Posted: November 17, 2009
Grant Woods’ famous 1930 “American Gothic” painting is an icon of what some people believe sustainable agriculture should be. Ma and Pa Kettle on the little idyllic farmstead making a living on the soil with their bare hands. Notice how miserable they look.
With all the talk these days about lifecycle analysis and carbon footprints, modern agriculture methods have increased our efficiency and therefore reduced our carbon footprint. A group of researchers led by Jude Capper with Washington State University, took a ‘life-cycle assessment’ (LCA) approach to evaluating foods for environmental impact and found that efficiency is more sustainable.
Intuitively, today’s modern production practices often seem to have a higher environmental impact than the “idyllic” management practices of the 1940s. Nonetheless, when assessed on a whole-system basis, greenhouse gas emissions per gallon of milk produced are 63 percent lower. In 2007, the U.S. dairy industry produced 8.3 billion more gallons of milk than in 1944, but due to improved productivity, the carbon footprint of the entire dairy farm industry was reduced by 41 percent during the same time period.
Pasture- or grass-fed meat also is growing in popularity, with the perception that it is more eco-friendly than conventionally produced beef. However, the time needed to grow an animal to slaughter weight is nearly double that of animals fed corn. This means that energy use and greenhouse gas emissions per pound of beef are increased three-fold in grass-fed beef cattle. In total, finishing the current U.S. population of 9.8 million fed-cattle on pasture would require an extra 60 million acres of land. Again, the intuitively environmentally friendly option has a far higher resource and environmental cost.
The study also finds that transportation efficiency often means that “locally grown” food may have a higher environmental impact.
“As an example, one dozen eggs, transported several hundred miles to a grocery store in a tractor-trailer that can carry 23,400 dozen eggs is a more fuel-efficient, eco-friendly option than a dozen eggs purchased at a farmers’ market (4.5 times more fuel used) or local farm (17.2 times more fuel used).”
Interesting stuff. Read the report here.