foreign land by cheap foreign laborers) then you would be correct that buying local has fewer "food miles" on it. But it is far from clear that buying overpriced food farther from home than your local grocery store makes sense even if you buy into the GHG hypothesis.
Personally I think that global poverty is a more pressing issue than global warming, and I can do more to address the former by buying what I want at the lowest prices (quality adjusted of course) I can find. It is not clear to me that anything I do with regards to the latter will matter. The only way that AGW will be solved, assuming it can be solved, is with affordable technology.
Voluntarily reducing the market for such technology by reducing my energy purchases seems to me to hinder such technology development.
Posted by: happyjuggler0 at Jul 25, 2007 11:20:00 AM
Ever consider finding out if your supermarket uses local growers and deciding upon your food choices that way? I try and buy local foods at the store, write down to my bacon.
Posted by: Jacob at Jul 25, 2007 11:24:30 AM
Maybe the best solution would be a local grower with home delivery options a la Fresh Direct.
Posted by: fustercluck at Jul 25, 2007 11:49:52 AM
Your caveats at the end are important ones. Produce must go through a local shipping by truck, whether or not the added stage of long-distance sea transport is added.
I would also point out, as Ralph Borsodi observed 80 years ago, the cheapest option of all is to raise the food at the point of consumption. He added up the total cost of all inputs in growing and canning his own vegetables--including the market value of his and his wife's labor--and found that the overall cost was about a third less than buying them at the store. The average person can supply himself with better produce for less labor than it takes to earn the money to buy it, and at the same time reduce his dependence on wage labor and his fear of the sack.
Posted by: Kevin Carson at Jul 25, 2007 12:34:47 PM
Kevin_Carson: What does Ralph_Borsodi's calculation from a hundred years ago have to do with anything?
I'm *pretty* sure factor prices have changed since then, rendering whatever numbers he used then moot. The
issue of whether it's cheaper to produce at the point of consumption is an empirical one, which can't be
calculated for all times and places with certainty now.
I also think the calculation doesn't account for how the food's market value should be counted as income
in the tax code and therefore taxed. I know, I know, "The income tax shouldn't exist" and all, but if it
didn't exist, the store bought stuff would be cheaper too. It would be odd indeed for the proof of local
being better, to hinge on favorable tax treatment.
Posted by: Person at Jul 25, 2007 1:33:28 PM
The local food movement makes more sense if you understand it as a piece of a larger whole, together with eating organically-raised and in-season foods. The 'local' part, taken alone, doesn't always make sense -- just like the 'organic' label taken alone doesn't. Local is often a good proxy for in-season, however, especially taken in combination with price.
If your personal utility function doesn't value those things, the whole thing seems rather silly.
Posted by: dexev at Jul 25, 2007 2:43:11 PM
Maybe someone should share this article with Elizabeth Edwards. According to this article (http://www.freerepublic.com/focus/f-news/1870978/posts?page=85) she is under the opposite impression.
Posted by: Billy at Jul 25, 2007 4:01:26 PM
don't forget land use considerations. If we get our food from the place where yields are highest, we don't need as much farmland per pound of food. Farmland is not environmentally nice, not even when it's organic. It's monoculture, not hospitable for native species, wildlife, etc.
Posted by: Bill Conerly at Jul 25, 2007 4:10:35 PM
"But grow that Vermont lettuce late in the season in a heated greenhouse and its energy impact leapfrogs the imported option."
Strawman - the point of buying local is to buy things in season. If you have to grow it in a greenhouese, eat something else.
"Imagine a farmers market 5 miles outside of town. Imagine 1000 trips a day to that farmers market.
Imagine two grocery stores in town where everyone is on average 1 mile from one of the stores. Imagine "
Imagine 250 trips a day to the farmers' market becuase people form informal neighborhood co-ops to save time; forget global warming and high-mindedness. Imagine all kinds of things - you can manipulate hypotheticals to illustrate or "prove" anything you like.
Posted by: Jim at Jul 25, 2007 4:16:43 PM
How much would it cost to import a vine-ripened tomato or a tree-ripened peach from Chile? One problem is that quality has become subservient to cost, specifically the ability of the produce to survive shipping.
Of course if you want to let the market solve the problem you would increase the price of the energy to reflect the true future costs, presumably by a tax. This is interference in the market by government, but government interference in agriculture is nothing new.
Posted by: skeptonomist at Jul 25, 2007 4:23:21 PM
"The marginal extra energy it takes to transport a single bunch of bananas packed in with 60,000 tons of other cargo on a container ship is more than an order of magnitude less than that required to move them with a couple hundred pounds of cargo in a car or small truck."
But since the bananas would turn into mush if they were shipped that way, they are actually shipped in special refrigerated ships, and I expect the energy use of climate control for a week is more than that to move the ship. Since I can get bananas for about 50 cents at the produce store, the energey use still isn't that great.
Posted by: sort_of_knowledgable at Jul 25, 2007 5:54:02 PM
Still I expect most produce shipped over an ocean has a significantly larger energy cost due to the climate control concerns, or the higher energy cost of air freight.
Posted by: sort_of_knowledgable at Jul 25, 2007 6:05:22 PM
Yes, the point of local food is to grow it in season. It even tastes better when it's grown at the right time--surprise. Try reading Barbara Kingsolver's Animal, Vegetable, Miracle about her family's change to local food production and growing their own.
Posted by: Brad at Jul 25, 2007 8:11:46 PM
I am surprised by the level of hypotheticals and assumptions going on in this discussion, and even in the original post. All of this comes down to lack of knowledge, and thus differing assumptions that take the place of real data. Every piece of packaged food in a store in the US has a label indicating how many calories are in the food. A carbon tax would very simply and effectively add the (unclean) external energy content of the food to the price, making it much easier to decide. And there is no "but it is too hard to figure out" argument. It just takes political will.
Posted by: Seth Delackner at Jul 25, 2007 11:17:16 PM
A noble idea, but isn't a bit easier to compute the caloric content, of, say a box of cookies than it is to determine the total energy costs associated with that product? It might be easy (-ier) to calculate the energy cost of making and packaging the box of cookies, but the cost of getting it into the hands of the consumer: not so clear.
The latter cost would be tied to the method(s) of shipment (which could vary), what % of a given shipment that box of cookies comprised (which could vary greatly), and the location of the consumer's supermarket relative to distribution points.
Posted by: fustercluck at Jul 25, 2007 11:54:48 PM
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Posted by: dhdxjx at Jul 26, 2007 4:06:35 AM
The farmer's markets in my area are no further away than the grocery stores.
A good way to buy local is to by from a CSA-- Consumer Supported Agriculture, where the consumer contracts with the farmer for a share of each week's produce. The farmer packs up boxes of fruit and vegetables each week, and delivers them to central locations in towns, where the consumers pick them up. The consumer gets ultrafresh local produce, and the farmer gets a guaranteed supply of customers because the consumers pay in advance.
I pick up my CSA box by bike.
Posted by: Cardinal Fang at Jul 26, 2007 10:09:30 PM
I think every aspect of production of consumes energy. You can't just focus on the most visible consumption.
For example, production of a Toyota Prius consumes energy, more than a car with a conventional drivetrain. But you pay for all of that additional consumption in the price. So maybe sticking with considering price is not as bad a rue of thumb as it may seem when it comes to environmental effects.
I am more concerned about distortions in the market such as subsidies that essentially deceive you about true costs of things. We don't pay the true cost of corn, for example, or the true cost of oil (military costs, building dykes to keep NYC from going under water, etc.)
Posted by: Alan Brown at Jul 27, 2007 1:14:55 AM
Alan Brown makes the point that most others miss. Price is a rough but viable proxy for lifecycle energy usage in commodity products. The fewer market distortions, the better a proxy.
Bigger question for commenters -- do you view food as a commodity, or as a discretionary consumer good?
If the latter, you should be grateful that you are amongst a fortunate minority of humans, and realize that your own choices in the matter almost certainly do not reflect an optimal strategy for feeding the world.
Posted by: Bob Knaus at Jul 27, 2007 7:25:47 AM
