I just finished an omelette with eggs and spinach from a nearby farm. It tasted good, I supported local business and I helped the environment. You could say that I had my cake (but it was spinach) and ate it too.
But, here is the surprise.
If you care about your carbon footprint, then eating local is not the answer. Yes, food miles do create greenhouse gases. But a Carnegie Mellon study has concluded that the environmental impact of transporting food is relatively minimal. Instead, it’s all about dietary shift. For less than one day a week, we just have to switch from meat and dairy to chicken, fish, eggs, or a vegetable-based diet to achieve the environmental benefit of buying 100% local.
In addition, economist Steve Landsburg says that even if we wanted to use cost/benefit analysis to prove the total impact of local sourcing, it would be impossible. How can we judge whether land should have been used for tomatoes or grapes, or if local farmers would have been better off transporting their produce elsewhere or even if it was best to buy Chilean grapes because Chile is the most efficient place to grow them? Then also, there are workers, a ripple of energy use, equipment and countless other considerations.
Instead he says just to look at price.
Using a tomato as an example, Landsburg explains that the price conveys all we need to know. Assume, for example, that the local tomato laborers would have been more efficient growing grapes. As a result, the tomato supply curve would shift up and to the left because of lower yielding fields, and the price of tomatoes would increase. You don’t have to ask specifically about cost and benefit because a high or low price provides the answer.
So, did my omelette help the planet more than steak? I am not so sure.
A thanks to the Freakonomics people who suggested that “We Eat What We Are” and reminded me of locavore dilemmas. And here, economist Steven Landsburg disagrees with environmental locavores while this paper and this paper provide more information about the carbon footprint of our diet.