The following post is an excerpt and ellaboration of a longer post I wrote entitled The Future of Zambian Agriculture.
The dialogue surrounding the commercialization of food is fraught with unintuitive results that seem to run counter to much of the public discourse regarding the benefits of local, organic food sourcing. Many consumers and advocates around the world now view locally grown, organic produce as superior — both environmentally and in terms of health — to large-scale agribusiness reliant on extensive use of genetically modified organisms (GMOs).
Some NGOs beg to differ, however. Chief among them is the powerful Bill and Melinda Gates Foundation, which has recently invested more than $1.8 billion in agricultural development, primarily in Africa, with hundreds of millions directed toward GMO crop programs. The foundation is drawing on a growing body of research that, perhaps surprisingly, suggests GMOs may provide a healthy, environmentally friendly, and highly productive agricultural option.
For instance, in 2008 two researchers from Carnegie Mellons published a study in Environmental Science and Technology, which looked at the lifecycle greenhouse gas (GHG) emissions of food production. Surprisingly, the study found that the production phase dominated all other phases of the cycle, accounting for a staggering 83% of emissions. All told transportation made up just 15% of GHG emissions despite an average “food-mile” distribution distance of 6,760 km when all transportation factors were added. The authors found that cutting meat consumption just slightly was much more effective at cutting total GHG emissions than consuming locally grown food. A 2011 study published in the same journal by a team of researchers at UC-Santa Barbra found similar results.
When economist Steve Sexton examined the efficiency of local versus commercial agriculture in the Unites States, he found an all-local, “150 food-mile rule” would require an extra 214 million acres of arable land, a roughly 30 percent increase in fuel costs, and increased fertilizer use between 35 and 61 percent depending on the crop. “The direct environmental costs of large-scale agriculture are clearly non-trivial,” wrote Sexton, however, the key question, he concluded, is whether a system based on local agriculture is superior in terms of its environmental, economic, and health outcomes.
A study published earlier this year in the journal Nature found that Bt cotton, a common genetically engineered version of the crop, reduces pesticide use, thereby encouraging natural predators that can help minimize the harmful aphid population. What’s more, these benefits extended to crops like soybeans and groundnuts in neighboring fields. The study was conducted over a twenty-year period (1990 – 2011) and took place in China where 95% of the cotton grown is now of the BT cotton variety. A separate study, which appeared late last year, also in the journal Nature, found that globally, non-organic growing methods produced five to 35% more yield than organic crops. Since GHG emissions are embodied mostly in production, higher per-hector yields mean a more environmentally friendly product.
Even the technologically conservative Amish have embraced GMOs. “Amish law doesn’t say anything about growing genetically modified tobacco,” Amish tobacco farmer Dan Dienner told Joshua Davis of Wired Magazine back in 2003.
The benefits of high-productivity are especially evident when compared with the effects of locally grown food. As economist Ed Glaser has point out on many occasions (see here, here, and here, for instance) “the city” is the most efficient social arrangement in human history along a number of dimensions — including that of the environment. One big contribution of cities is that they increase population densities and allow people to live closer to work. Cities also contribute greatly to energy savings. Glaser finds that “[e]lectricity use is about 88 percent higher in the average single-family detached home than in the average apartment in a big building.” Urban gardening and locally grown food simply acts to decrease densities, which leads to more carbon output. Glaser estimates that allotting just 10% of farmland into urban areas would increase carbon emissions by 75%.
For those with a sophisticated palate, organic food may taste markedly better; and, indeed, certain types of fine dinning may necessitate limited quantities of local ingredients. For most of us, however, the difference in taste between the produce and meats we can buy at a modern supermarket any day of the week and what may be available at the Sunday farmer’s market is minimal. The question is whether, on net, eating food that tastes marginally better and is slightly fresher calls for what would amount to a drastic increase in carbon output. I don’t think it does, and presented with the evidence I think local-food advocates would agree. Technology may one day change this calculus, but for now I see the cost of local food far outweighing any benefits. Also, note that current evidence does not support the view that organic foods produce better health outcomes.
Others stress the community aspect of local food and community gardens. First, it hardly needs to be said that these farming and distribution arrangements are simply one of many, many ways that community can be promoted for any given neighborhood, town, or city. Second, this argument is highly variant on the definition of “community” being used. If I feel that, for example, we should promote the concept of a “world-wide community,” any notions that I should help my neighbor down the street at the expense of a Mexican tomato farmer quickly becomes misplaced.
 Bill and Melinda Gates Foundation, “Agricultural Development Strategy Overview”, August 2011.
 Christopher L. Weber and H. Scott Matthews, “Food-Miles and the Relative Climate Impacts of Food Choices in the United States,” Environmental Science & Technology 42, no. 10 (May 1, 2008): 3508–3513.
 David A. Cleveland et al., “Effect of Localizing Fruit and Vegetable Consumption on Greenhouse Gas Emissions and Nutrition, Santa Barbara County,” Environmental Science & Technology 45, no. 10 (May 15, 2011): 4555–4562.
 Steve Sexton, “Does Local Production Improve Environmental and Health Outcomes?,” Agricultural and Resource Economics Update 13, no. 2 (2009): 5–8.
 Verena Seufert, Navin Ramankutty, and Jonathan A. Foley, “Comparing the Yields of Organic and Conventional Agriculture,” Nature 485, no. 7397 (May 10, 2012): 229–232.