As a Husky, I should be glad when anyone these days ranks the University of Washington 4th in the nation in anything. I would, however, prefer it if the ranking was actually legitimate.

In the Sierra Club's ranking of the top 10 green schools, or "Cool Schools," it ranks the U Dub at number four. They note the "UW pays compulsive attention to buying local: More than half of the school's food is produced within 250 miles of campus." There's only one problem: this might actually do more harm to the planet than good.

There are numerous studies that demonstrate the "buy local" movement isn't based in science. Here are just a few.

Steve Sexton of the University of California, Berkeley analyzed what he calls a "pseudo-locavore" model where local foods are purchased as much as possible. He notes that average environmental impacts would significantly increase, including:

...corn acreage increases 27 percent or 22 million acres, and soybean acres increase 18 percent or 14 million acres. Fertilizer use would increase at least 35 percent for corn, and 54 percent for soybeans, while fuel use would climb 23 percent and 34 percent, for corn and soybeans, respectively. Chemical demand would grow 23 percent and 20 percent for the two crops, respectively.

Growing food where yields are poor more than offsets the projected reductions in transportation emissions.

The reason buying local food is often worse is that focusing on transportation ignores the vast majority of energy inputs. Two researchers found that even when food travels long distances, more than 1,000 miles, "Transportation as a whole represents only 11% of life-cycle GHG emissions, and final delivery from producer to retail contributes only 4%." Ignoring crop yields in favor of "food miles" results in a significant waste of resources.

This effect is so powerful that buying local doesn't help even when you live in a county that is heavily agricultural. For example, researchers at University of California Santa Barbara decided to calculate the impact of a 100% locavore diet for the county. By the way, agriculture is Santa Barbara County's top economic sector.

The result? Here is what the lead author says:

...we found that it wouldn't make a lot of difference. Our savings in greenhouse gas emissions, per household, as a proportion of the total food system greenhouse gas emissions, was less than one percent.

Imagine the results when applied to an urban area like King County. Emissions would likely increase.

One final consideration is the mode of transportation. Shipping by train uses about one-third the amount of energy as shipping by truck. So, buying food that travels twice the distance by rail than by truck can actually reduce the overall energy input.

Ultimately, resources cost money. If food costs more, it is likely because there are more resources used to produce and transport it. Price is a pretty good indicator of the environmental footprint of food.

I must admit, I like my local farmers' market and I go there almost every weekend. I have also enjoyed a bumper crop of potatoes in my own garden this year.

But I don't pretend that I'm saving the planet with my behaviors. Neither should the Sierra Club nor the U Dub.