The urban farming ‘revolution’ has a fatal flaw

quarta-feira, abril 17, 2019

Most of New York City’s urban farms are on rooftops, while some are inside buildings and shipping containers.

Commercial urban agriculture in New York City has provided questionable environmental gains, and has not significantly improved urban food security. These are the findings of a recent case study of New York City which shows that, despite the fanfare over commercial urban farming, it will need a careful re-evaluation if it’s going to play a sustainable role in our future food systems.

The rise of commercial controlled-environment agriculture (CEA)—comprised of large scale rooftop farms, vertical, and indoor farms—is a bid to re-envision cities as places where we could produce food more sustainably in the future. Proponents see CEA as a way to bring agriculture closer to urban populations, thereby increasing food security, and improving agriculture’s environmental footprint by reducing the emissions associated with the production and transport of food.

But the researchers on the new paper wanted to explore whether these theoretical benefits are occurring in reality.

They focused on New York City, where CEA has dramatically increased in the last decade. Looking at 10 farms that produce roof- and indoor-grown vegetables at commercial scales, they investigated how much food the farms are producing, who it’s reaching, and how much space is available to expand CEA into.

They found that the biggest of these 10 commercial farms is around a third of an acre in size. Most are on roofs spread across New York City, and some are inside buildings and shipping containers. Mainly, these farms are producing impressive amounts of leafy greens such as lettuce, and herbs; some also produce fish.

But while rooftop farms rely on natural sunlight to feed the crops, indoor farms use artificial lights. These farms potentially have a greater energy footprint even than conventional outdoors farms, the researchers say–challenging the assumption that urban farms are less impactful than conventional ones.

Some farms also embraced high-tech systems, such as wind, rain, temperature, and humidity detectors and indoor heating, to enhance growing conditions in environments that aren’t naturally suited to agriculture. These elevate the energy costs of the food produced, and may be giving CEA an unexpectedly high carbon footprint, the researchers say.

Furthermore, the predominantly grown foods—such as lettuce—aren’t of great nutritional value for the urban population, especially those threatened by food insecurity. Most produce from CEAs is sold at a premium, something that partly reflects the cost of the real estate used to grow the food. Consequently, that produce is typically grown for high-end food stores and restaurants, meaning it’s unlikely to reach low-income urban populations who need it most.

The researchers also think it’s unlikely that CEA—which currently occupies just 3.09 acres in New York City—could expand into the roughly 1,864 acres they estimate is still suitable for urban farming in New York City.

The rising cost of real estate might put these urban acres beyond the reach of new farming start ups, they think. These companies also face increasing competition from a growing number of farms springing up on the outskirts of cities—where land is cheaper and there’s space to produce more food, while also benefiting from urban proximity.

With its one-city focus, the research isn’t representative of what might be unfolding in other places around the world. Other cities may be having more success—for instance, Tokyo has gained global attention for its large scale vertical farming efforts. Yet as a case study, it does reveal useful lessons—especially for cities wanting to meet the original twin goals of urban agriculture: equitably increasing access to food, at a lower environmental cost.

The researchers note first of all that CEA is optimal in places where less supplemental heat and light is needed to grow food. More thought might also be given to the nutritional value and cost of foods grown, to generate benefits for all the city’s residents, not just high-income ones. The researchers question whether smaller, community-driven plots of urban agriculture—like community gardens, school, and prison farms—might actually do a better job of providing food to at-risk city residents, compared to commercial urban farms that inevitably have to focus on profits.

Based on the study of New York, the researchers caution: “CEA may be touted as an exciting set of technologies with great promise, but it is unlikely to offer a panacea for social problems or an unqualified urban agricultural revolution.”

It’s easy to be drawn in by the dystopian allure of vertical farms and underground greens nestled into our cities. But until we’ve streamlined its role, we should perhaps not overstate what commercial urban agriculture can do—or, instead be guided by cities where there are stronger signs of social and environmental success.

Source: Goodman et. al. “Will the urban agricultural revolution be vertical and soilless? A case study of controlled environment agriculture in New York City.” Land Use Policy. 2019.

This piece was originally published on Anthropocene Magazine, a publication of Future Earth dedicated to creating a Human Age we actually want to live in.

Page: Quartz