If you’re eating locally for ecological reasons, you’re doing it wrong.
It’s not that there are no reasons to eat locally; if we’re talking about the economic and cultural benefit to local producers and sellers, that is another story. But ecologically, since transport makes up a negligible part of the ecological impact of food (see the chart below), it is better to make use of an idea I call comparative ecological advantage (defined after the chart).
What is comparative ecological advantage?
It should be clear that not every region, state, or country can easily produce every kind of food. Kansas may be perfect for growing grain, Wyoming is ideal for grazing cattle, and Southern California is excellent for growing fruits and vegetables. Similarly, avocados grow relatively better in Mexico and oats grow better in Scotland. None of these natural advantages are insurmountable — we can always create greenhouses, hydroponic systems, and microclimates to grow everything anywhere, even in space. But at what cost? Bringing water to the desert, heating winter greenhouses, and replacing tropical soils come at an immense environmental cost that defeats the point of eating in environmentally responsible ways. We can think of eating locally at any cost and refusing to transport food long distance as a form of ecological mercantilism.
In the 1800s, David Ricardo helped to deconstruct the accepted wisdom that countries should strive to produce everything they need internally and import as little as possible (mercantilism). He showed mathematically that it produced more prosperity for everyone if countries specialized in what they could produce most efficiently, and then freely traded internationally. This idea was called “comparative advantage” — the thing that a country was best equipped to produce, relative to the other things that they could choose to produce. This destruction of the prevailing logic of mercantilism unlocked the first era of globalization and created the trading system that we still use today, two centuries later. The exact same logic — the faulty logic of ecological mercantilism and the economic logic of ecological comparative advantage — is at work today. Since the environmental cost of transport is so low (and falling, as vehicles get more efficient and solar-powered cargo ships become more popular), having each area produce the goods that grow best with minimal watering, climate control, and mechanical and chemical intervention, then trading, is the most environmentally neutral path. Just as in the 19th century, let us specialize, trade, and reap the fruits of global integrated markets for the benefit of all mankind.
Less desirable alternatives
Of course, we could also go another route: maybe each country or region should only eat the things that it can grow well in the vicinity. But we need to think this through a bit. Self-sufficiency in food is an unreachable dream for many regions of the world (see the chart below). Some countries like Argentina or Australia are lucky exceptions — they are sparsely populated with lots of arable land, and thus able to feed themselves many times over. However, countries like The Netherlands, Belgium, and Norway, for example, can only produce 50% of the food they consume. When we consider that countries like Australia or Canada are overwhelmingly producing things like meat and grain, it means these areas would be faced with rather poor diets were they to eat only locally produced foods. To implement local-only consumption globally in nutritionally and culturally acceptable ways, there would need a restructuring of the entire population of the world into high-fertility areas (which would necessitate converting the land of these high-fertility areas into buildings, the most ecologically destructive thing we can do). But why would it be better than a system of production and exchange according to comparative ecological advantage?