I’ve started listening to podcasts, especially when I’m cooking. One of my favorites is Freakonomics, where economists and others debunk common assumptions that affect the way we make decisions. This intriguing episode, You Are What You Eat 2, asked whether eating food grown locally will help the environment.
Santa Barbara is in the top one percent of agriculture producing counties in the United States. So you would think that it could survive quite well on local produce alone.
However, when a mudslide blocked the roads and railroads, the grocery stores shelves emptied out. Farmers who couldn’t ship out their produce tried to make a bargain with the groceries. The groceries refused to buy the food, saying it would be breaking their contract with suppliers.
Freakonomics interviewed David Cleveland, a professor at the University of California at Santa Barbara and an expert on the environment. He had heard about the popular trend to eat local. As a scientist, he wanted to know more.
If localization could work anywhere, it would work in Santa Barbara. Despite all of the farmer’s markets and community supported agriculture, 95% of Santa Barbara’s produce is imported while 99% is exported. So Cleveland decided to predict what would happen if Santa Barbara went “locavore” and residents ate only produce grown on local farms.
He found that nutrition-wise, they would come out even. But surprisingly, the potential savings in greenhouse gas emissions per household, as a portion of food production costs in a household, came out to less than 1%. Food transport accounts for only 0.1% of the EPA’s estimated greenhouse emissions rate per person.
Transportation accounts for 7% of the overall energy used in food production. It’s more efficient to grow a single type of food on a large farm, then ship it throughout the world.
So while intuitively it makes sense to grow food near where it is eaten, it’s not as effective as we might think.
An article by Weber and Matthews found that only 5% of carbon dioxide emissions from food production is related to transportation. Most emissions come from the production itself, depending on the product. For example, animal products require more energy resources than grains.
It requires five times more greenhouse emissions to grow tomatoes in a greenhouse in England than in Spain, which already has a suitable climate. If you give up global food system, you require more artificial conditions that use energy.
So while eating locally has some impact, the podcast concluded with two much more effective ways of reducing greenhouse emissions.
- Encourage public policy that supports the development of urban areas. Urban living gets short shrift among environmentalists, but when people live closer together they require much less energy. Especially when they live in high-rises.
- Reduce the production of greenhouse-gas intensive foods, especially red meat and dairy products. By cutting out red meat and dairy for one day a week, the average consumer is that you could cut greenhouse gases more than by buying everything locally. Cows emit methane, which is a greenhouse gas 20 times more potent than carbon dioxide. They suggested eating kangaroos instead.
Do you find this surprising? I did.
You may also enjoy: