There is a growing movement in the west to eat locally-produced food (grown within, say, 100 miles of your location) on the grounds that it is allegedly better for the environment. Here (via Andrew Sullivan) is an excellent takedown of that viewpoint, showing that freighting of food contributes negligibly to emission of greenhouse gases, and hothouses in temperate countries are far worse offenders. Sample quote:
Local food production does not always produce fewer greenhouse gas emissions. For example, the 2005 DEFRA study found that British tomato growers emit 2.4 metric tons of carbon dioxide for each ton of tomatoes grown compared to 0.6 tons of carbon dioxide for each ton of Spanish tomatoes. The difference is British tomatoes are produced in heated greenhouses. Another study found that cold storage of British apples produced more carbon dioxide than shipping New Zealand apples by sea to London. In addition, U.K. dairy farmers use twice as much energy to produce a metric ton of milk solids than do New Zealand farmers. Other researchers have determined that Kenyan cut rose growers emit 6 metric tons of carbon dioxide per 12,000 roses compared to the 35 tons of carbon dioxide emitted by their Dutch competitors. Kenyan roses grow in sunny fields whereas Dutch roses grow in heated greenhouses.
Nevertheless, organic food activists in Britain's Soil Association argued for lifting the organic certification from Kenyan food exports because they are brought into Britain on airplanes. Some high-end British retailers have begun slapping a label featuring an airplane on various food products to indicate that they have been air freighted. Kenyan growers cannily responded by launching their own "Grown Under the Sun" label, pointing out that their agricultural production methods emit far less greenhouse gases than many crops grown in Britain do.
A die-hard response to the above studies would be: Don't eat either British or Spanish tomatoes out of season; don't cold store apples, dry them in the sun instead; don't ever eat dairy products; and give your true love a bouquet of in-season root vegetables for Valentine's Day...
However, they only peripherally touch on how this issue relates to food production in developing countries. Here is a key issue that has always bothered me -- in India, where we have practically non-existent cold storage and food freighting facilities, produce rots rapidly, and a good crop is paradoxically bad news for the farmers. Year after year we read of the throwaway prices at which farmers are forced to sell their mangoes, tomatoes, onions, or whatever it is; and of course, at times of scarcity prices shoot through the roof. Those mangoes would be welcomed in temperate countries (or, indeed, in other parts of India where the glut didn't happen), but there is no way to get them from one place to another without rotting.
It is undeniable that produce tastes best when fresh, but cold-stored vegetables and fruits are better than none at all. Food miles are enforced on us by our lack of infrastructure, and it seems obvious to me that they are bad both for our farmers and for our consumers.