An investigation into globalisation, food miles and the hidden carbon footprint behind eight everyday products sold in Luxembourg supermarkets.
"Food miles" refers to the distance food travels from where it is produced to where it is consumed. As globalisation has reshaped agriculture and retail over the last fifty years, a tomato in a Luxembourg supermarket might come from Morocco, an avocado from Peru, and salmon from Norway — all available year-round, regardless of season. Cheaper transport, refrigerated shipping and free-trade agreements have made this global supply chain possible.
Luxembourg is a particularly interesting case study. As a small, landlocked country with limited domestic agriculture and one of the highest GDPs per capita in the world, it imports the majority of its food. Its supermarkets stock products from every continent, making it an excellent lens through which to study how globalisation drives up food miles — and what that means for our carbon footprint.
Products that travel the greatest distance by air freight will have a significantly higher carbon footprint than those transported by road or sea, regardless of total distance travelled.
Eight products picked from a typical Luxembourg supermarket shop — and the routes that brought them here.
To collect primary data for this investigation, I visited a Cactus supermarket in Luxembourg and physically checked the country of origin labels on each of the eight products studied. This fieldwork confirmed the origins used in this project: tomatoes from Morocco, bananas from Colombia, beef from Ireland, rice from India, avocados from Peru, strawberries from Spain, salmon from Norway, and olive oil from Greece. Distances were then calculated using distancecalculator.net, and CO₂ emission factors were sourced from DEFRA and Our World in Data. I had also planned to conduct a short interview with a supermarket manager to gain a professional perspective on sourcing decisions and supply chain logistics. Unfortunately, this was not possible due to a scheduling conflict. The primary data collected from product label verification therefore forms the main fieldwork component of this investigation.
As shown in the flow-line map above, the majority of the eight products studied travel over 1,800 km to reach Luxembourg, with avocados from Peru covering the greatest distance at 9,800 km.
| Product | Country of origin | Distance to Luxembourg | Transport | CO₂ (g / kg) |
|---|---|---|---|---|
| 🍅Tomatoes | Morocco | 2,600 km | road | 180 |
| 🍌Bananas | Colombia | 8,900 km | sea | 160 |
| 🥩Beef | Ireland | 1,800 km | road | 270 |
| 🍚Rice | India | 7,500 km | sea | 140 |
| 🥑Avocados | Peru | 9,800 km | air | 2,400 |
| 🍓Strawberries | Spain | 1,600 km | road | 150 |
| 🐟Salmon | Norway | 1,900 km | road | 210 |
| 🫒Olive oil | Greece | 2,100 km | road | 130 |
CO₂ emissions per kilogram, broken down by the dominant mode of transport used to get each item to Luxembourg.
Note: avocados are flown from Peru — air freight is roughly 50× more carbon-intensive per kilometre than sea freight, which is why their bar dwarfs the others.
As the bar chart clearly illustrates, avocados transported by air freight generate significantly more CO₂ per kilogram (2,400 g) than any other product — over 13 times more than olive oil shipped by road from Greece (130 g).
Pick a product to see its origin, journey distance, transport mode and estimated emissions.
Transport impact — Road freight falls between sea and air in emissions intensity. Refrigerated lorries crossing Europe add a steady CO₂ cost. For regional routes — like tomatoes from Morocco or beef from Ireland — it is often the only practical option.
Supermarkets rely on global supply chains for clear economic reasons. Producing tomatoes in Morocco or strawberries in Spain is cheaper than heating Luxembourgish greenhouses through winter. Bananas and rice simply cannot be grown commercially in Western Europe at all. Consumers, meanwhile, have come to expect any product, in any season, at a low price — and large retailers compete fiercely on exactly those terms.
The environmental cost is harder to see on the price tag. Air-freighting avocados from Peru emits roughly fifteen times more CO₂ per kilogram than shipping bananas from Colombia by sea, even though the distance is similar. Refrigerated road transport across Europe adds further emissions, and processing, packaging and waste compound the footprint.
The result is a trade-off at the heart of modern food systems: globalisation makes food cheap and abundant, but it externalises the climate cost. Reducing food miles — by buying seasonal, local and lower-impact products — is one of the most direct individual contributions to reducing a country's carbon footprint.
This investigation showed that the eight products studied travel a combined 36,200 kilometres to reach a Luxembourg supermarket. Avocados from Peru alone generate more than ten times the per-kilogram CO₂ of any other product in the study — a direct result of air freight.
On a personal level, this project changed how I think about my weekly shop. I used to assume "fresh" meant "low impact". In reality, a frozen, sea-shipped product can easily outperform a fresh, air-freighted one on climate grounds. Food miles are a concrete way to see globalisation written into our daily lives, and they connect directly to the wider geographical concepts of sustainability, the carbon footprint and the global economy.
To investigate the impact of globalisation on the food miles and carbon footprint of everyday supermarket products sold in Luxembourg.
Interactive website including written geographical analysis, a digital flow-line map, CO₂ bar charts, and a Food Miles Calculator.
Where do the everyday supermarket products sold in Luxembourg originate from, and how far do they travel?
What is the carbon footprint of transporting these products to Luxembourg?
Why do supermarkets prioritise global supply chains over local sourcing, and what are the trade-offs?