Simplistic thinking continues on the global warming front.
My wife and I make it a habit to shop at our town's weekly farmers market for fresh fruits and vegetables.
But for some activists, eating local foods is no longer just a pleasure—it is a moral obligation. Why? Because locally produced foods are supposed to be better for the planet than foods shipped thousands of miles across oceans and continents.
In the United States, a 2007 analysis found that transporting food from producers to retailers accounted for only 4 percent of greenhouse emissions related to food. According to a 2000 study, agriculture was responsible for 7.7 percent of total U.S. greenhouse gas emissions. In that study, food transport accounted for 14 percent of the greenhouse gas emissions associated with agriculture, which means that food transport is responsible for about 1 percent of total U.S. greenhouse gas emissions.
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.