Super fact 30: Eating locally is often promoted as an environmentally friendly choice, but that is not always the case.
Whether the food you eat is sustainable and environmentally friendly or not depends on a lot of factors including agricultural methods, whether greenhouse farming or monocropping was used, and whether the crop is natural to its environment. In addition, inefficient local transportation can result in higher emissions than faraway transport by ships and trains. If a crop is grown locally in greenhouses, the extra energy that is needed, and the resulting extra carbon emissions are often much larger than the emissions from the transport.
I consider this a super fact because it is often assumed that buying locally is the best choice for the environment. After all, transporting something across the world causes a lot of emissions, right? It turns out not to be that simple.
Articles on Transportation of Food in my French Book
The first time this issue was brought to my attention was in my French class. I am learning French, just as a hobby. There was an article in our French book on the transportation of food around the world “Notre planète ne tourne pas rond!”.
We read that cashews were grown in the Ivory Coast in Africa and then sent for peeling and cleaning in Brazil and then sent to France to be sold. The cashews travelled 10,000 kilometers or 6.250 miles. We read about cod that was caught in Norway then sent to China to be cut into filets and then sent to France to be sold. That cod travelled 15,000 kilometers. We all thought it was crazy, and very bad for the environment, so much unnecessary emissions from transportation. But we all learned a few new French words.
Then at our next class, we turned the page “Consommer local, vraiment bon pour la planète?” / “Consuming locally, really good for the planet?”. Wait what? The next article confused us since it stated that in many cases eating locally was bad for the environment, not good for the environment. Transporting the food around the globe might be good for the environment.
Incidentally, at the time I was reading “Not the End of the World, How we can be the first generation to build a sustainable planet” by Hannah Richie, the research director for “Our World in Data”. “Our World in Data” is a highly regarded free and open-source website that collects and analysis vetted statistics on a large range of topics. In that book she stated that the data showed that tomatoes imported to Sweden from Spain caused less carbon emission than tomatoes grown locally in Sweden.
The Problem with Locally Grown Tomatoes
This article from University of Southern Denmark claim that importing tomatoes from warm countries are better for the environment than buying locally. The reason being that when tomatoes are grown in an open field, the production emits an average of 80 kg CO2 per ton, but if the tomatoes are grown in a greenhouse, they emit up to 700 kg CO2 per ton. In northern countries it is common to grow tomatoes in greenhouses, especially when they are out of season. The long transport of the tomatoes causes much less emissions than that.
This scientific article analyses the issue a bit deeper and concludes that “that the distance travelled by the tomatoes is not the most important environmental burden”. Whether the tomatoes were grown in greenhouses or not matters a lot, but there are many other factors. In short, it is complicated.
This study of local vs. imported tomato production in Canada concludes that locally grown tomatoes grown in greenhouses on average cause 1,070 grams of carbon emissions per kilo of tomatoes grown and tomatoes grown open field in Mexico cause 775 grams of carbon emissions per kilo of tomatoes, despite the 3,800-kilometer journey from Mexico to Ontario, Canada. The reason for the higher emissions for locally grown tomatoes is again that greenhouses use a lot of energy.
Naturally, this would change if you grew the tomatoes in season without using greenhouses. The article also notes that carbon emissions are not the only issue for sustainability. Water usage is another important factor.
The Problem with Locally Grown Vegetables and Fruits
Tomatoes are just one example. The same hold true for cucumbers, lettuce and salad greens, potatoes, bell peppers, hot peppers, green beans and other bean varieties, berries, pineapples, bananas, mangoes, other tropical fruits. In addition, some of these crops can deplete the soil and require large amounts of water, which can be bad if they are being cultivated in areas where water resources are already scarce such as growing avocados in California. In general, growing vegetables and fruits in their natural environment tends to be the most sustainable.
The Problem with Locally Grown Apples
The problem with apples tends to be the opposite, geography wise. In warmer areas, they might require significant water resources or chemical inputs to thrive. Apples from cooler climates need less water and fewer chemicals, reducing their ecological impact.
Local versus Imported It’s Complicated
I should point out that growing locally sometimes being worse for the environment than importing does not mean that importing produce is better for the environment. It just means that it is complicated and that you need to make that determination on a case-by-case basis. The environment is also not the only concern. Another consideration is the protection of local farmers and the local economy.
My opinion is, instead of worrying a lot about local versus imported produce, it is better to focus on things that we know cause a lot of emissions. A dirty grid, coal power stations, a non-hybrid SUV with an internal combustion engine, unnecessary business trips, eating a lot of red meat, basically start with the low hanging fruit.
