After writing about flying, its connection to climate change, and what you should do about it, I next tackled local food production as a topic for my Evidence-Based Policy series. The reasons for this are that buying local is also a top topic among eco-conscious people and it’s equally riddled with misconception as aviation. Buying local food from the farmer’s market is being touted as one of the purest environmental acts which a citizen can do in their daily life.
Yet again, moral issues are conflated with the actual fact-based issues at hand. If you care about CO2 emission for instance, the agricultural production of food makes up most of the CO2 released into the atmosphere. Transport of food is actually negligible with regards to emission. Especially if you choose a tranport form which scales really well, such as huge container ships which have the lowest emissions (and transport costs) per vegetable. Considering the disproportionally high impact of production on the CO2 footprint of produce, where and under which conditions you produce makes the largest impact. So producing a vegetable in lush New Zealand and transporting it to arid Arizona is ironically a lot better for the environment than buying local vegetables in Arizona. Grow where best suited and buy to minimize emissions, not to maximize the feel-good factor.