Local food always has a lower carbon footprint
Transportation typically accounts for only a small share, often under 10 percent, of the total greenhouse gas footprint of food, while what type of food is eaten, particularly meat versus plant-based options, and how it is produced generally matter far more than how far it traveled.
What we know
Buying local food is often promoted as a straightforward way to reduce the carbon footprint of eating, based on the intuitive idea that shorter transportation distances mean lower emissions. Life cycle assessments of food systems show that transportation is usually a minor contributor to a food item's total greenhouse gas footprint compared to the emissions generated during production itself.
A widely cited 2018 study published in Science by Joseph Poore and Thomas Nemecek, analyzing data from roughly 38,700 farms across 119 countries, found that transportation accounts for a global average of under 6 percent of the greenhouse gas emissions associated with food, while land use change, farm-stage production processes such as fertilizer use and livestock digestion, and processing account for the large majority of emissions. The same study found that food type matters enormously: producing beef generates roughly 60 kilograms of CO2-equivalent per kilogram of product on average, while producing peas generates under 1 kilogram of CO2-equivalent per kilogram, a difference of roughly two orders of magnitude that dwarfs any plausible savings from shortening transportation distance.
This does not mean transportation emissions are irrelevant in every case, particularly for foods transported by air freight, which is far more emissions-intensive per kilogram than sea or rail freight. Fresh produce flown internationally, such as certain out-of-season fruits and cut flowers, can carry a meaningfully larger transportation footprint than the same product shipped by sea or grown locally in season. However, most bulk food commodities, including grains and many staple crops, are transported by ship or rail, which are comparatively efficient per unit of food moved, meaning the local food to distant food comparison for most products is not as significant as intuition suggests.
Another complicating factor is that food grown locally out of season sometimes requires heated greenhouses or energy-intensive storage, which can generate more emissions than importing the same food from a region where it grows naturally in that season and is shipped efficiently. A frequently cited example from a 2008 lifecycle comparison found that tomatoes grown in heated Northern European greenhouses in winter had a higher carbon footprint than tomatoes grown outdoors in Southern Europe and transported north by truck.
None of this means that local food sourcing lacks any benefits. It can support regional agricultural economies, sometimes involves fewer intermediary processing steps, and may align with other goals like supporting smaller farms or reducing packaging. But as a specific strategy for lowering the carbon footprint of one's diet, the evidence indicates that shifting the composition of what is eaten, reducing red meat and dairy consumption in particular, produces far larger emissions reductions than sourcing the same foods locally. Organizations including the World Resources Institute and the Intergovernmental Panel on Climate Change's land use reports have both emphasized dietary composition as a higher-leverage lever than food miles for reducing the climate footprint of food systems, a conclusion that has increasingly informed official dietary guidance in several countries seeking to align national food policy more closely with broader climate goals over time.
Common claims
- Buying local food significantly reduces your carbon footprintFalse for most foods - transport is a minor share of emissions
- Local beef has a lower carbon footprint than imported vegetablesFalse - what you eat matters far more than where it comes from
- Air-freighted foods have high transport emissionsTrue - the main exception where transport significantly affects footprint
Evidence hierarchy
All sources
- You want to reduce the carbon footprint of your food? Focus on what you eat, not whether it's localOur World in Data · 2020
- How Green is Local Food?Columbia University State of the Planet · 2012
- Reducing food's environmental impacts through producers and consumersScience · 2018
- Food and Climate ChangeWorld Resources Institute · 2019