2 May 2016

Is locally produced food better for the environment?

Robin writes:*

Over the last decade or so, 'locavore' movements have been gaining traction. Consumers are showing an increasing interest in locally produced food and are willing to spend extra on it. People buy locally for lots of reasons. Local food is thought to be fresher, more nutritious and better tasting. Consuming it is a way to increase self-reliance in terms of food production and a way to support the local economy and farming communities. Seemingly the most important reason to buy locally produced food is an interest in lowering the environmental impact of food production. This last argument is questionable.

Why? Locally produced food is mostly inefficient. In Economics classes, we are taught that specialisation according to comparative advantage and subsequent trading leads to welfare gains for all parties involved. This principle seems to be especially applicable to agricultural products since their production costs depend on the natural qualities of the environment (e.g. soil quality, rainfall and temperature). Foregoing comparative advantage and economies of scale to localize food production means that more inputs must be used for the same amount of food output.

Steven Sexton estimated [pdf] the environmental effects of a 'pseudo-locavore' system in the US where every state that produces a crop grows only enough for its own population (and thus trades nothing). Each state must also start growing other crops that it previously imported. He finds that for the production of soybeans, for example, land use would increase by 18%, fertiliser use would increase by 55% and fuel use would increase by 34%. This increased demand for inputs that is associated with local food production would possibly increase CO2 emissions and environmental pollution per unit, rather than decrease them.

Local food production might have environmental benefits in that food does not need to be transported as far, but even this is questionable. Weber and Matthews estimate [pdf] that transportation represents only 11% of greenhouse gas emissions associated with food production. 83% of GHGs are actually emitted during the production phase, which, as mentioned, would likely be even more polluting in a locavore system. In fact, the benefits of shifting from red meat and dairy products to chicken, fish or vegetables for just one day a week reduces GHG emissions much more than buying all locally produced food.

Bottom Line: Locally produced food isn't necessarily better for the environment.

* Please comment on these posts from my environmental economics students, to help them with unclear analysis, alternative perspectives, better data, etc.


Ed Dolan said...

You conclude, "Locally produced food isn't necessarily better for the environment." I agree that that conclusion is sound.

Some of your sources, however, appear to go farther. The Sexton and Dubner links, as I read them, either explicitly or implicitly make the argument that local food production is necessarily worse for the environment, with perhaps a few exceptions.

I would also like to comment on the argument that nonlocal food can be more "efficient." No doubt there are cases in which that is true. For example, European efforts to promote use of locally produced beet sugar instead of imported cane sugar would appear to be a case in point.

However, sugar is a special case, since beet and cane sugar are chemically identical. The efficiency argument holds only if there is no difference in quality, but often there is. For example, commercially produced baked goods (at least in the US) typically use the cheapest oils, especially soy, corn, and cottonseed oil. Nutritional analysis notes that these oils have a high ratio of omega-6 to omega-3 fats, so that they are not nutritionally equivalent to slightly more expensive(but arguably more healthful) oils like olive, peanut, or canola oils that are more often used by home cooks. So to say that it is more efficient to eat industrial cinnamon rolls than to bake them at home is not a comparison of equals.

In short, the tradeoffs in food choices are multidimensional. Arguments by either environmentalists or their critics that single out one variable like food miles can easily be misleading.

Isabel said...

Hi Robin,

Though you raise an interesting question here whether local food is indeed better for the environment as opposed to commonly perceived, I'd like to comment on your statement 'seemingly the most important reason to buy locally produced food is an interest in lowering the environmental impact of food production.'

I believe that for many an equally important reason to buy locally is because of greater food transparency. Because of increasing farm sizes and manufacturing companies, the complexity of the food chain increases and thus tracing back where your food comes from becomes more difficult. On the contrary, local farmers can often tell you how the food was produced. They therefore often promote a safer food supply.

Though I am aware this statement can also be contested, I wanted to raise your awareness on this point too!

Silas Gairdner said...

I think this is a good argument for an interesting topic, but I think it is important to add some nuances to take into account relevant external factors. In particular I'd make it more clear that consumer choice is a key part of this argument. You say:

"Foregoing comparative advantage and economies of scale to localize food production means that more inputs must be used for the same amount of food output."

I agree - if you make it intrinsic in your argument that this is a particularly relevant stance due to current buying patterns. For example it is unlikely potatoes produced in season, in your garden in the Netherlands, come with the same environmental impact as the potatoes from Israel that I saw in Albert Heijn the other day. So your argument makes sense in the wider context of consumer demand where local food might entail unsustainable veg such as tomatoes produced in the Netherlands in the winter, which of course have a higher environmental impact than their sunny-country alternative. (Even locavores are tempted by out-of-season local veg!)

If we didn't demand exotic (read: out of season) food types then probably the environmental impact of local food would be a less relevant argument. Instead, supermarkets (and progress in logistics) have taken the seasonality out of produce so that consumers are able to maintain inherently unsustainable food demands, such as all-year-round asparagus. Admittedly, some areas of the world simply can't even supply seasonal food demand due to geographic constraints (globalisation has been good for these areas).

Also, to add to Isabel's point, I'd emphasize the importance of buying (some) local food not only for environmental and transparency reasons but also for its taste. Food that takes less time to process and transport is going to be fresher, and as far as I know, fresh food tastes better. That said perhaps it isn't only the fresh part that makes local food taste better, but the grower and the retailer. Guy Watson, founder of Riverford, the largest organic veg box scheme in the UK, has an interesting experience of this. He describes surveying a carrot crop with various prospective supermarket-buyers. The supermarket reps were interested in two things - size and form - where no one was interested in the actual taste (Guy being the only one to actually eat one of the carrots...). It goes without saying that growing for size, form and productivity doesn't necessarily exclude local growers

Post a Comment

Note: only a member of this blog may post a comment.