The mantra of "eat local" is often touted as a key strategy for reducing the environmental impact of your diet. However, this advice, while well-intentioned, frequently misses the mark. When we consider the overall carbon footprint of food, focusing solely on geographical proximity can be misleading.
It’s a common assumption that transporting food over long distances contributes significantly to its carbon emissions. Yet, surprisingly, transportation accounts for a relatively small fraction of the total emissions from the global food system. In fact, globally, transport is responsible for only about 5% of emissions related to food. The vast majority of food-related greenhouse gases originate from land use changes and the processes involved in Food Production itself, right on the farm.
This means that the type of food we choose to eat has a far greater impact on our dietary carbon footprint than the distance it travels to reach our plates. To illustrate, consider beef and peas. The production of one kilogram of beef generates a staggering 60 kilograms of greenhouse gasses (measured as CO2 equivalents). In stark contrast, producing a kilogram of peas results in just 1 kilogram of greenhouse gasses. This enormous difference in emissions stemming from food production methods overshadows any minor variations due to transportation, regardless of whether the beef or peas are sourced locally or shipped across continents.
Greenhouse gas emissions per kilogram of food product
The reason transportation’s share of food emissions is so modest comes down to the efficiency of shipping. The overwhelming majority of internationally traded food travels by sea, not by air. Air freight, which is significantly more carbon-intensive, accounts for a minuscule 0.16% of food miles. While air transport does dramatically increase emissions – emitting 50 times more CO2 equivalent per tonne kilometer than boat transport – it’s simply not the dominant mode for global food trade.
Ocean shipping, on the other hand, is a remarkably carbon-efficient method for moving goods. Even when food journeys across vast oceans, the carbon emissions from shipping remain relatively low. A prime example is avocados. Shipping one kilogram of avocados from Mexico to the United Kingdom, a considerable distance, generates only 0.21kg of CO2 equivalent in transport emissions. This represents a mere 8% of the avocado’s total carbon footprint.
Therefore, even for food items transported halfway around the world, the emissions associated with their transportation are considerably less than those generated by locally-produced animal products. If your goal is to minimize the carbon footprint of your food choices and support more sustainable food production, shifting your focus from food miles to the types of food you consume is a far more impactful approach.
