Thursday, June 14, 2012

The 10,000 Mile Diet

This article, Shop locally, eat globally? , appeared in today's edition of our university bulletin. I thought it was worth posting a link because, unfortunately, many of my relatives, friends, and colleagues think you can support a large city by only eating food grown within one hundred miles (161 kilometers).



Desrochers is the co-author of The Locavore’s Dilemma: In Praise of the 10,000-mile Diet, in which he argues that we should stop obsessing about how many miles our food has travelled to get to our dinner plate.



  1. Nothing new here; a far back as the early 2000's there were papers addressing the environmental impact of moving food en-bulk thousands of km by mass-transport (which, per tonne moved, is very energy efficient), compared to moving the same amount of food "locally" using conventional transport (medium/large trucks). Even then, it was clear that for most foods, it was "greener" to produce remotely and transport en bulk than to produce/transport locally.

    The trendies/greenies didn't accept it then. I doubt they'll accept it now.


    I admit that I don't know, but I'd bet that the financial gain of the merchants is enough to make it happen.

  3. This is one of those arguments which is only true for a given value of "true".

    The "10,000 Mile Diet" is not sustainable. People like this idiot Desrochers say "but locally-grown food is unappetizing, and moving food around is good for the economy", as though that's relevant. Unsustainable means it's going to end sooner or later. You can whine all you like about profits, or lentils, or what-have-you, but as far as anyone has been able to prove, we're up against physics.

    "But" you cry -- in this very post, in fact -- "big cities can't feed themselves sustainably on only locally-grown foods!" This is, in fact, only true for some big cities. Ontario, possibly -- although it's interesting that the people making these arguments are careful to never actually allow for the things that locavores and ecologists actually suggest, such as deliberately reducing density or eliminating lawns in favor of gardens, on the grounds that this is "impossible" -- as though economics is going to trump physics when the fossil fuels run out. Even as far north as Chicago, though, relatively minor changes would allow a quite large number of people to mostly feed themselves for most of the year if they really had to, and unless there's entirely unprecedented and unlooked-for technology waiting in the wings they're going to have to within a couple of centuries. It will require changes in how the city is organized, but not an end to the city.

    Look, we know for a fact that humanity is going to have to make radical changes in the way we organize ourselves and live our lives. Even if we don't cut back on fossil fuels and keep pushing towards the stuff recently pointed out in Nature, things are going to have to change out of necessity. People like Desrochers simply can't conceive of the broad-scale societal changes which reality is going to impose on us, and so they wave their hands and tell us that the unsustainable will keep going forever, even though this is a contradiction in terms.

    1. Good points, and this also cuts to the heart of the AGW 'debate'. Libertarians and others can deny AGW till the cows come home, and squash any and all 'tree-hugger' measures just because of the source of the sentiment. They could even be right - maybe the climate won't change. Or maybe fossil fuels will run out before there is a significant impact on climate. A nice self-limiting cap on AGW, let's all breathe a sigh of relief that we averted that disaster ... now, about getting food to the people ...

      Of course, all we can do is defer. But opposing emission-limiting measures on the grounds that the AGW science might be wrong misses the point. Governments can't say it directly, but we are running out, and measures to slow down our consumption should be a prime focus irrespective of AGW - different question, same answer. "The economy", you say? Try running an economy when you can't move stuff.

    2. The "10,000 Mile Diet" is not sustainable
      Actually, studies suggest that the 10,000 mile diet (note: in N. America is more a 5000km diet) it is more sustainable than a local one, a few examples:

      Reality is that transportation only accounts for about 4% the emissions released in the "life cycle" of a food item. Local factors influence a foods CO2 footprint much more than transport - i.e. hothouse Ontario tomatoes release ~4X the CO2 of tomatoes grown in mexico and shipped by train. Even when looking at just transport, it is far more efficient to ship food long distances by mass transport than short distance by trucks.

      such as deliberately reducing density or eliminating lawns in favor of gardens
      My wife and I have an enormous garden, dedicating a significant portion of our 1/4 acre lot to vegetable production (the portion of our yard under cultivation is larger than the average yard you'd find in a city like Toronto or Calgary). Even with that, we are unable to produce enough vegetables for us for a year - so it is, indeed, impossible for the average home owner to feed themselves - at least, its not possible in southern Ontario. Having grown up in Calgary (and worked on farms in the area), I know first hand that yields are even lower there.

      Moreover, there is an environmental cost even here - the cost of storage. Refrigeration or freezing (or canning - we do it all) consume energy. Given the high efficiency of mass transport, versus the low efficiency of domestic appliances, I have my doubts that you end up ahead.

    3. I'm don't understand why you would suggest that reducing density is a good thing. It would inevitably entail using up good arable land for habitation. Furthermore, how does low-density help preserve areas for wildlife? The sprawl we see in our urban areas produces huge carbon emissions and is completely unsustainable.
