http://www.itwire.com/content/view/18545/1... / Please go read the whole thing, it was hard to excerpt while retaining the meaning, but isn't real long.

According to a comprehensive study by Carnegie Mellon University engineers, the type of food eaten by U.S. consumers is more important than the distance it travels in helping to reduce greenhouse gas emissions and, thus, global warming.

The two researchers found that food in the United States travels, on average, 1,020 miles (1,640 kilometers) to be delivered and 4,200 miles (6,760 kilometers) for its life-cycle supply chain.

Although food is transported long distances in the United States, the researchers found that the “production” phase of food to consumers (the agricultural production and industrial preparation stages) contributes more to GHG emissions (83%) than its transportation phase (11%), with the final delivery from producer to retailer only contributing 4%.

Weber adds his advice (which he says has been given for generations), “Eat a healthy balanced diet, with a minimum of processed food. Eat a moderate amount of dairy and meat. Eat more whole grains and veggies. Following that advice will probably reduce your carbon footprint."