Some food for thought

There’s little debate, then, that energy use in the present global food system is unsustainable. Between 1997 and 2002, in fact, over 80 percent of the increase in annual U.S. energy consumption was food related. And estimates for 2007 suggest the U.S. food system accounted for nearly 16 percent of the nation’s total energy budget, up from 14.4 percent in 2002, according to the report, which measured both the direct energy used to power machines and appliances (like trucks and microwave ovens) as well as the “embodied” energy used to manufacture, store and distribute food products.

Kamyar Enshayan, director of the Center for Energy & Environmental Education at the University of Northern Iowa. “We’ve created a food system that relies heavily on fossil energy, and it’s become so globalized that there are literally grapes from South Africa in the grocery store in Cedar Falls, Iowa. It’s a long-distance shipping economy, which makes all of us vulnerable to disruptions in the supply chain and other unforeseen emergencies...We have the best soils and a great climate and yet, most of what we eat is imported,” says Enshayan. “You have to step back and say, ‘Wait, why is a region like Iowa not feeding itself?”

Many environmentalists insist the answer is to “buy local,” since fewer transport miles translate into fuel savings and fewer emissions yet a 2001 study published by the Leopold Center for Sustainable Agriculture at Iowa State University, the conventional food transportation system, which uses national suppliers to stock grocery stores with fruits and vegetables is, indeed, the most energy intensive. But the local system touted by conservationists, in which farmers market directly to consumers through community supported agriculture enterprises like farmers markets, was also found to be less efficient than using a regional network of suppliers. “From a purely transportation perspective, the regional system was by far the most efficient,” says Pirog, associate director of the Leopold Center, who maintains the findings are equally valid today. “We found that the regional food system was anywhere from 8 to 17 times more fuel efficient than the national system, but also 4 times more efficient than the local system.”
While some studies have shown that vegetables grown locally require two to three times less energy than their imported counterparts, a 2008 study at Cornell University surprisingly found that it required four to six times more energy to produce perishable crops year-round in greenhouses in upstate New York than to truck them in from California. That’s partly because of the increased fossil fuels required to heat the greenhouses, but also because the larger mega-farms in the West benefit from economies of scale, or the cost and energy advantages of producing large volumes.

“The production and distribution of food has long been known to be a major source of green house gas and other environmental emissions" writes Christopher Weber, an environmental engineering professor at Carnegie Mellon University, in a 2008 paper called “Food-Miles and the Relative Climate Impacts of Food Choices in the Unites States” that he co-authored.

By far the use of energy-intensive technologies as a substitute for manual labor is the biggest contributor. An example: High tech, energy-intensive hen houses — and the growing use of liquid, frozen and dried egg products (instead of whole eggs) — increased energy use per egg by 40 percent between 1997 to 2002, the USDA report found. Also our penchant for labor saving technologies in households are the biggest energy users in the food chain — 29 percent of total food system energy use. “Consumers are relying on blenders and food processors instead of knives and chipping blocks...”

A more immediate solution (from an environmental perspective) to reduce energy consumption may be to change the way we eat. Red meat is about 150 percent more intensive on green house gas emissions than chicken or fish.

Taken from here