Food trade plays a key role in achieving global food security. With a growing consumer demand for diverse food products, transportation has emerged as a key link in food supply chains. We estimate the carbon footprint of food-miles by using a global multi-region accounting framework. We calculate food-miles based on the countries and sectors of origin and the destination countries, and distinguish the relevant international and domestic transport distances and commodity masses. When the entire upstream food supply chain is considered, global food-miles correspond to about 3.0 GtCO2e (3.5–7.5 times higher than previously estimated), indicating that transport accounts for about 19% of total food-system emissions (stemming from transport, production and land-use change). Global freight transport associated with vegetable and fruit consumption contributes 36% of food-miles emissions—almost twice the amount of greenhouse gases released during their production. To mitigate the environmental impact of food, a shift towards plant-based foods must be coupled with more locally produced items, mainly in affluent countries.

The researchers also estimated the global food-system emissions to be 15.8 GtCO₂e, equating to 30% of the world’s GHG emissions. With global food expenditure around US$5 trillion (€4.85 trillion) in 2017 and the global population rising annually, it is useful to consider the impacts of food miles on climate change. The researchers say that this should be coupled with more locally produced food items and add that improved food security through better food-systems management also requires integration of environmental protection targets.