Examining The Urban Agriculture Debate
Recently, there has been an influx of articles criticizing the environmental impacts of urban agriculture. The articles are based on a study from the University of Michigan that looks at the carbon footprint of urban agriculture.
The widespread coverage, and to some degree, misrepresentation of the study by the media has triggered backlash from scientists and urban farmers alike.
Like any climate issue, urban agriculture is neither completely good nor completely bad. There’s nuance to the conversation, so it’s important to consider both the pros and cons.
Pros
A 2022 Alberta Land Institute (ALI) study examined urban agriculture and other agricultural green infrastructure as nature-based solutions to mitigate the effects of climate change. The study highlights the many faceted benefits of urban agriculture, but also discusses some of the challenges.
Cities all over the world are grappling with increased food demand due to population growth. The increased demand is putting pressure on food production systems, many of which are already facing additional environmental challenges as a result of climate change.
Urban agriculture provides an opportunity for increased food production within agricultural centres, where 80% of total food produced is consumed.
Additionally, food grown in urban settings does not need to be transported to urban centers. The transportation of food from rural farms to urban centers, also known as food miles, account for 19% of total food system emissions.
Urban agriculture and other agricultural green infrastructure introduces greenspaces to otherwise unusable spaces like parking lots, abandoned properties and rooftops. Rooftops, in particular, take up 85% of urban areas and are largely unused.
In addition to producing food, these greenspaces increase biodiversity, mitigate urban heat island effects, reduce pollution, and mitigate flood and drought risk. Green roofs and green walls can protect buildings from weather damage and modulate building temperatures, which reduces energy consumption.
By reducing pressure on rural producers to develop new agricultural land to meet food demands, urban agriculture also protects natural areas from conversion.
Nature and green spaces have been directly linked to healthier mental and emotional states for people in urban settings.
Green spaces like parks and urban forests provide relaxing public spaces and facilitate social interaction while urban gardens cultivate social connection.
Kevin Jones, an associate professor in the department of resource economics and environmental sociology in the faculty of ALES studies the social aspects of urban agriculture.
Jones emphasizes that gardens encourage people to work together to find solutions to climate issues.
“That process of working together in a landscape, working with growing a garden is a really important and, kind of, magical process for figuring out really these complex scenarios,” says Jones.
Community gardens foster a sense of belonging and provide a benefit to their immediate communities by providing food security.
To learn more about the social effects of urban agriculture, check out the June episode of the Land Use Podcast: How Urban Farms Benefit Communities with Kevin Jones.
Cons
All of the benefits aside, urban agriculture isn’t all sunshine and vegetables. The study that has driven the debate about urban agriculture was published in nature cities in January of this year. It highlights the carbon footprint created by some types of urban agriculture.
Several news outlets released stories on the study with sensational headlines decrying urban agriculture’s environmental impact.
Most of the articles published did go on to discuss the findings of the study, but only after enticing readers with shocking headlines like “Urban Farming Has A Shockingly High Climate Cost.”
The articles sparked backlash from urban farmers, gardeners and students. Some criticized the design of the study while others were concerned about how the sensationalized publicity of the paper would negatively impact advocacy for urban farming.
The study, though certainly poorly communicated by the media, did provide some insight into urban agriculture practices that may unnecessarily be contributing to carbon emissions, particularly low tech urban agriculture sites like community gardens and backyard gardens.
The most widely publicized finding from the study is that food produced at urban agriculture sites is more carbon intensive than food produced by conventional agriculture.
Perhaps a more significant finding, however, is that the largest driver of carbon emissions from low tech urban agriculture sites is infrastructure.
For example, the materials used for building raised beds have a high carbon footprint when constructed from new materials. Raised beds that are used longer will therefore have a lower carbon footprint per serving of food grown than beds that are used short term.
Unfortunately, many urban agriculture sites end up being short term due to development needs within the city. In fact a third of community gardens do not last for over ten years.
Urban agriculture sites also tend to use potable city water for irrigation, which produces carbon due to the pumping, water filtration and distribution.
Other drawbacks include the cost of building and maintaining urban agriculture sites, competition with housing or renewable energy projects for space and reliance on community support and participation.
Some other studies have examined urban agriculture as being a potential cause of green gentrification, though there’s little evidence that this is the case.
Solutions
None of the drawbacks discussed in the University of Michigan study or ALI’s research have been highlighted with the intent of undermining the urban agriculture movement. Rather, these shortcomings are an opportunity to improve urban agriculture.
Crop selection can help urban agriculture sites reduce carbon emissions by selecting low carbon intensity produce or by selecting produce that has high food miles when grown and distributed through conventional agriculture practices.
The carbon footprint of infrastructure can be mitigated by using materials classified as ‘urban waste.’
Extending the lifespan of infrastructure will further reduce the carbon footprint per serving. Urban agriculture sites established on non-competing spaces may have a longer lifespan since they are less likely to be considered for redevelopment.
Instead of using potable water, urban agriculture sites can make use of rainwater and greywater for irrigation.
The use of agroecology can reduce the amount of labour required to maintain urban agriculture. Some amount of community involvement and cooperation will still be required.
ALI’s study suggests that municipalities work together with relevant stakeholders to develop urban agriculture strategies. Additionally, increasing awareness of the other benefits of urban agriculture, aside from food production, may help bolster public support and interest.
Urban agriculture will be key to building resilience in cities, building communities and mitigating a multitude of climate issues. In order to maximize the benefits, it’s important to consider how urban agriculture practices can be improved.
For more information on urban agriculture, check out these sources:
Exploring Potential Nature-Based Solutions in the Alberta Context
The Land Use Podcast How Urban Farms Benefit Communities with Kevin Jones
Comparing the carbon footprints of urban and conventional agriculture
Even gardens have a carbon footprint. Here's how to reduce the climate impact of urban farming
Gardeners are fuming about a study that found produce from urban farms has a high carbon footprint