How sustainable is local food?
This week, the Freakonomics podcast challenged the notion that localization is a remedy to the social and environmental problems associated with the global food system. The podcast begins by interviewing David Cleveland, an environmental studies professor at the University of California Santa Barbara. Santa Barbara county is one of the largest food producers in the United States, growing $1.2 billion dollars of produce each year. Cleveland decided to explore how much of this produce is consumed in Santa Barbara county.
CLEVELAND: This is what really shocked us: we found that when you added up all these different ways in which locally grown produce got to people in Santa Barbara County, that less than five percent of the fruits and vegetables consumed in Santa Barbara County were actually grown in Santa Barbara County, and the other ninety-five percent were imported.
Next, Cleveland looked at what the impact would be of 100% localization of the Santa Barbara. Surprising (at least for local food advocates like myself) Cleveland found that this would have no impact on people’s nutrition which was found to only increase with income. Moreover, he found that it would have little effect on reducing GHG emissions.
CLEVELAND: We wanted to look at what effect 100 percent localization of the Santa Barbara County system — which is a physically and biologically a very feasible thing to do — what effect would that have on greenhouse gas emissions? And we found that it wouldn’t make a lot of difference. Our savings in greenhouse gas emissions, per household, as a proportion of the total food system greenhouse gas emissions, was less than one percent.
If you work or study in a field related to agriculture, this may not come as much of a surprise to you. The global food system is a major source of greenhouse gasses. According to the IPCC, around 10-12% of anthropogenic green house gas emissions comes from the agricultural sector; however, the majority of the these emissions are not from the transport of food, but its production. Modern industrial agriculture demands huge quantities of fertilizers in order to replenish nutrients stripped from soil from intensive growing practices and lack of crop rotation. The production of inorganic fertilizers is an incredibly energy intensive process. Furthermore, their use is a leading cause of ground water contamination and are largely responsible for oceanic deadzones
Local food producers are just as capable of using harmful inorganic fertilizers, pesticides and herbicides as those on the other side of the continent. Buying from your local farmer will not off-set the emissions associated with a diet composed primarily of meat (responsible for 18-50% of global GHG emissions). Furthermore, as Vancouverites, embracing local food but not changing the unseasonal diets we have become accustomed to is inherently unsustainable. Building heated greenhouses so we can have fresh tomatoes year round completely defeats the purpose of eating local. Embracing local food requires us to simultaneously change our diets to accommodate seasons and produce food that is best suited for our climate.
That being said, this isn’t a reason to jump off the local food bandwagon completely. Reducing “food miles” is one of many reasons for developing local food economies. Localization provides communities with food security, and mitigates the risk of food shortages in the event supply shocks in other markets and reduces dependence on an increasingly uncertain supply of fossil fuels.
Furthermore, the podcast does not mention the uncertainty in calculating the effects of transportation on climate change. As I’ll write about in another post, there is significant uncertainty regarding the impact of aircraft emissions on climate change, as the net effect of emitting greenhouse gasses at altitude and formation of jet contrails is unknown. Given that much of the international transport of agricultural produce is by air freight, it is overly confident to claim that transport is a marginal contribution to agriculture’s impact on climate change. Additionally, the challenges of regulating the safety of global food imports given the discrepancy in national food regulations and enforcement is ignored.
As a student of Land and Food Systems and an advocate for developing a stronger local food economy, I believe completely discounting the value of localization is misguided. However, the podcast does highlight that simply buying local is not the end-all remedy for our broken food system. In order to reduce the environmental impacts associated with industrial agriculture, there must be fundamental changes not only in where our food comes from, but in all facets of its production and our within our own diets.