Buy local! Eat with the seasons! Reduce your food miles! These slogans are commonly used by groups who promote a more ethical and ecological approach to eating. And, at first, they seem like uncomplicated, good advice. Why wouldn’t I be alarmed to hear that much of the food in the grocery store travels hundreds, and often thousands, of kilometres before reaching the grocery store shelves? It’s easy to think that there’s a straightforward relationship between reducing food miles and reducing greenhouse gas emissions. As always, however, the truth is more complex.
Let’s consider the example of seafood consumed in Australia. A 2015 study examined the carbon footprint (or CF, meaning total greenhouse gas emissions) of the production and distribution of a selection of seafood products commonly eaten in Australia, comparing imported and domestically produced products. They found that seafood that was imported into Australia did not necessarily have a smaller CF than domestically produced seafood. Often the CF of an imported product could be significantly lower, because the imported product was produced with far fewer GHG emissions, and the CF was still smaller even when transport emissions were factored. In other cases, the CF of an imported product was lower because of differences in the mode of transport used. They cite, for example, the comparison of rock lobsters coming from nearby New Zealand and American lobsters coming from North America. The American lobsters travelling to Australia are frequently transported by ship in refrigerated containers (across a distance of ~29,000 km), whereas much of the rock lobsters coming from New Zealand are airfreighted resulting in a much higher CF.
What seafood product was consumed, how it was produced or harvested, and the mode of transportation were much more significant contributors to greenhouse gas emissions than was the distance travelled from producer to plate.
Sustainability is more than just minimizing greenhouse gas emissions, however. One interesting 2017 study from Europe attempted to measure the “localness” of commonly eaten foods and to relate localness to performance on social, economic, health, and environmental measures of sustainability. They looked at cheese, bread, ham, and wine as case studies.
The first interesting thing that I took from this paper was their approach to quantifying the localness of these products. They look well beyond the now mainstream notion of food miles, which tracks the distance travelled by a food to reach the consumer. In addition, they account for the distance that the inputs into productions systems travels, including feed, fertilizer, and processing ingredients such as the rennet used to make cheese. Because they take this life cycle approach to quantifying localness, they find that the animal-based foods that they analyze tend to have lower localness scores, because so many of the inputs to animal production travel vast distances. It is not unusual, for example, for animal feeds to travel from South America to Europe.
Many of the foods that we see as being local are still very much international, in a way that is far too invisible to consumers. Among the inputs to production, the authors of this paper also look at the distance that farm and food processing labourers travel, casting some light on the fact that there are many essential workers on farms and in processing plants who are very far from home.
The authors of this paper find that foods with high localness scores often score high on the social, health, and economic dimensions of sustainability. However, these authors also note that localness is not a good proxy for sustainability when it comes to some important environmental dimensions, most notably climate change. So here again, we see that localness alone is insufficient to tick all our sustainability boxes.
One of the first questions I ask when I’m trying to assess the strength of sustainability solutions is: “How does this solution scale?” That is, how does it work at local and regional scales? How about at national or global scales? In the context of eating local, then, it is important to consider how feasible it would be to localize food systems at different scales and in different parts of the world.
A paper published earlier this year helps us to begin to answer this question. The authors attempt to quantify the theoretical global minimum distance to satisfy global food consumption requirements for six specific crop types (maize, rice, temperate cereals, tropical cereals, tropical roots and pulses), taking into account existing global transport networks and spatial variability in the suitability (climate, soil, etc.) of different regions for the production of these crops. They then visualize the potential for local self-sufficiency for the different food crops using foodsheds (the geographic area required to provide enough food for a particular population).
There’s a lot to dig into in this paper, and I recommend that you read it, but there are a few key take-aways that I’d like to bring forward here. Although results vary across different regions and for different crops, taken together the authors estimate that the weighted mean distance travelled by all six crops from producer to consumer was 2200 km. This mean distance is dominated by temperate cereals and rice, which are traded in massive quantities the world over. Their analysis shows and that, at current production and consumption rates, only 11-28% of the global population could satisfy their crop-specific demands within 100 km, even when food flows are optimized. In addition to food flow optimization, the authors explore the potential impact of increased yields, dietary shifts, and food loss reduction and find that these may facilitate an increase in local self-sufficiency, but that these interventions may also introduce unforeseen and undesirable trade-offs.
This global analysis helps to highlight some of the complexities of the global food system that are often missing from the global vs local discourse, where one or the other is put forward as always best and always more sustainable.
I often buy food from local (Nova Scotian) producers, and I do take note of which foods in grocery stores are supplied locally as well. When I choose to buy grains, pulses, and field-grown vegetables and fruits locally, I have the piece of mind of knowing that these relatively low-impact foods haven’t been transported long distances or airfreighted in fresh from some far-off location. Furthermore, as someone who spends most of my waking hours contemplating food sustainability and food futures, I appreciate that buying local helps me to forge a relationship with farmers in my region. I can support producers who are thoughtful land stewards, seeking to produce the most food with the smallest impact. And I can deepen my understanding of food systems by learning about the challenges faced by, and the opportunities enjoyed by, the farmers in my region. Lucky for me, I buy from a farmer who sends out e-newsletters describing activities on their vegetable farm!
But is buying local my first or only priority when I’m making decisions about how to eat sustainably? No, it is not. Of course, all else being equal, you can reduce your carbon footprint by buying a local product over its imported equivalent. But take note of that qualifier – all else being equal – because therein lies the rub. The main contributor to environmental impacts is not typically transport, or packaging or processing either for that matter; it’s usually the agricultural production stage. And, therefore, different foods contribute very differently to environmental impacts, as I discussed in my fourth blog.
So that means that if your priority is reducing environmental impacts, then what you eat (especially how much meat and dairy) and how that food is farmed or harvested are more important than how far it has travelled. Furthermore, even when we zoom in to look at the impacts of food transport, the mode of transportation matters far more than the distance travelled. If your favourite food travels by airplane before it reaches your mouth, food miles matter very much indeed (bad news for the fancy chefs who insist on using only the finest ingredients flown in fresh from around the world!). If your favourite food travels by ship or train, food miles matter far less.
So what am I saying here? Am I saying don’t buy local, or that buying local never matters? Nope, I am not. Far be it from me to tell you, dear reader, what to eat and where to purchase your food. I don’t know you: I don’t know what your values and priorities are, I don’t what your health and nutritional needs are, I don’t know if you’re paid a living wage, I don’t know what foods are accessible to you, I don’t know what foods are culturally important to you, and I don’t know where in the world you live!
And that’s exactly the point — there are no silver bullet solutions to food sustainability challenges, and therefore solutions will need to be found and enacted at the scales of the individual, the community, the region, the nation, and the globe. Buying local has many social, local economic, and personal benefits, and sometimes has environmental benefits as well. On its own, however, it’s not enough. Meeting the goal of eradicating hunger and malnutrition will require that the world’s food products are produced sustainably and distributed fairly, sometimes locally and sometimes globally.
Photo by Shelley Pauls on Unsplash
