© Shutterstock / mariakraynova - Cargo plane
The environmental impact of transporting food is measured in food miles, indicating how much carbon dioxide (CO2) is produced to transport a tonne of food over a unit of distance (kilometres or miles). Cargo ships have the lowest CO2 emissions, with between 15 and 30 grammes per tonne of food per kilometre, followed by trains, cars and lorries. Aeroplanes have the greatest impact, emitting between 570 and 1580 grammes per tonne per kilometre.
Once consumers realise the environmental cost of transporting food halfway around the world, they may wonder if it is acceptable for food products to be available all year long. But the problem is more complicated than it seems. Carbon dioxide emissions produced during transportation are just part of a food product’s carbon footprint, used to calculate greenhouse gas emissions during the production, distribution and consumption of food.
It is particularly important to also take into account the energy used to cultivate, store and process foodstuffs. The four-week journey for a fresh spring apple to travel in a container ship from New Zealand to Europe consumes less energy than a local apple kept in cold storage for several months. Similarly, a kilo of strawberries exported from Spain by lorry is less damaging to the climate than a kilo of strawberries grown locally in a heated greenhouse.
From an environmental perspective, making the right choice is not always clear at all, and buying local is not necessarily more environmentally-friendly. Choice may, however, be guided by socio-economic concerns, with the idea of supporting regional businesses and the growth of small producers.