Boulder County is looking at some kind of county-wide sustainability program, with an associated tax which will be on the ballot this fall. The City of Boulder is revising its Climate Action Plan, looking toward a goal of climate neutrality in 2050. An extension of the tax which supports our climate work will also be on the ballot in the fall. One thing that none of that money should go toward? Urban farming.
I know — that’s an unpopular thing to say. People here love the idea of urban farming. We’ve got Growing Gardens and a huge community garden in North Boulder, and just a block away from my house is the Flatirons Neighborhood Farm, a micro CSA. I like these organizations too, and I enjoy being exposed to the miraculous process of food production — taking air, sunlight, water, soil and seeds and from them creating a feast. Everybody should experience it at some point, especially children, so they know where food really comes from. But at the end of the day, in the context of a city, or even a town, this can only be an educational tool. A spectator sport. A part time hobby for a few of us. It can never scale up to feed even a small fraction of the citizenry. Any serious attempt to do so would utterly destroy the city, and there are many very, very good environmental and climate related reasons why we should not want to do that. Why we should be building the best possible cities, not disassembling them. They need to be dense and durable, beautiful, livable, and humane.
To understand why urban farming can never scale up to feed us all, let’s look instead at Boulder County as an example. Can even the county feed itself? If not, then the city certainly cannot. The county has a population of 300,000, and an area of 2,000 km2. However, the western two-thirds of the county’s area is mountainous, and unsuitable for food production, so that means we’ve really only got about 667 km2 to work with, or 66,700 hectares. On average, it takes about half a hectare to produce food for one person with a typical US diet. Half a hectare per person, times 300,000 people is about 150,000 hectares, which is more than twice the arable land in the county. Okay, fine. Say we all go vegetarian and fat-free then. Cutting out all the meat and fat from a typical US diet reduces the required land area by half. A quarter hectare per person, times 300,000 people is about 75,000 hectares, which is roughly the amount of potentially arable land in Boulder County. So, within the county, if we’re all fat-free vegetarians, we might just barely be able to grow enough food for everyone. That is, if we had the water resources required to intensively cultivate all of the somewhat flat land in the county, which we don’t really — not without bringing it to the Front Range from the Western Slope through tunnels that pass under the Continental Divide. Not without bringing it south from the Laramie River Valley too. But let’s ignore the water issue (and Denver) for the moment, and assume we could import enough from the nearby mountains if we wanted to. It’s maybe just barely feasible, on an order-of-magnitude basis, to feed the county with its own produce.
Maybe we could improve on that with much more intensive farming practices, and much more water efficient irrigation methods (both of which would increase the cost of food production). How much more productive would we have to make our agricultural system (on a food per unit area basis) to be able to feed the 100,000 Boulder residents using only the land area within the city of Boulder? Boulder’s area is about 6600 hectares, so that means we’ve got about 0.066 hectares per person to work with. That’s about quadruple the productivity of the above scenario (with 0.25 hectares per person, eating no meat or fat). Is that attainable? Maybe… but it would mean dedicating every last square meter of space within the city limits to intensive food production! This scenario is not a solution!
Furthermore, Boulder is far from being a dense city. Urban spaces which are dense enough to obviate automobile usage, making walking and transit convenient for most of the population and dramatically reducing transportation related energy usage, have at least several times as many people per unit area as we do. For those cities, no plausible increase in farming intensity can hope to feed the population, even if every square meter of the city were dedicated to food production.
Cities import food. They have always imported food. So long as we use air, sunlight, water soil and seeds to make food, cities will import food. To argue for “urban agriculture” as a way to produce a significant portion of our food is to argue against cities altogether, and cities are good for the environment. Very good in fact, as demonstrated in this EPA study (and many others) looking at the effects of development patterns on energy usage. Putting people close to each other and the things they want to have access to every day dramatically reduces transportation energy use. Attached dwellings can be made far more energy efficient more cost effectively than detached dwellings. Putting people close together means they can more effectively share resources which would otherwise languish most of the time, if each and every person or household had to own their own copy. Furthermore, life in cities — especially good cities — is generally better. Social and economic opportunities are greater in cities, and cities are much more culturally diverse, more cosmopolitan.
Now, do cities need to import their food from other continents? No, we do not need to airlift asparagus from Argentina to Boulder in November. Can we reduce GHG emissions and energy consumption from the food production system? We have to, but transportation is only a small part of that problem. Synthetic fertilizers, pesticides and the fuel used in tillage, not to mention the intrinsic caloric inefficiency of meat production, play larger roles. Can we create more sustainable food economies, with fewer unaccounted for externalities by localizing a significant chunk of our food production and enjoying seasonal cuisine? Enthusiastically yes! But when it comes to food, “local” means it came from somewhere in the county, or even the state. If it’s all going to come from your backyard, then you’re going to live on a farmstead, and you’re either going to live in isolation, or, more likely, you’re going to use vast quantities of fossil fuels and public infrastructure to assuage that geographic isolation.
So please, for the love of the Earth, stop pitching “urban agriculture” as a way to feed our cities. It’s an important educational tool and an enjoyable hobby, but it’s not a means of large scale production, and it never will be.