Urban Agriculture: What It Can and Cannot Do for the City

Urban agriculture is the production of food within and around cities, in community gardens, rooftops, vacant lots, agricultural parks and peri-urban belts, and it has become one of the most cited answers to the food vulnerability of cities that import almost everything they eat. Two researchers help to situate its real potential: Karen Seto, a geographer at Yale University and lead author of Intergovernmental Panel on Climate Change reports, who has measured how urban expansion consumes the planet's best farmland, and Henk de Zeeuw, founder of the Dutch RUAF foundation, who has advised Global South cities on urban agriculture policy for decades. Their common lesson is that urban agriculture will not feed cities, but it can make them more resilient, fairer and more sustainable.

Karen Seto: urban expansion consumes the best cropland

Seto supplies the warning. Her studies of 2012 and 2017 projected that urban expansion to 2030 will occupy between two and three percent of the world's cropland, but that this land is among the most productive, because cities were born beside fertile soils and rivers, so the loss of production exceeds the loss of area and concentrates in Asia and Africa. A city's first food policy, in her reading, is not to destroy its agricultural belt with sprawl; conserving and activating peri-urban land, as the agricultural parks of Milan or the Baix Llobregat do, protects more food than any urban garden.

Henk de Zeeuw and RUAF: urban agriculture in Southern cities

De Zeeuw supplies the experience of the South. In cities such as Lima, Kampala, Rosario or Accra, urban agriculture employs hundreds of thousands of families who grow vegetables, raise animals and recycle organic waste on vacant lots, riverbanks and yards, and supplies a significant share of the fresh vegetables consumed. His work with RUAF showed that integrating it into planning, with secure access to land and water, technical support and local markets, improves food security for poor households, creates jobs, manages waste and reduces vulnerability to supply and price shocks. Rosario, in Argentina, has since the 2001 crisis turned hundreds of hectares into gardens that now supply municipal markets.

Environmental benefits measured carefully: Havana and Detroit

The environmental benefits are real but must be measured carefully. Shortening the distance between production and consumption cuts transport emissions, though those are a small fraction of the total food footprint, dominated by production and diet. Gardens and green roofs also provide shade, rainwater retention, biodiversity and public space, and peri-urban farming maintains landscapes that buffer floods and heat. Havana, which developed a network of organopónicos from the 1990s out of necessity, and Detroit, which has turned vacant lots into farms, show that urban agriculture thrives where land is available and policy sustains it.

Limits and urban food policy

The limits are equally clear. Urban production covers a fraction of a large city's demand, mostly in fresh produce, and cannot replace the grains, proteins and oils that require extensive land; vertical and indoor farming consume much energy and are profitable only in niches; and gardens can become instruments of green gentrification if they raise prices in the neighbourhoods that receive them. Seto and De Zeeuw agree that urban food policy must combine local production with protected peri-urban land, local markets, waste reduction and economic access to food.

The lesson of urban agriculture is that its value lies in resilience and justice more than in self-sufficiency. A city with gardens, agricultural parks, local markets and a protected farm belt withstands a supply crisis better, offers fresh food to those least able to pay and preserves the soils that sprawl destroys. Seto teaches how to protect the land and De Zeeuw how to farm it with those who need it, and that combination is the food policy cities can decide for themselves.